David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1 | /* |
Grant Likely | ca632f5 | 2011-06-06 01:16:30 -0600 | [diff] [blame] | 2 | * SPI init/core code |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 3 | * |
| 4 | * Copyright (C) 2005 David Brownell |
Grant Likely | d57a428 | 2012-04-07 14:16:53 -0600 | [diff] [blame] | 5 | * Copyright (C) 2008 Secret Lab Technologies Ltd. |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 2 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program; if not, write to the Free Software |
| 19 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 20 | */ |
| 21 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 22 | #include <linux/kernel.h> |
Grant Likely | d57a428 | 2012-04-07 14:16:53 -0600 | [diff] [blame] | 23 | #include <linux/kmod.h> |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 24 | #include <linux/device.h> |
| 25 | #include <linux/init.h> |
| 26 | #include <linux/cache.h> |
Mark Brown | 99adef3 | 2014-01-16 12:22:43 +0000 | [diff] [blame] | 27 | #include <linux/dma-mapping.h> |
| 28 | #include <linux/dmaengine.h> |
Matthias Kaehlcke | 9404082 | 2007-07-17 04:04:16 -0700 | [diff] [blame] | 29 | #include <linux/mutex.h> |
Sinan Akman | 2b7a32f | 2010-10-02 21:28:29 -0600 | [diff] [blame] | 30 | #include <linux/of_device.h> |
Grant Likely | d57a428 | 2012-04-07 14:16:53 -0600 | [diff] [blame] | 31 | #include <linux/of_irq.h> |
Sylwester Nawrocki | 86be408 | 2014-06-18 17:29:32 +0200 | [diff] [blame] | 32 | #include <linux/clk/clk-conf.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 33 | #include <linux/slab.h> |
Anton Vorontsov | e0626e3 | 2009-09-22 16:46:08 -0700 | [diff] [blame] | 34 | #include <linux/mod_devicetable.h> |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 35 | #include <linux/spi/spi.h> |
Jean-Christophe PLAGNIOL-VILLARD | 7431798 | 2012-11-15 20:19:57 +0100 | [diff] [blame] | 36 | #include <linux/of_gpio.h> |
Mark Brown | 3ae22e8 | 2010-12-25 15:32:27 +0100 | [diff] [blame] | 37 | #include <linux/pm_runtime.h> |
Ulf Hansson | f48c767 | 2014-09-29 13:58:47 +0200 | [diff] [blame] | 38 | #include <linux/pm_domain.h> |
Paul Gortmaker | 025ed13 | 2011-07-10 12:57:55 -0400 | [diff] [blame] | 39 | #include <linux/export.h> |
Clark Williams | 8bd75c7 | 2013-02-07 09:47:07 -0600 | [diff] [blame] | 40 | #include <linux/sched/rt.h> |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 41 | #include <linux/delay.h> |
| 42 | #include <linux/kthread.h> |
Mika Westerberg | 64bee4d | 2012-11-30 12:37:53 +0100 | [diff] [blame] | 43 | #include <linux/ioport.h> |
| 44 | #include <linux/acpi.h> |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 45 | |
Mark Brown | 56ec197 | 2013-10-07 19:33:53 +0100 | [diff] [blame] | 46 | #define CREATE_TRACE_POINTS |
| 47 | #include <trace/events/spi.h> |
| 48 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 49 | static void spidev_release(struct device *dev) |
| 50 | { |
Hans-Peter Nilsson | 0ffa028 | 2007-02-12 00:52:45 -0800 | [diff] [blame] | 51 | struct spi_device *spi = to_spi_device(dev); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 52 | |
| 53 | /* spi masters may cleanup for released devices */ |
| 54 | if (spi->master->cleanup) |
| 55 | spi->master->cleanup(spi); |
| 56 | |
David Brownell | 0c86846 | 2006-01-08 13:34:25 -0800 | [diff] [blame] | 57 | spi_master_put(spi->master); |
Roman Tereshonkov | 07a389f | 2010-04-12 09:56:35 +0000 | [diff] [blame] | 58 | kfree(spi); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 59 | } |
| 60 | |
| 61 | static ssize_t |
| 62 | modalias_show(struct device *dev, struct device_attribute *a, char *buf) |
| 63 | { |
| 64 | const struct spi_device *spi = to_spi_device(dev); |
Zhang Rui | 8c4ff6d | 2014-01-14 16:46:37 +0800 | [diff] [blame] | 65 | int len; |
| 66 | |
| 67 | len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1); |
| 68 | if (len != -ENODEV) |
| 69 | return len; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 70 | |
Grant Likely | d8e328b | 2012-05-20 00:08:13 -0600 | [diff] [blame] | 71 | return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 72 | } |
Greg Kroah-Hartman | aa7da56 | 2013-10-07 18:27:38 -0700 | [diff] [blame] | 73 | static DEVICE_ATTR_RO(modalias); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 74 | |
Greg Kroah-Hartman | aa7da56 | 2013-10-07 18:27:38 -0700 | [diff] [blame] | 75 | static struct attribute *spi_dev_attrs[] = { |
| 76 | &dev_attr_modalias.attr, |
| 77 | NULL, |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 78 | }; |
Greg Kroah-Hartman | aa7da56 | 2013-10-07 18:27:38 -0700 | [diff] [blame] | 79 | ATTRIBUTE_GROUPS(spi_dev); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 80 | |
| 81 | /* modalias support makes "modprobe $MODALIAS" new-style hotplug work, |
| 82 | * and the sysfs version makes coldplug work too. |
| 83 | */ |
| 84 | |
Anton Vorontsov | 75368bf | 2009-09-22 16:46:04 -0700 | [diff] [blame] | 85 | static const struct spi_device_id *spi_match_id(const struct spi_device_id *id, |
| 86 | const struct spi_device *sdev) |
| 87 | { |
| 88 | while (id->name[0]) { |
| 89 | if (!strcmp(sdev->modalias, id->name)) |
| 90 | return id; |
| 91 | id++; |
| 92 | } |
| 93 | return NULL; |
| 94 | } |
| 95 | |
| 96 | const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev) |
| 97 | { |
| 98 | const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver); |
| 99 | |
| 100 | return spi_match_id(sdrv->id_table, sdev); |
| 101 | } |
| 102 | EXPORT_SYMBOL_GPL(spi_get_device_id); |
| 103 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 104 | static int spi_match_device(struct device *dev, struct device_driver *drv) |
| 105 | { |
| 106 | const struct spi_device *spi = to_spi_device(dev); |
Anton Vorontsov | 75368bf | 2009-09-22 16:46:04 -0700 | [diff] [blame] | 107 | const struct spi_driver *sdrv = to_spi_driver(drv); |
| 108 | |
Sinan Akman | 2b7a32f | 2010-10-02 21:28:29 -0600 | [diff] [blame] | 109 | /* Attempt an OF style match */ |
| 110 | if (of_driver_match_device(dev, drv)) |
| 111 | return 1; |
| 112 | |
Mika Westerberg | 64bee4d | 2012-11-30 12:37:53 +0100 | [diff] [blame] | 113 | /* Then try ACPI */ |
| 114 | if (acpi_driver_match_device(dev, drv)) |
| 115 | return 1; |
| 116 | |
Anton Vorontsov | 75368bf | 2009-09-22 16:46:04 -0700 | [diff] [blame] | 117 | if (sdrv->id_table) |
| 118 | return !!spi_match_id(sdrv->id_table, spi); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 119 | |
Kay Sievers | 35f74fc | 2009-01-06 10:44:37 -0800 | [diff] [blame] | 120 | return strcmp(spi->modalias, drv->name) == 0; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 121 | } |
| 122 | |
Kay Sievers | 7eff2e7 | 2007-08-14 15:15:12 +0200 | [diff] [blame] | 123 | static int spi_uevent(struct device *dev, struct kobj_uevent_env *env) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 124 | { |
| 125 | const struct spi_device *spi = to_spi_device(dev); |
Zhang Rui | 8c4ff6d | 2014-01-14 16:46:37 +0800 | [diff] [blame] | 126 | int rc; |
| 127 | |
| 128 | rc = acpi_device_uevent_modalias(dev, env); |
| 129 | if (rc != -ENODEV) |
| 130 | return rc; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 131 | |
Anton Vorontsov | e0626e3 | 2009-09-22 16:46:08 -0700 | [diff] [blame] | 132 | add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 133 | return 0; |
| 134 | } |
| 135 | |
Mark Brown | 3ae22e8 | 2010-12-25 15:32:27 +0100 | [diff] [blame] | 136 | #ifdef CONFIG_PM_SLEEP |
| 137 | static int spi_legacy_suspend(struct device *dev, pm_message_t message) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 138 | { |
David Brownell | 3c72426 | 2008-02-06 01:38:10 -0800 | [diff] [blame] | 139 | int value = 0; |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 140 | struct spi_driver *drv = to_spi_driver(dev->driver); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 141 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 142 | /* suspend will stop irqs and dma; no more i/o */ |
David Brownell | 3c72426 | 2008-02-06 01:38:10 -0800 | [diff] [blame] | 143 | if (drv) { |
| 144 | if (drv->suspend) |
| 145 | value = drv->suspend(to_spi_device(dev), message); |
| 146 | else |
| 147 | dev_dbg(dev, "... can't suspend\n"); |
| 148 | } |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 149 | return value; |
| 150 | } |
| 151 | |
Mark Brown | 3ae22e8 | 2010-12-25 15:32:27 +0100 | [diff] [blame] | 152 | static int spi_legacy_resume(struct device *dev) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 153 | { |
David Brownell | 3c72426 | 2008-02-06 01:38:10 -0800 | [diff] [blame] | 154 | int value = 0; |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 155 | struct spi_driver *drv = to_spi_driver(dev->driver); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 156 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 157 | /* resume may restart the i/o queue */ |
David Brownell | 3c72426 | 2008-02-06 01:38:10 -0800 | [diff] [blame] | 158 | if (drv) { |
| 159 | if (drv->resume) |
| 160 | value = drv->resume(to_spi_device(dev)); |
| 161 | else |
| 162 | dev_dbg(dev, "... can't resume\n"); |
| 163 | } |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 164 | return value; |
| 165 | } |
| 166 | |
Mark Brown | 3ae22e8 | 2010-12-25 15:32:27 +0100 | [diff] [blame] | 167 | static int spi_pm_suspend(struct device *dev) |
| 168 | { |
| 169 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
| 170 | |
| 171 | if (pm) |
| 172 | return pm_generic_suspend(dev); |
| 173 | else |
| 174 | return spi_legacy_suspend(dev, PMSG_SUSPEND); |
| 175 | } |
| 176 | |
| 177 | static int spi_pm_resume(struct device *dev) |
| 178 | { |
| 179 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
| 180 | |
| 181 | if (pm) |
| 182 | return pm_generic_resume(dev); |
| 183 | else |
| 184 | return spi_legacy_resume(dev); |
| 185 | } |
| 186 | |
| 187 | static int spi_pm_freeze(struct device *dev) |
| 188 | { |
| 189 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
| 190 | |
| 191 | if (pm) |
| 192 | return pm_generic_freeze(dev); |
| 193 | else |
| 194 | return spi_legacy_suspend(dev, PMSG_FREEZE); |
| 195 | } |
| 196 | |
| 197 | static int spi_pm_thaw(struct device *dev) |
| 198 | { |
| 199 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
| 200 | |
| 201 | if (pm) |
| 202 | return pm_generic_thaw(dev); |
| 203 | else |
| 204 | return spi_legacy_resume(dev); |
| 205 | } |
| 206 | |
| 207 | static int spi_pm_poweroff(struct device *dev) |
| 208 | { |
| 209 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
| 210 | |
| 211 | if (pm) |
| 212 | return pm_generic_poweroff(dev); |
| 213 | else |
| 214 | return spi_legacy_suspend(dev, PMSG_HIBERNATE); |
| 215 | } |
| 216 | |
| 217 | static int spi_pm_restore(struct device *dev) |
| 218 | { |
| 219 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
| 220 | |
| 221 | if (pm) |
| 222 | return pm_generic_restore(dev); |
| 223 | else |
| 224 | return spi_legacy_resume(dev); |
| 225 | } |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 226 | #else |
Mark Brown | 3ae22e8 | 2010-12-25 15:32:27 +0100 | [diff] [blame] | 227 | #define spi_pm_suspend NULL |
| 228 | #define spi_pm_resume NULL |
| 229 | #define spi_pm_freeze NULL |
| 230 | #define spi_pm_thaw NULL |
| 231 | #define spi_pm_poweroff NULL |
| 232 | #define spi_pm_restore NULL |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 233 | #endif |
| 234 | |
Mark Brown | 3ae22e8 | 2010-12-25 15:32:27 +0100 | [diff] [blame] | 235 | static const struct dev_pm_ops spi_pm = { |
| 236 | .suspend = spi_pm_suspend, |
| 237 | .resume = spi_pm_resume, |
| 238 | .freeze = spi_pm_freeze, |
| 239 | .thaw = spi_pm_thaw, |
| 240 | .poweroff = spi_pm_poweroff, |
| 241 | .restore = spi_pm_restore, |
| 242 | SET_RUNTIME_PM_OPS( |
| 243 | pm_generic_runtime_suspend, |
| 244 | pm_generic_runtime_resume, |
Rafael J. Wysocki | 45f0a85 | 2013-06-03 21:49:52 +0200 | [diff] [blame] | 245 | NULL |
Mark Brown | 3ae22e8 | 2010-12-25 15:32:27 +0100 | [diff] [blame] | 246 | ) |
| 247 | }; |
| 248 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 249 | struct bus_type spi_bus_type = { |
| 250 | .name = "spi", |
Greg Kroah-Hartman | aa7da56 | 2013-10-07 18:27:38 -0700 | [diff] [blame] | 251 | .dev_groups = spi_dev_groups, |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 252 | .match = spi_match_device, |
| 253 | .uevent = spi_uevent, |
Mark Brown | 3ae22e8 | 2010-12-25 15:32:27 +0100 | [diff] [blame] | 254 | .pm = &spi_pm, |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 255 | }; |
| 256 | EXPORT_SYMBOL_GPL(spi_bus_type); |
| 257 | |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 258 | |
| 259 | static int spi_drv_probe(struct device *dev) |
| 260 | { |
| 261 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); |
Mika Westerberg | 33cf00e | 2013-10-10 13:28:48 +0300 | [diff] [blame] | 262 | int ret; |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 263 | |
Sylwester Nawrocki | 86be408 | 2014-06-18 17:29:32 +0200 | [diff] [blame] | 264 | ret = of_clk_set_defaults(dev->of_node, false); |
| 265 | if (ret) |
| 266 | return ret; |
| 267 | |
Ulf Hansson | 676e7c2 | 2014-09-19 20:27:41 +0200 | [diff] [blame] | 268 | ret = dev_pm_domain_attach(dev, true); |
| 269 | if (ret != -EPROBE_DEFER) { |
| 270 | ret = sdrv->probe(to_spi_device(dev)); |
| 271 | if (ret) |
| 272 | dev_pm_domain_detach(dev, true); |
| 273 | } |
Mika Westerberg | 33cf00e | 2013-10-10 13:28:48 +0300 | [diff] [blame] | 274 | |
| 275 | return ret; |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 276 | } |
| 277 | |
| 278 | static int spi_drv_remove(struct device *dev) |
| 279 | { |
| 280 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); |
Mika Westerberg | 33cf00e | 2013-10-10 13:28:48 +0300 | [diff] [blame] | 281 | int ret; |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 282 | |
Jean Delvare | aec35f4 | 2014-02-13 15:28:41 +0100 | [diff] [blame] | 283 | ret = sdrv->remove(to_spi_device(dev)); |
Ulf Hansson | 676e7c2 | 2014-09-19 20:27:41 +0200 | [diff] [blame] | 284 | dev_pm_domain_detach(dev, true); |
Mika Westerberg | 33cf00e | 2013-10-10 13:28:48 +0300 | [diff] [blame] | 285 | |
| 286 | return ret; |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 287 | } |
| 288 | |
| 289 | static void spi_drv_shutdown(struct device *dev) |
| 290 | { |
| 291 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); |
| 292 | |
| 293 | sdrv->shutdown(to_spi_device(dev)); |
| 294 | } |
| 295 | |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 296 | /** |
| 297 | * spi_register_driver - register a SPI driver |
| 298 | * @sdrv: the driver to register |
| 299 | * Context: can sleep |
| 300 | */ |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 301 | int spi_register_driver(struct spi_driver *sdrv) |
| 302 | { |
| 303 | sdrv->driver.bus = &spi_bus_type; |
| 304 | if (sdrv->probe) |
| 305 | sdrv->driver.probe = spi_drv_probe; |
| 306 | if (sdrv->remove) |
| 307 | sdrv->driver.remove = spi_drv_remove; |
| 308 | if (sdrv->shutdown) |
| 309 | sdrv->driver.shutdown = spi_drv_shutdown; |
| 310 | return driver_register(&sdrv->driver); |
| 311 | } |
| 312 | EXPORT_SYMBOL_GPL(spi_register_driver); |
| 313 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 314 | /*-------------------------------------------------------------------------*/ |
| 315 | |
| 316 | /* SPI devices should normally not be created by SPI device drivers; that |
| 317 | * would make them board-specific. Similarly with SPI master drivers. |
| 318 | * Device registration normally goes into like arch/.../mach.../board-YYY.c |
| 319 | * with other readonly (flashable) information about mainboard devices. |
| 320 | */ |
| 321 | |
| 322 | struct boardinfo { |
| 323 | struct list_head list; |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 324 | struct spi_board_info board_info; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 325 | }; |
| 326 | |
| 327 | static LIST_HEAD(board_list); |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 328 | static LIST_HEAD(spi_master_list); |
| 329 | |
| 330 | /* |
| 331 | * Used to protect add/del opertion for board_info list and |
| 332 | * spi_master list, and their matching process |
| 333 | */ |
Matthias Kaehlcke | 9404082 | 2007-07-17 04:04:16 -0700 | [diff] [blame] | 334 | static DEFINE_MUTEX(board_lock); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 335 | |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 336 | /** |
| 337 | * spi_alloc_device - Allocate a new SPI device |
| 338 | * @master: Controller to which device is connected |
| 339 | * Context: can sleep |
| 340 | * |
| 341 | * Allows a driver to allocate and initialize a spi_device without |
| 342 | * registering it immediately. This allows a driver to directly |
| 343 | * fill the spi_device with device parameters before calling |
| 344 | * spi_add_device() on it. |
| 345 | * |
| 346 | * Caller is responsible to call spi_add_device() on the returned |
| 347 | * spi_device structure to add it to the SPI master. If the caller |
| 348 | * needs to discard the spi_device without adding it, then it should |
| 349 | * call spi_dev_put() on it. |
| 350 | * |
| 351 | * Returns a pointer to the new device, or NULL. |
| 352 | */ |
| 353 | struct spi_device *spi_alloc_device(struct spi_master *master) |
| 354 | { |
| 355 | struct spi_device *spi; |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 356 | |
| 357 | if (!spi_master_get(master)) |
| 358 | return NULL; |
| 359 | |
Jingoo Han | 5fe5f05 | 2013-10-14 10:31:51 +0900 | [diff] [blame] | 360 | spi = kzalloc(sizeof(*spi), GFP_KERNEL); |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 361 | if (!spi) { |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 362 | spi_master_put(master); |
| 363 | return NULL; |
| 364 | } |
| 365 | |
| 366 | spi->master = master; |
Laurent Pinchart | 178db7d | 2011-12-12 01:15:06 +0100 | [diff] [blame] | 367 | spi->dev.parent = &master->dev; |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 368 | spi->dev.bus = &spi_bus_type; |
| 369 | spi->dev.release = spidev_release; |
Andreas Larsson | 446411e | 2013-02-13 14:20:25 +0100 | [diff] [blame] | 370 | spi->cs_gpio = -ENOENT; |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 371 | device_initialize(&spi->dev); |
| 372 | return spi; |
| 373 | } |
| 374 | EXPORT_SYMBOL_GPL(spi_alloc_device); |
| 375 | |
Jarkko Nikula | e13ac47 | 2013-11-14 14:03:53 +0200 | [diff] [blame] | 376 | static void spi_dev_set_name(struct spi_device *spi) |
| 377 | { |
| 378 | struct acpi_device *adev = ACPI_COMPANION(&spi->dev); |
| 379 | |
| 380 | if (adev) { |
| 381 | dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev)); |
| 382 | return; |
| 383 | } |
| 384 | |
| 385 | dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev), |
| 386 | spi->chip_select); |
| 387 | } |
| 388 | |
Mika Westerberg | b6fb8d3 | 2014-01-09 15:23:55 +0200 | [diff] [blame] | 389 | static int spi_dev_check(struct device *dev, void *data) |
| 390 | { |
| 391 | struct spi_device *spi = to_spi_device(dev); |
| 392 | struct spi_device *new_spi = data; |
| 393 | |
| 394 | if (spi->master == new_spi->master && |
| 395 | spi->chip_select == new_spi->chip_select) |
| 396 | return -EBUSY; |
| 397 | return 0; |
| 398 | } |
| 399 | |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 400 | /** |
| 401 | * spi_add_device - Add spi_device allocated with spi_alloc_device |
| 402 | * @spi: spi_device to register |
| 403 | * |
| 404 | * Companion function to spi_alloc_device. Devices allocated with |
| 405 | * spi_alloc_device can be added onto the spi bus with this function. |
| 406 | * |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 407 | * Returns 0 on success; negative errno on failure |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 408 | */ |
| 409 | int spi_add_device(struct spi_device *spi) |
| 410 | { |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 411 | static DEFINE_MUTEX(spi_add_lock); |
Jean-Christophe PLAGNIOL-VILLARD | 7431798 | 2012-11-15 20:19:57 +0100 | [diff] [blame] | 412 | struct spi_master *master = spi->master; |
| 413 | struct device *dev = master->dev.parent; |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 414 | int status; |
| 415 | |
| 416 | /* Chipselects are numbered 0..max; validate. */ |
Jean-Christophe PLAGNIOL-VILLARD | 7431798 | 2012-11-15 20:19:57 +0100 | [diff] [blame] | 417 | if (spi->chip_select >= master->num_chipselect) { |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 418 | dev_err(dev, "cs%d >= max %d\n", |
| 419 | spi->chip_select, |
Jean-Christophe PLAGNIOL-VILLARD | 7431798 | 2012-11-15 20:19:57 +0100 | [diff] [blame] | 420 | master->num_chipselect); |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 421 | return -EINVAL; |
| 422 | } |
| 423 | |
| 424 | /* Set the bus ID string */ |
Jarkko Nikula | e13ac47 | 2013-11-14 14:03:53 +0200 | [diff] [blame] | 425 | spi_dev_set_name(spi); |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 426 | |
| 427 | /* We need to make sure there's no other device with this |
| 428 | * chipselect **BEFORE** we call setup(), else we'll trash |
| 429 | * its configuration. Lock against concurrent add() calls. |
| 430 | */ |
| 431 | mutex_lock(&spi_add_lock); |
| 432 | |
Mika Westerberg | b6fb8d3 | 2014-01-09 15:23:55 +0200 | [diff] [blame] | 433 | status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check); |
| 434 | if (status) { |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 435 | dev_err(dev, "chipselect %d already in use\n", |
| 436 | spi->chip_select); |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 437 | goto done; |
| 438 | } |
| 439 | |
Jean-Christophe PLAGNIOL-VILLARD | 7431798 | 2012-11-15 20:19:57 +0100 | [diff] [blame] | 440 | if (master->cs_gpios) |
| 441 | spi->cs_gpio = master->cs_gpios[spi->chip_select]; |
| 442 | |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 443 | /* Drivers may modify this initial i/o setup, but will |
| 444 | * normally rely on the device being setup. Devices |
| 445 | * using SPI_CS_HIGH can't coexist well otherwise... |
| 446 | */ |
David Brownell | 7d07719 | 2009-06-17 16:26:03 -0700 | [diff] [blame] | 447 | status = spi_setup(spi); |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 448 | if (status < 0) { |
Linus Walleij | eb288a1 | 2010-10-21 21:06:44 +0200 | [diff] [blame] | 449 | dev_err(dev, "can't setup %s, status %d\n", |
| 450 | dev_name(&spi->dev), status); |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 451 | goto done; |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 452 | } |
| 453 | |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 454 | /* Device may be bound to an active driver when this returns */ |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 455 | status = device_add(&spi->dev); |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 456 | if (status < 0) |
Linus Walleij | eb288a1 | 2010-10-21 21:06:44 +0200 | [diff] [blame] | 457 | dev_err(dev, "can't add %s, status %d\n", |
| 458 | dev_name(&spi->dev), status); |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 459 | else |
Kay Sievers | 35f74fc | 2009-01-06 10:44:37 -0800 | [diff] [blame] | 460 | dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 461 | |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 462 | done: |
| 463 | mutex_unlock(&spi_add_lock); |
| 464 | return status; |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 465 | } |
| 466 | EXPORT_SYMBOL_GPL(spi_add_device); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 467 | |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 468 | /** |
| 469 | * spi_new_device - instantiate one new SPI device |
| 470 | * @master: Controller to which device is connected |
| 471 | * @chip: Describes the SPI device |
| 472 | * Context: can sleep |
| 473 | * |
| 474 | * On typical mainboards, this is purely internal; and it's not needed |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 475 | * after board init creates the hard-wired devices. Some development |
| 476 | * platforms may not be able to use spi_register_board_info though, and |
| 477 | * this is exported so that for example a USB or parport based adapter |
| 478 | * driver could add devices (which it would learn about out-of-band). |
David Brownell | 082c8cb | 2007-07-31 00:39:45 -0700 | [diff] [blame] | 479 | * |
| 480 | * Returns the new device, or NULL. |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 481 | */ |
Adrian Bunk | e9d5a46 | 2007-03-26 21:32:23 -0800 | [diff] [blame] | 482 | struct spi_device *spi_new_device(struct spi_master *master, |
| 483 | struct spi_board_info *chip) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 484 | { |
| 485 | struct spi_device *proxy; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 486 | int status; |
| 487 | |
David Brownell | 082c8cb | 2007-07-31 00:39:45 -0700 | [diff] [blame] | 488 | /* NOTE: caller did any chip->bus_num checks necessary. |
| 489 | * |
| 490 | * Also, unless we change the return value convention to use |
| 491 | * error-or-pointer (not NULL-or-pointer), troubleshootability |
| 492 | * suggests syslogged diagnostics are best here (ugh). |
| 493 | */ |
| 494 | |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 495 | proxy = spi_alloc_device(master); |
| 496 | if (!proxy) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 497 | return NULL; |
| 498 | |
Grant Likely | 102eb97 | 2008-07-23 21:29:55 -0700 | [diff] [blame] | 499 | WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias)); |
| 500 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 501 | proxy->chip_select = chip->chip_select; |
| 502 | proxy->max_speed_hz = chip->max_speed_hz; |
David Brownell | 980a01c | 2006-06-28 07:47:15 -0700 | [diff] [blame] | 503 | proxy->mode = chip->mode; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 504 | proxy->irq = chip->irq; |
Grant Likely | 102eb97 | 2008-07-23 21:29:55 -0700 | [diff] [blame] | 505 | strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias)); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 506 | proxy->dev.platform_data = (void *) chip->platform_data; |
| 507 | proxy->controller_data = chip->controller_data; |
| 508 | proxy->controller_state = NULL; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 509 | |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 510 | status = spi_add_device(proxy); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 511 | if (status < 0) { |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 512 | spi_dev_put(proxy); |
| 513 | return NULL; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 514 | } |
| 515 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 516 | return proxy; |
| 517 | } |
| 518 | EXPORT_SYMBOL_GPL(spi_new_device); |
| 519 | |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 520 | static void spi_match_master_to_boardinfo(struct spi_master *master, |
| 521 | struct spi_board_info *bi) |
| 522 | { |
| 523 | struct spi_device *dev; |
| 524 | |
| 525 | if (master->bus_num != bi->bus_num) |
| 526 | return; |
| 527 | |
| 528 | dev = spi_new_device(master, bi); |
| 529 | if (!dev) |
| 530 | dev_err(master->dev.parent, "can't create new device for %s\n", |
| 531 | bi->modalias); |
| 532 | } |
| 533 | |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 534 | /** |
| 535 | * spi_register_board_info - register SPI devices for a given board |
| 536 | * @info: array of chip descriptors |
| 537 | * @n: how many descriptors are provided |
| 538 | * Context: can sleep |
| 539 | * |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 540 | * Board-specific early init code calls this (probably during arch_initcall) |
| 541 | * with segments of the SPI device table. Any device nodes are created later, |
| 542 | * after the relevant parent SPI controller (bus_num) is defined. We keep |
| 543 | * this table of devices forever, so that reloading a controller driver will |
| 544 | * not make Linux forget about these hard-wired devices. |
| 545 | * |
| 546 | * Other code can also call this, e.g. a particular add-on board might provide |
| 547 | * SPI devices through its expansion connector, so code initializing that board |
| 548 | * would naturally declare its SPI devices. |
| 549 | * |
| 550 | * The board info passed can safely be __initdata ... but be careful of |
| 551 | * any embedded pointers (platform_data, etc), they're copied as-is. |
| 552 | */ |
Grant Likely | fd4a319 | 2012-12-07 16:57:14 +0000 | [diff] [blame] | 553 | int spi_register_board_info(struct spi_board_info const *info, unsigned n) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 554 | { |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 555 | struct boardinfo *bi; |
| 556 | int i; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 557 | |
Xiubo Li | c7908a3 | 2014-09-24 14:30:29 +0800 | [diff] [blame] | 558 | if (!n) |
| 559 | return -EINVAL; |
| 560 | |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 561 | bi = kzalloc(n * sizeof(*bi), GFP_KERNEL); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 562 | if (!bi) |
| 563 | return -ENOMEM; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 564 | |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 565 | for (i = 0; i < n; i++, bi++, info++) { |
| 566 | struct spi_master *master; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 567 | |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 568 | memcpy(&bi->board_info, info, sizeof(*info)); |
| 569 | mutex_lock(&board_lock); |
| 570 | list_add_tail(&bi->list, &board_list); |
| 571 | list_for_each_entry(master, &spi_master_list, list) |
| 572 | spi_match_master_to_boardinfo(master, &bi->board_info); |
| 573 | mutex_unlock(&board_lock); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 574 | } |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 575 | |
| 576 | return 0; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 577 | } |
| 578 | |
| 579 | /*-------------------------------------------------------------------------*/ |
| 580 | |
Mark Brown | b158935 | 2013-10-05 11:50:40 +0100 | [diff] [blame] | 581 | static void spi_set_cs(struct spi_device *spi, bool enable) |
| 582 | { |
| 583 | if (spi->mode & SPI_CS_HIGH) |
| 584 | enable = !enable; |
| 585 | |
| 586 | if (spi->cs_gpio >= 0) |
| 587 | gpio_set_value(spi->cs_gpio, !enable); |
| 588 | else if (spi->master->set_cs) |
| 589 | spi->master->set_cs(spi, !enable); |
| 590 | } |
| 591 | |
Geert Uytterhoeven | 2de440f | 2014-05-02 06:29:34 +0200 | [diff] [blame] | 592 | #ifdef CONFIG_HAS_DMA |
Mark Brown | 6ad45a2 | 2014-02-02 13:47:47 +0000 | [diff] [blame] | 593 | static int spi_map_buf(struct spi_master *master, struct device *dev, |
| 594 | struct sg_table *sgt, void *buf, size_t len, |
| 595 | enum dma_data_direction dir) |
| 596 | { |
| 597 | const bool vmalloced_buf = is_vmalloc_addr(buf); |
| 598 | const int desc_len = vmalloced_buf ? PAGE_SIZE : master->max_dma_len; |
| 599 | const int sgs = DIV_ROUND_UP(len, desc_len); |
| 600 | struct page *vm_page; |
| 601 | void *sg_buf; |
| 602 | size_t min; |
| 603 | int i, ret; |
| 604 | |
| 605 | ret = sg_alloc_table(sgt, sgs, GFP_KERNEL); |
| 606 | if (ret != 0) |
| 607 | return ret; |
| 608 | |
| 609 | for (i = 0; i < sgs; i++) { |
| 610 | min = min_t(size_t, len, desc_len); |
| 611 | |
| 612 | if (vmalloced_buf) { |
| 613 | vm_page = vmalloc_to_page(buf); |
| 614 | if (!vm_page) { |
| 615 | sg_free_table(sgt); |
| 616 | return -ENOMEM; |
| 617 | } |
| 618 | sg_buf = page_address(vm_page) + |
| 619 | ((size_t)buf & ~PAGE_MASK); |
| 620 | } else { |
| 621 | sg_buf = buf; |
| 622 | } |
| 623 | |
| 624 | sg_set_buf(&sgt->sgl[i], sg_buf, min); |
| 625 | |
| 626 | buf += min; |
| 627 | len -= min; |
| 628 | } |
| 629 | |
| 630 | ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir); |
Geert Uytterhoeven | 89e4b66 | 2014-07-10 15:29:32 +0200 | [diff] [blame] | 631 | if (!ret) |
| 632 | ret = -ENOMEM; |
Mark Brown | 6ad45a2 | 2014-02-02 13:47:47 +0000 | [diff] [blame] | 633 | if (ret < 0) { |
| 634 | sg_free_table(sgt); |
| 635 | return ret; |
| 636 | } |
| 637 | |
| 638 | sgt->nents = ret; |
| 639 | |
| 640 | return 0; |
| 641 | } |
| 642 | |
| 643 | static void spi_unmap_buf(struct spi_master *master, struct device *dev, |
| 644 | struct sg_table *sgt, enum dma_data_direction dir) |
| 645 | { |
| 646 | if (sgt->orig_nents) { |
| 647 | dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir); |
| 648 | sg_free_table(sgt); |
| 649 | } |
| 650 | } |
| 651 | |
Geert Uytterhoeven | 2de440f | 2014-05-02 06:29:34 +0200 | [diff] [blame] | 652 | static int __spi_map_msg(struct spi_master *master, struct spi_message *msg) |
Mark Brown | 99adef3 | 2014-01-16 12:22:43 +0000 | [diff] [blame] | 653 | { |
Mark Brown | 99adef3 | 2014-01-16 12:22:43 +0000 | [diff] [blame] | 654 | struct device *tx_dev, *rx_dev; |
| 655 | struct spi_transfer *xfer; |
Mark Brown | 6ad45a2 | 2014-02-02 13:47:47 +0000 | [diff] [blame] | 656 | int ret; |
Mark Brown | 3a2eba9 | 2014-01-28 20:17:03 +0000 | [diff] [blame] | 657 | |
Mark Brown | 6ad45a2 | 2014-02-02 13:47:47 +0000 | [diff] [blame] | 658 | if (!master->can_dma) |
Mark Brown | 99adef3 | 2014-01-16 12:22:43 +0000 | [diff] [blame] | 659 | return 0; |
| 660 | |
Geert Uytterhoeven | 3fc2542 | 2014-07-10 15:29:33 +0200 | [diff] [blame] | 661 | tx_dev = master->dma_tx->device->dev; |
| 662 | rx_dev = master->dma_rx->device->dev; |
Mark Brown | 99adef3 | 2014-01-16 12:22:43 +0000 | [diff] [blame] | 663 | |
| 664 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
| 665 | if (!master->can_dma(master, msg->spi, xfer)) |
| 666 | continue; |
| 667 | |
| 668 | if (xfer->tx_buf != NULL) { |
Mark Brown | 6ad45a2 | 2014-02-02 13:47:47 +0000 | [diff] [blame] | 669 | ret = spi_map_buf(master, tx_dev, &xfer->tx_sg, |
| 670 | (void *)xfer->tx_buf, xfer->len, |
| 671 | DMA_TO_DEVICE); |
| 672 | if (ret != 0) |
| 673 | return ret; |
Mark Brown | 99adef3 | 2014-01-16 12:22:43 +0000 | [diff] [blame] | 674 | } |
| 675 | |
| 676 | if (xfer->rx_buf != NULL) { |
Mark Brown | 6ad45a2 | 2014-02-02 13:47:47 +0000 | [diff] [blame] | 677 | ret = spi_map_buf(master, rx_dev, &xfer->rx_sg, |
| 678 | xfer->rx_buf, xfer->len, |
| 679 | DMA_FROM_DEVICE); |
| 680 | if (ret != 0) { |
| 681 | spi_unmap_buf(master, tx_dev, &xfer->tx_sg, |
| 682 | DMA_TO_DEVICE); |
| 683 | return ret; |
Mark Brown | 99adef3 | 2014-01-16 12:22:43 +0000 | [diff] [blame] | 684 | } |
| 685 | } |
| 686 | } |
| 687 | |
| 688 | master->cur_msg_mapped = true; |
| 689 | |
| 690 | return 0; |
| 691 | } |
| 692 | |
| 693 | static int spi_unmap_msg(struct spi_master *master, struct spi_message *msg) |
| 694 | { |
| 695 | struct spi_transfer *xfer; |
| 696 | struct device *tx_dev, *rx_dev; |
| 697 | |
Mark Brown | 6ad45a2 | 2014-02-02 13:47:47 +0000 | [diff] [blame] | 698 | if (!master->cur_msg_mapped || !master->can_dma) |
Mark Brown | 99adef3 | 2014-01-16 12:22:43 +0000 | [diff] [blame] | 699 | return 0; |
| 700 | |
Geert Uytterhoeven | 3fc2542 | 2014-07-10 15:29:33 +0200 | [diff] [blame] | 701 | tx_dev = master->dma_tx->device->dev; |
| 702 | rx_dev = master->dma_rx->device->dev; |
Mark Brown | 99adef3 | 2014-01-16 12:22:43 +0000 | [diff] [blame] | 703 | |
| 704 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
| 705 | if (!master->can_dma(master, msg->spi, xfer)) |
| 706 | continue; |
| 707 | |
Mark Brown | 6ad45a2 | 2014-02-02 13:47:47 +0000 | [diff] [blame] | 708 | spi_unmap_buf(master, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE); |
| 709 | spi_unmap_buf(master, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE); |
Mark Brown | 99adef3 | 2014-01-16 12:22:43 +0000 | [diff] [blame] | 710 | } |
| 711 | |
| 712 | return 0; |
| 713 | } |
Geert Uytterhoeven | 2de440f | 2014-05-02 06:29:34 +0200 | [diff] [blame] | 714 | #else /* !CONFIG_HAS_DMA */ |
| 715 | static inline int __spi_map_msg(struct spi_master *master, |
| 716 | struct spi_message *msg) |
| 717 | { |
| 718 | return 0; |
| 719 | } |
| 720 | |
| 721 | static inline int spi_unmap_msg(struct spi_master *master, |
| 722 | struct spi_message *msg) |
| 723 | { |
| 724 | return 0; |
| 725 | } |
| 726 | #endif /* !CONFIG_HAS_DMA */ |
| 727 | |
| 728 | static int spi_map_msg(struct spi_master *master, struct spi_message *msg) |
| 729 | { |
| 730 | struct spi_transfer *xfer; |
| 731 | void *tmp; |
| 732 | unsigned int max_tx, max_rx; |
| 733 | |
| 734 | if (master->flags & (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX)) { |
| 735 | max_tx = 0; |
| 736 | max_rx = 0; |
| 737 | |
| 738 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
| 739 | if ((master->flags & SPI_MASTER_MUST_TX) && |
| 740 | !xfer->tx_buf) |
| 741 | max_tx = max(xfer->len, max_tx); |
| 742 | if ((master->flags & SPI_MASTER_MUST_RX) && |
| 743 | !xfer->rx_buf) |
| 744 | max_rx = max(xfer->len, max_rx); |
| 745 | } |
| 746 | |
| 747 | if (max_tx) { |
| 748 | tmp = krealloc(master->dummy_tx, max_tx, |
| 749 | GFP_KERNEL | GFP_DMA); |
| 750 | if (!tmp) |
| 751 | return -ENOMEM; |
| 752 | master->dummy_tx = tmp; |
| 753 | memset(tmp, 0, max_tx); |
| 754 | } |
| 755 | |
| 756 | if (max_rx) { |
| 757 | tmp = krealloc(master->dummy_rx, max_rx, |
| 758 | GFP_KERNEL | GFP_DMA); |
| 759 | if (!tmp) |
| 760 | return -ENOMEM; |
| 761 | master->dummy_rx = tmp; |
| 762 | } |
| 763 | |
| 764 | if (max_tx || max_rx) { |
| 765 | list_for_each_entry(xfer, &msg->transfers, |
| 766 | transfer_list) { |
| 767 | if (!xfer->tx_buf) |
| 768 | xfer->tx_buf = master->dummy_tx; |
| 769 | if (!xfer->rx_buf) |
| 770 | xfer->rx_buf = master->dummy_rx; |
| 771 | } |
| 772 | } |
| 773 | } |
| 774 | |
| 775 | return __spi_map_msg(master, msg); |
| 776 | } |
Mark Brown | 99adef3 | 2014-01-16 12:22:43 +0000 | [diff] [blame] | 777 | |
Mark Brown | b158935 | 2013-10-05 11:50:40 +0100 | [diff] [blame] | 778 | /* |
| 779 | * spi_transfer_one_message - Default implementation of transfer_one_message() |
| 780 | * |
| 781 | * This is a standard implementation of transfer_one_message() for |
| 782 | * drivers which impelment a transfer_one() operation. It provides |
| 783 | * standard handling of delays and chip select management. |
| 784 | */ |
| 785 | static int spi_transfer_one_message(struct spi_master *master, |
| 786 | struct spi_message *msg) |
| 787 | { |
| 788 | struct spi_transfer *xfer; |
Mark Brown | b158935 | 2013-10-05 11:50:40 +0100 | [diff] [blame] | 789 | bool keep_cs = false; |
| 790 | int ret = 0; |
Mark Brown | 16a0ce4 | 2014-01-30 22:16:41 +0000 | [diff] [blame] | 791 | int ms = 1; |
Mark Brown | b158935 | 2013-10-05 11:50:40 +0100 | [diff] [blame] | 792 | |
| 793 | spi_set_cs(msg->spi, true); |
| 794 | |
| 795 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
| 796 | trace_spi_transfer_start(msg, xfer); |
| 797 | |
Mark Brown | 38ec10f | 2014-08-16 16:27:41 +0100 | [diff] [blame] | 798 | if (xfer->tx_buf || xfer->rx_buf) { |
| 799 | reinit_completion(&master->xfer_completion); |
Mark Brown | b158935 | 2013-10-05 11:50:40 +0100 | [diff] [blame] | 800 | |
Mark Brown | 38ec10f | 2014-08-16 16:27:41 +0100 | [diff] [blame] | 801 | ret = master->transfer_one(master, msg->spi, xfer); |
| 802 | if (ret < 0) { |
| 803 | dev_err(&msg->spi->dev, |
| 804 | "SPI transfer failed: %d\n", ret); |
| 805 | goto out; |
| 806 | } |
Mark Brown | b158935 | 2013-10-05 11:50:40 +0100 | [diff] [blame] | 807 | |
Mark Brown | 38ec10f | 2014-08-16 16:27:41 +0100 | [diff] [blame] | 808 | if (ret > 0) { |
| 809 | ret = 0; |
| 810 | ms = xfer->len * 8 * 1000 / xfer->speed_hz; |
| 811 | ms += ms + 100; /* some tolerance */ |
Mark Brown | 16a0ce4 | 2014-01-30 22:16:41 +0000 | [diff] [blame] | 812 | |
Mark Brown | 38ec10f | 2014-08-16 16:27:41 +0100 | [diff] [blame] | 813 | ms = wait_for_completion_timeout(&master->xfer_completion, |
| 814 | msecs_to_jiffies(ms)); |
| 815 | } |
Mark Brown | 16a0ce4 | 2014-01-30 22:16:41 +0000 | [diff] [blame] | 816 | |
Mark Brown | 38ec10f | 2014-08-16 16:27:41 +0100 | [diff] [blame] | 817 | if (ms == 0) { |
| 818 | dev_err(&msg->spi->dev, |
| 819 | "SPI transfer timed out\n"); |
| 820 | msg->status = -ETIMEDOUT; |
| 821 | } |
| 822 | } else { |
| 823 | if (xfer->len) |
| 824 | dev_err(&msg->spi->dev, |
| 825 | "Bufferless transfer has length %u\n", |
| 826 | xfer->len); |
Axel Lin | 13a4279 | 2014-01-18 22:05:22 +0800 | [diff] [blame] | 827 | } |
Mark Brown | b158935 | 2013-10-05 11:50:40 +0100 | [diff] [blame] | 828 | |
| 829 | trace_spi_transfer_stop(msg, xfer); |
| 830 | |
| 831 | if (msg->status != -EINPROGRESS) |
| 832 | goto out; |
| 833 | |
| 834 | if (xfer->delay_usecs) |
| 835 | udelay(xfer->delay_usecs); |
| 836 | |
| 837 | if (xfer->cs_change) { |
| 838 | if (list_is_last(&xfer->transfer_list, |
| 839 | &msg->transfers)) { |
| 840 | keep_cs = true; |
| 841 | } else { |
Mark Brown | 0b73aa6 | 2014-03-29 23:48:07 +0000 | [diff] [blame] | 842 | spi_set_cs(msg->spi, false); |
| 843 | udelay(10); |
| 844 | spi_set_cs(msg->spi, true); |
Mark Brown | b158935 | 2013-10-05 11:50:40 +0100 | [diff] [blame] | 845 | } |
| 846 | } |
| 847 | |
| 848 | msg->actual_length += xfer->len; |
| 849 | } |
| 850 | |
| 851 | out: |
| 852 | if (ret != 0 || !keep_cs) |
| 853 | spi_set_cs(msg->spi, false); |
| 854 | |
| 855 | if (msg->status == -EINPROGRESS) |
| 856 | msg->status = ret; |
| 857 | |
| 858 | spi_finalize_current_message(master); |
| 859 | |
| 860 | return ret; |
| 861 | } |
| 862 | |
| 863 | /** |
| 864 | * spi_finalize_current_transfer - report completion of a transfer |
Thierry Reding | 2c67568 | 2014-08-08 13:02:36 +0200 | [diff] [blame] | 865 | * @master: the master reporting completion |
Mark Brown | b158935 | 2013-10-05 11:50:40 +0100 | [diff] [blame] | 866 | * |
| 867 | * Called by SPI drivers using the core transfer_one_message() |
| 868 | * implementation to notify it that the current interrupt driven |
Geert Uytterhoeven | 9e8f488 | 2014-01-21 16:10:05 +0100 | [diff] [blame] | 869 | * transfer has finished and the next one may be scheduled. |
Mark Brown | b158935 | 2013-10-05 11:50:40 +0100 | [diff] [blame] | 870 | */ |
| 871 | void spi_finalize_current_transfer(struct spi_master *master) |
| 872 | { |
| 873 | complete(&master->xfer_completion); |
| 874 | } |
| 875 | EXPORT_SYMBOL_GPL(spi_finalize_current_transfer); |
| 876 | |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 877 | /** |
| 878 | * spi_pump_messages - kthread work function which processes spi message queue |
| 879 | * @work: pointer to kthread work struct contained in the master struct |
| 880 | * |
| 881 | * This function checks if there is any spi message in the queue that |
| 882 | * needs processing and if so call out to the driver to initialize hardware |
| 883 | * and transfer each message. |
| 884 | * |
| 885 | */ |
| 886 | static void spi_pump_messages(struct kthread_work *work) |
| 887 | { |
| 888 | struct spi_master *master = |
| 889 | container_of(work, struct spi_master, pump_messages); |
| 890 | unsigned long flags; |
| 891 | bool was_busy = false; |
| 892 | int ret; |
| 893 | |
| 894 | /* Lock queue and check for queue work */ |
| 895 | spin_lock_irqsave(&master->queue_lock, flags); |
| 896 | if (list_empty(&master->queue) || !master->running) { |
Bryan Freed | b0b36b8 | 2013-03-13 11:17:40 -0700 | [diff] [blame] | 897 | if (!master->busy) { |
| 898 | spin_unlock_irqrestore(&master->queue_lock, flags); |
| 899 | return; |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 900 | } |
| 901 | master->busy = false; |
| 902 | spin_unlock_irqrestore(&master->queue_lock, flags); |
Mark Brown | 3a2eba9 | 2014-01-28 20:17:03 +0000 | [diff] [blame] | 903 | kfree(master->dummy_rx); |
| 904 | master->dummy_rx = NULL; |
| 905 | kfree(master->dummy_tx); |
| 906 | master->dummy_tx = NULL; |
Bryan Freed | b0b36b8 | 2013-03-13 11:17:40 -0700 | [diff] [blame] | 907 | if (master->unprepare_transfer_hardware && |
| 908 | master->unprepare_transfer_hardware(master)) |
| 909 | dev_err(&master->dev, |
| 910 | "failed to unprepare transfer hardware\n"); |
Mark Brown | 49834de | 2013-07-28 14:47:02 +0100 | [diff] [blame] | 911 | if (master->auto_runtime_pm) { |
| 912 | pm_runtime_mark_last_busy(master->dev.parent); |
| 913 | pm_runtime_put_autosuspend(master->dev.parent); |
| 914 | } |
Mark Brown | 56ec197 | 2013-10-07 19:33:53 +0100 | [diff] [blame] | 915 | trace_spi_master_idle(master); |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 916 | return; |
| 917 | } |
| 918 | |
| 919 | /* Make sure we are not already running a message */ |
| 920 | if (master->cur_msg) { |
| 921 | spin_unlock_irqrestore(&master->queue_lock, flags); |
| 922 | return; |
| 923 | } |
| 924 | /* Extract head of queue */ |
| 925 | master->cur_msg = |
Axel Lin | a89e2d2 | 2014-01-09 16:03:58 +0800 | [diff] [blame] | 926 | list_first_entry(&master->queue, struct spi_message, queue); |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 927 | |
| 928 | list_del_init(&master->cur_msg->queue); |
| 929 | if (master->busy) |
| 930 | was_busy = true; |
| 931 | else |
| 932 | master->busy = true; |
| 933 | spin_unlock_irqrestore(&master->queue_lock, flags); |
| 934 | |
Mark Brown | 49834de | 2013-07-28 14:47:02 +0100 | [diff] [blame] | 935 | if (!was_busy && master->auto_runtime_pm) { |
| 936 | ret = pm_runtime_get_sync(master->dev.parent); |
| 937 | if (ret < 0) { |
| 938 | dev_err(&master->dev, "Failed to power device: %d\n", |
| 939 | ret); |
| 940 | return; |
| 941 | } |
| 942 | } |
| 943 | |
Mark Brown | 56ec197 | 2013-10-07 19:33:53 +0100 | [diff] [blame] | 944 | if (!was_busy) |
| 945 | trace_spi_master_busy(master); |
| 946 | |
Shubhrajyoti D | 7dfd2bd | 2012-05-10 19:20:41 +0530 | [diff] [blame] | 947 | if (!was_busy && master->prepare_transfer_hardware) { |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 948 | ret = master->prepare_transfer_hardware(master); |
| 949 | if (ret) { |
| 950 | dev_err(&master->dev, |
| 951 | "failed to prepare transfer hardware\n"); |
Mark Brown | 49834de | 2013-07-28 14:47:02 +0100 | [diff] [blame] | 952 | |
| 953 | if (master->auto_runtime_pm) |
| 954 | pm_runtime_put(master->dev.parent); |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 955 | return; |
| 956 | } |
| 957 | } |
| 958 | |
Mark Brown | 56ec197 | 2013-10-07 19:33:53 +0100 | [diff] [blame] | 959 | trace_spi_message_start(master->cur_msg); |
| 960 | |
Mark Brown | 2841a5f | 2013-10-05 00:23:12 +0100 | [diff] [blame] | 961 | if (master->prepare_message) { |
| 962 | ret = master->prepare_message(master, master->cur_msg); |
| 963 | if (ret) { |
| 964 | dev_err(&master->dev, |
| 965 | "failed to prepare message: %d\n", ret); |
| 966 | master->cur_msg->status = ret; |
| 967 | spi_finalize_current_message(master); |
| 968 | return; |
| 969 | } |
| 970 | master->cur_msg_prepared = true; |
| 971 | } |
| 972 | |
Mark Brown | 99adef3 | 2014-01-16 12:22:43 +0000 | [diff] [blame] | 973 | ret = spi_map_msg(master, master->cur_msg); |
| 974 | if (ret) { |
| 975 | master->cur_msg->status = ret; |
| 976 | spi_finalize_current_message(master); |
| 977 | return; |
| 978 | } |
| 979 | |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 980 | ret = master->transfer_one_message(master, master->cur_msg); |
| 981 | if (ret) { |
| 982 | dev_err(&master->dev, |
Geert Uytterhoeven | 1f802f8 | 2014-01-28 10:33:03 +0100 | [diff] [blame] | 983 | "failed to transfer one message from queue\n"); |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 984 | return; |
| 985 | } |
| 986 | } |
| 987 | |
| 988 | static int spi_init_queue(struct spi_master *master) |
| 989 | { |
| 990 | struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; |
| 991 | |
| 992 | INIT_LIST_HEAD(&master->queue); |
| 993 | spin_lock_init(&master->queue_lock); |
| 994 | |
| 995 | master->running = false; |
| 996 | master->busy = false; |
| 997 | |
| 998 | init_kthread_worker(&master->kworker); |
| 999 | master->kworker_task = kthread_run(kthread_worker_fn, |
Kees Cook | f170168 | 2013-07-03 15:04:58 -0700 | [diff] [blame] | 1000 | &master->kworker, "%s", |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 1001 | dev_name(&master->dev)); |
| 1002 | if (IS_ERR(master->kworker_task)) { |
| 1003 | dev_err(&master->dev, "failed to create message pump task\n"); |
| 1004 | return -ENOMEM; |
| 1005 | } |
| 1006 | init_kthread_work(&master->pump_messages, spi_pump_messages); |
| 1007 | |
| 1008 | /* |
| 1009 | * Master config will indicate if this controller should run the |
| 1010 | * message pump with high (realtime) priority to reduce the transfer |
| 1011 | * latency on the bus by minimising the delay between a transfer |
| 1012 | * request and the scheduling of the message pump thread. Without this |
| 1013 | * setting the message pump thread will remain at default priority. |
| 1014 | */ |
| 1015 | if (master->rt) { |
| 1016 | dev_info(&master->dev, |
| 1017 | "will run message pump with realtime priority\n"); |
| 1018 | sched_setscheduler(master->kworker_task, SCHED_FIFO, ¶m); |
| 1019 | } |
| 1020 | |
| 1021 | return 0; |
| 1022 | } |
| 1023 | |
| 1024 | /** |
| 1025 | * spi_get_next_queued_message() - called by driver to check for queued |
| 1026 | * messages |
| 1027 | * @master: the master to check for queued messages |
| 1028 | * |
| 1029 | * If there are more messages in the queue, the next message is returned from |
| 1030 | * this call. |
| 1031 | */ |
| 1032 | struct spi_message *spi_get_next_queued_message(struct spi_master *master) |
| 1033 | { |
| 1034 | struct spi_message *next; |
| 1035 | unsigned long flags; |
| 1036 | |
| 1037 | /* get a pointer to the next message, if any */ |
| 1038 | spin_lock_irqsave(&master->queue_lock, flags); |
Axel Lin | 1cfd97f | 2014-01-02 15:16:40 +0800 | [diff] [blame] | 1039 | next = list_first_entry_or_null(&master->queue, struct spi_message, |
| 1040 | queue); |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 1041 | spin_unlock_irqrestore(&master->queue_lock, flags); |
| 1042 | |
| 1043 | return next; |
| 1044 | } |
| 1045 | EXPORT_SYMBOL_GPL(spi_get_next_queued_message); |
| 1046 | |
| 1047 | /** |
| 1048 | * spi_finalize_current_message() - the current message is complete |
| 1049 | * @master: the master to return the message to |
| 1050 | * |
| 1051 | * Called by the driver to notify the core that the message in the front of the |
| 1052 | * queue is complete and can be removed from the queue. |
| 1053 | */ |
| 1054 | void spi_finalize_current_message(struct spi_master *master) |
| 1055 | { |
| 1056 | struct spi_message *mesg; |
| 1057 | unsigned long flags; |
Mark Brown | 2841a5f | 2013-10-05 00:23:12 +0100 | [diff] [blame] | 1058 | int ret; |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 1059 | |
| 1060 | spin_lock_irqsave(&master->queue_lock, flags); |
| 1061 | mesg = master->cur_msg; |
| 1062 | master->cur_msg = NULL; |
| 1063 | |
| 1064 | queue_kthread_work(&master->kworker, &master->pump_messages); |
| 1065 | spin_unlock_irqrestore(&master->queue_lock, flags); |
| 1066 | |
Mark Brown | 99adef3 | 2014-01-16 12:22:43 +0000 | [diff] [blame] | 1067 | spi_unmap_msg(master, mesg); |
| 1068 | |
Mark Brown | 2841a5f | 2013-10-05 00:23:12 +0100 | [diff] [blame] | 1069 | if (master->cur_msg_prepared && master->unprepare_message) { |
| 1070 | ret = master->unprepare_message(master, mesg); |
| 1071 | if (ret) { |
| 1072 | dev_err(&master->dev, |
| 1073 | "failed to unprepare message: %d\n", ret); |
| 1074 | } |
| 1075 | } |
| 1076 | master->cur_msg_prepared = false; |
| 1077 | |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 1078 | mesg->state = NULL; |
| 1079 | if (mesg->complete) |
| 1080 | mesg->complete(mesg->context); |
Mark Brown | 56ec197 | 2013-10-07 19:33:53 +0100 | [diff] [blame] | 1081 | |
| 1082 | trace_spi_message_done(mesg); |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 1083 | } |
| 1084 | EXPORT_SYMBOL_GPL(spi_finalize_current_message); |
| 1085 | |
| 1086 | static int spi_start_queue(struct spi_master *master) |
| 1087 | { |
| 1088 | unsigned long flags; |
| 1089 | |
| 1090 | spin_lock_irqsave(&master->queue_lock, flags); |
| 1091 | |
| 1092 | if (master->running || master->busy) { |
| 1093 | spin_unlock_irqrestore(&master->queue_lock, flags); |
| 1094 | return -EBUSY; |
| 1095 | } |
| 1096 | |
| 1097 | master->running = true; |
| 1098 | master->cur_msg = NULL; |
| 1099 | spin_unlock_irqrestore(&master->queue_lock, flags); |
| 1100 | |
| 1101 | queue_kthread_work(&master->kworker, &master->pump_messages); |
| 1102 | |
| 1103 | return 0; |
| 1104 | } |
| 1105 | |
| 1106 | static int spi_stop_queue(struct spi_master *master) |
| 1107 | { |
| 1108 | unsigned long flags; |
| 1109 | unsigned limit = 500; |
| 1110 | int ret = 0; |
| 1111 | |
| 1112 | spin_lock_irqsave(&master->queue_lock, flags); |
| 1113 | |
| 1114 | /* |
| 1115 | * This is a bit lame, but is optimized for the common execution path. |
| 1116 | * A wait_queue on the master->busy could be used, but then the common |
| 1117 | * execution path (pump_messages) would be required to call wake_up or |
| 1118 | * friends on every SPI message. Do this instead. |
| 1119 | */ |
| 1120 | while ((!list_empty(&master->queue) || master->busy) && limit--) { |
| 1121 | spin_unlock_irqrestore(&master->queue_lock, flags); |
Axel Lin | f97b26b | 2014-02-21 09:15:18 +0800 | [diff] [blame] | 1122 | usleep_range(10000, 11000); |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 1123 | spin_lock_irqsave(&master->queue_lock, flags); |
| 1124 | } |
| 1125 | |
| 1126 | if (!list_empty(&master->queue) || master->busy) |
| 1127 | ret = -EBUSY; |
| 1128 | else |
| 1129 | master->running = false; |
| 1130 | |
| 1131 | spin_unlock_irqrestore(&master->queue_lock, flags); |
| 1132 | |
| 1133 | if (ret) { |
| 1134 | dev_warn(&master->dev, |
| 1135 | "could not stop message queue\n"); |
| 1136 | return ret; |
| 1137 | } |
| 1138 | return ret; |
| 1139 | } |
| 1140 | |
| 1141 | static int spi_destroy_queue(struct spi_master *master) |
| 1142 | { |
| 1143 | int ret; |
| 1144 | |
| 1145 | ret = spi_stop_queue(master); |
| 1146 | |
| 1147 | /* |
| 1148 | * flush_kthread_worker will block until all work is done. |
| 1149 | * If the reason that stop_queue timed out is that the work will never |
| 1150 | * finish, then it does no good to call flush/stop thread, so |
| 1151 | * return anyway. |
| 1152 | */ |
| 1153 | if (ret) { |
| 1154 | dev_err(&master->dev, "problem destroying queue\n"); |
| 1155 | return ret; |
| 1156 | } |
| 1157 | |
| 1158 | flush_kthread_worker(&master->kworker); |
| 1159 | kthread_stop(master->kworker_task); |
| 1160 | |
| 1161 | return 0; |
| 1162 | } |
| 1163 | |
| 1164 | /** |
| 1165 | * spi_queued_transfer - transfer function for queued transfers |
| 1166 | * @spi: spi device which is requesting transfer |
| 1167 | * @msg: spi message which is to handled is queued to driver queue |
| 1168 | */ |
| 1169 | static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg) |
| 1170 | { |
| 1171 | struct spi_master *master = spi->master; |
| 1172 | unsigned long flags; |
| 1173 | |
| 1174 | spin_lock_irqsave(&master->queue_lock, flags); |
| 1175 | |
| 1176 | if (!master->running) { |
| 1177 | spin_unlock_irqrestore(&master->queue_lock, flags); |
| 1178 | return -ESHUTDOWN; |
| 1179 | } |
| 1180 | msg->actual_length = 0; |
| 1181 | msg->status = -EINPROGRESS; |
| 1182 | |
| 1183 | list_add_tail(&msg->queue, &master->queue); |
Axel Lin | 96b3eac | 2013-08-22 23:41:34 +0800 | [diff] [blame] | 1184 | if (!master->busy) |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 1185 | queue_kthread_work(&master->kworker, &master->pump_messages); |
| 1186 | |
| 1187 | spin_unlock_irqrestore(&master->queue_lock, flags); |
| 1188 | return 0; |
| 1189 | } |
| 1190 | |
| 1191 | static int spi_master_initialize_queue(struct spi_master *master) |
| 1192 | { |
| 1193 | int ret; |
| 1194 | |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 1195 | master->transfer = spi_queued_transfer; |
Mark Brown | b158935 | 2013-10-05 11:50:40 +0100 | [diff] [blame] | 1196 | if (!master->transfer_one_message) |
| 1197 | master->transfer_one_message = spi_transfer_one_message; |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 1198 | |
| 1199 | /* Initialize and start queue */ |
| 1200 | ret = spi_init_queue(master); |
| 1201 | if (ret) { |
| 1202 | dev_err(&master->dev, "problem initializing queue\n"); |
| 1203 | goto err_init_queue; |
| 1204 | } |
Mark Brown | c3676d5 | 2014-05-01 10:47:52 -0700 | [diff] [blame] | 1205 | master->queued = true; |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 1206 | ret = spi_start_queue(master); |
| 1207 | if (ret) { |
| 1208 | dev_err(&master->dev, "problem starting queue\n"); |
| 1209 | goto err_start_queue; |
| 1210 | } |
| 1211 | |
| 1212 | return 0; |
| 1213 | |
| 1214 | err_start_queue: |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 1215 | spi_destroy_queue(master); |
Mark Brown | c3676d5 | 2014-05-01 10:47:52 -0700 | [diff] [blame] | 1216 | err_init_queue: |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 1217 | return ret; |
| 1218 | } |
| 1219 | |
| 1220 | /*-------------------------------------------------------------------------*/ |
| 1221 | |
Andreas Larsson | 7cb9436 | 2012-12-04 15:09:38 +0100 | [diff] [blame] | 1222 | #if defined(CONFIG_OF) |
Grant Likely | d57a428 | 2012-04-07 14:16:53 -0600 | [diff] [blame] | 1223 | /** |
| 1224 | * of_register_spi_devices() - Register child devices onto the SPI bus |
| 1225 | * @master: Pointer to spi_master device |
| 1226 | * |
| 1227 | * Registers an spi_device for each child node of master node which has a 'reg' |
| 1228 | * property. |
| 1229 | */ |
| 1230 | static void of_register_spi_devices(struct spi_master *master) |
| 1231 | { |
| 1232 | struct spi_device *spi; |
| 1233 | struct device_node *nc; |
Grant Likely | d57a428 | 2012-04-07 14:16:53 -0600 | [diff] [blame] | 1234 | int rc; |
Trent Piepho | 89da429 | 2013-09-27 05:37:25 -0700 | [diff] [blame] | 1235 | u32 value; |
Grant Likely | d57a428 | 2012-04-07 14:16:53 -0600 | [diff] [blame] | 1236 | |
| 1237 | if (!master->dev.of_node) |
| 1238 | return; |
| 1239 | |
Alexander Sverdlin | f3b6159 | 2012-11-29 08:59:29 +0100 | [diff] [blame] | 1240 | for_each_available_child_of_node(master->dev.of_node, nc) { |
Grant Likely | d57a428 | 2012-04-07 14:16:53 -0600 | [diff] [blame] | 1241 | /* Alloc an spi_device */ |
| 1242 | spi = spi_alloc_device(master); |
| 1243 | if (!spi) { |
| 1244 | dev_err(&master->dev, "spi_device alloc error for %s\n", |
| 1245 | nc->full_name); |
| 1246 | spi_dev_put(spi); |
| 1247 | continue; |
| 1248 | } |
| 1249 | |
| 1250 | /* Select device driver */ |
| 1251 | if (of_modalias_node(nc, spi->modalias, |
| 1252 | sizeof(spi->modalias)) < 0) { |
| 1253 | dev_err(&master->dev, "cannot find modalias for %s\n", |
| 1254 | nc->full_name); |
| 1255 | spi_dev_put(spi); |
| 1256 | continue; |
| 1257 | } |
| 1258 | |
| 1259 | /* Device address */ |
Trent Piepho | 89da429 | 2013-09-27 05:37:25 -0700 | [diff] [blame] | 1260 | rc = of_property_read_u32(nc, "reg", &value); |
| 1261 | if (rc) { |
| 1262 | dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n", |
| 1263 | nc->full_name, rc); |
Grant Likely | d57a428 | 2012-04-07 14:16:53 -0600 | [diff] [blame] | 1264 | spi_dev_put(spi); |
| 1265 | continue; |
| 1266 | } |
Trent Piepho | 89da429 | 2013-09-27 05:37:25 -0700 | [diff] [blame] | 1267 | spi->chip_select = value; |
Grant Likely | d57a428 | 2012-04-07 14:16:53 -0600 | [diff] [blame] | 1268 | |
| 1269 | /* Mode (clock phase/polarity/etc.) */ |
| 1270 | if (of_find_property(nc, "spi-cpha", NULL)) |
| 1271 | spi->mode |= SPI_CPHA; |
| 1272 | if (of_find_property(nc, "spi-cpol", NULL)) |
| 1273 | spi->mode |= SPI_CPOL; |
| 1274 | if (of_find_property(nc, "spi-cs-high", NULL)) |
| 1275 | spi->mode |= SPI_CS_HIGH; |
Lars-Peter Clausen | c20151d | 2012-12-06 16:55:33 +0100 | [diff] [blame] | 1276 | if (of_find_property(nc, "spi-3wire", NULL)) |
| 1277 | spi->mode |= SPI_3WIRE; |
Zhao Qiang | cd6339e | 2014-04-01 17:10:50 +0800 | [diff] [blame] | 1278 | if (of_find_property(nc, "spi-lsb-first", NULL)) |
| 1279 | spi->mode |= SPI_LSB_FIRST; |
Grant Likely | d57a428 | 2012-04-07 14:16:53 -0600 | [diff] [blame] | 1280 | |
wangyuhang | f477b7f | 2013-08-11 18:15:17 +0800 | [diff] [blame] | 1281 | /* Device DUAL/QUAD mode */ |
Trent Piepho | 89da429 | 2013-09-27 05:37:25 -0700 | [diff] [blame] | 1282 | if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) { |
| 1283 | switch (value) { |
| 1284 | case 1: |
Mark Brown | a822e99 | 2013-08-30 23:19:40 +0100 | [diff] [blame] | 1285 | break; |
Trent Piepho | 89da429 | 2013-09-27 05:37:25 -0700 | [diff] [blame] | 1286 | case 2: |
Mark Brown | a822e99 | 2013-08-30 23:19:40 +0100 | [diff] [blame] | 1287 | spi->mode |= SPI_TX_DUAL; |
| 1288 | break; |
Trent Piepho | 89da429 | 2013-09-27 05:37:25 -0700 | [diff] [blame] | 1289 | case 4: |
Mark Brown | a822e99 | 2013-08-30 23:19:40 +0100 | [diff] [blame] | 1290 | spi->mode |= SPI_TX_QUAD; |
| 1291 | break; |
| 1292 | default: |
Geert Uytterhoeven | 80874d8 | 2014-05-26 14:05:25 +0200 | [diff] [blame] | 1293 | dev_warn(&master->dev, |
| 1294 | "spi-tx-bus-width %d not supported\n", |
| 1295 | value); |
| 1296 | break; |
Mark Brown | a822e99 | 2013-08-30 23:19:40 +0100 | [diff] [blame] | 1297 | } |
wangyuhang | f477b7f | 2013-08-11 18:15:17 +0800 | [diff] [blame] | 1298 | } |
| 1299 | |
Trent Piepho | 89da429 | 2013-09-27 05:37:25 -0700 | [diff] [blame] | 1300 | if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) { |
| 1301 | switch (value) { |
| 1302 | case 1: |
Mark Brown | a822e99 | 2013-08-30 23:19:40 +0100 | [diff] [blame] | 1303 | break; |
Trent Piepho | 89da429 | 2013-09-27 05:37:25 -0700 | [diff] [blame] | 1304 | case 2: |
Mark Brown | a822e99 | 2013-08-30 23:19:40 +0100 | [diff] [blame] | 1305 | spi->mode |= SPI_RX_DUAL; |
| 1306 | break; |
Trent Piepho | 89da429 | 2013-09-27 05:37:25 -0700 | [diff] [blame] | 1307 | case 4: |
Mark Brown | a822e99 | 2013-08-30 23:19:40 +0100 | [diff] [blame] | 1308 | spi->mode |= SPI_RX_QUAD; |
| 1309 | break; |
| 1310 | default: |
Geert Uytterhoeven | 80874d8 | 2014-05-26 14:05:25 +0200 | [diff] [blame] | 1311 | dev_warn(&master->dev, |
| 1312 | "spi-rx-bus-width %d not supported\n", |
| 1313 | value); |
| 1314 | break; |
Mark Brown | a822e99 | 2013-08-30 23:19:40 +0100 | [diff] [blame] | 1315 | } |
wangyuhang | f477b7f | 2013-08-11 18:15:17 +0800 | [diff] [blame] | 1316 | } |
| 1317 | |
Grant Likely | d57a428 | 2012-04-07 14:16:53 -0600 | [diff] [blame] | 1318 | /* Device speed */ |
Trent Piepho | 89da429 | 2013-09-27 05:37:25 -0700 | [diff] [blame] | 1319 | rc = of_property_read_u32(nc, "spi-max-frequency", &value); |
| 1320 | if (rc) { |
| 1321 | dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n", |
| 1322 | nc->full_name, rc); |
Grant Likely | d57a428 | 2012-04-07 14:16:53 -0600 | [diff] [blame] | 1323 | spi_dev_put(spi); |
| 1324 | continue; |
| 1325 | } |
Trent Piepho | 89da429 | 2013-09-27 05:37:25 -0700 | [diff] [blame] | 1326 | spi->max_speed_hz = value; |
Grant Likely | d57a428 | 2012-04-07 14:16:53 -0600 | [diff] [blame] | 1327 | |
| 1328 | /* IRQ */ |
| 1329 | spi->irq = irq_of_parse_and_map(nc, 0); |
| 1330 | |
| 1331 | /* Store a pointer to the node in the device structure */ |
| 1332 | of_node_get(nc); |
| 1333 | spi->dev.of_node = nc; |
| 1334 | |
| 1335 | /* Register the new device */ |
Mathias Krause | 70fac17 | 2013-08-31 20:24:14 +0200 | [diff] [blame] | 1336 | request_module("%s%s", SPI_MODULE_PREFIX, spi->modalias); |
Grant Likely | d57a428 | 2012-04-07 14:16:53 -0600 | [diff] [blame] | 1337 | rc = spi_add_device(spi); |
| 1338 | if (rc) { |
| 1339 | dev_err(&master->dev, "spi_device register error %s\n", |
| 1340 | nc->full_name); |
| 1341 | spi_dev_put(spi); |
| 1342 | } |
| 1343 | |
| 1344 | } |
| 1345 | } |
| 1346 | #else |
| 1347 | static void of_register_spi_devices(struct spi_master *master) { } |
| 1348 | #endif |
| 1349 | |
Mika Westerberg | 64bee4d | 2012-11-30 12:37:53 +0100 | [diff] [blame] | 1350 | #ifdef CONFIG_ACPI |
| 1351 | static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) |
| 1352 | { |
| 1353 | struct spi_device *spi = data; |
| 1354 | |
| 1355 | if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { |
| 1356 | struct acpi_resource_spi_serialbus *sb; |
| 1357 | |
| 1358 | sb = &ares->data.spi_serial_bus; |
| 1359 | if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) { |
| 1360 | spi->chip_select = sb->device_selection; |
| 1361 | spi->max_speed_hz = sb->connection_speed; |
| 1362 | |
| 1363 | if (sb->clock_phase == ACPI_SPI_SECOND_PHASE) |
| 1364 | spi->mode |= SPI_CPHA; |
| 1365 | if (sb->clock_polarity == ACPI_SPI_START_HIGH) |
| 1366 | spi->mode |= SPI_CPOL; |
| 1367 | if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH) |
| 1368 | spi->mode |= SPI_CS_HIGH; |
| 1369 | } |
| 1370 | } else if (spi->irq < 0) { |
| 1371 | struct resource r; |
| 1372 | |
| 1373 | if (acpi_dev_resource_interrupt(ares, 0, &r)) |
| 1374 | spi->irq = r.start; |
| 1375 | } |
| 1376 | |
| 1377 | /* Always tell the ACPI core to skip this resource */ |
| 1378 | return 1; |
| 1379 | } |
| 1380 | |
| 1381 | static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level, |
| 1382 | void *data, void **return_value) |
| 1383 | { |
| 1384 | struct spi_master *master = data; |
| 1385 | struct list_head resource_list; |
| 1386 | struct acpi_device *adev; |
| 1387 | struct spi_device *spi; |
| 1388 | int ret; |
| 1389 | |
| 1390 | if (acpi_bus_get_device(handle, &adev)) |
| 1391 | return AE_OK; |
| 1392 | if (acpi_bus_get_status(adev) || !adev->status.present) |
| 1393 | return AE_OK; |
| 1394 | |
| 1395 | spi = spi_alloc_device(master); |
| 1396 | if (!spi) { |
| 1397 | dev_err(&master->dev, "failed to allocate SPI device for %s\n", |
| 1398 | dev_name(&adev->dev)); |
| 1399 | return AE_NO_MEMORY; |
| 1400 | } |
| 1401 | |
Rafael J. Wysocki | 7b19981 | 2013-11-11 22:41:56 +0100 | [diff] [blame] | 1402 | ACPI_COMPANION_SET(&spi->dev, adev); |
Mika Westerberg | 64bee4d | 2012-11-30 12:37:53 +0100 | [diff] [blame] | 1403 | spi->irq = -1; |
| 1404 | |
| 1405 | INIT_LIST_HEAD(&resource_list); |
| 1406 | ret = acpi_dev_get_resources(adev, &resource_list, |
| 1407 | acpi_spi_add_resource, spi); |
| 1408 | acpi_dev_free_resource_list(&resource_list); |
| 1409 | |
| 1410 | if (ret < 0 || !spi->max_speed_hz) { |
| 1411 | spi_dev_put(spi); |
| 1412 | return AE_OK; |
| 1413 | } |
| 1414 | |
Mika Westerberg | 33cf00e | 2013-10-10 13:28:48 +0300 | [diff] [blame] | 1415 | adev->power.flags.ignore_parent = true; |
Jarkko Nikula | cf9eb39 | 2013-10-10 17:19:17 +0300 | [diff] [blame] | 1416 | strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias)); |
Mika Westerberg | 64bee4d | 2012-11-30 12:37:53 +0100 | [diff] [blame] | 1417 | if (spi_add_device(spi)) { |
Mika Westerberg | 33cf00e | 2013-10-10 13:28:48 +0300 | [diff] [blame] | 1418 | adev->power.flags.ignore_parent = false; |
Mika Westerberg | 64bee4d | 2012-11-30 12:37:53 +0100 | [diff] [blame] | 1419 | dev_err(&master->dev, "failed to add SPI device %s from ACPI\n", |
| 1420 | dev_name(&adev->dev)); |
| 1421 | spi_dev_put(spi); |
| 1422 | } |
| 1423 | |
| 1424 | return AE_OK; |
| 1425 | } |
| 1426 | |
| 1427 | static void acpi_register_spi_devices(struct spi_master *master) |
| 1428 | { |
| 1429 | acpi_status status; |
| 1430 | acpi_handle handle; |
| 1431 | |
Rafael J. Wysocki | 2989617 | 2013-04-01 00:21:08 +0000 | [diff] [blame] | 1432 | handle = ACPI_HANDLE(master->dev.parent); |
Mika Westerberg | 64bee4d | 2012-11-30 12:37:53 +0100 | [diff] [blame] | 1433 | if (!handle) |
| 1434 | return; |
| 1435 | |
| 1436 | status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, |
| 1437 | acpi_spi_add_device, NULL, |
| 1438 | master, NULL); |
| 1439 | if (ACPI_FAILURE(status)) |
| 1440 | dev_warn(&master->dev, "failed to enumerate SPI slaves\n"); |
| 1441 | } |
| 1442 | #else |
| 1443 | static inline void acpi_register_spi_devices(struct spi_master *master) {} |
| 1444 | #endif /* CONFIG_ACPI */ |
| 1445 | |
Tony Jones | 49dce68 | 2007-10-16 01:27:48 -0700 | [diff] [blame] | 1446 | static void spi_master_release(struct device *dev) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1447 | { |
| 1448 | struct spi_master *master; |
| 1449 | |
Tony Jones | 49dce68 | 2007-10-16 01:27:48 -0700 | [diff] [blame] | 1450 | master = container_of(dev, struct spi_master, dev); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1451 | kfree(master); |
| 1452 | } |
| 1453 | |
| 1454 | static struct class spi_master_class = { |
| 1455 | .name = "spi_master", |
| 1456 | .owner = THIS_MODULE, |
Tony Jones | 49dce68 | 2007-10-16 01:27:48 -0700 | [diff] [blame] | 1457 | .dev_release = spi_master_release, |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1458 | }; |
| 1459 | |
| 1460 | |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 1461 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1462 | /** |
| 1463 | * spi_alloc_master - allocate SPI master controller |
| 1464 | * @dev: the controller, possibly using the platform_bus |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 1465 | * @size: how much zeroed driver-private data to allocate; the pointer to this |
Tony Jones | 49dce68 | 2007-10-16 01:27:48 -0700 | [diff] [blame] | 1466 | * memory is in the driver_data field of the returned device, |
David Brownell | 0c86846 | 2006-01-08 13:34:25 -0800 | [diff] [blame] | 1467 | * accessible with spi_master_get_devdata(). |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 1468 | * Context: can sleep |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1469 | * |
| 1470 | * This call is used only by SPI master controller drivers, which are the |
| 1471 | * only ones directly touching chip registers. It's how they allocate |
dmitry pervushin | ba1a051 | 2006-05-20 15:00:14 -0700 | [diff] [blame] | 1472 | * an spi_master structure, prior to calling spi_register_master(). |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1473 | * |
| 1474 | * This must be called from context that can sleep. It returns the SPI |
| 1475 | * master structure on success, else NULL. |
| 1476 | * |
| 1477 | * The caller is responsible for assigning the bus number and initializing |
dmitry pervushin | ba1a051 | 2006-05-20 15:00:14 -0700 | [diff] [blame] | 1478 | * the master's methods before calling spi_register_master(); and (after errors |
Uwe Kleine-König | eb4af0f | 2012-02-23 10:40:14 +0100 | [diff] [blame] | 1479 | * adding the device) calling spi_master_put() and kfree() to prevent a memory |
| 1480 | * leak. |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1481 | */ |
Adrian Bunk | e9d5a46 | 2007-03-26 21:32:23 -0800 | [diff] [blame] | 1482 | struct spi_master *spi_alloc_master(struct device *dev, unsigned size) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1483 | { |
| 1484 | struct spi_master *master; |
| 1485 | |
David Brownell | 0c86846 | 2006-01-08 13:34:25 -0800 | [diff] [blame] | 1486 | if (!dev) |
| 1487 | return NULL; |
| 1488 | |
Jingoo Han | 5fe5f05 | 2013-10-14 10:31:51 +0900 | [diff] [blame] | 1489 | master = kzalloc(size + sizeof(*master), GFP_KERNEL); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1490 | if (!master) |
| 1491 | return NULL; |
| 1492 | |
Tony Jones | 49dce68 | 2007-10-16 01:27:48 -0700 | [diff] [blame] | 1493 | device_initialize(&master->dev); |
Grant Likely | 1e8a52e | 2012-05-19 23:42:08 -0600 | [diff] [blame] | 1494 | master->bus_num = -1; |
| 1495 | master->num_chipselect = 1; |
Tony Jones | 49dce68 | 2007-10-16 01:27:48 -0700 | [diff] [blame] | 1496 | master->dev.class = &spi_master_class; |
| 1497 | master->dev.parent = get_device(dev); |
David Brownell | 0c86846 | 2006-01-08 13:34:25 -0800 | [diff] [blame] | 1498 | spi_master_set_devdata(master, &master[1]); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1499 | |
| 1500 | return master; |
| 1501 | } |
| 1502 | EXPORT_SYMBOL_GPL(spi_alloc_master); |
| 1503 | |
Jean-Christophe PLAGNIOL-VILLARD | 7431798 | 2012-11-15 20:19:57 +0100 | [diff] [blame] | 1504 | #ifdef CONFIG_OF |
| 1505 | static int of_spi_register_master(struct spi_master *master) |
| 1506 | { |
Grant Likely | e80beb2 | 2013-02-12 17:48:37 +0000 | [diff] [blame] | 1507 | int nb, i, *cs; |
Jean-Christophe PLAGNIOL-VILLARD | 7431798 | 2012-11-15 20:19:57 +0100 | [diff] [blame] | 1508 | struct device_node *np = master->dev.of_node; |
| 1509 | |
| 1510 | if (!np) |
| 1511 | return 0; |
| 1512 | |
| 1513 | nb = of_gpio_named_count(np, "cs-gpios"); |
Jingoo Han | 5fe5f05 | 2013-10-14 10:31:51 +0900 | [diff] [blame] | 1514 | master->num_chipselect = max_t(int, nb, master->num_chipselect); |
Jean-Christophe PLAGNIOL-VILLARD | 7431798 | 2012-11-15 20:19:57 +0100 | [diff] [blame] | 1515 | |
Andreas Larsson | 8ec5d84 | 2013-02-13 14:23:24 +0100 | [diff] [blame] | 1516 | /* Return error only for an incorrectly formed cs-gpios property */ |
| 1517 | if (nb == 0 || nb == -ENOENT) |
Jean-Christophe PLAGNIOL-VILLARD | 7431798 | 2012-11-15 20:19:57 +0100 | [diff] [blame] | 1518 | return 0; |
Andreas Larsson | 8ec5d84 | 2013-02-13 14:23:24 +0100 | [diff] [blame] | 1519 | else if (nb < 0) |
| 1520 | return nb; |
Jean-Christophe PLAGNIOL-VILLARD | 7431798 | 2012-11-15 20:19:57 +0100 | [diff] [blame] | 1521 | |
| 1522 | cs = devm_kzalloc(&master->dev, |
| 1523 | sizeof(int) * master->num_chipselect, |
| 1524 | GFP_KERNEL); |
| 1525 | master->cs_gpios = cs; |
| 1526 | |
| 1527 | if (!master->cs_gpios) |
| 1528 | return -ENOMEM; |
| 1529 | |
Andreas Larsson | 0da83bb | 2013-01-29 15:53:40 +0100 | [diff] [blame] | 1530 | for (i = 0; i < master->num_chipselect; i++) |
Andreas Larsson | 446411e | 2013-02-13 14:20:25 +0100 | [diff] [blame] | 1531 | cs[i] = -ENOENT; |
Jean-Christophe PLAGNIOL-VILLARD | 7431798 | 2012-11-15 20:19:57 +0100 | [diff] [blame] | 1532 | |
| 1533 | for (i = 0; i < nb; i++) |
| 1534 | cs[i] = of_get_named_gpio(np, "cs-gpios", i); |
| 1535 | |
| 1536 | return 0; |
| 1537 | } |
| 1538 | #else |
| 1539 | static int of_spi_register_master(struct spi_master *master) |
| 1540 | { |
| 1541 | return 0; |
| 1542 | } |
| 1543 | #endif |
| 1544 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1545 | /** |
| 1546 | * spi_register_master - register SPI master controller |
| 1547 | * @master: initialized master, originally from spi_alloc_master() |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 1548 | * Context: can sleep |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1549 | * |
| 1550 | * SPI master controllers connect to their drivers using some non-SPI bus, |
| 1551 | * such as the platform bus. The final stage of probe() in that code |
| 1552 | * includes calling spi_register_master() to hook up to this SPI bus glue. |
| 1553 | * |
| 1554 | * SPI controllers use board specific (often SOC specific) bus numbers, |
| 1555 | * and board-specific addressing for SPI devices combines those numbers |
| 1556 | * with chip select numbers. Since SPI does not directly support dynamic |
| 1557 | * device identification, boards need configuration tables telling which |
| 1558 | * chip is at which address. |
| 1559 | * |
| 1560 | * This must be called from context that can sleep. It returns zero on |
| 1561 | * success, else a negative error code (dropping the master's refcount). |
David Brownell | 0c86846 | 2006-01-08 13:34:25 -0800 | [diff] [blame] | 1562 | * After a successful return, the caller is responsible for calling |
| 1563 | * spi_unregister_master(). |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1564 | */ |
Adrian Bunk | e9d5a46 | 2007-03-26 21:32:23 -0800 | [diff] [blame] | 1565 | int spi_register_master(struct spi_master *master) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1566 | { |
David Brownell | e44a45a | 2007-06-03 13:50:40 -0700 | [diff] [blame] | 1567 | static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1); |
Tony Jones | 49dce68 | 2007-10-16 01:27:48 -0700 | [diff] [blame] | 1568 | struct device *dev = master->dev.parent; |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 1569 | struct boardinfo *bi; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1570 | int status = -ENODEV; |
| 1571 | int dynamic = 0; |
| 1572 | |
David Brownell | 0c86846 | 2006-01-08 13:34:25 -0800 | [diff] [blame] | 1573 | if (!dev) |
| 1574 | return -ENODEV; |
| 1575 | |
Jean-Christophe PLAGNIOL-VILLARD | 7431798 | 2012-11-15 20:19:57 +0100 | [diff] [blame] | 1576 | status = of_spi_register_master(master); |
| 1577 | if (status) |
| 1578 | return status; |
| 1579 | |
David Brownell | 082c8cb | 2007-07-31 00:39:45 -0700 | [diff] [blame] | 1580 | /* even if it's just one always-selected device, there must |
| 1581 | * be at least one chipselect |
| 1582 | */ |
| 1583 | if (master->num_chipselect == 0) |
| 1584 | return -EINVAL; |
| 1585 | |
Grant Likely | bb29785 | 2012-12-21 19:32:09 +0000 | [diff] [blame] | 1586 | if ((master->bus_num < 0) && master->dev.of_node) |
| 1587 | master->bus_num = of_alias_get_id(master->dev.of_node, "spi"); |
| 1588 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1589 | /* convention: dynamically assigned bus IDs count down from the max */ |
David Brownell | a020ed7 | 2006-04-03 15:49:04 -0700 | [diff] [blame] | 1590 | if (master->bus_num < 0) { |
David Brownell | 082c8cb | 2007-07-31 00:39:45 -0700 | [diff] [blame] | 1591 | /* FIXME switch to an IDR based scheme, something like |
| 1592 | * I2C now uses, so we can't run out of "dynamic" IDs |
| 1593 | */ |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1594 | master->bus_num = atomic_dec_return(&dyn_bus_id); |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 1595 | dynamic = 1; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1596 | } |
| 1597 | |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 1598 | spin_lock_init(&master->bus_lock_spinlock); |
| 1599 | mutex_init(&master->bus_lock_mutex); |
| 1600 | master->bus_lock_flag = 0; |
Mark Brown | b158935 | 2013-10-05 11:50:40 +0100 | [diff] [blame] | 1601 | init_completion(&master->xfer_completion); |
Mark Brown | 6ad45a2 | 2014-02-02 13:47:47 +0000 | [diff] [blame] | 1602 | if (!master->max_dma_len) |
| 1603 | master->max_dma_len = INT_MAX; |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 1604 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1605 | /* register the device, then userspace will see it. |
| 1606 | * registration fails if the bus ID is in use. |
| 1607 | */ |
Kay Sievers | 35f74fc | 2009-01-06 10:44:37 -0800 | [diff] [blame] | 1608 | dev_set_name(&master->dev, "spi%u", master->bus_num); |
Tony Jones | 49dce68 | 2007-10-16 01:27:48 -0700 | [diff] [blame] | 1609 | status = device_add(&master->dev); |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 1610 | if (status < 0) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1611 | goto done; |
Kay Sievers | 35f74fc | 2009-01-06 10:44:37 -0800 | [diff] [blame] | 1612 | dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev), |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1613 | dynamic ? " (dynamic)" : ""); |
| 1614 | |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 1615 | /* If we're using a queued driver, start the queue */ |
| 1616 | if (master->transfer) |
| 1617 | dev_info(dev, "master is unqueued, this is deprecated\n"); |
| 1618 | else { |
| 1619 | status = spi_master_initialize_queue(master); |
| 1620 | if (status) { |
Axel Lin | e93b072 | 2013-08-31 20:25:52 +0800 | [diff] [blame] | 1621 | device_del(&master->dev); |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 1622 | goto done; |
| 1623 | } |
| 1624 | } |
| 1625 | |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 1626 | mutex_lock(&board_lock); |
| 1627 | list_add_tail(&master->list, &spi_master_list); |
| 1628 | list_for_each_entry(bi, &board_list, list) |
| 1629 | spi_match_master_to_boardinfo(master, &bi->board_info); |
| 1630 | mutex_unlock(&board_lock); |
| 1631 | |
Mika Westerberg | 64bee4d | 2012-11-30 12:37:53 +0100 | [diff] [blame] | 1632 | /* Register devices from the device tree and ACPI */ |
Anatolij Gustschin | 12b15e8 | 2010-07-27 22:35:58 +0200 | [diff] [blame] | 1633 | of_register_spi_devices(master); |
Mika Westerberg | 64bee4d | 2012-11-30 12:37:53 +0100 | [diff] [blame] | 1634 | acpi_register_spi_devices(master); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1635 | done: |
| 1636 | return status; |
| 1637 | } |
| 1638 | EXPORT_SYMBOL_GPL(spi_register_master); |
| 1639 | |
Mark Brown | 666d5b4 | 2013-08-31 18:50:52 +0100 | [diff] [blame] | 1640 | static void devm_spi_unregister(struct device *dev, void *res) |
| 1641 | { |
| 1642 | spi_unregister_master(*(struct spi_master **)res); |
| 1643 | } |
| 1644 | |
| 1645 | /** |
| 1646 | * dev_spi_register_master - register managed SPI master controller |
| 1647 | * @dev: device managing SPI master |
| 1648 | * @master: initialized master, originally from spi_alloc_master() |
| 1649 | * Context: can sleep |
| 1650 | * |
| 1651 | * Register a SPI device as with spi_register_master() which will |
| 1652 | * automatically be unregister |
| 1653 | */ |
| 1654 | int devm_spi_register_master(struct device *dev, struct spi_master *master) |
| 1655 | { |
| 1656 | struct spi_master **ptr; |
| 1657 | int ret; |
| 1658 | |
| 1659 | ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL); |
| 1660 | if (!ptr) |
| 1661 | return -ENOMEM; |
| 1662 | |
| 1663 | ret = spi_register_master(master); |
Stephen Warren | 4b92894 | 2013-11-21 16:11:15 -0700 | [diff] [blame] | 1664 | if (!ret) { |
Mark Brown | 666d5b4 | 2013-08-31 18:50:52 +0100 | [diff] [blame] | 1665 | *ptr = master; |
| 1666 | devres_add(dev, ptr); |
| 1667 | } else { |
| 1668 | devres_free(ptr); |
| 1669 | } |
| 1670 | |
| 1671 | return ret; |
| 1672 | } |
| 1673 | EXPORT_SYMBOL_GPL(devm_spi_register_master); |
| 1674 | |
David Lamparter | 3486008 | 2010-08-30 23:54:17 +0200 | [diff] [blame] | 1675 | static int __unregister(struct device *dev, void *null) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1676 | { |
David Lamparter | 3486008 | 2010-08-30 23:54:17 +0200 | [diff] [blame] | 1677 | spi_unregister_device(to_spi_device(dev)); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1678 | return 0; |
| 1679 | } |
| 1680 | |
| 1681 | /** |
| 1682 | * spi_unregister_master - unregister SPI master controller |
| 1683 | * @master: the master being unregistered |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 1684 | * Context: can sleep |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1685 | * |
| 1686 | * This call is used only by SPI master controller drivers, which are the |
| 1687 | * only ones directly touching chip registers. |
| 1688 | * |
| 1689 | * This must be called from context that can sleep. |
| 1690 | */ |
| 1691 | void spi_unregister_master(struct spi_master *master) |
| 1692 | { |
Jeff Garzik | 89fc9a1 | 2006-12-06 20:35:35 -0800 | [diff] [blame] | 1693 | int dummy; |
| 1694 | |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 1695 | if (master->queued) { |
| 1696 | if (spi_destroy_queue(master)) |
| 1697 | dev_err(&master->dev, "queue remove failed\n"); |
| 1698 | } |
| 1699 | |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 1700 | mutex_lock(&board_lock); |
| 1701 | list_del(&master->list); |
| 1702 | mutex_unlock(&board_lock); |
| 1703 | |
Sebastian Andrzej Siewior | 97dbf37 | 2010-12-21 17:24:31 -0800 | [diff] [blame] | 1704 | dummy = device_for_each_child(&master->dev, NULL, __unregister); |
Tony Jones | 49dce68 | 2007-10-16 01:27:48 -0700 | [diff] [blame] | 1705 | device_unregister(&master->dev); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1706 | } |
| 1707 | EXPORT_SYMBOL_GPL(spi_unregister_master); |
| 1708 | |
Linus Walleij | ffbbdd21 | 2012-02-22 10:05:38 +0100 | [diff] [blame] | 1709 | int spi_master_suspend(struct spi_master *master) |
| 1710 | { |
| 1711 | int ret; |
| 1712 | |
| 1713 | /* Basically no-ops for non-queued masters */ |
| 1714 | if (!master->queued) |
| 1715 | return 0; |
| 1716 | |
| 1717 | ret = spi_stop_queue(master); |
| 1718 | if (ret) |
| 1719 | dev_err(&master->dev, "queue stop failed\n"); |
| 1720 | |
| 1721 | return ret; |
| 1722 | } |
| 1723 | EXPORT_SYMBOL_GPL(spi_master_suspend); |
| 1724 | |
| 1725 | int spi_master_resume(struct spi_master *master) |
| 1726 | { |
| 1727 | int ret; |
| 1728 | |
| 1729 | if (!master->queued) |
| 1730 | return 0; |
| 1731 | |
| 1732 | ret = spi_start_queue(master); |
| 1733 | if (ret) |
| 1734 | dev_err(&master->dev, "queue restart failed\n"); |
| 1735 | |
| 1736 | return ret; |
| 1737 | } |
| 1738 | EXPORT_SYMBOL_GPL(spi_master_resume); |
| 1739 | |
Michał Mirosław | 9f3b795 | 2013-02-01 20:40:17 +0100 | [diff] [blame] | 1740 | static int __spi_master_match(struct device *dev, const void *data) |
Dave Young | 5ed2c83 | 2008-01-22 15:14:18 +0800 | [diff] [blame] | 1741 | { |
| 1742 | struct spi_master *m; |
Michał Mirosław | 9f3b795 | 2013-02-01 20:40:17 +0100 | [diff] [blame] | 1743 | const u16 *bus_num = data; |
Dave Young | 5ed2c83 | 2008-01-22 15:14:18 +0800 | [diff] [blame] | 1744 | |
| 1745 | m = container_of(dev, struct spi_master, dev); |
| 1746 | return m->bus_num == *bus_num; |
| 1747 | } |
| 1748 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1749 | /** |
| 1750 | * spi_busnum_to_master - look up master associated with bus_num |
| 1751 | * @bus_num: the master's bus number |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 1752 | * Context: can sleep |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1753 | * |
| 1754 | * This call may be used with devices that are registered after |
| 1755 | * arch init time. It returns a refcounted pointer to the relevant |
| 1756 | * spi_master (which the caller must release), or NULL if there is |
| 1757 | * no such master registered. |
| 1758 | */ |
| 1759 | struct spi_master *spi_busnum_to_master(u16 bus_num) |
| 1760 | { |
Tony Jones | 49dce68 | 2007-10-16 01:27:48 -0700 | [diff] [blame] | 1761 | struct device *dev; |
Atsushi Nemoto | 1e9a51d | 2007-01-26 00:56:54 -0800 | [diff] [blame] | 1762 | struct spi_master *master = NULL; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1763 | |
Greg Kroah-Hartman | 695794a | 2008-05-22 17:21:08 -0400 | [diff] [blame] | 1764 | dev = class_find_device(&spi_master_class, NULL, &bus_num, |
Dave Young | 5ed2c83 | 2008-01-22 15:14:18 +0800 | [diff] [blame] | 1765 | __spi_master_match); |
| 1766 | if (dev) |
| 1767 | master = container_of(dev, struct spi_master, dev); |
| 1768 | /* reference got in class_find_device */ |
Atsushi Nemoto | 1e9a51d | 2007-01-26 00:56:54 -0800 | [diff] [blame] | 1769 | return master; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1770 | } |
| 1771 | EXPORT_SYMBOL_GPL(spi_busnum_to_master); |
| 1772 | |
| 1773 | |
| 1774 | /*-------------------------------------------------------------------------*/ |
| 1775 | |
David Brownell | 7d07719 | 2009-06-17 16:26:03 -0700 | [diff] [blame] | 1776 | /* Core methods for SPI master protocol drivers. Some of the |
| 1777 | * other core methods are currently defined as inline functions. |
| 1778 | */ |
| 1779 | |
| 1780 | /** |
| 1781 | * spi_setup - setup SPI mode and clock rate |
| 1782 | * @spi: the device whose settings are being modified |
| 1783 | * Context: can sleep, and no requests are queued to the device |
| 1784 | * |
| 1785 | * SPI protocol drivers may need to update the transfer mode if the |
| 1786 | * device doesn't work with its default. They may likewise need |
| 1787 | * to update clock rates or word sizes from initial values. This function |
| 1788 | * changes those settings, and must be called from a context that can sleep. |
| 1789 | * Except for SPI_CS_HIGH, which takes effect immediately, the changes take |
| 1790 | * effect the next time the device is selected and data is transferred to |
| 1791 | * or from it. When this function returns, the spi device is deselected. |
| 1792 | * |
| 1793 | * Note that this call will fail if the protocol driver specifies an option |
| 1794 | * that the underlying controller or its driver does not support. For |
| 1795 | * example, not all hardware supports wire transfers using nine bit words, |
| 1796 | * LSB-first wire encoding, or active-high chipselects. |
| 1797 | */ |
| 1798 | int spi_setup(struct spi_device *spi) |
| 1799 | { |
Geert Uytterhoeven | 83596fb | 2014-04-14 19:39:53 +0200 | [diff] [blame] | 1800 | unsigned bad_bits, ugly_bits; |
Laxman Dewangan | caae070 | 2012-11-09 14:35:22 +0530 | [diff] [blame] | 1801 | int status = 0; |
David Brownell | 7d07719 | 2009-06-17 16:26:03 -0700 | [diff] [blame] | 1802 | |
wangyuhang | f477b7f | 2013-08-11 18:15:17 +0800 | [diff] [blame] | 1803 | /* check mode to prevent that DUAL and QUAD set at the same time |
| 1804 | */ |
| 1805 | if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) || |
| 1806 | ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) { |
| 1807 | dev_err(&spi->dev, |
| 1808 | "setup: can not select dual and quad at the same time\n"); |
| 1809 | return -EINVAL; |
| 1810 | } |
| 1811 | /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden |
| 1812 | */ |
| 1813 | if ((spi->mode & SPI_3WIRE) && (spi->mode & |
| 1814 | (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD))) |
| 1815 | return -EINVAL; |
David Brownell | e7db06b | 2009-06-17 16:26:04 -0700 | [diff] [blame] | 1816 | /* help drivers fail *cleanly* when they need options |
| 1817 | * that aren't supported with their current master |
| 1818 | */ |
| 1819 | bad_bits = spi->mode & ~spi->master->mode_bits; |
Geert Uytterhoeven | 83596fb | 2014-04-14 19:39:53 +0200 | [diff] [blame] | 1820 | ugly_bits = bad_bits & |
| 1821 | (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD); |
| 1822 | if (ugly_bits) { |
| 1823 | dev_warn(&spi->dev, |
| 1824 | "setup: ignoring unsupported mode bits %x\n", |
| 1825 | ugly_bits); |
| 1826 | spi->mode &= ~ugly_bits; |
| 1827 | bad_bits &= ~ugly_bits; |
| 1828 | } |
David Brownell | e7db06b | 2009-06-17 16:26:04 -0700 | [diff] [blame] | 1829 | if (bad_bits) { |
Linus Walleij | eb288a1 | 2010-10-21 21:06:44 +0200 | [diff] [blame] | 1830 | dev_err(&spi->dev, "setup: unsupported mode bits %x\n", |
David Brownell | e7db06b | 2009-06-17 16:26:04 -0700 | [diff] [blame] | 1831 | bad_bits); |
| 1832 | return -EINVAL; |
| 1833 | } |
| 1834 | |
David Brownell | 7d07719 | 2009-06-17 16:26:03 -0700 | [diff] [blame] | 1835 | if (!spi->bits_per_word) |
| 1836 | spi->bits_per_word = 8; |
| 1837 | |
Axel Lin | 052eb2d4 | 2014-02-10 00:08:05 +0800 | [diff] [blame] | 1838 | if (!spi->max_speed_hz) |
| 1839 | spi->max_speed_hz = spi->master->max_speed_hz; |
| 1840 | |
Laxman Dewangan | caae070 | 2012-11-09 14:35:22 +0530 | [diff] [blame] | 1841 | if (spi->master->setup) |
| 1842 | status = spi->master->setup(spi); |
David Brownell | 7d07719 | 2009-06-17 16:26:03 -0700 | [diff] [blame] | 1843 | |
Jingoo Han | 5fe5f05 | 2013-10-14 10:31:51 +0900 | [diff] [blame] | 1844 | dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n", |
David Brownell | 7d07719 | 2009-06-17 16:26:03 -0700 | [diff] [blame] | 1845 | (int) (spi->mode & (SPI_CPOL | SPI_CPHA)), |
| 1846 | (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "", |
| 1847 | (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "", |
| 1848 | (spi->mode & SPI_3WIRE) ? "3wire, " : "", |
| 1849 | (spi->mode & SPI_LOOP) ? "loopback, " : "", |
| 1850 | spi->bits_per_word, spi->max_speed_hz, |
| 1851 | status); |
| 1852 | |
| 1853 | return status; |
| 1854 | } |
| 1855 | EXPORT_SYMBOL_GPL(spi_setup); |
| 1856 | |
Mark Brown | 9080873 | 2013-11-13 23:44:15 +0000 | [diff] [blame] | 1857 | static int __spi_validate(struct spi_device *spi, struct spi_message *message) |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 1858 | { |
| 1859 | struct spi_master *master = spi->master; |
Laxman Dewangan | e6811d1 | 2012-11-09 14:36:45 +0530 | [diff] [blame] | 1860 | struct spi_transfer *xfer; |
Atsushi Nemoto | 6ea3129 | 2014-02-28 23:03:16 +0900 | [diff] [blame] | 1861 | int w_size; |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 1862 | |
Mark Brown | 24a0013 | 2013-07-10 15:05:40 +0100 | [diff] [blame] | 1863 | if (list_empty(&message->transfers)) |
| 1864 | return -EINVAL; |
Mark Brown | 24a0013 | 2013-07-10 15:05:40 +0100 | [diff] [blame] | 1865 | |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 1866 | /* Half-duplex links include original MicroWire, and ones with |
| 1867 | * only one data pin like SPI_3WIRE (switches direction) or where |
| 1868 | * either MOSI or MISO is missing. They can also be caused by |
| 1869 | * software limitations. |
| 1870 | */ |
| 1871 | if ((master->flags & SPI_MASTER_HALF_DUPLEX) |
| 1872 | || (spi->mode & SPI_3WIRE)) { |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 1873 | unsigned flags = master->flags; |
| 1874 | |
| 1875 | list_for_each_entry(xfer, &message->transfers, transfer_list) { |
| 1876 | if (xfer->rx_buf && xfer->tx_buf) |
| 1877 | return -EINVAL; |
| 1878 | if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf) |
| 1879 | return -EINVAL; |
| 1880 | if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf) |
| 1881 | return -EINVAL; |
| 1882 | } |
| 1883 | } |
| 1884 | |
Laxman Dewangan | e6811d1 | 2012-11-09 14:36:45 +0530 | [diff] [blame] | 1885 | /** |
Laxman Dewangan | 059b8ff | 2013-01-05 00:17:14 +0530 | [diff] [blame] | 1886 | * Set transfer bits_per_word and max speed as spi device default if |
| 1887 | * it is not set for this transfer. |
wangyuhang | f477b7f | 2013-08-11 18:15:17 +0800 | [diff] [blame] | 1888 | * Set transfer tx_nbits and rx_nbits as single transfer default |
| 1889 | * (SPI_NBITS_SINGLE) if it is not set for this transfer. |
Laxman Dewangan | e6811d1 | 2012-11-09 14:36:45 +0530 | [diff] [blame] | 1890 | */ |
| 1891 | list_for_each_entry(xfer, &message->transfers, transfer_list) { |
Sourav Poddar | 078726c | 2013-07-18 15:31:25 +0530 | [diff] [blame] | 1892 | message->frame_length += xfer->len; |
Laxman Dewangan | e6811d1 | 2012-11-09 14:36:45 +0530 | [diff] [blame] | 1893 | if (!xfer->bits_per_word) |
| 1894 | xfer->bits_per_word = spi->bits_per_word; |
Axel Lin | a6f87fa | 2014-03-17 10:08:12 +0800 | [diff] [blame] | 1895 | |
| 1896 | if (!xfer->speed_hz) |
Laxman Dewangan | 059b8ff | 2013-01-05 00:17:14 +0530 | [diff] [blame] | 1897 | xfer->speed_hz = spi->max_speed_hz; |
Axel Lin | a6f87fa | 2014-03-17 10:08:12 +0800 | [diff] [blame] | 1898 | |
| 1899 | if (master->max_speed_hz && |
| 1900 | xfer->speed_hz > master->max_speed_hz) |
| 1901 | xfer->speed_hz = master->max_speed_hz; |
Gabor Juhos | 56ede94 | 2013-08-14 10:25:28 +0200 | [diff] [blame] | 1902 | |
Stephen Warren | 543bb25 | 2013-03-26 20:37:57 -0600 | [diff] [blame] | 1903 | if (master->bits_per_word_mask) { |
| 1904 | /* Only 32 bits fit in the mask */ |
| 1905 | if (xfer->bits_per_word > 32) |
| 1906 | return -EINVAL; |
| 1907 | if (!(master->bits_per_word_mask & |
| 1908 | BIT(xfer->bits_per_word - 1))) |
| 1909 | return -EINVAL; |
| 1910 | } |
Mark Brown | a2fd4f9 | 2013-07-10 14:57:26 +0100 | [diff] [blame] | 1911 | |
Ivan T. Ivanov | 4d94bd2 | 2014-02-20 12:02:08 +0200 | [diff] [blame] | 1912 | /* |
| 1913 | * SPI transfer length should be multiple of SPI word size |
| 1914 | * where SPI word size should be power-of-two multiple |
| 1915 | */ |
| 1916 | if (xfer->bits_per_word <= 8) |
| 1917 | w_size = 1; |
| 1918 | else if (xfer->bits_per_word <= 16) |
| 1919 | w_size = 2; |
| 1920 | else |
| 1921 | w_size = 4; |
| 1922 | |
Ivan T. Ivanov | 4d94bd2 | 2014-02-20 12:02:08 +0200 | [diff] [blame] | 1923 | /* No partial transfers accepted */ |
Atsushi Nemoto | 6ea3129 | 2014-02-28 23:03:16 +0900 | [diff] [blame] | 1924 | if (xfer->len % w_size) |
Ivan T. Ivanov | 4d94bd2 | 2014-02-20 12:02:08 +0200 | [diff] [blame] | 1925 | return -EINVAL; |
| 1926 | |
Mark Brown | a2fd4f9 | 2013-07-10 14:57:26 +0100 | [diff] [blame] | 1927 | if (xfer->speed_hz && master->min_speed_hz && |
| 1928 | xfer->speed_hz < master->min_speed_hz) |
| 1929 | return -EINVAL; |
wangyuhang | f477b7f | 2013-08-11 18:15:17 +0800 | [diff] [blame] | 1930 | |
| 1931 | if (xfer->tx_buf && !xfer->tx_nbits) |
| 1932 | xfer->tx_nbits = SPI_NBITS_SINGLE; |
| 1933 | if (xfer->rx_buf && !xfer->rx_nbits) |
| 1934 | xfer->rx_nbits = SPI_NBITS_SINGLE; |
| 1935 | /* check transfer tx/rx_nbits: |
Geert Uytterhoeven | 1afd998 | 2014-01-12 14:00:29 +0100 | [diff] [blame] | 1936 | * 1. check the value matches one of single, dual and quad |
| 1937 | * 2. check tx/rx_nbits match the mode in spi_device |
wangyuhang | f477b7f | 2013-08-11 18:15:17 +0800 | [diff] [blame] | 1938 | */ |
Sourav Poddar | db90a44 | 2013-08-22 21:20:48 +0530 | [diff] [blame] | 1939 | if (xfer->tx_buf) { |
| 1940 | if (xfer->tx_nbits != SPI_NBITS_SINGLE && |
| 1941 | xfer->tx_nbits != SPI_NBITS_DUAL && |
| 1942 | xfer->tx_nbits != SPI_NBITS_QUAD) |
| 1943 | return -EINVAL; |
| 1944 | if ((xfer->tx_nbits == SPI_NBITS_DUAL) && |
| 1945 | !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD))) |
| 1946 | return -EINVAL; |
| 1947 | if ((xfer->tx_nbits == SPI_NBITS_QUAD) && |
| 1948 | !(spi->mode & SPI_TX_QUAD)) |
| 1949 | return -EINVAL; |
Sourav Poddar | db90a44 | 2013-08-22 21:20:48 +0530 | [diff] [blame] | 1950 | } |
wangyuhang | f477b7f | 2013-08-11 18:15:17 +0800 | [diff] [blame] | 1951 | /* check transfer rx_nbits */ |
Sourav Poddar | db90a44 | 2013-08-22 21:20:48 +0530 | [diff] [blame] | 1952 | if (xfer->rx_buf) { |
| 1953 | if (xfer->rx_nbits != SPI_NBITS_SINGLE && |
| 1954 | xfer->rx_nbits != SPI_NBITS_DUAL && |
| 1955 | xfer->rx_nbits != SPI_NBITS_QUAD) |
| 1956 | return -EINVAL; |
| 1957 | if ((xfer->rx_nbits == SPI_NBITS_DUAL) && |
| 1958 | !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD))) |
| 1959 | return -EINVAL; |
| 1960 | if ((xfer->rx_nbits == SPI_NBITS_QUAD) && |
| 1961 | !(spi->mode & SPI_RX_QUAD)) |
| 1962 | return -EINVAL; |
Sourav Poddar | db90a44 | 2013-08-22 21:20:48 +0530 | [diff] [blame] | 1963 | } |
Laxman Dewangan | e6811d1 | 2012-11-09 14:36:45 +0530 | [diff] [blame] | 1964 | } |
| 1965 | |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 1966 | message->status = -EINPROGRESS; |
Mark Brown | 9080873 | 2013-11-13 23:44:15 +0000 | [diff] [blame] | 1967 | |
| 1968 | return 0; |
| 1969 | } |
| 1970 | |
| 1971 | static int __spi_async(struct spi_device *spi, struct spi_message *message) |
| 1972 | { |
| 1973 | struct spi_master *master = spi->master; |
| 1974 | |
| 1975 | message->spi = spi; |
| 1976 | |
| 1977 | trace_spi_message_submit(message); |
| 1978 | |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 1979 | return master->transfer(spi, message); |
| 1980 | } |
| 1981 | |
David Brownell | 568d069 | 2009-09-22 16:46:18 -0700 | [diff] [blame] | 1982 | /** |
| 1983 | * spi_async - asynchronous SPI transfer |
| 1984 | * @spi: device with which data will be exchanged |
| 1985 | * @message: describes the data transfers, including completion callback |
| 1986 | * Context: any (irqs may be blocked, etc) |
| 1987 | * |
| 1988 | * This call may be used in_irq and other contexts which can't sleep, |
| 1989 | * as well as from task contexts which can sleep. |
| 1990 | * |
| 1991 | * The completion callback is invoked in a context which can't sleep. |
| 1992 | * Before that invocation, the value of message->status is undefined. |
| 1993 | * When the callback is issued, message->status holds either zero (to |
| 1994 | * indicate complete success) or a negative error code. After that |
| 1995 | * callback returns, the driver which issued the transfer request may |
| 1996 | * deallocate the associated memory; it's no longer in use by any SPI |
| 1997 | * core or controller driver code. |
| 1998 | * |
| 1999 | * Note that although all messages to a spi_device are handled in |
| 2000 | * FIFO order, messages may go to different devices in other orders. |
| 2001 | * Some device might be higher priority, or have various "hard" access |
| 2002 | * time requirements, for example. |
| 2003 | * |
| 2004 | * On detection of any fault during the transfer, processing of |
| 2005 | * the entire message is aborted, and the device is deselected. |
| 2006 | * Until returning from the associated message completion callback, |
| 2007 | * no other spi_message queued to that device will be processed. |
| 2008 | * (This rule applies equally to all the synchronous transfer calls, |
| 2009 | * which are wrappers around this core asynchronous primitive.) |
| 2010 | */ |
| 2011 | int spi_async(struct spi_device *spi, struct spi_message *message) |
| 2012 | { |
| 2013 | struct spi_master *master = spi->master; |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 2014 | int ret; |
| 2015 | unsigned long flags; |
David Brownell | 568d069 | 2009-09-22 16:46:18 -0700 | [diff] [blame] | 2016 | |
Mark Brown | 9080873 | 2013-11-13 23:44:15 +0000 | [diff] [blame] | 2017 | ret = __spi_validate(spi, message); |
| 2018 | if (ret != 0) |
| 2019 | return ret; |
| 2020 | |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 2021 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); |
David Brownell | 568d069 | 2009-09-22 16:46:18 -0700 | [diff] [blame] | 2022 | |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 2023 | if (master->bus_lock_flag) |
| 2024 | ret = -EBUSY; |
| 2025 | else |
| 2026 | ret = __spi_async(spi, message); |
David Brownell | 568d069 | 2009-09-22 16:46:18 -0700 | [diff] [blame] | 2027 | |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 2028 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); |
| 2029 | |
| 2030 | return ret; |
David Brownell | 568d069 | 2009-09-22 16:46:18 -0700 | [diff] [blame] | 2031 | } |
| 2032 | EXPORT_SYMBOL_GPL(spi_async); |
| 2033 | |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 2034 | /** |
| 2035 | * spi_async_locked - version of spi_async with exclusive bus usage |
| 2036 | * @spi: device with which data will be exchanged |
| 2037 | * @message: describes the data transfers, including completion callback |
| 2038 | * Context: any (irqs may be blocked, etc) |
| 2039 | * |
| 2040 | * This call may be used in_irq and other contexts which can't sleep, |
| 2041 | * as well as from task contexts which can sleep. |
| 2042 | * |
| 2043 | * The completion callback is invoked in a context which can't sleep. |
| 2044 | * Before that invocation, the value of message->status is undefined. |
| 2045 | * When the callback is issued, message->status holds either zero (to |
| 2046 | * indicate complete success) or a negative error code. After that |
| 2047 | * callback returns, the driver which issued the transfer request may |
| 2048 | * deallocate the associated memory; it's no longer in use by any SPI |
| 2049 | * core or controller driver code. |
| 2050 | * |
| 2051 | * Note that although all messages to a spi_device are handled in |
| 2052 | * FIFO order, messages may go to different devices in other orders. |
| 2053 | * Some device might be higher priority, or have various "hard" access |
| 2054 | * time requirements, for example. |
| 2055 | * |
| 2056 | * On detection of any fault during the transfer, processing of |
| 2057 | * the entire message is aborted, and the device is deselected. |
| 2058 | * Until returning from the associated message completion callback, |
| 2059 | * no other spi_message queued to that device will be processed. |
| 2060 | * (This rule applies equally to all the synchronous transfer calls, |
| 2061 | * which are wrappers around this core asynchronous primitive.) |
| 2062 | */ |
| 2063 | int spi_async_locked(struct spi_device *spi, struct spi_message *message) |
| 2064 | { |
| 2065 | struct spi_master *master = spi->master; |
| 2066 | int ret; |
| 2067 | unsigned long flags; |
| 2068 | |
Mark Brown | 9080873 | 2013-11-13 23:44:15 +0000 | [diff] [blame] | 2069 | ret = __spi_validate(spi, message); |
| 2070 | if (ret != 0) |
| 2071 | return ret; |
| 2072 | |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 2073 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); |
| 2074 | |
| 2075 | ret = __spi_async(spi, message); |
| 2076 | |
| 2077 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); |
| 2078 | |
| 2079 | return ret; |
| 2080 | |
| 2081 | } |
| 2082 | EXPORT_SYMBOL_GPL(spi_async_locked); |
| 2083 | |
David Brownell | 7d07719 | 2009-06-17 16:26:03 -0700 | [diff] [blame] | 2084 | |
| 2085 | /*-------------------------------------------------------------------------*/ |
| 2086 | |
| 2087 | /* Utility methods for SPI master protocol drivers, layered on |
| 2088 | * top of the core. Some other utility methods are defined as |
| 2089 | * inline functions. |
| 2090 | */ |
| 2091 | |
Andrew Morton | 5d870c8 | 2006-01-11 11:23:49 -0800 | [diff] [blame] | 2092 | static void spi_complete(void *arg) |
| 2093 | { |
| 2094 | complete(arg); |
| 2095 | } |
| 2096 | |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 2097 | static int __spi_sync(struct spi_device *spi, struct spi_message *message, |
| 2098 | int bus_locked) |
| 2099 | { |
| 2100 | DECLARE_COMPLETION_ONSTACK(done); |
| 2101 | int status; |
| 2102 | struct spi_master *master = spi->master; |
| 2103 | |
| 2104 | message->complete = spi_complete; |
| 2105 | message->context = &done; |
| 2106 | |
| 2107 | if (!bus_locked) |
| 2108 | mutex_lock(&master->bus_lock_mutex); |
| 2109 | |
| 2110 | status = spi_async_locked(spi, message); |
| 2111 | |
| 2112 | if (!bus_locked) |
| 2113 | mutex_unlock(&master->bus_lock_mutex); |
| 2114 | |
| 2115 | if (status == 0) { |
| 2116 | wait_for_completion(&done); |
| 2117 | status = message->status; |
| 2118 | } |
| 2119 | message->context = NULL; |
| 2120 | return status; |
| 2121 | } |
| 2122 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2123 | /** |
| 2124 | * spi_sync - blocking/synchronous SPI data transfers |
| 2125 | * @spi: device with which data will be exchanged |
| 2126 | * @message: describes the data transfers |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 2127 | * Context: can sleep |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2128 | * |
| 2129 | * This call may only be used from a context that may sleep. The sleep |
| 2130 | * is non-interruptible, and has no timeout. Low-overhead controller |
| 2131 | * drivers may DMA directly into and out of the message buffers. |
| 2132 | * |
| 2133 | * Note that the SPI device's chip select is active during the message, |
| 2134 | * and then is normally disabled between messages. Drivers for some |
| 2135 | * frequently-used devices may want to minimize costs of selecting a chip, |
| 2136 | * by leaving it selected in anticipation that the next message will go |
| 2137 | * to the same chip. (That may increase power usage.) |
| 2138 | * |
David Brownell | 0c86846 | 2006-01-08 13:34:25 -0800 | [diff] [blame] | 2139 | * Also, the caller is guaranteeing that the memory associated with the |
| 2140 | * message will not be freed before this call returns. |
| 2141 | * |
Marc Pignat | 9b938b7 | 2007-12-04 23:45:10 -0800 | [diff] [blame] | 2142 | * It returns zero on success, else a negative error code. |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2143 | */ |
| 2144 | int spi_sync(struct spi_device *spi, struct spi_message *message) |
| 2145 | { |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 2146 | return __spi_sync(spi, message, 0); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2147 | } |
| 2148 | EXPORT_SYMBOL_GPL(spi_sync); |
| 2149 | |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 2150 | /** |
| 2151 | * spi_sync_locked - version of spi_sync with exclusive bus usage |
| 2152 | * @spi: device with which data will be exchanged |
| 2153 | * @message: describes the data transfers |
| 2154 | * Context: can sleep |
| 2155 | * |
| 2156 | * This call may only be used from a context that may sleep. The sleep |
| 2157 | * is non-interruptible, and has no timeout. Low-overhead controller |
| 2158 | * drivers may DMA directly into and out of the message buffers. |
| 2159 | * |
| 2160 | * This call should be used by drivers that require exclusive access to the |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 2161 | * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 2162 | * be released by a spi_bus_unlock call when the exclusive access is over. |
| 2163 | * |
| 2164 | * It returns zero on success, else a negative error code. |
| 2165 | */ |
| 2166 | int spi_sync_locked(struct spi_device *spi, struct spi_message *message) |
| 2167 | { |
| 2168 | return __spi_sync(spi, message, 1); |
| 2169 | } |
| 2170 | EXPORT_SYMBOL_GPL(spi_sync_locked); |
| 2171 | |
| 2172 | /** |
| 2173 | * spi_bus_lock - obtain a lock for exclusive SPI bus usage |
| 2174 | * @master: SPI bus master that should be locked for exclusive bus access |
| 2175 | * Context: can sleep |
| 2176 | * |
| 2177 | * This call may only be used from a context that may sleep. The sleep |
| 2178 | * is non-interruptible, and has no timeout. |
| 2179 | * |
| 2180 | * This call should be used by drivers that require exclusive access to the |
| 2181 | * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the |
| 2182 | * exclusive access is over. Data transfer must be done by spi_sync_locked |
| 2183 | * and spi_async_locked calls when the SPI bus lock is held. |
| 2184 | * |
| 2185 | * It returns zero on success, else a negative error code. |
| 2186 | */ |
| 2187 | int spi_bus_lock(struct spi_master *master) |
| 2188 | { |
| 2189 | unsigned long flags; |
| 2190 | |
| 2191 | mutex_lock(&master->bus_lock_mutex); |
| 2192 | |
| 2193 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); |
| 2194 | master->bus_lock_flag = 1; |
| 2195 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); |
| 2196 | |
| 2197 | /* mutex remains locked until spi_bus_unlock is called */ |
| 2198 | |
| 2199 | return 0; |
| 2200 | } |
| 2201 | EXPORT_SYMBOL_GPL(spi_bus_lock); |
| 2202 | |
| 2203 | /** |
| 2204 | * spi_bus_unlock - release the lock for exclusive SPI bus usage |
| 2205 | * @master: SPI bus master that was locked for exclusive bus access |
| 2206 | * Context: can sleep |
| 2207 | * |
| 2208 | * This call may only be used from a context that may sleep. The sleep |
| 2209 | * is non-interruptible, and has no timeout. |
| 2210 | * |
| 2211 | * This call releases an SPI bus lock previously obtained by an spi_bus_lock |
| 2212 | * call. |
| 2213 | * |
| 2214 | * It returns zero on success, else a negative error code. |
| 2215 | */ |
| 2216 | int spi_bus_unlock(struct spi_master *master) |
| 2217 | { |
| 2218 | master->bus_lock_flag = 0; |
| 2219 | |
| 2220 | mutex_unlock(&master->bus_lock_mutex); |
| 2221 | |
| 2222 | return 0; |
| 2223 | } |
| 2224 | EXPORT_SYMBOL_GPL(spi_bus_unlock); |
| 2225 | |
David Brownell | a9948b6 | 2006-04-02 10:37:40 -0800 | [diff] [blame] | 2226 | /* portable code must never pass more than 32 bytes */ |
Jingoo Han | 5fe5f05 | 2013-10-14 10:31:51 +0900 | [diff] [blame] | 2227 | #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2228 | |
| 2229 | static u8 *buf; |
| 2230 | |
| 2231 | /** |
| 2232 | * spi_write_then_read - SPI synchronous write followed by read |
| 2233 | * @spi: device with which data will be exchanged |
| 2234 | * @txbuf: data to be written (need not be dma-safe) |
| 2235 | * @n_tx: size of txbuf, in bytes |
Jiri Pirko | 2757049 | 2009-06-17 16:26:06 -0700 | [diff] [blame] | 2236 | * @rxbuf: buffer into which data will be read (need not be dma-safe) |
| 2237 | * @n_rx: size of rxbuf, in bytes |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 2238 | * Context: can sleep |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2239 | * |
| 2240 | * This performs a half duplex MicroWire style transaction with the |
| 2241 | * device, sending txbuf and then reading rxbuf. The return value |
| 2242 | * is zero for success, else a negative errno status code. |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 2243 | * This call may only be used from a context that may sleep. |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2244 | * |
David Brownell | 0c86846 | 2006-01-08 13:34:25 -0800 | [diff] [blame] | 2245 | * Parameters to this routine are always copied using a small buffer; |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 2246 | * portable code should never use this for more than 32 bytes. |
| 2247 | * Performance-sensitive or bulk transfer code should instead use |
David Brownell | 0c86846 | 2006-01-08 13:34:25 -0800 | [diff] [blame] | 2248 | * spi_{async,sync}() calls with dma-safe buffers. |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2249 | */ |
| 2250 | int spi_write_then_read(struct spi_device *spi, |
Mark Brown | 0c4a159 | 2011-05-11 00:09:30 +0200 | [diff] [blame] | 2251 | const void *txbuf, unsigned n_tx, |
| 2252 | void *rxbuf, unsigned n_rx) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2253 | { |
David Brownell | 068f407 | 2007-12-04 23:45:09 -0800 | [diff] [blame] | 2254 | static DEFINE_MUTEX(lock); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2255 | |
| 2256 | int status; |
| 2257 | struct spi_message message; |
David Brownell | bdff549 | 2009-04-13 14:39:57 -0700 | [diff] [blame] | 2258 | struct spi_transfer x[2]; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2259 | u8 *local_buf; |
| 2260 | |
Mark Brown | b3a223e | 2012-12-02 12:54:25 +0900 | [diff] [blame] | 2261 | /* Use preallocated DMA-safe buffer if we can. We can't avoid |
| 2262 | * copying here, (as a pure convenience thing), but we can |
| 2263 | * keep heap costs out of the hot path unless someone else is |
| 2264 | * using the pre-allocated buffer or the transfer is too large. |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2265 | */ |
Mark Brown | b3a223e | 2012-12-02 12:54:25 +0900 | [diff] [blame] | 2266 | if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) { |
Mark Brown | 2cd94c8 | 2013-01-27 14:35:04 +0800 | [diff] [blame] | 2267 | local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx), |
| 2268 | GFP_KERNEL | GFP_DMA); |
Mark Brown | b3a223e | 2012-12-02 12:54:25 +0900 | [diff] [blame] | 2269 | if (!local_buf) |
| 2270 | return -ENOMEM; |
| 2271 | } else { |
| 2272 | local_buf = buf; |
| 2273 | } |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2274 | |
Vitaly Wool | 8275c64 | 2006-01-08 13:34:28 -0800 | [diff] [blame] | 2275 | spi_message_init(&message); |
Jingoo Han | 5fe5f05 | 2013-10-14 10:31:51 +0900 | [diff] [blame] | 2276 | memset(x, 0, sizeof(x)); |
David Brownell | bdff549 | 2009-04-13 14:39:57 -0700 | [diff] [blame] | 2277 | if (n_tx) { |
| 2278 | x[0].len = n_tx; |
| 2279 | spi_message_add_tail(&x[0], &message); |
| 2280 | } |
| 2281 | if (n_rx) { |
| 2282 | x[1].len = n_rx; |
| 2283 | spi_message_add_tail(&x[1], &message); |
| 2284 | } |
Vitaly Wool | 8275c64 | 2006-01-08 13:34:28 -0800 | [diff] [blame] | 2285 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2286 | memcpy(local_buf, txbuf, n_tx); |
David Brownell | bdff549 | 2009-04-13 14:39:57 -0700 | [diff] [blame] | 2287 | x[0].tx_buf = local_buf; |
| 2288 | x[1].rx_buf = local_buf + n_tx; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2289 | |
| 2290 | /* do the i/o */ |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2291 | status = spi_sync(spi, &message); |
Marc Pignat | 9b938b7 | 2007-12-04 23:45:10 -0800 | [diff] [blame] | 2292 | if (status == 0) |
David Brownell | bdff549 | 2009-04-13 14:39:57 -0700 | [diff] [blame] | 2293 | memcpy(rxbuf, x[1].rx_buf, n_rx); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2294 | |
David Brownell | bdff549 | 2009-04-13 14:39:57 -0700 | [diff] [blame] | 2295 | if (x[0].tx_buf == buf) |
David Brownell | 068f407 | 2007-12-04 23:45:09 -0800 | [diff] [blame] | 2296 | mutex_unlock(&lock); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2297 | else |
| 2298 | kfree(local_buf); |
| 2299 | |
| 2300 | return status; |
| 2301 | } |
| 2302 | EXPORT_SYMBOL_GPL(spi_write_then_read); |
| 2303 | |
| 2304 | /*-------------------------------------------------------------------------*/ |
| 2305 | |
| 2306 | static int __init spi_init(void) |
| 2307 | { |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 2308 | int status; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2309 | |
Christoph Lameter | e94b176 | 2006-12-06 20:33:17 -0800 | [diff] [blame] | 2310 | buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL); |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 2311 | if (!buf) { |
| 2312 | status = -ENOMEM; |
| 2313 | goto err0; |
| 2314 | } |
| 2315 | |
| 2316 | status = bus_register(&spi_bus_type); |
| 2317 | if (status < 0) |
| 2318 | goto err1; |
| 2319 | |
| 2320 | status = class_register(&spi_master_class); |
| 2321 | if (status < 0) |
| 2322 | goto err2; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2323 | return 0; |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 2324 | |
| 2325 | err2: |
| 2326 | bus_unregister(&spi_bus_type); |
| 2327 | err1: |
| 2328 | kfree(buf); |
| 2329 | buf = NULL; |
| 2330 | err0: |
| 2331 | return status; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2332 | } |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 2333 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2334 | /* board_info is normally registered in arch_initcall(), |
| 2335 | * but even essential drivers wait till later |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 2336 | * |
| 2337 | * REVISIT only boardinfo really needs static linking. the rest (device and |
| 2338 | * driver registration) _could_ be dynamically linked (modular) ... costs |
| 2339 | * include needing to have boardinfo data structures be much more public. |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2340 | */ |
David Brownell | 673c0c0 | 2008-10-15 22:02:46 -0700 | [diff] [blame] | 2341 | postcore_initcall(spi_init); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 2342 | |