Pileus Git - ~andy/linux/blob - 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  * @us:         spi device
  60  * @rx:         single rx buffer storage
  61  * @tx:         single tx buffer storage
  62  **/
  63 struct kxsd9_state {
  64         struct mutex buf_lock;
  65         struct spi_device *us;
  66         u8 rx[KXSD9_STATE_RX_SIZE] ____cacheline_aligned;
  67         u8 tx[KXSD9_STATE_TX_SIZE];
  68 };
  69
  70 /* This may want to move to mili g to allow for non integer ranges */
  71 static ssize_t kxsd9_read_scale(struct device *dev,
  72                                 struct device_attribute *attr,
  73                                 char *buf)
  74 {
  75         int ret;
  76         ssize_t len = 0;
  77         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  78         struct kxsd9_state *st = iio_priv(indio_dev);
  79         struct spi_transfer xfer = {
  80                 .bits_per_word = 8,
  81                 .len = 2,
  82                 .cs_change = 1,
  83                 .tx_buf = st->tx,
  84                 .rx_buf = st->rx,
  85         };
  86         struct spi_message msg;
  87
  88         mutex_lock(&st->buf_lock);
  89         st->tx[0] = KXSD9_READ(KXSD9_REG_CTRL_C);
  90         st->tx[1] = 0;
  91         spi_message_init(&msg);
  92         spi_message_add_tail(&xfer, &msg);
  93         ret = spi_sync(st->us, &msg);
  94         if (ret)
  95                 goto error_ret;
  96
  97         switch (st->rx[1] & KXSD9_FS_MASK) {
  98         case KXSD9_FS_8:
  99                 len += sprintf(buf, "%s\n", KXSD9_SCALE_8G);
 100                 break;
 101         case KXSD9_FS_6:
 102                 len += sprintf(buf, "%s\n", KXSD9_SCALE_6G);
 103                 break;
 104         case KXSD9_FS_4:
 105                 len += sprintf(buf, "%s\n", KXSD9_SCALE_4G);
 106                 break;
 107         case KXSD9_FS_2:
 108                 len += sprintf(buf, "%s\n", KXSD9_SCALE_2G);
 109                 break;
 110         }
 111
 112 error_ret:
 113         mutex_unlock(&st->buf_lock);
 114
 115         return ret ? ret : len;
 116 }
 117 static ssize_t kxsd9_write_scale(struct device *dev,
 118                                  struct device_attribute *attr,
 119                                  const char *buf,
 120                                  size_t len)
 121 {
 122
 123         struct spi_message msg;
 124         int ret;
 125         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 126         struct kxsd9_state *st = iio_priv(indio_dev);
 127         u8 val;
 128         struct spi_transfer xfers[] = {
 129                 {
 130                         .bits_per_word = 8,
 131                         .len = 2,
 132                         .cs_change = 1,
 133                         .tx_buf = st->tx,
 134                         .rx_buf = st->rx,
 135                 }, {
 136                         .bits_per_word = 8,
 137                         .len = 2,
 138                         .cs_change = 1,
 139                         .tx_buf = st->tx,
 140                 },
 141         };
 142
 143         if (!strncmp(buf, KXSD9_SCALE_8G,
 144                      strlen(buf) < strlen(KXSD9_SCALE_8G)
 145                      ? strlen(buf) : strlen(KXSD9_SCALE_8G)))
 146                 val = KXSD9_FS_8;
 147         else if (!strncmp(buf, KXSD9_SCALE_6G,
 148                           strlen(buf) < strlen(KXSD9_SCALE_6G)
 149                           ? strlen(buf) : strlen(KXSD9_SCALE_6G)))
 150                 val = KXSD9_FS_6;
 151         else if (!strncmp(buf, KXSD9_SCALE_4G,
 152                           strlen(buf) < strlen(KXSD9_SCALE_4G)
 153                           ? strlen(buf) : strlen(KXSD9_SCALE_4G)))
 154                 val = KXSD9_FS_4;
 155         else if (!strncmp(buf, KXSD9_SCALE_2G,
 156                           strlen(buf) < strlen(KXSD9_SCALE_2G)
 157                           ? strlen(buf) : strlen(KXSD9_SCALE_2G)))
 158                 val = KXSD9_FS_2;
 159         else
 160                 return -EINVAL;
 161
 162         mutex_lock(&st->buf_lock);
 163         st->tx[0] = KXSD9_READ(KXSD9_REG_CTRL_C);
 164         st->tx[1] = 0;
 165         spi_message_init(&msg);
 166         spi_message_add_tail(&xfers[0], &msg);
 167         ret = spi_sync(st->us, &msg);
 168         if (ret)
 169                 goto error_ret;
 170         st->tx[0] = KXSD9_WRITE(KXSD9_REG_CTRL_C);
 171         st->tx[1] = (st->rx[1] & ~KXSD9_FS_MASK) | val;
 172
 173         spi_message_init(&msg);
 174         spi_message_add_tail(&xfers[1], &msg);
 175         ret = spi_sync(st->us, &msg);
 176 error_ret:
 177         mutex_unlock(&st->buf_lock);
 178         return ret ? ret : len;
 179 }
 180
 181 static ssize_t kxsd9_read_accel(struct device *dev,
 182                                 struct device_attribute *attr,
 183                                 char *buf)
 184 {
 185         struct spi_message msg;
 186         int ret;
 187         ssize_t len = 0;
 188         u16 val;
 189         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 190         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 191         struct kxsd9_state *st = iio_priv(indio_dev);
 192         struct spi_transfer xfers[] = {
 193                 {
 194                         .bits_per_word = 8,
 195                         .len = 1,
 196                         .cs_change = 0,
 197                         .delay_usecs = 200,
 198                         .tx_buf = st->tx,
 199                 }, {
 200                         .bits_per_word = 8,
 201                         .len = 2,
 202                         .cs_change = 1,
 203                         .rx_buf = st->rx,
 204                 },
 205         };
 206
 207         mutex_lock(&st->buf_lock);
 208         st->tx[0] = KXSD9_READ(this_attr->address);
 209         spi_message_init(&msg);
 210         spi_message_add_tail(&xfers[0], &msg);
 211         spi_message_add_tail(&xfers[1], &msg);
 212         ret = spi_sync(st->us, &msg);
 213         if (ret)
 214                 goto error_ret;
 215         val = (((u16)(st->rx[0])) << 8) | (st->rx[1] & 0xF0);
 216         len = sprintf(buf, "%d\n", val);
 217 error_ret:
 218         mutex_unlock(&st->buf_lock);
 219
 220         return ret ? ret : len;
 221 }
 222
 223 static IIO_DEV_ATTR_ACCEL_X(kxsd9_read_accel, KXSD9_REG_X);
 224 static IIO_DEV_ATTR_ACCEL_Y(kxsd9_read_accel, KXSD9_REG_Y);
 225 static IIO_DEV_ATTR_ACCEL_Z(kxsd9_read_accel, KXSD9_REG_Z);
 226 static IIO_DEV_ATTR_IN_RAW(0, kxsd9_read_accel, KXSD9_REG_AUX);
 227
 228 static IIO_DEVICE_ATTR(accel_scale,
 229                 S_IRUGO | S_IWUSR,
 230                 kxsd9_read_scale,
 231                 kxsd9_write_scale,
 232                 0);
 233
 234 static IIO_CONST_ATTR(accel_scale_available,
 235                 KXSD9_SCALE_2G " "
 236                 KXSD9_SCALE_4G " "
 237                 KXSD9_SCALE_6G " "
 238                 KXSD9_SCALE_8G);
 239
 240 static struct attribute *kxsd9_attributes[] = {
 241         &iio_dev_attr_accel_x_raw.dev_attr.attr,
 242         &iio_dev_attr_accel_y_raw.dev_attr.attr,
 243         &iio_dev_attr_accel_z_raw.dev_attr.attr,
 244         &iio_dev_attr_in0_raw.dev_attr.attr,
 245         &iio_dev_attr_accel_scale.dev_attr.attr,
 246         &iio_const_attr_accel_scale_available.dev_attr.attr,
 247         NULL,
 248 };
 249
 250 static const struct attribute_group kxsd9_attribute_group = {
 251         .attrs = kxsd9_attributes,
 252 };
 253
 254 static int __devinit kxsd9_power_up(struct kxsd9_state *st)
 255 {
 256         struct spi_transfer xfers[2] = {
 257                 {
 258                         .bits_per_word = 8,
 259                         .len = 2,
 260                         .cs_change = 1,
 261                         .tx_buf = st->tx,
 262                 }, {
 263                         .bits_per_word = 8,
 264                         .len = 2,
 265                         .cs_change = 1,
 266                         .tx_buf = st->tx + 2,
 267                 },
 268         };
 269         struct spi_message msg;
 270         st->tx[0] = 0x0d;
 271         st->tx[1] = 0x40;
 272         st->tx[2] = 0x0c;
 273         st->tx[3] = 0x9b;
 274
 275         spi_message_init(&msg);
 276         spi_message_add_tail(&xfers[0], &msg);
 277         spi_message_add_tail(&xfers[1], &msg);
 278
 279         return spi_sync(st->us, &msg);
 280 };
 281
 282 static const struct iio_info kxsd9_info = {
 283         .attrs = &kxsd9_attribute_group,
 284         .driver_module = THIS_MODULE,
 285 };
 286
 287 static int __devinit kxsd9_probe(struct spi_device *spi)
 288 {
 289         struct iio_dev *indio_dev;
 290         struct kxsd9_state *st;
 291         int ret = 0;
 292
 293         indio_dev = iio_allocate_device(sizeof(*st));
 294         if (indio_dev == NULL) {
 295                 ret = -ENOMEM;
 296                 goto error_ret;
 297         }
 298         st = iio_priv(indio_dev);
 299         spi_set_drvdata(spi, indio_dev);
 300
 301         st->us = spi;
 302         mutex_init(&st->buf_lock);
 303
 304         indio_dev->dev.parent = &spi->dev;
 305         indio_dev->info = &kxsd9_info;
 306         indio_dev->modes = INDIO_DIRECT_MODE;
 307
 308         ret = iio_device_register(indio_dev);
 309         if (ret)
 310                 goto error_free_dev;
 311
 312         spi->mode = SPI_MODE_0;
 313         spi_setup(spi);
 314         kxsd9_power_up(st);
 315
 316         return 0;
 317
 318 error_free_dev:
 319         iio_free_device(indio_dev);
 320 error_ret:
 321         return ret;
 322 }
 323
 324 static int __devexit kxsd9_remove(struct spi_device *spi)
 325 {
 326         iio_device_unregister(spi_get_drvdata(spi));
 327
 328         return 0;
 329 }
 330
 331 static struct spi_driver kxsd9_driver = {
 332         .driver = {
 333                 .name = "kxsd9",
 334                 .owner = THIS_MODULE,
 335         },
 336         .probe = kxsd9_probe,
 337         .remove = __devexit_p(kxsd9_remove),
 338 };
 339
 340 static __init int kxsd9_spi_init(void)
 341 {
 342         return spi_register_driver(&kxsd9_driver);
 343 }
 344 module_init(kxsd9_spi_init);
 345
 346 static __exit void kxsd9_spi_exit(void)
 347 {
 348         spi_unregister_driver(&kxsd9_driver);
 349 }
 350 module_exit(kxsd9_spi_exit);
 351
 352 MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
 353 MODULE_DESCRIPTION("Kionix KXSD9 SPI driver");
 354 MODULE_LICENSE("GPL v2");