drivers/staging/iio/accel/kxsd9.c

   1 /*
   2  * kxsd9.c      simple support for the Kionix KXSD9 3D
   3  *              accelerometer.
   4  *
   5  * Copyright (c) 2008-2009 Jonathan Cameron <jic23@cam.ac.uk>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * The i2c interface is very similar, so shouldn't be a problem once
  12  * I have a suitable wire made up.
  13  *
  14  * TODO:        Support the motion detector
  15  *              Uses register address incrementing so could have a
  16  *              heavily optimized ring buffer access function.
  17  */
  18
  19 #include <linux/device.h>
  20 #include <linux/kernel.h>
  21 #include <linux/spi/spi.h>
  22 #include <linux/sysfs.h>
  23 #include <linux/slab.h>
  24
  25 #include "../iio.h"
  26 #include "../sysfs.h"
  27 #include "../adc/adc.h"
  28 #include "accel.h"
  29
  30 #define KXSD9_REG_X             0x00
  31 #define KXSD9_REG_Y             0x02
  32 #define KXSD9_REG_Z             0x04
  33 #define KXSD9_REG_AUX           0x06
  34 #define KXSD9_REG_RESET         0x0a
  35 #define KXSD9_REG_CTRL_C        0x0c
  36
  37 #define KXSD9_FS_8              0x00
  38 #define KXSD9_FS_6              0x01
  39 #define KXSD9_FS_4              0x02
  40 #define KXSD9_FS_2              0x03
  41 #define KXSD9_FS_MASK           0x03
  42
  43 #define KXSD9_REG_CTRL_B        0x0d
  44 #define KXSD9_REG_CTRL_A        0x0e
  45
  46 #define KXSD9_READ(a) (0x80 | (a))
  47 #define KXSD9_WRITE(a) (a)
  48
  49 #define KXSD9_SCALE_2G "0.011978"
  50 #define KXSD9_SCALE_4G "0.023927"
  51 #define KXSD9_SCALE_6G "0.035934"
  52 #define KXSD9_SCALE_8G "0.047853"
  53
  54 #define KXSD9_STATE_RX_SIZE 2
  55 #define KXSD9_STATE_TX_SIZE 4
  56 /**
  57  * struct kxsd9_state - device related storage
  58  * @buf_lock:   protect the rx and tx buffers.
  59  * @indio_dev:  associated industrial IO device
  60  * @us:         spi device
  61  * @rx:         single rx buffer storage
  62  * @tx:         single tx buffer storage
  63  **/
  64 struct kxsd9_state {
  65         struct mutex buf_lock;
  66         struct iio_dev *indio_dev;
  67         struct spi_device *us;
  68         u8 *rx;
  69         u8 *tx;
  70 };
  71
  72 /* This may want to move to mili g to allow for non integer ranges */
  73 static ssize_t kxsd9_read_scale(struct device *dev,
  74                                 struct device_attribute *attr,
  75                                 char *buf)
  76 {
  77         int ret;
  78         ssize_t len = 0;
  79         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  80         struct kxsd9_state *st = indio_dev->dev_data;
  81         struct spi_transfer xfer = {
  82                 .bits_per_word = 8,
  83                 .len = 2,
  84                 .cs_change = 1,
  85                 .tx_buf = st->tx,
  86                 .rx_buf = st->rx,
  87         };
  88         struct spi_message msg;
  89
  90         mutex_lock(&st->buf_lock);
  91         st->tx[0] = KXSD9_READ(KXSD9_REG_CTRL_C);
  92         st->tx[1] = 0;
  93         spi_message_init(&msg);
  94         spi_message_add_tail(&xfer, &msg);
  95         ret = spi_sync(st->us, &msg);
  96         if (ret)
  97                 goto error_ret;
  98
  99         switch (st->rx[1] & KXSD9_FS_MASK) {
 100         case KXSD9_FS_8:
 101                 len += sprintf(buf, "%s\n", KXSD9_SCALE_8G);
 102                 break;
 103         case KXSD9_FS_6:
 104                 len += sprintf(buf, "%s\n", KXSD9_SCALE_6G);
 105                 break;
 106         case KXSD9_FS_4:
 107                 len += sprintf(buf, "%s\n", KXSD9_SCALE_4G);
 108                 break;
 109         case KXSD9_FS_2:
 110                 len += sprintf(buf, "%s\n", KXSD9_SCALE_2G);
 111                 break;
 112         }
 113
 114 error_ret:
 115         mutex_unlock(&st->buf_lock);
 116
 117         return ret ? ret : len;
 118 }
 119 static ssize_t kxsd9_write_scale(struct device *dev,
 120                                  struct device_attribute *attr,
 121                                  const char *buf,
 122                                  size_t len)
 123 {
 124
 125         struct spi_message msg;
 126         int ret;
 127         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 128         struct kxsd9_state *st = indio_dev->dev_data;
 129         u8 val;
 130         struct spi_transfer xfers[] = {
 131                 {
 132                         .bits_per_word = 8,
 133                         .len = 2,
 134                         .cs_change = 1,
 135                         .tx_buf = st->tx,
 136                         .rx_buf = st->rx,
 137                 }, {
 138                         .bits_per_word = 8,
 139                         .len = 2,
 140                         .cs_change = 1,
 141                         .tx_buf = st->tx,
 142                 },
 143         };
 144
 145         if (!strncmp(buf, KXSD9_SCALE_8G,
 146                      strlen(buf) < strlen(KXSD9_SCALE_8G)
 147                      ? strlen(buf) : strlen(KXSD9_SCALE_8G)))
 148                 val = KXSD9_FS_8;
 149         else if (!strncmp(buf, KXSD9_SCALE_6G,
 150                           strlen(buf) < strlen(KXSD9_SCALE_6G)
 151                           ? strlen(buf) : strlen(KXSD9_SCALE_6G)))
 152                 val = KXSD9_FS_6;
 153         else if (!strncmp(buf, KXSD9_SCALE_4G,
 154                           strlen(buf) < strlen(KXSD9_SCALE_4G)
 155                           ? strlen(buf) : strlen(KXSD9_SCALE_4G)))
 156                 val = KXSD9_FS_4;
 157         else if (!strncmp(buf, KXSD9_SCALE_2G,
 158                           strlen(buf) < strlen(KXSD9_SCALE_2G)
 159                           ? strlen(buf) : strlen(KXSD9_SCALE_2G)))
 160                 val = KXSD9_FS_2;
 161         else
 162                 return -EINVAL;
 163
 164         mutex_lock(&st->buf_lock);
 165         st->tx[0] = KXSD9_READ(KXSD9_REG_CTRL_C);
 166         st->tx[1] = 0;
 167         spi_message_init(&msg);
 168         spi_message_add_tail(&xfers[0], &msg);
 169         ret = spi_sync(st->us, &msg);
 170         if (ret)
 171                 goto error_ret;
 172         st->tx[0] = KXSD9_WRITE(KXSD9_REG_CTRL_C);
 173         st->tx[1] = (st->rx[1] & ~KXSD9_FS_MASK) | val;
 174
 175         spi_message_init(&msg);
 176         spi_message_add_tail(&xfers[1], &msg);
 177         ret = spi_sync(st->us, &msg);
 178 error_ret:
 179         mutex_unlock(&st->buf_lock);
 180         return ret ? ret : len;
 181 }
 182
 183 static ssize_t kxsd9_read_accel(struct device *dev,
 184                                 struct device_attribute *attr,
 185                                 char *buf)
 186 {
 187         struct spi_message msg;
 188         int ret;
 189         ssize_t len = 0;
 190         u16 val;
 191         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 192         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 193         struct kxsd9_state *st = indio_dev->dev_data;
 194         struct spi_transfer xfers[] = {
 195                 {
 196                         .bits_per_word = 8,
 197                         .len = 1,
 198                         .cs_change = 0,
 199                         .delay_usecs = 200,
 200                         .tx_buf = st->tx,
 201                 }, {
 202                         .bits_per_word = 8,
 203                         .len = 2,
 204                         .cs_change = 1,
 205                         .rx_buf = st->rx,
 206                 },
 207         };
 208
 209         mutex_lock(&st->buf_lock);
 210         st->tx[0] = KXSD9_READ(this_attr->address);
 211         spi_message_init(&msg);
 212         spi_message_add_tail(&xfers[0], &msg);
 213         spi_message_add_tail(&xfers[1], &msg);
 214         ret = spi_sync(st->us, &msg);
 215         if (ret)
 216                 goto error_ret;
 217         val = (((u16)(st->rx[0])) << 8) | (st->rx[1] & 0xF0);
 218         len = sprintf(buf, "%d\n", val);
 219 error_ret:
 220         mutex_unlock(&st->buf_lock);
 221
 222         return ret ? ret : len;
 223 }
 224
 225 static IIO_DEV_ATTR_ACCEL_X(kxsd9_read_accel, KXSD9_REG_X);
 226 static IIO_DEV_ATTR_ACCEL_Y(kxsd9_read_accel, KXSD9_REG_Y);
 227 static IIO_DEV_ATTR_ACCEL_Z(kxsd9_read_accel, KXSD9_REG_Z);
 228 static IIO_DEV_ATTR_IN_RAW(0, kxsd9_read_accel, KXSD9_REG_AUX);
 229
 230 static IIO_DEVICE_ATTR(accel_scale,
 231                 S_IRUGO | S_IWUSR,
 232                 kxsd9_read_scale,
 233                 kxsd9_write_scale,
 234                 0);
 235
 236 static IIO_CONST_ATTR(accel_scale_available,
 237                 KXSD9_SCALE_2G " "
 238                 KXSD9_SCALE_4G " "
 239                 KXSD9_SCALE_6G " "
 240                 KXSD9_SCALE_8G);
 241
 242 static struct attribute *kxsd9_attributes[] = {
 243         &iio_dev_attr_accel_x_raw.dev_attr.attr,
 244         &iio_dev_attr_accel_y_raw.dev_attr.attr,
 245         &iio_dev_attr_accel_z_raw.dev_attr.attr,
 246         &iio_dev_attr_in0_raw.dev_attr.attr,
 247         &iio_dev_attr_accel_scale.dev_attr.attr,
 248         &iio_const_attr_accel_scale_available.dev_attr.attr,
 249         NULL,
 250 };
 251
 252 static const struct attribute_group kxsd9_attribute_group = {
 253         .attrs = kxsd9_attributes,
 254 };
 255
 256 static int __devinit kxsd9_power_up(struct spi_device *spi)
 257 {
 258         int ret;
 259         struct spi_transfer xfers[2] = {
 260                 {
 261                         .bits_per_word = 8,
 262                         .len = 2,
 263                         .cs_change = 1,
 264                 }, {
 265                         .bits_per_word = 8,
 266                         .len = 2,
 267                         .cs_change = 1,
 268                 },
 269         };
 270         struct spi_message msg;
 271         u8 *tx2;
 272         u8 *tx = kmalloc(2, GFP_KERNEL);
 273
 274         if (tx == NULL) {
 275                 ret = -ENOMEM;
 276                 goto error_ret;
 277         }
 278         tx2 = kmalloc(2, GFP_KERNEL);
 279         if (tx2 == NULL) {
 280                 ret = -ENOMEM;
 281                 goto error_free_tx;
 282         }
 283         tx[0] = 0x0d;
 284         tx[1] = 0x40;
 285
 286         tx2[0] = 0x0c;
 287         tx2[1] = 0x9b;
 288
 289         xfers[0].tx_buf = tx;
 290         xfers[1].tx_buf = tx2;
 291         spi_message_init(&msg);
 292         spi_message_add_tail(&xfers[0], &msg);
 293         spi_message_add_tail(&xfers[1], &msg);
 294         ret = spi_sync(spi, &msg);
 295
 296         kfree(tx2);
 297 error_free_tx:
 298         kfree(tx);
 299 error_ret:
 300         return ret;
 301
 302 };
 303
 304 static const struct iio_info kxsd9_info = {
 305         .attrs = &kxsd9_attribute_group,
 306         .driver_module = THIS_MODULE,
 307 };
 308
 309 static int __devinit kxsd9_probe(struct spi_device *spi)
 310 {
 311
 312         struct kxsd9_state *st;
 313         int ret = 0;
 314
 315         st = kzalloc(sizeof(*st), GFP_KERNEL);
 316         if (st == NULL) {
 317                 ret = -ENOMEM;
 318                 goto error_ret;
 319         }
 320         spi_set_drvdata(spi, st);
 321
 322         st->rx = kmalloc(sizeof(*st->rx)*KXSD9_STATE_RX_SIZE,
 323                          GFP_KERNEL);
 324         if (st->rx == NULL) {
 325                 ret = -ENOMEM;
 326                 goto error_free_st;
 327         }
 328         st->tx = kmalloc(sizeof(*st->tx)*KXSD9_STATE_TX_SIZE,
 329                          GFP_KERNEL);
 330         if (st->tx == NULL) {
 331                 ret = -ENOMEM;
 332                 goto error_free_rx;
 333         }
 334
 335         st->us = spi;
 336         mutex_init(&st->buf_lock);
 337         st->indio_dev = iio_allocate_device(0);
 338         if (st->indio_dev == NULL) {
 339                 ret = -ENOMEM;
 340                 goto error_free_tx;
 341         }
 342         st->indio_dev->dev.parent = &spi->dev;
 343         st->indio_dev->info = &kxsd9_info;
 344         st->indio_dev->dev_data = (void *)(st);
 345         st->indio_dev->modes = INDIO_DIRECT_MODE;
 346
 347         ret = iio_device_register(st->indio_dev);
 348         if (ret)
 349                 goto error_free_dev;
 350
 351         spi->mode = SPI_MODE_0;
 352         spi_setup(spi);
 353         kxsd9_power_up(spi);
 354
 355         return 0;
 356
 357 error_free_dev:
 358         iio_free_device(st->indio_dev);
 359 error_free_tx:
 360         kfree(st->tx);
 361 error_free_rx:
 362         kfree(st->rx);
 363 error_free_st:
 364         kfree(st);
 365 error_ret:
 366         return ret;
 367 }
 368
 369 static int __devexit kxsd9_remove(struct spi_device *spi)
 370 {
 371         struct kxsd9_state *st = spi_get_drvdata(spi);
 372
 373         iio_device_unregister(st->indio_dev);
 374         kfree(st->tx);
 375         kfree(st->rx);
 376         kfree(st);
 377
 378         return 0;
 379 }
 380
 381 static struct spi_driver kxsd9_driver = {
 382         .driver = {
 383                 .name = "kxsd9",
 384                 .owner = THIS_MODULE,
 385         },
 386         .probe = kxsd9_probe,
 387         .remove = __devexit_p(kxsd9_remove),
 388 };
 389
 390 static __init int kxsd9_spi_init(void)
 391 {
 392         return spi_register_driver(&kxsd9_driver);
 393 }
 394 module_init(kxsd9_spi_init);
 395
 396 static __exit void kxsd9_spi_exit(void)
 397 {
 398         spi_unregister_driver(&kxsd9_driver);
 399 }
 400 module_exit(kxsd9_spi_exit);
 401
 402 MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
 403 MODULE_DESCRIPTION("Kionix KXSD9 SPI driver");
 404 MODULE_LICENSE("GPL v2");