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 |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; either version 2 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License |
| 17 | * along with this program; if not, write to the Free Software |
| 18 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 19 | */ |
| 20 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 21 | #include <linux/kernel.h> |
| 22 | #include <linux/device.h> |
| 23 | #include <linux/init.h> |
| 24 | #include <linux/cache.h> |
Matthias Kaehlcke | 9404082 | 2007-07-17 04:04:16 -0700 | [diff] [blame] | 25 | #include <linux/mutex.h> |
Sinan Akman | 2b7a32f | 2010-10-02 21:28:29 -0600 | [diff] [blame] | 26 | #include <linux/of_device.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 27 | #include <linux/slab.h> |
Anton Vorontsov | e0626e3 | 2009-09-22 16:46:08 -0700 | [diff] [blame] | 28 | #include <linux/mod_devicetable.h> |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 29 | #include <linux/spi/spi.h> |
Anatolij Gustschin | 12b15e8 | 2010-07-27 22:35:58 +0200 | [diff] [blame] | 30 | #include <linux/of_spi.h> |
Mark Brown | 3ae22e8 | 2010-12-25 15:32:27 +0100 | [diff] [blame] | 31 | #include <linux/pm_runtime.h> |
Paul Gortmaker | 025ed13 | 2011-07-10 12:57:55 -0400 | [diff] [blame] | 32 | #include <linux/export.h> |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 33 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 34 | static void spidev_release(struct device *dev) |
| 35 | { |
Hans-Peter Nilsson | 0ffa028 | 2007-02-12 00:52:45 -0800 | [diff] [blame] | 36 | struct spi_device *spi = to_spi_device(dev); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 37 | |
| 38 | /* spi masters may cleanup for released devices */ |
| 39 | if (spi->master->cleanup) |
| 40 | spi->master->cleanup(spi); |
| 41 | |
David Brownell | 0c86846 | 2006-01-08 13:34:25 -0800 | [diff] [blame] | 42 | spi_master_put(spi->master); |
Roman Tereshonkov | 07a389f | 2010-04-12 09:56:35 +0000 | [diff] [blame] | 43 | kfree(spi); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 44 | } |
| 45 | |
| 46 | static ssize_t |
| 47 | modalias_show(struct device *dev, struct device_attribute *a, char *buf) |
| 48 | { |
| 49 | const struct spi_device *spi = to_spi_device(dev); |
| 50 | |
Kay Sievers | 35f74fc | 2009-01-06 10:44:37 -0800 | [diff] [blame] | 51 | return sprintf(buf, "%s\n", spi->modalias); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 52 | } |
| 53 | |
| 54 | static struct device_attribute spi_dev_attrs[] = { |
| 55 | __ATTR_RO(modalias), |
| 56 | __ATTR_NULL, |
| 57 | }; |
| 58 | |
| 59 | /* modalias support makes "modprobe $MODALIAS" new-style hotplug work, |
| 60 | * and the sysfs version makes coldplug work too. |
| 61 | */ |
| 62 | |
Anton Vorontsov | 75368bf | 2009-09-22 16:46:04 -0700 | [diff] [blame] | 63 | static const struct spi_device_id *spi_match_id(const struct spi_device_id *id, |
| 64 | const struct spi_device *sdev) |
| 65 | { |
| 66 | while (id->name[0]) { |
| 67 | if (!strcmp(sdev->modalias, id->name)) |
| 68 | return id; |
| 69 | id++; |
| 70 | } |
| 71 | return NULL; |
| 72 | } |
| 73 | |
| 74 | const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev) |
| 75 | { |
| 76 | const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver); |
| 77 | |
| 78 | return spi_match_id(sdrv->id_table, sdev); |
| 79 | } |
| 80 | EXPORT_SYMBOL_GPL(spi_get_device_id); |
| 81 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 82 | static int spi_match_device(struct device *dev, struct device_driver *drv) |
| 83 | { |
| 84 | const struct spi_device *spi = to_spi_device(dev); |
Anton Vorontsov | 75368bf | 2009-09-22 16:46:04 -0700 | [diff] [blame] | 85 | const struct spi_driver *sdrv = to_spi_driver(drv); |
| 86 | |
Sinan Akman | 2b7a32f | 2010-10-02 21:28:29 -0600 | [diff] [blame] | 87 | /* Attempt an OF style match */ |
| 88 | if (of_driver_match_device(dev, drv)) |
| 89 | return 1; |
| 90 | |
Anton Vorontsov | 75368bf | 2009-09-22 16:46:04 -0700 | [diff] [blame] | 91 | if (sdrv->id_table) |
| 92 | return !!spi_match_id(sdrv->id_table, spi); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 93 | |
Kay Sievers | 35f74fc | 2009-01-06 10:44:37 -0800 | [diff] [blame] | 94 | return strcmp(spi->modalias, drv->name) == 0; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 95 | } |
| 96 | |
Kay Sievers | 7eff2e7 | 2007-08-14 15:15:12 +0200 | [diff] [blame] | 97 | static int spi_uevent(struct device *dev, struct kobj_uevent_env *env) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 98 | { |
| 99 | const struct spi_device *spi = to_spi_device(dev); |
| 100 | |
Anton Vorontsov | e0626e3 | 2009-09-22 16:46:08 -0700 | [diff] [blame] | 101 | add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 102 | return 0; |
| 103 | } |
| 104 | |
Mark Brown | 3ae22e8 | 2010-12-25 15:32:27 +0100 | [diff] [blame] | 105 | #ifdef CONFIG_PM_SLEEP |
| 106 | static int spi_legacy_suspend(struct device *dev, pm_message_t message) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 107 | { |
David Brownell | 3c72426 | 2008-02-06 01:38:10 -0800 | [diff] [blame] | 108 | int value = 0; |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 109 | struct spi_driver *drv = to_spi_driver(dev->driver); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 110 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 111 | /* suspend will stop irqs and dma; no more i/o */ |
David Brownell | 3c72426 | 2008-02-06 01:38:10 -0800 | [diff] [blame] | 112 | if (drv) { |
| 113 | if (drv->suspend) |
| 114 | value = drv->suspend(to_spi_device(dev), message); |
| 115 | else |
| 116 | dev_dbg(dev, "... can't suspend\n"); |
| 117 | } |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 118 | return value; |
| 119 | } |
| 120 | |
Mark Brown | 3ae22e8 | 2010-12-25 15:32:27 +0100 | [diff] [blame] | 121 | static int spi_legacy_resume(struct device *dev) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 122 | { |
David Brownell | 3c72426 | 2008-02-06 01:38:10 -0800 | [diff] [blame] | 123 | int value = 0; |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 124 | struct spi_driver *drv = to_spi_driver(dev->driver); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 125 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 126 | /* resume may restart the i/o queue */ |
David Brownell | 3c72426 | 2008-02-06 01:38:10 -0800 | [diff] [blame] | 127 | if (drv) { |
| 128 | if (drv->resume) |
| 129 | value = drv->resume(to_spi_device(dev)); |
| 130 | else |
| 131 | dev_dbg(dev, "... can't resume\n"); |
| 132 | } |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 133 | return value; |
| 134 | } |
| 135 | |
Mark Brown | 3ae22e8 | 2010-12-25 15:32:27 +0100 | [diff] [blame] | 136 | static int spi_pm_suspend(struct device *dev) |
| 137 | { |
| 138 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
| 139 | |
| 140 | if (pm) |
| 141 | return pm_generic_suspend(dev); |
| 142 | else |
| 143 | return spi_legacy_suspend(dev, PMSG_SUSPEND); |
| 144 | } |
| 145 | |
| 146 | static int spi_pm_resume(struct device *dev) |
| 147 | { |
| 148 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
| 149 | |
| 150 | if (pm) |
| 151 | return pm_generic_resume(dev); |
| 152 | else |
| 153 | return spi_legacy_resume(dev); |
| 154 | } |
| 155 | |
| 156 | static int spi_pm_freeze(struct device *dev) |
| 157 | { |
| 158 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
| 159 | |
| 160 | if (pm) |
| 161 | return pm_generic_freeze(dev); |
| 162 | else |
| 163 | return spi_legacy_suspend(dev, PMSG_FREEZE); |
| 164 | } |
| 165 | |
| 166 | static int spi_pm_thaw(struct device *dev) |
| 167 | { |
| 168 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
| 169 | |
| 170 | if (pm) |
| 171 | return pm_generic_thaw(dev); |
| 172 | else |
| 173 | return spi_legacy_resume(dev); |
| 174 | } |
| 175 | |
| 176 | static int spi_pm_poweroff(struct device *dev) |
| 177 | { |
| 178 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
| 179 | |
| 180 | if (pm) |
| 181 | return pm_generic_poweroff(dev); |
| 182 | else |
| 183 | return spi_legacy_suspend(dev, PMSG_HIBERNATE); |
| 184 | } |
| 185 | |
| 186 | static int spi_pm_restore(struct device *dev) |
| 187 | { |
| 188 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
| 189 | |
| 190 | if (pm) |
| 191 | return pm_generic_restore(dev); |
| 192 | else |
| 193 | return spi_legacy_resume(dev); |
| 194 | } |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 195 | #else |
Mark Brown | 3ae22e8 | 2010-12-25 15:32:27 +0100 | [diff] [blame] | 196 | #define spi_pm_suspend NULL |
| 197 | #define spi_pm_resume NULL |
| 198 | #define spi_pm_freeze NULL |
| 199 | #define spi_pm_thaw NULL |
| 200 | #define spi_pm_poweroff NULL |
| 201 | #define spi_pm_restore NULL |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 202 | #endif |
| 203 | |
Mark Brown | 3ae22e8 | 2010-12-25 15:32:27 +0100 | [diff] [blame] | 204 | static const struct dev_pm_ops spi_pm = { |
| 205 | .suspend = spi_pm_suspend, |
| 206 | .resume = spi_pm_resume, |
| 207 | .freeze = spi_pm_freeze, |
| 208 | .thaw = spi_pm_thaw, |
| 209 | .poweroff = spi_pm_poweroff, |
| 210 | .restore = spi_pm_restore, |
| 211 | SET_RUNTIME_PM_OPS( |
| 212 | pm_generic_runtime_suspend, |
| 213 | pm_generic_runtime_resume, |
| 214 | pm_generic_runtime_idle |
| 215 | ) |
| 216 | }; |
| 217 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 218 | struct bus_type spi_bus_type = { |
| 219 | .name = "spi", |
| 220 | .dev_attrs = spi_dev_attrs, |
| 221 | .match = spi_match_device, |
| 222 | .uevent = spi_uevent, |
Mark Brown | 3ae22e8 | 2010-12-25 15:32:27 +0100 | [diff] [blame] | 223 | .pm = &spi_pm, |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 224 | }; |
| 225 | EXPORT_SYMBOL_GPL(spi_bus_type); |
| 226 | |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 227 | |
| 228 | static int spi_drv_probe(struct device *dev) |
| 229 | { |
| 230 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); |
| 231 | |
| 232 | return sdrv->probe(to_spi_device(dev)); |
| 233 | } |
| 234 | |
| 235 | static int spi_drv_remove(struct device *dev) |
| 236 | { |
| 237 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); |
| 238 | |
| 239 | return sdrv->remove(to_spi_device(dev)); |
| 240 | } |
| 241 | |
| 242 | static void spi_drv_shutdown(struct device *dev) |
| 243 | { |
| 244 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); |
| 245 | |
| 246 | sdrv->shutdown(to_spi_device(dev)); |
| 247 | } |
| 248 | |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 249 | /** |
| 250 | * spi_register_driver - register a SPI driver |
| 251 | * @sdrv: the driver to register |
| 252 | * Context: can sleep |
| 253 | */ |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 254 | int spi_register_driver(struct spi_driver *sdrv) |
| 255 | { |
| 256 | sdrv->driver.bus = &spi_bus_type; |
| 257 | if (sdrv->probe) |
| 258 | sdrv->driver.probe = spi_drv_probe; |
| 259 | if (sdrv->remove) |
| 260 | sdrv->driver.remove = spi_drv_remove; |
| 261 | if (sdrv->shutdown) |
| 262 | sdrv->driver.shutdown = spi_drv_shutdown; |
| 263 | return driver_register(&sdrv->driver); |
| 264 | } |
| 265 | EXPORT_SYMBOL_GPL(spi_register_driver); |
| 266 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 267 | /*-------------------------------------------------------------------------*/ |
| 268 | |
| 269 | /* SPI devices should normally not be created by SPI device drivers; that |
| 270 | * would make them board-specific. Similarly with SPI master drivers. |
| 271 | * Device registration normally goes into like arch/.../mach.../board-YYY.c |
| 272 | * with other readonly (flashable) information about mainboard devices. |
| 273 | */ |
| 274 | |
| 275 | struct boardinfo { |
| 276 | struct list_head list; |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 277 | struct spi_board_info board_info; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 278 | }; |
| 279 | |
| 280 | static LIST_HEAD(board_list); |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 281 | static LIST_HEAD(spi_master_list); |
| 282 | |
| 283 | /* |
| 284 | * Used to protect add/del opertion for board_info list and |
| 285 | * spi_master list, and their matching process |
| 286 | */ |
Matthias Kaehlcke | 9404082 | 2007-07-17 04:04:16 -0700 | [diff] [blame] | 287 | static DEFINE_MUTEX(board_lock); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 288 | |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 289 | /** |
| 290 | * spi_alloc_device - Allocate a new SPI device |
| 291 | * @master: Controller to which device is connected |
| 292 | * Context: can sleep |
| 293 | * |
| 294 | * Allows a driver to allocate and initialize a spi_device without |
| 295 | * registering it immediately. This allows a driver to directly |
| 296 | * fill the spi_device with device parameters before calling |
| 297 | * spi_add_device() on it. |
| 298 | * |
| 299 | * Caller is responsible to call spi_add_device() on the returned |
| 300 | * spi_device structure to add it to the SPI master. If the caller |
| 301 | * needs to discard the spi_device without adding it, then it should |
| 302 | * call spi_dev_put() on it. |
| 303 | * |
| 304 | * Returns a pointer to the new device, or NULL. |
| 305 | */ |
| 306 | struct spi_device *spi_alloc_device(struct spi_master *master) |
| 307 | { |
| 308 | struct spi_device *spi; |
| 309 | struct device *dev = master->dev.parent; |
| 310 | |
| 311 | if (!spi_master_get(master)) |
| 312 | return NULL; |
| 313 | |
| 314 | spi = kzalloc(sizeof *spi, GFP_KERNEL); |
| 315 | if (!spi) { |
| 316 | dev_err(dev, "cannot alloc spi_device\n"); |
| 317 | spi_master_put(master); |
| 318 | return NULL; |
| 319 | } |
| 320 | |
| 321 | spi->master = master; |
Laurent Pinchart | 178db7d | 2011-12-12 01:15:06 +0100 | [diff] [blame^] | 322 | spi->dev.parent = &master->dev; |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 323 | spi->dev.bus = &spi_bus_type; |
| 324 | spi->dev.release = spidev_release; |
| 325 | device_initialize(&spi->dev); |
| 326 | return spi; |
| 327 | } |
| 328 | EXPORT_SYMBOL_GPL(spi_alloc_device); |
| 329 | |
| 330 | /** |
| 331 | * spi_add_device - Add spi_device allocated with spi_alloc_device |
| 332 | * @spi: spi_device to register |
| 333 | * |
| 334 | * Companion function to spi_alloc_device. Devices allocated with |
| 335 | * spi_alloc_device can be added onto the spi bus with this function. |
| 336 | * |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 337 | * Returns 0 on success; negative errno on failure |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 338 | */ |
| 339 | int spi_add_device(struct spi_device *spi) |
| 340 | { |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 341 | static DEFINE_MUTEX(spi_add_lock); |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 342 | struct device *dev = spi->master->dev.parent; |
Roman Tereshonkov | 8ec130a | 2010-04-16 09:52:59 +0000 | [diff] [blame] | 343 | struct device *d; |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 344 | int status; |
| 345 | |
| 346 | /* Chipselects are numbered 0..max; validate. */ |
| 347 | if (spi->chip_select >= spi->master->num_chipselect) { |
| 348 | dev_err(dev, "cs%d >= max %d\n", |
| 349 | spi->chip_select, |
| 350 | spi->master->num_chipselect); |
| 351 | return -EINVAL; |
| 352 | } |
| 353 | |
| 354 | /* Set the bus ID string */ |
Kay Sievers | 35f74fc | 2009-01-06 10:44:37 -0800 | [diff] [blame] | 355 | dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev), |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 356 | spi->chip_select); |
| 357 | |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 358 | |
| 359 | /* We need to make sure there's no other device with this |
| 360 | * chipselect **BEFORE** we call setup(), else we'll trash |
| 361 | * its configuration. Lock against concurrent add() calls. |
| 362 | */ |
| 363 | mutex_lock(&spi_add_lock); |
| 364 | |
Roman Tereshonkov | 8ec130a | 2010-04-16 09:52:59 +0000 | [diff] [blame] | 365 | d = bus_find_device_by_name(&spi_bus_type, NULL, dev_name(&spi->dev)); |
| 366 | if (d != NULL) { |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 367 | dev_err(dev, "chipselect %d already in use\n", |
| 368 | spi->chip_select); |
Roman Tereshonkov | 8ec130a | 2010-04-16 09:52:59 +0000 | [diff] [blame] | 369 | put_device(d); |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 370 | status = -EBUSY; |
| 371 | goto done; |
| 372 | } |
| 373 | |
| 374 | /* Drivers may modify this initial i/o setup, but will |
| 375 | * normally rely on the device being setup. Devices |
| 376 | * using SPI_CS_HIGH can't coexist well otherwise... |
| 377 | */ |
David Brownell | 7d07719 | 2009-06-17 16:26:03 -0700 | [diff] [blame] | 378 | status = spi_setup(spi); |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 379 | if (status < 0) { |
Linus Walleij | eb288a1 | 2010-10-21 21:06:44 +0200 | [diff] [blame] | 380 | dev_err(dev, "can't setup %s, status %d\n", |
| 381 | dev_name(&spi->dev), status); |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 382 | goto done; |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 383 | } |
| 384 | |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 385 | /* Device may be bound to an active driver when this returns */ |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 386 | status = device_add(&spi->dev); |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 387 | if (status < 0) |
Linus Walleij | eb288a1 | 2010-10-21 21:06:44 +0200 | [diff] [blame] | 388 | dev_err(dev, "can't add %s, status %d\n", |
| 389 | dev_name(&spi->dev), status); |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 390 | else |
Kay Sievers | 35f74fc | 2009-01-06 10:44:37 -0800 | [diff] [blame] | 391 | dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 392 | |
David Brownell | e48880e | 2008-08-15 00:40:44 -0700 | [diff] [blame] | 393 | done: |
| 394 | mutex_unlock(&spi_add_lock); |
| 395 | return status; |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 396 | } |
| 397 | EXPORT_SYMBOL_GPL(spi_add_device); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 398 | |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 399 | /** |
| 400 | * spi_new_device - instantiate one new SPI device |
| 401 | * @master: Controller to which device is connected |
| 402 | * @chip: Describes the SPI device |
| 403 | * Context: can sleep |
| 404 | * |
| 405 | * On typical mainboards, this is purely internal; and it's not needed |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 406 | * after board init creates the hard-wired devices. Some development |
| 407 | * platforms may not be able to use spi_register_board_info though, and |
| 408 | * this is exported so that for example a USB or parport based adapter |
| 409 | * driver could add devices (which it would learn about out-of-band). |
David Brownell | 082c8cb | 2007-07-31 00:39:45 -0700 | [diff] [blame] | 410 | * |
| 411 | * Returns the new device, or NULL. |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 412 | */ |
Adrian Bunk | e9d5a46 | 2007-03-26 21:32:23 -0800 | [diff] [blame] | 413 | struct spi_device *spi_new_device(struct spi_master *master, |
| 414 | struct spi_board_info *chip) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 415 | { |
| 416 | struct spi_device *proxy; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 417 | int status; |
| 418 | |
David Brownell | 082c8cb | 2007-07-31 00:39:45 -0700 | [diff] [blame] | 419 | /* NOTE: caller did any chip->bus_num checks necessary. |
| 420 | * |
| 421 | * Also, unless we change the return value convention to use |
| 422 | * error-or-pointer (not NULL-or-pointer), troubleshootability |
| 423 | * suggests syslogged diagnostics are best here (ugh). |
| 424 | */ |
| 425 | |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 426 | proxy = spi_alloc_device(master); |
| 427 | if (!proxy) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 428 | return NULL; |
| 429 | |
Grant Likely | 102eb97 | 2008-07-23 21:29:55 -0700 | [diff] [blame] | 430 | WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias)); |
| 431 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 432 | proxy->chip_select = chip->chip_select; |
| 433 | proxy->max_speed_hz = chip->max_speed_hz; |
David Brownell | 980a01c | 2006-06-28 07:47:15 -0700 | [diff] [blame] | 434 | proxy->mode = chip->mode; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 435 | proxy->irq = chip->irq; |
Grant Likely | 102eb97 | 2008-07-23 21:29:55 -0700 | [diff] [blame] | 436 | strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias)); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 437 | proxy->dev.platform_data = (void *) chip->platform_data; |
| 438 | proxy->controller_data = chip->controller_data; |
| 439 | proxy->controller_state = NULL; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 440 | |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 441 | status = spi_add_device(proxy); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 442 | if (status < 0) { |
Grant Likely | dc87c98 | 2008-05-15 16:50:22 -0600 | [diff] [blame] | 443 | spi_dev_put(proxy); |
| 444 | return NULL; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 445 | } |
| 446 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 447 | return proxy; |
| 448 | } |
| 449 | EXPORT_SYMBOL_GPL(spi_new_device); |
| 450 | |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 451 | static void spi_match_master_to_boardinfo(struct spi_master *master, |
| 452 | struct spi_board_info *bi) |
| 453 | { |
| 454 | struct spi_device *dev; |
| 455 | |
| 456 | if (master->bus_num != bi->bus_num) |
| 457 | return; |
| 458 | |
| 459 | dev = spi_new_device(master, bi); |
| 460 | if (!dev) |
| 461 | dev_err(master->dev.parent, "can't create new device for %s\n", |
| 462 | bi->modalias); |
| 463 | } |
| 464 | |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 465 | /** |
| 466 | * spi_register_board_info - register SPI devices for a given board |
| 467 | * @info: array of chip descriptors |
| 468 | * @n: how many descriptors are provided |
| 469 | * Context: can sleep |
| 470 | * |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 471 | * Board-specific early init code calls this (probably during arch_initcall) |
| 472 | * with segments of the SPI device table. Any device nodes are created later, |
| 473 | * after the relevant parent SPI controller (bus_num) is defined. We keep |
| 474 | * this table of devices forever, so that reloading a controller driver will |
| 475 | * not make Linux forget about these hard-wired devices. |
| 476 | * |
| 477 | * Other code can also call this, e.g. a particular add-on board might provide |
| 478 | * SPI devices through its expansion connector, so code initializing that board |
| 479 | * would naturally declare its SPI devices. |
| 480 | * |
| 481 | * The board info passed can safely be __initdata ... but be careful of |
| 482 | * any embedded pointers (platform_data, etc), they're copied as-is. |
| 483 | */ |
| 484 | int __init |
| 485 | spi_register_board_info(struct spi_board_info const *info, unsigned n) |
| 486 | { |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 487 | struct boardinfo *bi; |
| 488 | int i; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 489 | |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 490 | bi = kzalloc(n * sizeof(*bi), GFP_KERNEL); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 491 | if (!bi) |
| 492 | return -ENOMEM; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 493 | |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 494 | for (i = 0; i < n; i++, bi++, info++) { |
| 495 | struct spi_master *master; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 496 | |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 497 | memcpy(&bi->board_info, info, sizeof(*info)); |
| 498 | mutex_lock(&board_lock); |
| 499 | list_add_tail(&bi->list, &board_list); |
| 500 | list_for_each_entry(master, &spi_master_list, list) |
| 501 | spi_match_master_to_boardinfo(master, &bi->board_info); |
| 502 | mutex_unlock(&board_lock); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 503 | } |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 504 | |
| 505 | return 0; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 506 | } |
| 507 | |
| 508 | /*-------------------------------------------------------------------------*/ |
| 509 | |
Tony Jones | 49dce68 | 2007-10-16 01:27:48 -0700 | [diff] [blame] | 510 | static void spi_master_release(struct device *dev) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 511 | { |
| 512 | struct spi_master *master; |
| 513 | |
Tony Jones | 49dce68 | 2007-10-16 01:27:48 -0700 | [diff] [blame] | 514 | master = container_of(dev, struct spi_master, dev); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 515 | kfree(master); |
| 516 | } |
| 517 | |
| 518 | static struct class spi_master_class = { |
| 519 | .name = "spi_master", |
| 520 | .owner = THIS_MODULE, |
Tony Jones | 49dce68 | 2007-10-16 01:27:48 -0700 | [diff] [blame] | 521 | .dev_release = spi_master_release, |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 522 | }; |
| 523 | |
| 524 | |
| 525 | /** |
| 526 | * spi_alloc_master - allocate SPI master controller |
| 527 | * @dev: the controller, possibly using the platform_bus |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 528 | * @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] | 529 | * memory is in the driver_data field of the returned device, |
David Brownell | 0c86846 | 2006-01-08 13:34:25 -0800 | [diff] [blame] | 530 | * accessible with spi_master_get_devdata(). |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 531 | * Context: can sleep |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 532 | * |
| 533 | * This call is used only by SPI master controller drivers, which are the |
| 534 | * only ones directly touching chip registers. It's how they allocate |
dmitry pervushin | ba1a051 | 2006-05-20 15:00:14 -0700 | [diff] [blame] | 535 | * an spi_master structure, prior to calling spi_register_master(). |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 536 | * |
| 537 | * This must be called from context that can sleep. It returns the SPI |
| 538 | * master structure on success, else NULL. |
| 539 | * |
| 540 | * The caller is responsible for assigning the bus number and initializing |
dmitry pervushin | ba1a051 | 2006-05-20 15:00:14 -0700 | [diff] [blame] | 541 | * the master's methods before calling spi_register_master(); and (after errors |
David Brownell | 0c86846 | 2006-01-08 13:34:25 -0800 | [diff] [blame] | 542 | * adding the device) calling spi_master_put() to prevent a memory leak. |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 543 | */ |
Adrian Bunk | e9d5a46 | 2007-03-26 21:32:23 -0800 | [diff] [blame] | 544 | struct spi_master *spi_alloc_master(struct device *dev, unsigned size) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 545 | { |
| 546 | struct spi_master *master; |
| 547 | |
David Brownell | 0c86846 | 2006-01-08 13:34:25 -0800 | [diff] [blame] | 548 | if (!dev) |
| 549 | return NULL; |
| 550 | |
Christoph Lameter | e94b176 | 2006-12-06 20:33:17 -0800 | [diff] [blame] | 551 | master = kzalloc(size + sizeof *master, GFP_KERNEL); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 552 | if (!master) |
| 553 | return NULL; |
| 554 | |
Tony Jones | 49dce68 | 2007-10-16 01:27:48 -0700 | [diff] [blame] | 555 | device_initialize(&master->dev); |
| 556 | master->dev.class = &spi_master_class; |
| 557 | master->dev.parent = get_device(dev); |
David Brownell | 0c86846 | 2006-01-08 13:34:25 -0800 | [diff] [blame] | 558 | spi_master_set_devdata(master, &master[1]); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 559 | |
| 560 | return master; |
| 561 | } |
| 562 | EXPORT_SYMBOL_GPL(spi_alloc_master); |
| 563 | |
| 564 | /** |
| 565 | * spi_register_master - register SPI master controller |
| 566 | * @master: initialized master, originally from spi_alloc_master() |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 567 | * Context: can sleep |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 568 | * |
| 569 | * SPI master controllers connect to their drivers using some non-SPI bus, |
| 570 | * such as the platform bus. The final stage of probe() in that code |
| 571 | * includes calling spi_register_master() to hook up to this SPI bus glue. |
| 572 | * |
| 573 | * SPI controllers use board specific (often SOC specific) bus numbers, |
| 574 | * and board-specific addressing for SPI devices combines those numbers |
| 575 | * with chip select numbers. Since SPI does not directly support dynamic |
| 576 | * device identification, boards need configuration tables telling which |
| 577 | * chip is at which address. |
| 578 | * |
| 579 | * This must be called from context that can sleep. It returns zero on |
| 580 | * success, else a negative error code (dropping the master's refcount). |
David Brownell | 0c86846 | 2006-01-08 13:34:25 -0800 | [diff] [blame] | 581 | * After a successful return, the caller is responsible for calling |
| 582 | * spi_unregister_master(). |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 583 | */ |
Adrian Bunk | e9d5a46 | 2007-03-26 21:32:23 -0800 | [diff] [blame] | 584 | int spi_register_master(struct spi_master *master) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 585 | { |
David Brownell | e44a45a | 2007-06-03 13:50:40 -0700 | [diff] [blame] | 586 | static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1); |
Tony Jones | 49dce68 | 2007-10-16 01:27:48 -0700 | [diff] [blame] | 587 | struct device *dev = master->dev.parent; |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 588 | struct boardinfo *bi; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 589 | int status = -ENODEV; |
| 590 | int dynamic = 0; |
| 591 | |
David Brownell | 0c86846 | 2006-01-08 13:34:25 -0800 | [diff] [blame] | 592 | if (!dev) |
| 593 | return -ENODEV; |
| 594 | |
David Brownell | 082c8cb | 2007-07-31 00:39:45 -0700 | [diff] [blame] | 595 | /* even if it's just one always-selected device, there must |
| 596 | * be at least one chipselect |
| 597 | */ |
| 598 | if (master->num_chipselect == 0) |
| 599 | return -EINVAL; |
| 600 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 601 | /* convention: dynamically assigned bus IDs count down from the max */ |
David Brownell | a020ed7 | 2006-04-03 15:49:04 -0700 | [diff] [blame] | 602 | if (master->bus_num < 0) { |
David Brownell | 082c8cb | 2007-07-31 00:39:45 -0700 | [diff] [blame] | 603 | /* FIXME switch to an IDR based scheme, something like |
| 604 | * I2C now uses, so we can't run out of "dynamic" IDs |
| 605 | */ |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 606 | master->bus_num = atomic_dec_return(&dyn_bus_id); |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 607 | dynamic = 1; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 608 | } |
| 609 | |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 610 | spin_lock_init(&master->bus_lock_spinlock); |
| 611 | mutex_init(&master->bus_lock_mutex); |
| 612 | master->bus_lock_flag = 0; |
| 613 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 614 | /* register the device, then userspace will see it. |
| 615 | * registration fails if the bus ID is in use. |
| 616 | */ |
Kay Sievers | 35f74fc | 2009-01-06 10:44:37 -0800 | [diff] [blame] | 617 | dev_set_name(&master->dev, "spi%u", master->bus_num); |
Tony Jones | 49dce68 | 2007-10-16 01:27:48 -0700 | [diff] [blame] | 618 | status = device_add(&master->dev); |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 619 | if (status < 0) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 620 | goto done; |
Kay Sievers | 35f74fc | 2009-01-06 10:44:37 -0800 | [diff] [blame] | 621 | dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev), |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 622 | dynamic ? " (dynamic)" : ""); |
| 623 | |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 624 | mutex_lock(&board_lock); |
| 625 | list_add_tail(&master->list, &spi_master_list); |
| 626 | list_for_each_entry(bi, &board_list, list) |
| 627 | spi_match_master_to_boardinfo(master, &bi->board_info); |
| 628 | mutex_unlock(&board_lock); |
| 629 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 630 | status = 0; |
Anatolij Gustschin | 12b15e8 | 2010-07-27 22:35:58 +0200 | [diff] [blame] | 631 | |
| 632 | /* Register devices from the device tree */ |
| 633 | of_register_spi_devices(master); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 634 | done: |
| 635 | return status; |
| 636 | } |
| 637 | EXPORT_SYMBOL_GPL(spi_register_master); |
| 638 | |
| 639 | |
David Lamparter | 3486008 | 2010-08-30 23:54:17 +0200 | [diff] [blame] | 640 | static int __unregister(struct device *dev, void *null) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 641 | { |
David Lamparter | 3486008 | 2010-08-30 23:54:17 +0200 | [diff] [blame] | 642 | spi_unregister_device(to_spi_device(dev)); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 643 | return 0; |
| 644 | } |
| 645 | |
| 646 | /** |
| 647 | * spi_unregister_master - unregister SPI master controller |
| 648 | * @master: the master being unregistered |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 649 | * Context: can sleep |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 650 | * |
| 651 | * This call is used only by SPI master controller drivers, which are the |
| 652 | * only ones directly touching chip registers. |
| 653 | * |
| 654 | * This must be called from context that can sleep. |
| 655 | */ |
| 656 | void spi_unregister_master(struct spi_master *master) |
| 657 | { |
Jeff Garzik | 89fc9a1 | 2006-12-06 20:35:35 -0800 | [diff] [blame] | 658 | int dummy; |
| 659 | |
Feng Tang | 2b9603a | 2010-08-02 15:52:15 +0800 | [diff] [blame] | 660 | mutex_lock(&board_lock); |
| 661 | list_del(&master->list); |
| 662 | mutex_unlock(&board_lock); |
| 663 | |
Sebastian Andrzej Siewior | 97dbf37 | 2010-12-21 17:24:31 -0800 | [diff] [blame] | 664 | dummy = device_for_each_child(&master->dev, NULL, __unregister); |
Tony Jones | 49dce68 | 2007-10-16 01:27:48 -0700 | [diff] [blame] | 665 | device_unregister(&master->dev); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 666 | } |
| 667 | EXPORT_SYMBOL_GPL(spi_unregister_master); |
| 668 | |
Dave Young | 5ed2c83 | 2008-01-22 15:14:18 +0800 | [diff] [blame] | 669 | static int __spi_master_match(struct device *dev, void *data) |
| 670 | { |
| 671 | struct spi_master *m; |
| 672 | u16 *bus_num = data; |
| 673 | |
| 674 | m = container_of(dev, struct spi_master, dev); |
| 675 | return m->bus_num == *bus_num; |
| 676 | } |
| 677 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 678 | /** |
| 679 | * spi_busnum_to_master - look up master associated with bus_num |
| 680 | * @bus_num: the master's bus number |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 681 | * Context: can sleep |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 682 | * |
| 683 | * This call may be used with devices that are registered after |
| 684 | * arch init time. It returns a refcounted pointer to the relevant |
| 685 | * spi_master (which the caller must release), or NULL if there is |
| 686 | * no such master registered. |
| 687 | */ |
| 688 | struct spi_master *spi_busnum_to_master(u16 bus_num) |
| 689 | { |
Tony Jones | 49dce68 | 2007-10-16 01:27:48 -0700 | [diff] [blame] | 690 | struct device *dev; |
Atsushi Nemoto | 1e9a51d | 2007-01-26 00:56:54 -0800 | [diff] [blame] | 691 | struct spi_master *master = NULL; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 692 | |
Greg Kroah-Hartman | 695794a | 2008-05-22 17:21:08 -0400 | [diff] [blame] | 693 | dev = class_find_device(&spi_master_class, NULL, &bus_num, |
Dave Young | 5ed2c83 | 2008-01-22 15:14:18 +0800 | [diff] [blame] | 694 | __spi_master_match); |
| 695 | if (dev) |
| 696 | master = container_of(dev, struct spi_master, dev); |
| 697 | /* reference got in class_find_device */ |
Atsushi Nemoto | 1e9a51d | 2007-01-26 00:56:54 -0800 | [diff] [blame] | 698 | return master; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 699 | } |
| 700 | EXPORT_SYMBOL_GPL(spi_busnum_to_master); |
| 701 | |
| 702 | |
| 703 | /*-------------------------------------------------------------------------*/ |
| 704 | |
David Brownell | 7d07719 | 2009-06-17 16:26:03 -0700 | [diff] [blame] | 705 | /* Core methods for SPI master protocol drivers. Some of the |
| 706 | * other core methods are currently defined as inline functions. |
| 707 | */ |
| 708 | |
| 709 | /** |
| 710 | * spi_setup - setup SPI mode and clock rate |
| 711 | * @spi: the device whose settings are being modified |
| 712 | * Context: can sleep, and no requests are queued to the device |
| 713 | * |
| 714 | * SPI protocol drivers may need to update the transfer mode if the |
| 715 | * device doesn't work with its default. They may likewise need |
| 716 | * to update clock rates or word sizes from initial values. This function |
| 717 | * changes those settings, and must be called from a context that can sleep. |
| 718 | * Except for SPI_CS_HIGH, which takes effect immediately, the changes take |
| 719 | * effect the next time the device is selected and data is transferred to |
| 720 | * or from it. When this function returns, the spi device is deselected. |
| 721 | * |
| 722 | * Note that this call will fail if the protocol driver specifies an option |
| 723 | * that the underlying controller or its driver does not support. For |
| 724 | * example, not all hardware supports wire transfers using nine bit words, |
| 725 | * LSB-first wire encoding, or active-high chipselects. |
| 726 | */ |
| 727 | int spi_setup(struct spi_device *spi) |
| 728 | { |
David Brownell | e7db06b | 2009-06-17 16:26:04 -0700 | [diff] [blame] | 729 | unsigned bad_bits; |
David Brownell | 7d07719 | 2009-06-17 16:26:03 -0700 | [diff] [blame] | 730 | int status; |
| 731 | |
David Brownell | e7db06b | 2009-06-17 16:26:04 -0700 | [diff] [blame] | 732 | /* help drivers fail *cleanly* when they need options |
| 733 | * that aren't supported with their current master |
| 734 | */ |
| 735 | bad_bits = spi->mode & ~spi->master->mode_bits; |
| 736 | if (bad_bits) { |
Linus Walleij | eb288a1 | 2010-10-21 21:06:44 +0200 | [diff] [blame] | 737 | dev_err(&spi->dev, "setup: unsupported mode bits %x\n", |
David Brownell | e7db06b | 2009-06-17 16:26:04 -0700 | [diff] [blame] | 738 | bad_bits); |
| 739 | return -EINVAL; |
| 740 | } |
| 741 | |
David Brownell | 7d07719 | 2009-06-17 16:26:03 -0700 | [diff] [blame] | 742 | if (!spi->bits_per_word) |
| 743 | spi->bits_per_word = 8; |
| 744 | |
| 745 | status = spi->master->setup(spi); |
| 746 | |
| 747 | dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s" |
| 748 | "%u bits/w, %u Hz max --> %d\n", |
| 749 | (int) (spi->mode & (SPI_CPOL | SPI_CPHA)), |
| 750 | (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "", |
| 751 | (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "", |
| 752 | (spi->mode & SPI_3WIRE) ? "3wire, " : "", |
| 753 | (spi->mode & SPI_LOOP) ? "loopback, " : "", |
| 754 | spi->bits_per_word, spi->max_speed_hz, |
| 755 | status); |
| 756 | |
| 757 | return status; |
| 758 | } |
| 759 | EXPORT_SYMBOL_GPL(spi_setup); |
| 760 | |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 761 | static int __spi_async(struct spi_device *spi, struct spi_message *message) |
| 762 | { |
| 763 | struct spi_master *master = spi->master; |
| 764 | |
| 765 | /* Half-duplex links include original MicroWire, and ones with |
| 766 | * only one data pin like SPI_3WIRE (switches direction) or where |
| 767 | * either MOSI or MISO is missing. They can also be caused by |
| 768 | * software limitations. |
| 769 | */ |
| 770 | if ((master->flags & SPI_MASTER_HALF_DUPLEX) |
| 771 | || (spi->mode & SPI_3WIRE)) { |
| 772 | struct spi_transfer *xfer; |
| 773 | unsigned flags = master->flags; |
| 774 | |
| 775 | list_for_each_entry(xfer, &message->transfers, transfer_list) { |
| 776 | if (xfer->rx_buf && xfer->tx_buf) |
| 777 | return -EINVAL; |
| 778 | if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf) |
| 779 | return -EINVAL; |
| 780 | if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf) |
| 781 | return -EINVAL; |
| 782 | } |
| 783 | } |
| 784 | |
| 785 | message->spi = spi; |
| 786 | message->status = -EINPROGRESS; |
| 787 | return master->transfer(spi, message); |
| 788 | } |
| 789 | |
David Brownell | 568d069 | 2009-09-22 16:46:18 -0700 | [diff] [blame] | 790 | /** |
| 791 | * spi_async - asynchronous SPI transfer |
| 792 | * @spi: device with which data will be exchanged |
| 793 | * @message: describes the data transfers, including completion callback |
| 794 | * Context: any (irqs may be blocked, etc) |
| 795 | * |
| 796 | * This call may be used in_irq and other contexts which can't sleep, |
| 797 | * as well as from task contexts which can sleep. |
| 798 | * |
| 799 | * The completion callback is invoked in a context which can't sleep. |
| 800 | * Before that invocation, the value of message->status is undefined. |
| 801 | * When the callback is issued, message->status holds either zero (to |
| 802 | * indicate complete success) or a negative error code. After that |
| 803 | * callback returns, the driver which issued the transfer request may |
| 804 | * deallocate the associated memory; it's no longer in use by any SPI |
| 805 | * core or controller driver code. |
| 806 | * |
| 807 | * Note that although all messages to a spi_device are handled in |
| 808 | * FIFO order, messages may go to different devices in other orders. |
| 809 | * Some device might be higher priority, or have various "hard" access |
| 810 | * time requirements, for example. |
| 811 | * |
| 812 | * On detection of any fault during the transfer, processing of |
| 813 | * the entire message is aborted, and the device is deselected. |
| 814 | * Until returning from the associated message completion callback, |
| 815 | * no other spi_message queued to that device will be processed. |
| 816 | * (This rule applies equally to all the synchronous transfer calls, |
| 817 | * which are wrappers around this core asynchronous primitive.) |
| 818 | */ |
| 819 | int spi_async(struct spi_device *spi, struct spi_message *message) |
| 820 | { |
| 821 | struct spi_master *master = spi->master; |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 822 | int ret; |
| 823 | unsigned long flags; |
David Brownell | 568d069 | 2009-09-22 16:46:18 -0700 | [diff] [blame] | 824 | |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 825 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); |
David Brownell | 568d069 | 2009-09-22 16:46:18 -0700 | [diff] [blame] | 826 | |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 827 | if (master->bus_lock_flag) |
| 828 | ret = -EBUSY; |
| 829 | else |
| 830 | ret = __spi_async(spi, message); |
David Brownell | 568d069 | 2009-09-22 16:46:18 -0700 | [diff] [blame] | 831 | |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 832 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); |
| 833 | |
| 834 | return ret; |
David Brownell | 568d069 | 2009-09-22 16:46:18 -0700 | [diff] [blame] | 835 | } |
| 836 | EXPORT_SYMBOL_GPL(spi_async); |
| 837 | |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 838 | /** |
| 839 | * spi_async_locked - version of spi_async with exclusive bus usage |
| 840 | * @spi: device with which data will be exchanged |
| 841 | * @message: describes the data transfers, including completion callback |
| 842 | * Context: any (irqs may be blocked, etc) |
| 843 | * |
| 844 | * This call may be used in_irq and other contexts which can't sleep, |
| 845 | * as well as from task contexts which can sleep. |
| 846 | * |
| 847 | * The completion callback is invoked in a context which can't sleep. |
| 848 | * Before that invocation, the value of message->status is undefined. |
| 849 | * When the callback is issued, message->status holds either zero (to |
| 850 | * indicate complete success) or a negative error code. After that |
| 851 | * callback returns, the driver which issued the transfer request may |
| 852 | * deallocate the associated memory; it's no longer in use by any SPI |
| 853 | * core or controller driver code. |
| 854 | * |
| 855 | * Note that although all messages to a spi_device are handled in |
| 856 | * FIFO order, messages may go to different devices in other orders. |
| 857 | * Some device might be higher priority, or have various "hard" access |
| 858 | * time requirements, for example. |
| 859 | * |
| 860 | * On detection of any fault during the transfer, processing of |
| 861 | * the entire message is aborted, and the device is deselected. |
| 862 | * Until returning from the associated message completion callback, |
| 863 | * no other spi_message queued to that device will be processed. |
| 864 | * (This rule applies equally to all the synchronous transfer calls, |
| 865 | * which are wrappers around this core asynchronous primitive.) |
| 866 | */ |
| 867 | int spi_async_locked(struct spi_device *spi, struct spi_message *message) |
| 868 | { |
| 869 | struct spi_master *master = spi->master; |
| 870 | int ret; |
| 871 | unsigned long flags; |
| 872 | |
| 873 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); |
| 874 | |
| 875 | ret = __spi_async(spi, message); |
| 876 | |
| 877 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); |
| 878 | |
| 879 | return ret; |
| 880 | |
| 881 | } |
| 882 | EXPORT_SYMBOL_GPL(spi_async_locked); |
| 883 | |
David Brownell | 7d07719 | 2009-06-17 16:26:03 -0700 | [diff] [blame] | 884 | |
| 885 | /*-------------------------------------------------------------------------*/ |
| 886 | |
| 887 | /* Utility methods for SPI master protocol drivers, layered on |
| 888 | * top of the core. Some other utility methods are defined as |
| 889 | * inline functions. |
| 890 | */ |
| 891 | |
Andrew Morton | 5d870c8 | 2006-01-11 11:23:49 -0800 | [diff] [blame] | 892 | static void spi_complete(void *arg) |
| 893 | { |
| 894 | complete(arg); |
| 895 | } |
| 896 | |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 897 | static int __spi_sync(struct spi_device *spi, struct spi_message *message, |
| 898 | int bus_locked) |
| 899 | { |
| 900 | DECLARE_COMPLETION_ONSTACK(done); |
| 901 | int status; |
| 902 | struct spi_master *master = spi->master; |
| 903 | |
| 904 | message->complete = spi_complete; |
| 905 | message->context = &done; |
| 906 | |
| 907 | if (!bus_locked) |
| 908 | mutex_lock(&master->bus_lock_mutex); |
| 909 | |
| 910 | status = spi_async_locked(spi, message); |
| 911 | |
| 912 | if (!bus_locked) |
| 913 | mutex_unlock(&master->bus_lock_mutex); |
| 914 | |
| 915 | if (status == 0) { |
| 916 | wait_for_completion(&done); |
| 917 | status = message->status; |
| 918 | } |
| 919 | message->context = NULL; |
| 920 | return status; |
| 921 | } |
| 922 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 923 | /** |
| 924 | * spi_sync - blocking/synchronous SPI data transfers |
| 925 | * @spi: device with which data will be exchanged |
| 926 | * @message: describes the data transfers |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 927 | * Context: can sleep |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 928 | * |
| 929 | * This call may only be used from a context that may sleep. The sleep |
| 930 | * is non-interruptible, and has no timeout. Low-overhead controller |
| 931 | * drivers may DMA directly into and out of the message buffers. |
| 932 | * |
| 933 | * Note that the SPI device's chip select is active during the message, |
| 934 | * and then is normally disabled between messages. Drivers for some |
| 935 | * frequently-used devices may want to minimize costs of selecting a chip, |
| 936 | * by leaving it selected in anticipation that the next message will go |
| 937 | * to the same chip. (That may increase power usage.) |
| 938 | * |
David Brownell | 0c86846 | 2006-01-08 13:34:25 -0800 | [diff] [blame] | 939 | * Also, the caller is guaranteeing that the memory associated with the |
| 940 | * message will not be freed before this call returns. |
| 941 | * |
Marc Pignat | 9b938b7 | 2007-12-04 23:45:10 -0800 | [diff] [blame] | 942 | * It returns zero on success, else a negative error code. |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 943 | */ |
| 944 | int spi_sync(struct spi_device *spi, struct spi_message *message) |
| 945 | { |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 946 | return __spi_sync(spi, message, 0); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 947 | } |
| 948 | EXPORT_SYMBOL_GPL(spi_sync); |
| 949 | |
Ernst Schwab | cf32b71 | 2010-06-28 17:49:29 -0700 | [diff] [blame] | 950 | /** |
| 951 | * spi_sync_locked - version of spi_sync with exclusive bus usage |
| 952 | * @spi: device with which data will be exchanged |
| 953 | * @message: describes the data transfers |
| 954 | * Context: can sleep |
| 955 | * |
| 956 | * This call may only be used from a context that may sleep. The sleep |
| 957 | * is non-interruptible, and has no timeout. Low-overhead controller |
| 958 | * drivers may DMA directly into and out of the message buffers. |
| 959 | * |
| 960 | * 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] | 961 | * 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] | 962 | * be released by a spi_bus_unlock call when the exclusive access is over. |
| 963 | * |
| 964 | * It returns zero on success, else a negative error code. |
| 965 | */ |
| 966 | int spi_sync_locked(struct spi_device *spi, struct spi_message *message) |
| 967 | { |
| 968 | return __spi_sync(spi, message, 1); |
| 969 | } |
| 970 | EXPORT_SYMBOL_GPL(spi_sync_locked); |
| 971 | |
| 972 | /** |
| 973 | * spi_bus_lock - obtain a lock for exclusive SPI bus usage |
| 974 | * @master: SPI bus master that should be locked for exclusive bus access |
| 975 | * Context: can sleep |
| 976 | * |
| 977 | * This call may only be used from a context that may sleep. The sleep |
| 978 | * is non-interruptible, and has no timeout. |
| 979 | * |
| 980 | * This call should be used by drivers that require exclusive access to the |
| 981 | * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the |
| 982 | * exclusive access is over. Data transfer must be done by spi_sync_locked |
| 983 | * and spi_async_locked calls when the SPI bus lock is held. |
| 984 | * |
| 985 | * It returns zero on success, else a negative error code. |
| 986 | */ |
| 987 | int spi_bus_lock(struct spi_master *master) |
| 988 | { |
| 989 | unsigned long flags; |
| 990 | |
| 991 | mutex_lock(&master->bus_lock_mutex); |
| 992 | |
| 993 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); |
| 994 | master->bus_lock_flag = 1; |
| 995 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); |
| 996 | |
| 997 | /* mutex remains locked until spi_bus_unlock is called */ |
| 998 | |
| 999 | return 0; |
| 1000 | } |
| 1001 | EXPORT_SYMBOL_GPL(spi_bus_lock); |
| 1002 | |
| 1003 | /** |
| 1004 | * spi_bus_unlock - release the lock for exclusive SPI bus usage |
| 1005 | * @master: SPI bus master that was locked for exclusive bus access |
| 1006 | * Context: can sleep |
| 1007 | * |
| 1008 | * This call may only be used from a context that may sleep. The sleep |
| 1009 | * is non-interruptible, and has no timeout. |
| 1010 | * |
| 1011 | * This call releases an SPI bus lock previously obtained by an spi_bus_lock |
| 1012 | * call. |
| 1013 | * |
| 1014 | * It returns zero on success, else a negative error code. |
| 1015 | */ |
| 1016 | int spi_bus_unlock(struct spi_master *master) |
| 1017 | { |
| 1018 | master->bus_lock_flag = 0; |
| 1019 | |
| 1020 | mutex_unlock(&master->bus_lock_mutex); |
| 1021 | |
| 1022 | return 0; |
| 1023 | } |
| 1024 | EXPORT_SYMBOL_GPL(spi_bus_unlock); |
| 1025 | |
David Brownell | a9948b6 | 2006-04-02 10:37:40 -0800 | [diff] [blame] | 1026 | /* portable code must never pass more than 32 bytes */ |
| 1027 | #define SPI_BUFSIZ max(32,SMP_CACHE_BYTES) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1028 | |
| 1029 | static u8 *buf; |
| 1030 | |
| 1031 | /** |
| 1032 | * spi_write_then_read - SPI synchronous write followed by read |
| 1033 | * @spi: device with which data will be exchanged |
| 1034 | * @txbuf: data to be written (need not be dma-safe) |
| 1035 | * @n_tx: size of txbuf, in bytes |
Jiri Pirko | 2757049 | 2009-06-17 16:26:06 -0700 | [diff] [blame] | 1036 | * @rxbuf: buffer into which data will be read (need not be dma-safe) |
| 1037 | * @n_rx: size of rxbuf, in bytes |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 1038 | * Context: can sleep |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1039 | * |
| 1040 | * This performs a half duplex MicroWire style transaction with the |
| 1041 | * device, sending txbuf and then reading rxbuf. The return value |
| 1042 | * is zero for success, else a negative errno status code. |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 1043 | * This call may only be used from a context that may sleep. |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1044 | * |
David Brownell | 0c86846 | 2006-01-08 13:34:25 -0800 | [diff] [blame] | 1045 | * Parameters to this routine are always copied using a small buffer; |
David Brownell | 33e34dc | 2007-05-08 00:32:21 -0700 | [diff] [blame] | 1046 | * portable code should never use this for more than 32 bytes. |
| 1047 | * Performance-sensitive or bulk transfer code should instead use |
David Brownell | 0c86846 | 2006-01-08 13:34:25 -0800 | [diff] [blame] | 1048 | * spi_{async,sync}() calls with dma-safe buffers. |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1049 | */ |
| 1050 | int spi_write_then_read(struct spi_device *spi, |
Mark Brown | 0c4a159 | 2011-05-11 00:09:30 +0200 | [diff] [blame] | 1051 | const void *txbuf, unsigned n_tx, |
| 1052 | void *rxbuf, unsigned n_rx) |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1053 | { |
David Brownell | 068f407 | 2007-12-04 23:45:09 -0800 | [diff] [blame] | 1054 | static DEFINE_MUTEX(lock); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1055 | |
| 1056 | int status; |
| 1057 | struct spi_message message; |
David Brownell | bdff549 | 2009-04-13 14:39:57 -0700 | [diff] [blame] | 1058 | struct spi_transfer x[2]; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1059 | u8 *local_buf; |
| 1060 | |
| 1061 | /* Use preallocated DMA-safe buffer. We can't avoid copying here, |
| 1062 | * (as a pure convenience thing), but we can keep heap costs |
| 1063 | * out of the hot path ... |
| 1064 | */ |
| 1065 | if ((n_tx + n_rx) > SPI_BUFSIZ) |
| 1066 | return -EINVAL; |
| 1067 | |
Vitaly Wool | 8275c64 | 2006-01-08 13:34:28 -0800 | [diff] [blame] | 1068 | spi_message_init(&message); |
David Brownell | bdff549 | 2009-04-13 14:39:57 -0700 | [diff] [blame] | 1069 | memset(x, 0, sizeof x); |
| 1070 | if (n_tx) { |
| 1071 | x[0].len = n_tx; |
| 1072 | spi_message_add_tail(&x[0], &message); |
| 1073 | } |
| 1074 | if (n_rx) { |
| 1075 | x[1].len = n_rx; |
| 1076 | spi_message_add_tail(&x[1], &message); |
| 1077 | } |
Vitaly Wool | 8275c64 | 2006-01-08 13:34:28 -0800 | [diff] [blame] | 1078 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1079 | /* ... unless someone else is using the pre-allocated buffer */ |
David Brownell | 068f407 | 2007-12-04 23:45:09 -0800 | [diff] [blame] | 1080 | if (!mutex_trylock(&lock)) { |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1081 | local_buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL); |
| 1082 | if (!local_buf) |
| 1083 | return -ENOMEM; |
| 1084 | } else |
| 1085 | local_buf = buf; |
| 1086 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1087 | memcpy(local_buf, txbuf, n_tx); |
David Brownell | bdff549 | 2009-04-13 14:39:57 -0700 | [diff] [blame] | 1088 | x[0].tx_buf = local_buf; |
| 1089 | x[1].rx_buf = local_buf + n_tx; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1090 | |
| 1091 | /* do the i/o */ |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1092 | status = spi_sync(spi, &message); |
Marc Pignat | 9b938b7 | 2007-12-04 23:45:10 -0800 | [diff] [blame] | 1093 | if (status == 0) |
David Brownell | bdff549 | 2009-04-13 14:39:57 -0700 | [diff] [blame] | 1094 | memcpy(rxbuf, x[1].rx_buf, n_rx); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1095 | |
David Brownell | bdff549 | 2009-04-13 14:39:57 -0700 | [diff] [blame] | 1096 | if (x[0].tx_buf == buf) |
David Brownell | 068f407 | 2007-12-04 23:45:09 -0800 | [diff] [blame] | 1097 | mutex_unlock(&lock); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1098 | else |
| 1099 | kfree(local_buf); |
| 1100 | |
| 1101 | return status; |
| 1102 | } |
| 1103 | EXPORT_SYMBOL_GPL(spi_write_then_read); |
| 1104 | |
| 1105 | /*-------------------------------------------------------------------------*/ |
| 1106 | |
| 1107 | static int __init spi_init(void) |
| 1108 | { |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 1109 | int status; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1110 | |
Christoph Lameter | e94b176 | 2006-12-06 20:33:17 -0800 | [diff] [blame] | 1111 | buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL); |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 1112 | if (!buf) { |
| 1113 | status = -ENOMEM; |
| 1114 | goto err0; |
| 1115 | } |
| 1116 | |
| 1117 | status = bus_register(&spi_bus_type); |
| 1118 | if (status < 0) |
| 1119 | goto err1; |
| 1120 | |
| 1121 | status = class_register(&spi_master_class); |
| 1122 | if (status < 0) |
| 1123 | goto err2; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1124 | return 0; |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 1125 | |
| 1126 | err2: |
| 1127 | bus_unregister(&spi_bus_type); |
| 1128 | err1: |
| 1129 | kfree(buf); |
| 1130 | buf = NULL; |
| 1131 | err0: |
| 1132 | return status; |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1133 | } |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 1134 | |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1135 | /* board_info is normally registered in arch_initcall(), |
| 1136 | * but even essential drivers wait till later |
David Brownell | b885244 | 2006-01-08 13:34:23 -0800 | [diff] [blame] | 1137 | * |
| 1138 | * REVISIT only boardinfo really needs static linking. the rest (device and |
| 1139 | * driver registration) _could_ be dynamically linked (modular) ... costs |
| 1140 | * include needing to have boardinfo data structures be much more public. |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1141 | */ |
David Brownell | 673c0c0 | 2008-10-15 22:02:46 -0700 | [diff] [blame] | 1142 | postcore_initcall(spi_init); |
David Brownell | 8ae12a0 | 2006-01-08 13:34:19 -0800 | [diff] [blame] | 1143 | |