Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 1 | /* |
Grant Likely | ca632f5 | 2011-06-06 01:16:30 -0600 | [diff] [blame] | 2 | * Simple synchronous userspace interface to SPI devices |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 3 | * |
| 4 | * Copyright (C) 2006 SWAPP |
| 5 | * Andrea Paterniani <a.paterniani@swapp-eng.it> |
| 6 | * Copyright (C) 2007 David Brownell (simplification, cleanup) |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; either version 2 of the License, or |
| 11 | * (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License |
| 19 | * along with this program; if not, write to the Free Software |
| 20 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 21 | */ |
| 22 | |
| 23 | #include <linux/init.h> |
| 24 | #include <linux/module.h> |
| 25 | #include <linux/ioctl.h> |
| 26 | #include <linux/fs.h> |
| 27 | #include <linux/device.h> |
David Brownell | b2c8dad | 2008-06-05 22:45:50 -0700 | [diff] [blame] | 28 | #include <linux/err.h> |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 29 | #include <linux/list.h> |
| 30 | #include <linux/errno.h> |
| 31 | #include <linux/mutex.h> |
| 32 | #include <linux/slab.h> |
Bernhard Walle | 7d48ec3 | 2011-02-03 09:37:18 +0100 | [diff] [blame] | 33 | #include <linux/compat.h> |
Maxime Ripard | 880cfd4 | 2012-10-31 11:30:08 +0100 | [diff] [blame] | 34 | #include <linux/of.h> |
| 35 | #include <linux/of_device.h> |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 36 | |
| 37 | #include <linux/spi/spi.h> |
| 38 | #include <linux/spi/spidev.h> |
| 39 | |
Jingoo Han | 95c63cf | 2013-10-14 10:36:54 +0900 | [diff] [blame] | 40 | #include <linux/uaccess.h> |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 41 | |
| 42 | |
| 43 | /* |
Uwe Kleine-König | b595076 | 2010-11-01 15:38:34 -0400 | [diff] [blame] | 44 | * This supports access to SPI devices using normal userspace I/O calls. |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 45 | * Note that while traditional UNIX/POSIX I/O semantics are half duplex, |
| 46 | * and often mask message boundaries, full SPI support requires full duplex |
Thadeu Lima de Souza Cascardo | 137f118 | 2009-10-22 17:34:29 -0200 | [diff] [blame] | 47 | * transfers. There are several kinds of internal message boundaries to |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 48 | * handle chipselect management and other protocol options. |
| 49 | * |
| 50 | * SPI has a character major number assigned. We allocate minor numbers |
| 51 | * dynamically using a bitmask. You must use hotplug tools, such as udev |
| 52 | * (or mdev with busybox) to create and destroy the /dev/spidevB.C device |
| 53 | * nodes, since there is no fixed association of minor numbers with any |
| 54 | * particular SPI bus or device. |
| 55 | */ |
| 56 | #define SPIDEV_MAJOR 153 /* assigned */ |
| 57 | #define N_SPI_MINORS 32 /* ... up to 256 */ |
| 58 | |
Thadeu Lima de Souza Cascardo | 8ae1c92 | 2009-12-14 14:20:23 -0800 | [diff] [blame] | 59 | static DECLARE_BITMAP(minors, N_SPI_MINORS); |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 60 | |
| 61 | |
Anton Vorontsov | 6f166e3 | 2007-07-31 00:38:43 -0700 | [diff] [blame] | 62 | /* Bit masks for spi_device.mode management. Note that incorrect |
David Brownell | b55f627 | 2009-06-30 11:41:26 -0700 | [diff] [blame] | 63 | * settings for some settings can cause *lots* of trouble for other |
| 64 | * devices on a shared bus: |
Anton Vorontsov | 6f166e3 | 2007-07-31 00:38:43 -0700 | [diff] [blame] | 65 | * |
David Brownell | b55f627 | 2009-06-30 11:41:26 -0700 | [diff] [blame] | 66 | * - CS_HIGH ... this device will be active when it shouldn't be |
| 67 | * - 3WIRE ... when active, it won't behave as it should |
| 68 | * - NO_CS ... there will be no explicit message boundaries; this |
| 69 | * is completely incompatible with the shared bus model |
| 70 | * - READY ... transfers may proceed when they shouldn't. |
| 71 | * |
| 72 | * REVISIT should changing those flags be privileged? |
Anton Vorontsov | 6f166e3 | 2007-07-31 00:38:43 -0700 | [diff] [blame] | 73 | */ |
| 74 | #define SPI_MODE_MASK (SPI_CPHA | SPI_CPOL | SPI_CS_HIGH \ |
David Brownell | b55f627 | 2009-06-30 11:41:26 -0700 | [diff] [blame] | 75 | | SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP \ |
Geert Uytterhoeven | dc64d39 | 2014-02-25 11:40:17 +0100 | [diff] [blame] | 76 | | SPI_NO_CS | SPI_READY | SPI_TX_DUAL \ |
| 77 | | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD) |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 78 | |
| 79 | struct spidev_data { |
David Brownell | b2c8dad | 2008-06-05 22:45:50 -0700 | [diff] [blame] | 80 | dev_t devt; |
David Brownell | 25d5cb4 | 2008-05-23 13:05:03 -0700 | [diff] [blame] | 81 | spinlock_t spi_lock; |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 82 | struct spi_device *spi; |
| 83 | struct list_head device_entry; |
| 84 | |
David Brownell | b2c8dad | 2008-06-05 22:45:50 -0700 | [diff] [blame] | 85 | /* buffer is NULL unless this device is open (users > 0) */ |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 86 | struct mutex buf_lock; |
| 87 | unsigned users; |
| 88 | u8 *buffer; |
| 89 | }; |
| 90 | |
| 91 | static LIST_HEAD(device_list); |
| 92 | static DEFINE_MUTEX(device_list_lock); |
| 93 | |
| 94 | static unsigned bufsiz = 4096; |
| 95 | module_param(bufsiz, uint, S_IRUGO); |
| 96 | MODULE_PARM_DESC(bufsiz, "data bytes in biggest supported SPI message"); |
| 97 | |
| 98 | /*-------------------------------------------------------------------------*/ |
| 99 | |
David Brownell | 25d5cb4 | 2008-05-23 13:05:03 -0700 | [diff] [blame] | 100 | /* |
| 101 | * We can't use the standard synchronous wrappers for file I/O; we |
| 102 | * need to protect against async removal of the underlying spi_device. |
| 103 | */ |
| 104 | static void spidev_complete(void *arg) |
| 105 | { |
| 106 | complete(arg); |
| 107 | } |
| 108 | |
| 109 | static ssize_t |
| 110 | spidev_sync(struct spidev_data *spidev, struct spi_message *message) |
| 111 | { |
| 112 | DECLARE_COMPLETION_ONSTACK(done); |
| 113 | int status; |
| 114 | |
| 115 | message->complete = spidev_complete; |
| 116 | message->context = &done; |
| 117 | |
| 118 | spin_lock_irq(&spidev->spi_lock); |
| 119 | if (spidev->spi == NULL) |
| 120 | status = -ESHUTDOWN; |
| 121 | else |
| 122 | status = spi_async(spidev->spi, message); |
| 123 | spin_unlock_irq(&spidev->spi_lock); |
| 124 | |
| 125 | if (status == 0) { |
| 126 | wait_for_completion(&done); |
| 127 | status = message->status; |
| 128 | if (status == 0) |
| 129 | status = message->actual_length; |
| 130 | } |
| 131 | return status; |
| 132 | } |
| 133 | |
| 134 | static inline ssize_t |
| 135 | spidev_sync_write(struct spidev_data *spidev, size_t len) |
| 136 | { |
| 137 | struct spi_transfer t = { |
| 138 | .tx_buf = spidev->buffer, |
| 139 | .len = len, |
| 140 | }; |
| 141 | struct spi_message m; |
| 142 | |
| 143 | spi_message_init(&m); |
| 144 | spi_message_add_tail(&t, &m); |
| 145 | return spidev_sync(spidev, &m); |
| 146 | } |
| 147 | |
| 148 | static inline ssize_t |
| 149 | spidev_sync_read(struct spidev_data *spidev, size_t len) |
| 150 | { |
| 151 | struct spi_transfer t = { |
| 152 | .rx_buf = spidev->buffer, |
| 153 | .len = len, |
| 154 | }; |
| 155 | struct spi_message m; |
| 156 | |
| 157 | spi_message_init(&m); |
| 158 | spi_message_add_tail(&t, &m); |
| 159 | return spidev_sync(spidev, &m); |
| 160 | } |
| 161 | |
| 162 | /*-------------------------------------------------------------------------*/ |
| 163 | |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 164 | /* Read-only message with current device setup */ |
| 165 | static ssize_t |
| 166 | spidev_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos) |
| 167 | { |
| 168 | struct spidev_data *spidev; |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 169 | ssize_t status = 0; |
| 170 | |
| 171 | /* chipselect only toggles at start or end of operation */ |
| 172 | if (count > bufsiz) |
| 173 | return -EMSGSIZE; |
| 174 | |
| 175 | spidev = filp->private_data; |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 176 | |
| 177 | mutex_lock(&spidev->buf_lock); |
David Brownell | 25d5cb4 | 2008-05-23 13:05:03 -0700 | [diff] [blame] | 178 | status = spidev_sync_read(spidev, count); |
Sebastian Siewior | 4b1295b | 2008-07-04 09:59:56 -0700 | [diff] [blame] | 179 | if (status > 0) { |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 180 | unsigned long missing; |
| 181 | |
Sebastian Siewior | 4b1295b | 2008-07-04 09:59:56 -0700 | [diff] [blame] | 182 | missing = copy_to_user(buf, spidev->buffer, status); |
| 183 | if (missing == status) |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 184 | status = -EFAULT; |
| 185 | else |
Sebastian Siewior | 4b1295b | 2008-07-04 09:59:56 -0700 | [diff] [blame] | 186 | status = status - missing; |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 187 | } |
| 188 | mutex_unlock(&spidev->buf_lock); |
| 189 | |
| 190 | return status; |
| 191 | } |
| 192 | |
| 193 | /* Write-only message with current device setup */ |
| 194 | static ssize_t |
| 195 | spidev_write(struct file *filp, const char __user *buf, |
| 196 | size_t count, loff_t *f_pos) |
| 197 | { |
| 198 | struct spidev_data *spidev; |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 199 | ssize_t status = 0; |
| 200 | unsigned long missing; |
| 201 | |
| 202 | /* chipselect only toggles at start or end of operation */ |
| 203 | if (count > bufsiz) |
| 204 | return -EMSGSIZE; |
| 205 | |
| 206 | spidev = filp->private_data; |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 207 | |
| 208 | mutex_lock(&spidev->buf_lock); |
| 209 | missing = copy_from_user(spidev->buffer, buf, count); |
Jingoo Han | 95c63cf | 2013-10-14 10:36:54 +0900 | [diff] [blame] | 210 | if (missing == 0) |
David Brownell | 25d5cb4 | 2008-05-23 13:05:03 -0700 | [diff] [blame] | 211 | status = spidev_sync_write(spidev, count); |
Jingoo Han | 95c63cf | 2013-10-14 10:36:54 +0900 | [diff] [blame] | 212 | else |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 213 | status = -EFAULT; |
| 214 | mutex_unlock(&spidev->buf_lock); |
| 215 | |
| 216 | return status; |
| 217 | } |
| 218 | |
| 219 | static int spidev_message(struct spidev_data *spidev, |
| 220 | struct spi_ioc_transfer *u_xfers, unsigned n_xfers) |
| 221 | { |
| 222 | struct spi_message msg; |
| 223 | struct spi_transfer *k_xfers; |
| 224 | struct spi_transfer *k_tmp; |
| 225 | struct spi_ioc_transfer *u_tmp; |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 226 | unsigned n, total; |
| 227 | u8 *buf; |
| 228 | int status = -EFAULT; |
| 229 | |
| 230 | spi_message_init(&msg); |
| 231 | k_xfers = kcalloc(n_xfers, sizeof(*k_tmp), GFP_KERNEL); |
| 232 | if (k_xfers == NULL) |
| 233 | return -ENOMEM; |
| 234 | |
| 235 | /* Construct spi_message, copying any tx data to bounce buffer. |
| 236 | * We walk the array of user-provided transfers, using each one |
| 237 | * to initialize a kernel version of the same transfer. |
| 238 | */ |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 239 | buf = spidev->buffer; |
| 240 | total = 0; |
| 241 | for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers; |
| 242 | n; |
| 243 | n--, k_tmp++, u_tmp++) { |
| 244 | k_tmp->len = u_tmp->len; |
| 245 | |
Domen Puncer | da90fa8 | 2007-05-23 13:57:39 -0700 | [diff] [blame] | 246 | total += k_tmp->len; |
| 247 | if (total > bufsiz) { |
| 248 | status = -EMSGSIZE; |
| 249 | goto done; |
| 250 | } |
| 251 | |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 252 | if (u_tmp->rx_buf) { |
| 253 | k_tmp->rx_buf = buf; |
David Brownell | 96ddbf5 | 2007-08-10 13:01:09 -0700 | [diff] [blame] | 254 | if (!access_ok(VERIFY_WRITE, (u8 __user *) |
Al Viro | 142956a | 2007-10-29 05:11:28 +0000 | [diff] [blame] | 255 | (uintptr_t) u_tmp->rx_buf, |
David Brownell | 96ddbf5 | 2007-08-10 13:01:09 -0700 | [diff] [blame] | 256 | u_tmp->len)) |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 257 | goto done; |
| 258 | } |
| 259 | if (u_tmp->tx_buf) { |
| 260 | k_tmp->tx_buf = buf; |
David Brownell | 4917d92 | 2007-07-17 04:04:04 -0700 | [diff] [blame] | 261 | if (copy_from_user(buf, (const u8 __user *) |
Al Viro | 142956a | 2007-10-29 05:11:28 +0000 | [diff] [blame] | 262 | (uintptr_t) u_tmp->tx_buf, |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 263 | u_tmp->len)) |
| 264 | goto done; |
| 265 | } |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 266 | buf += k_tmp->len; |
| 267 | |
| 268 | k_tmp->cs_change = !!u_tmp->cs_change; |
Geert Uytterhoeven | dc64d39 | 2014-02-25 11:40:17 +0100 | [diff] [blame] | 269 | k_tmp->tx_nbits = u_tmp->tx_nbits; |
| 270 | k_tmp->rx_nbits = u_tmp->rx_nbits; |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 271 | k_tmp->bits_per_word = u_tmp->bits_per_word; |
| 272 | k_tmp->delay_usecs = u_tmp->delay_usecs; |
| 273 | k_tmp->speed_hz = u_tmp->speed_hz; |
| 274 | #ifdef VERBOSE |
Florian Fainelli | 41df70d | 2009-12-07 14:28:43 +0000 | [diff] [blame] | 275 | dev_dbg(&spidev->spi->dev, |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 276 | " xfer len %zd %s%s%s%dbits %u usec %uHz\n", |
| 277 | u_tmp->len, |
| 278 | u_tmp->rx_buf ? "rx " : "", |
| 279 | u_tmp->tx_buf ? "tx " : "", |
| 280 | u_tmp->cs_change ? "cs " : "", |
Florian Fainelli | 41df70d | 2009-12-07 14:28:43 +0000 | [diff] [blame] | 281 | u_tmp->bits_per_word ? : spidev->spi->bits_per_word, |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 282 | u_tmp->delay_usecs, |
Florian Fainelli | 41df70d | 2009-12-07 14:28:43 +0000 | [diff] [blame] | 283 | u_tmp->speed_hz ? : spidev->spi->max_speed_hz); |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 284 | #endif |
| 285 | spi_message_add_tail(k_tmp, &msg); |
| 286 | } |
| 287 | |
David Brownell | 25d5cb4 | 2008-05-23 13:05:03 -0700 | [diff] [blame] | 288 | status = spidev_sync(spidev, &msg); |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 289 | if (status < 0) |
| 290 | goto done; |
| 291 | |
| 292 | /* copy any rx data out of bounce buffer */ |
| 293 | buf = spidev->buffer; |
| 294 | for (n = n_xfers, u_tmp = u_xfers; n; n--, u_tmp++) { |
| 295 | if (u_tmp->rx_buf) { |
David Brownell | 4917d92 | 2007-07-17 04:04:04 -0700 | [diff] [blame] | 296 | if (__copy_to_user((u8 __user *) |
Al Viro | 142956a | 2007-10-29 05:11:28 +0000 | [diff] [blame] | 297 | (uintptr_t) u_tmp->rx_buf, buf, |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 298 | u_tmp->len)) { |
| 299 | status = -EFAULT; |
| 300 | goto done; |
| 301 | } |
| 302 | } |
| 303 | buf += u_tmp->len; |
| 304 | } |
| 305 | status = total; |
| 306 | |
| 307 | done: |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 308 | kfree(k_xfers); |
| 309 | return status; |
| 310 | } |
| 311 | |
Alan Cox | 4ef754b | 2008-07-23 21:29:55 -0700 | [diff] [blame] | 312 | static long |
| 313 | spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 314 | { |
| 315 | int err = 0; |
| 316 | int retval = 0; |
| 317 | struct spidev_data *spidev; |
| 318 | struct spi_device *spi; |
| 319 | u32 tmp; |
| 320 | unsigned n_ioc; |
| 321 | struct spi_ioc_transfer *ioc; |
| 322 | |
| 323 | /* Check type and command number */ |
| 324 | if (_IOC_TYPE(cmd) != SPI_IOC_MAGIC) |
| 325 | return -ENOTTY; |
| 326 | |
| 327 | /* Check access direction once here; don't repeat below. |
| 328 | * IOC_DIR is from the user perspective, while access_ok is |
| 329 | * from the kernel perspective; so they look reversed. |
| 330 | */ |
| 331 | if (_IOC_DIR(cmd) & _IOC_READ) |
| 332 | err = !access_ok(VERIFY_WRITE, |
| 333 | (void __user *)arg, _IOC_SIZE(cmd)); |
| 334 | if (err == 0 && _IOC_DIR(cmd) & _IOC_WRITE) |
| 335 | err = !access_ok(VERIFY_READ, |
| 336 | (void __user *)arg, _IOC_SIZE(cmd)); |
| 337 | if (err) |
| 338 | return -EFAULT; |
| 339 | |
David Brownell | 25d5cb4 | 2008-05-23 13:05:03 -0700 | [diff] [blame] | 340 | /* guard against device removal before, or while, |
| 341 | * we issue this ioctl. |
| 342 | */ |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 343 | spidev = filp->private_data; |
David Brownell | 25d5cb4 | 2008-05-23 13:05:03 -0700 | [diff] [blame] | 344 | spin_lock_irq(&spidev->spi_lock); |
| 345 | spi = spi_dev_get(spidev->spi); |
| 346 | spin_unlock_irq(&spidev->spi_lock); |
| 347 | |
| 348 | if (spi == NULL) |
| 349 | return -ESHUTDOWN; |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 350 | |
Alan Cox | 4ef754b | 2008-07-23 21:29:55 -0700 | [diff] [blame] | 351 | /* use the buffer lock here for triple duty: |
| 352 | * - prevent I/O (from us) so calling spi_setup() is safe; |
| 353 | * - prevent concurrent SPI_IOC_WR_* from morphing |
| 354 | * data fields while SPI_IOC_RD_* reads them; |
| 355 | * - SPI_IOC_MESSAGE needs the buffer locked "normally". |
| 356 | */ |
| 357 | mutex_lock(&spidev->buf_lock); |
| 358 | |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 359 | switch (cmd) { |
| 360 | /* read requests */ |
| 361 | case SPI_IOC_RD_MODE: |
| 362 | retval = __put_user(spi->mode & SPI_MODE_MASK, |
| 363 | (__u8 __user *)arg); |
| 364 | break; |
Geert Uytterhoeven | dc64d39 | 2014-02-25 11:40:17 +0100 | [diff] [blame] | 365 | case SPI_IOC_RD_MODE32: |
| 366 | retval = __put_user(spi->mode & SPI_MODE_MASK, |
| 367 | (__u32 __user *)arg); |
| 368 | break; |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 369 | case SPI_IOC_RD_LSB_FIRST: |
| 370 | retval = __put_user((spi->mode & SPI_LSB_FIRST) ? 1 : 0, |
| 371 | (__u8 __user *)arg); |
| 372 | break; |
| 373 | case SPI_IOC_RD_BITS_PER_WORD: |
| 374 | retval = __put_user(spi->bits_per_word, (__u8 __user *)arg); |
| 375 | break; |
| 376 | case SPI_IOC_RD_MAX_SPEED_HZ: |
| 377 | retval = __put_user(spi->max_speed_hz, (__u32 __user *)arg); |
| 378 | break; |
| 379 | |
| 380 | /* write requests */ |
| 381 | case SPI_IOC_WR_MODE: |
Geert Uytterhoeven | dc64d39 | 2014-02-25 11:40:17 +0100 | [diff] [blame] | 382 | case SPI_IOC_WR_MODE32: |
| 383 | if (cmd == SPI_IOC_WR_MODE) |
| 384 | retval = __get_user(tmp, (u8 __user *)arg); |
| 385 | else |
| 386 | retval = __get_user(tmp, (u32 __user *)arg); |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 387 | if (retval == 0) { |
Geert Uytterhoeven | e645618 | 2014-02-25 11:40:16 +0100 | [diff] [blame] | 388 | u32 save = spi->mode; |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 389 | |
| 390 | if (tmp & ~SPI_MODE_MASK) { |
| 391 | retval = -EINVAL; |
| 392 | break; |
| 393 | } |
| 394 | |
| 395 | tmp |= spi->mode & ~SPI_MODE_MASK; |
Geert Uytterhoeven | dc64d39 | 2014-02-25 11:40:17 +0100 | [diff] [blame] | 396 | spi->mode = (u16)tmp; |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 397 | retval = spi_setup(spi); |
| 398 | if (retval < 0) |
| 399 | spi->mode = save; |
| 400 | else |
Geert Uytterhoeven | dc64d39 | 2014-02-25 11:40:17 +0100 | [diff] [blame] | 401 | dev_dbg(&spi->dev, "spi mode %x\n", tmp); |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 402 | } |
| 403 | break; |
| 404 | case SPI_IOC_WR_LSB_FIRST: |
| 405 | retval = __get_user(tmp, (__u8 __user *)arg); |
| 406 | if (retval == 0) { |
Geert Uytterhoeven | e645618 | 2014-02-25 11:40:16 +0100 | [diff] [blame] | 407 | u32 save = spi->mode; |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 408 | |
| 409 | if (tmp) |
| 410 | spi->mode |= SPI_LSB_FIRST; |
| 411 | else |
| 412 | spi->mode &= ~SPI_LSB_FIRST; |
| 413 | retval = spi_setup(spi); |
| 414 | if (retval < 0) |
| 415 | spi->mode = save; |
| 416 | else |
| 417 | dev_dbg(&spi->dev, "%csb first\n", |
| 418 | tmp ? 'l' : 'm'); |
| 419 | } |
| 420 | break; |
| 421 | case SPI_IOC_WR_BITS_PER_WORD: |
| 422 | retval = __get_user(tmp, (__u8 __user *)arg); |
| 423 | if (retval == 0) { |
| 424 | u8 save = spi->bits_per_word; |
| 425 | |
| 426 | spi->bits_per_word = tmp; |
| 427 | retval = spi_setup(spi); |
| 428 | if (retval < 0) |
| 429 | spi->bits_per_word = save; |
| 430 | else |
| 431 | dev_dbg(&spi->dev, "%d bits per word\n", tmp); |
| 432 | } |
| 433 | break; |
| 434 | case SPI_IOC_WR_MAX_SPEED_HZ: |
| 435 | retval = __get_user(tmp, (__u32 __user *)arg); |
| 436 | if (retval == 0) { |
| 437 | u32 save = spi->max_speed_hz; |
| 438 | |
| 439 | spi->max_speed_hz = tmp; |
| 440 | retval = spi_setup(spi); |
| 441 | if (retval < 0) |
| 442 | spi->max_speed_hz = save; |
| 443 | else |
| 444 | dev_dbg(&spi->dev, "%d Hz (max)\n", tmp); |
| 445 | } |
| 446 | break; |
| 447 | |
| 448 | default: |
| 449 | /* segmented and/or full-duplex I/O request */ |
| 450 | if (_IOC_NR(cmd) != _IOC_NR(SPI_IOC_MESSAGE(0)) |
David Brownell | 25d5cb4 | 2008-05-23 13:05:03 -0700 | [diff] [blame] | 451 | || _IOC_DIR(cmd) != _IOC_WRITE) { |
| 452 | retval = -ENOTTY; |
| 453 | break; |
| 454 | } |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 455 | |
| 456 | tmp = _IOC_SIZE(cmd); |
| 457 | if ((tmp % sizeof(struct spi_ioc_transfer)) != 0) { |
| 458 | retval = -EINVAL; |
| 459 | break; |
| 460 | } |
| 461 | n_ioc = tmp / sizeof(struct spi_ioc_transfer); |
| 462 | if (n_ioc == 0) |
| 463 | break; |
| 464 | |
| 465 | /* copy into scratch area */ |
| 466 | ioc = kmalloc(tmp, GFP_KERNEL); |
| 467 | if (!ioc) { |
| 468 | retval = -ENOMEM; |
| 469 | break; |
| 470 | } |
| 471 | if (__copy_from_user(ioc, (void __user *)arg, tmp)) { |
Florin Malita | 9bea3f2 | 2007-05-23 13:57:45 -0700 | [diff] [blame] | 472 | kfree(ioc); |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 473 | retval = -EFAULT; |
| 474 | break; |
| 475 | } |
| 476 | |
| 477 | /* translate to spi_message, execute */ |
| 478 | retval = spidev_message(spidev, ioc, n_ioc); |
| 479 | kfree(ioc); |
| 480 | break; |
| 481 | } |
Alan Cox | 4ef754b | 2008-07-23 21:29:55 -0700 | [diff] [blame] | 482 | |
| 483 | mutex_unlock(&spidev->buf_lock); |
David Brownell | 25d5cb4 | 2008-05-23 13:05:03 -0700 | [diff] [blame] | 484 | spi_dev_put(spi); |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 485 | return retval; |
| 486 | } |
| 487 | |
Bernhard Walle | 7d48ec3 | 2011-02-03 09:37:18 +0100 | [diff] [blame] | 488 | #ifdef CONFIG_COMPAT |
| 489 | static long |
| 490 | spidev_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) |
| 491 | { |
| 492 | return spidev_ioctl(filp, cmd, (unsigned long)compat_ptr(arg)); |
| 493 | } |
| 494 | #else |
| 495 | #define spidev_compat_ioctl NULL |
| 496 | #endif /* CONFIG_COMPAT */ |
| 497 | |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 498 | static int spidev_open(struct inode *inode, struct file *filp) |
| 499 | { |
| 500 | struct spidev_data *spidev; |
| 501 | int status = -ENXIO; |
| 502 | |
| 503 | mutex_lock(&device_list_lock); |
| 504 | |
| 505 | list_for_each_entry(spidev, &device_list, device_entry) { |
David Brownell | b2c8dad | 2008-06-05 22:45:50 -0700 | [diff] [blame] | 506 | if (spidev->devt == inode->i_rdev) { |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 507 | status = 0; |
| 508 | break; |
| 509 | } |
| 510 | } |
| 511 | if (status == 0) { |
| 512 | if (!spidev->buffer) { |
| 513 | spidev->buffer = kmalloc(bufsiz, GFP_KERNEL); |
| 514 | if (!spidev->buffer) { |
| 515 | dev_dbg(&spidev->spi->dev, "open/ENOMEM\n"); |
| 516 | status = -ENOMEM; |
| 517 | } |
| 518 | } |
| 519 | if (status == 0) { |
| 520 | spidev->users++; |
| 521 | filp->private_data = spidev; |
| 522 | nonseekable_open(inode, filp); |
| 523 | } |
| 524 | } else |
| 525 | pr_debug("spidev: nothing for minor %d\n", iminor(inode)); |
| 526 | |
| 527 | mutex_unlock(&device_list_lock); |
| 528 | return status; |
| 529 | } |
| 530 | |
| 531 | static int spidev_release(struct inode *inode, struct file *filp) |
| 532 | { |
| 533 | struct spidev_data *spidev; |
| 534 | int status = 0; |
| 535 | |
| 536 | mutex_lock(&device_list_lock); |
| 537 | spidev = filp->private_data; |
| 538 | filp->private_data = NULL; |
David Brownell | b2c8dad | 2008-06-05 22:45:50 -0700 | [diff] [blame] | 539 | |
| 540 | /* last close? */ |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 541 | spidev->users--; |
| 542 | if (!spidev->users) { |
David Brownell | b2c8dad | 2008-06-05 22:45:50 -0700 | [diff] [blame] | 543 | int dofree; |
| 544 | |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 545 | kfree(spidev->buffer); |
| 546 | spidev->buffer = NULL; |
David Brownell | b2c8dad | 2008-06-05 22:45:50 -0700 | [diff] [blame] | 547 | |
| 548 | /* ... after we unbound from the underlying device? */ |
| 549 | spin_lock_irq(&spidev->spi_lock); |
| 550 | dofree = (spidev->spi == NULL); |
| 551 | spin_unlock_irq(&spidev->spi_lock); |
| 552 | |
| 553 | if (dofree) |
| 554 | kfree(spidev); |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 555 | } |
| 556 | mutex_unlock(&device_list_lock); |
| 557 | |
| 558 | return status; |
| 559 | } |
| 560 | |
Alexey Dobriyan | 828c095 | 2009-10-01 15:43:56 -0700 | [diff] [blame] | 561 | static const struct file_operations spidev_fops = { |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 562 | .owner = THIS_MODULE, |
| 563 | /* REVISIT switch to aio primitives, so that userspace |
| 564 | * gets more complete API coverage. It'll simplify things |
| 565 | * too, except for the locking. |
| 566 | */ |
| 567 | .write = spidev_write, |
| 568 | .read = spidev_read, |
Alan Cox | 4ef754b | 2008-07-23 21:29:55 -0700 | [diff] [blame] | 569 | .unlocked_ioctl = spidev_ioctl, |
Bernhard Walle | 7d48ec3 | 2011-02-03 09:37:18 +0100 | [diff] [blame] | 570 | .compat_ioctl = spidev_compat_ioctl, |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 571 | .open = spidev_open, |
| 572 | .release = spidev_release, |
Arnd Bergmann | 6038f37 | 2010-08-15 18:52:59 +0200 | [diff] [blame] | 573 | .llseek = no_llseek, |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 574 | }; |
| 575 | |
| 576 | /*-------------------------------------------------------------------------*/ |
| 577 | |
| 578 | /* The main reason to have this class is to make mdev/udev create the |
| 579 | * /dev/spidevB.C character device nodes exposing our userspace API. |
| 580 | * It also simplifies memory management. |
| 581 | */ |
| 582 | |
David Brownell | b2c8dad | 2008-06-05 22:45:50 -0700 | [diff] [blame] | 583 | static struct class *spidev_class; |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 584 | |
| 585 | /*-------------------------------------------------------------------------*/ |
| 586 | |
Grant Likely | fd4a319 | 2012-12-07 16:57:14 +0000 | [diff] [blame] | 587 | static int spidev_probe(struct spi_device *spi) |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 588 | { |
| 589 | struct spidev_data *spidev; |
| 590 | int status; |
| 591 | unsigned long minor; |
| 592 | |
| 593 | /* Allocate driver data */ |
| 594 | spidev = kzalloc(sizeof(*spidev), GFP_KERNEL); |
| 595 | if (!spidev) |
| 596 | return -ENOMEM; |
| 597 | |
| 598 | /* Initialize the driver data */ |
| 599 | spidev->spi = spi; |
David Brownell | 25d5cb4 | 2008-05-23 13:05:03 -0700 | [diff] [blame] | 600 | spin_lock_init(&spidev->spi_lock); |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 601 | mutex_init(&spidev->buf_lock); |
| 602 | |
| 603 | INIT_LIST_HEAD(&spidev->device_entry); |
| 604 | |
| 605 | /* If we can allocate a minor number, hook up this device. |
| 606 | * Reusing minors is fine so long as udev or mdev is working. |
| 607 | */ |
| 608 | mutex_lock(&device_list_lock); |
Domen Puncer | 0a4dd77 | 2007-05-15 23:57:05 -0700 | [diff] [blame] | 609 | minor = find_first_zero_bit(minors, N_SPI_MINORS); |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 610 | if (minor < N_SPI_MINORS) { |
David Brownell | b2c8dad | 2008-06-05 22:45:50 -0700 | [diff] [blame] | 611 | struct device *dev; |
| 612 | |
| 613 | spidev->devt = MKDEV(SPIDEV_MAJOR, minor); |
Greg Kroah-Hartman | a9b1261 | 2008-07-21 20:03:34 -0700 | [diff] [blame] | 614 | dev = device_create(spidev_class, &spi->dev, spidev->devt, |
| 615 | spidev, "spidev%d.%d", |
| 616 | spi->master->bus_num, spi->chip_select); |
Rusty Russell | 8c6ffba | 2013-07-15 11:20:32 +0930 | [diff] [blame] | 617 | status = PTR_ERR_OR_ZERO(dev); |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 618 | } else { |
| 619 | dev_dbg(&spi->dev, "no minor number available!\n"); |
| 620 | status = -ENODEV; |
| 621 | } |
| 622 | if (status == 0) { |
| 623 | set_bit(minor, minors); |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 624 | list_add(&spidev->device_entry, &device_list); |
| 625 | } |
| 626 | mutex_unlock(&device_list_lock); |
| 627 | |
Wolfgang Ocker | aaacf4b | 2008-12-01 13:13:52 -0800 | [diff] [blame] | 628 | if (status == 0) |
| 629 | spi_set_drvdata(spi, spidev); |
| 630 | else |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 631 | kfree(spidev); |
| 632 | |
| 633 | return status; |
| 634 | } |
| 635 | |
Grant Likely | fd4a319 | 2012-12-07 16:57:14 +0000 | [diff] [blame] | 636 | static int spidev_remove(struct spi_device *spi) |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 637 | { |
David Brownell | b2c8dad | 2008-06-05 22:45:50 -0700 | [diff] [blame] | 638 | struct spidev_data *spidev = spi_get_drvdata(spi); |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 639 | |
David Brownell | 25d5cb4 | 2008-05-23 13:05:03 -0700 | [diff] [blame] | 640 | /* make sure ops on existing fds can abort cleanly */ |
| 641 | spin_lock_irq(&spidev->spi_lock); |
| 642 | spidev->spi = NULL; |
| 643 | spin_unlock_irq(&spidev->spi_lock); |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 644 | |
David Brownell | 25d5cb4 | 2008-05-23 13:05:03 -0700 | [diff] [blame] | 645 | /* prevent new opens */ |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 646 | mutex_lock(&device_list_lock); |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 647 | list_del(&spidev->device_entry); |
David Brownell | b2c8dad | 2008-06-05 22:45:50 -0700 | [diff] [blame] | 648 | device_destroy(spidev_class, spidev->devt); |
| 649 | clear_bit(MINOR(spidev->devt), minors); |
| 650 | if (spidev->users == 0) |
| 651 | kfree(spidev); |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 652 | mutex_unlock(&device_list_lock); |
| 653 | |
| 654 | return 0; |
| 655 | } |
| 656 | |
Maxime Ripard | 880cfd4 | 2012-10-31 11:30:08 +0100 | [diff] [blame] | 657 | static const struct of_device_id spidev_dt_ids[] = { |
Maxime Ripard | 8fad805 | 2012-10-31 11:30:09 +0100 | [diff] [blame] | 658 | { .compatible = "rohm,dh2228fv" }, |
Maxime Ripard | 880cfd4 | 2012-10-31 11:30:08 +0100 | [diff] [blame] | 659 | {}, |
| 660 | }; |
| 661 | |
| 662 | MODULE_DEVICE_TABLE(of, spidev_dt_ids); |
| 663 | |
Mike Frysinger | db389b6 | 2009-12-14 14:20:22 -0800 | [diff] [blame] | 664 | static struct spi_driver spidev_spi_driver = { |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 665 | .driver = { |
| 666 | .name = "spidev", |
| 667 | .owner = THIS_MODULE, |
Maxime Ripard | 880cfd4 | 2012-10-31 11:30:08 +0100 | [diff] [blame] | 668 | .of_match_table = of_match_ptr(spidev_dt_ids), |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 669 | }, |
| 670 | .probe = spidev_probe, |
Grant Likely | fd4a319 | 2012-12-07 16:57:14 +0000 | [diff] [blame] | 671 | .remove = spidev_remove, |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 672 | |
| 673 | /* NOTE: suspend/resume methods are not necessary here. |
| 674 | * We don't do anything except pass the requests to/from |
| 675 | * the underlying controller. The refrigerator handles |
| 676 | * most issues; the controller driver handles the rest. |
| 677 | */ |
| 678 | }; |
| 679 | |
| 680 | /*-------------------------------------------------------------------------*/ |
| 681 | |
| 682 | static int __init spidev_init(void) |
| 683 | { |
| 684 | int status; |
| 685 | |
| 686 | /* Claim our 256 reserved device numbers. Then register a class |
| 687 | * that will key udev/mdev to add/remove /dev nodes. Last, register |
| 688 | * the driver which manages those device numbers. |
| 689 | */ |
| 690 | BUILD_BUG_ON(N_SPI_MINORS > 256); |
| 691 | status = register_chrdev(SPIDEV_MAJOR, "spi", &spidev_fops); |
| 692 | if (status < 0) |
| 693 | return status; |
| 694 | |
David Brownell | b2c8dad | 2008-06-05 22:45:50 -0700 | [diff] [blame] | 695 | spidev_class = class_create(THIS_MODULE, "spidev"); |
| 696 | if (IS_ERR(spidev_class)) { |
Mike Frysinger | db389b6 | 2009-12-14 14:20:22 -0800 | [diff] [blame] | 697 | unregister_chrdev(SPIDEV_MAJOR, spidev_spi_driver.driver.name); |
David Brownell | b2c8dad | 2008-06-05 22:45:50 -0700 | [diff] [blame] | 698 | return PTR_ERR(spidev_class); |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 699 | } |
| 700 | |
Mike Frysinger | db389b6 | 2009-12-14 14:20:22 -0800 | [diff] [blame] | 701 | status = spi_register_driver(&spidev_spi_driver); |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 702 | if (status < 0) { |
David Brownell | b2c8dad | 2008-06-05 22:45:50 -0700 | [diff] [blame] | 703 | class_destroy(spidev_class); |
Mike Frysinger | db389b6 | 2009-12-14 14:20:22 -0800 | [diff] [blame] | 704 | unregister_chrdev(SPIDEV_MAJOR, spidev_spi_driver.driver.name); |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 705 | } |
| 706 | return status; |
| 707 | } |
| 708 | module_init(spidev_init); |
| 709 | |
| 710 | static void __exit spidev_exit(void) |
| 711 | { |
Mike Frysinger | db389b6 | 2009-12-14 14:20:22 -0800 | [diff] [blame] | 712 | spi_unregister_driver(&spidev_spi_driver); |
David Brownell | b2c8dad | 2008-06-05 22:45:50 -0700 | [diff] [blame] | 713 | class_destroy(spidev_class); |
Mike Frysinger | db389b6 | 2009-12-14 14:20:22 -0800 | [diff] [blame] | 714 | unregister_chrdev(SPIDEV_MAJOR, spidev_spi_driver.driver.name); |
Andrea Paterniani | 814a8d5 | 2007-05-08 00:32:15 -0700 | [diff] [blame] | 715 | } |
| 716 | module_exit(spidev_exit); |
| 717 | |
| 718 | MODULE_AUTHOR("Andrea Paterniani, <a.paterniani@swapp-eng.it>"); |
| 719 | MODULE_DESCRIPTION("User mode SPI device interface"); |
| 720 | MODULE_LICENSE("GPL"); |
Anton Vorontsov | e0626e3 | 2009-09-22 16:46:08 -0700 | [diff] [blame] | 721 | MODULE_ALIAS("spi:spidev"); |