drivers/iio/accel/bma220_spi.c

   1 /**
   2  * BMA220 Digital triaxial acceleration sensor driver
   3  *
   4  * Copyright (c) 2016, Intel Corporation.
   5  *
   6  * This file is subject to the terms and conditions of version 2 of
   7  * the GNU General Public License. See the file COPYING in the main
   8  * directory of this archive for more details.
   9  */
  10
  11 #include <linux/acpi.h>
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/iio/buffer.h>
  15 #include <linux/iio/iio.h>
  16 #include <linux/iio/sysfs.h>
  17 #include <linux/spi/spi.h>
  18 #include <linux/iio/trigger_consumer.h>
  19 #include <linux/iio/triggered_buffer.h>
  20
  21 #define BMA220_REG_ID                           0x00
  22 #define BMA220_REG_ACCEL_X                      0x02
  23 #define BMA220_REG_ACCEL_Y                      0x03
  24 #define BMA220_REG_ACCEL_Z                      0x04
  25 #define BMA220_REG_RANGE                        0x11
  26 #define BMA220_REG_SUSPEND                      0x18
  27
  28 #define BMA220_CHIP_ID                          0xDD
  29 #define BMA220_READ_MASK                        0x80
  30 #define BMA220_RANGE_MASK                       0x03
  31 #define BMA220_DATA_SHIFT                       2
  32 #define BMA220_SUSPEND_SLEEP                    0xFF
  33 #define BMA220_SUSPEND_WAKE                     0x00
  34
  35 #define BMA220_DEVICE_NAME                      "bma220"
  36 #define BMA220_SCALE_AVAILABLE                  "0.623 1.248 2.491 4.983"
  37
  38 #define BMA220_ACCEL_CHANNEL(index, reg, axis) {                        \
  39         .type = IIO_ACCEL,                                              \
  40         .address = reg,                                                 \
  41         .modified = 1,                                                  \
  42         .channel2 = IIO_MOD_##axis,                                     \
  43         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),                   \
  44         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),           \
  45         .scan_index = index,                                            \
  46         .scan_type = {                                                  \
  47                 .sign = 's',                                            \
  48                 .realbits = 6,                                          \
  49                 .storagebits = 8,                                       \
  50                 .shift = BMA220_DATA_SHIFT,                             \
  51                 .endianness = IIO_CPU,                                  \
  52         },                                                              \
  53 }
  54
  55 enum bma220_axis {
  56         AXIS_X,
  57         AXIS_Y,
  58         AXIS_Z,
  59 };
  60
  61 static IIO_CONST_ATTR(in_accel_scale_available, BMA220_SCALE_AVAILABLE);
  62
  63 static struct attribute *bma220_attributes[] = {
  64         &iio_const_attr_in_accel_scale_available.dev_attr.attr,
  65         NULL,
  66 };
  67
  68 static const struct attribute_group bma220_attribute_group = {
  69         .attrs = bma220_attributes,
  70 };
  71
  72 static const int bma220_scale_table[][4] = {
  73         {0, 623000}, {1, 248000}, {2, 491000}, {4, 983000}
  74 };
  75
  76 struct bma220_data {
  77         struct spi_device *spi_device;
  78         struct mutex lock;
  79         s8 buffer[16]; /* 3x8-bit channels + 5x8 padding + 8x8 timestamp */
  80         u8 tx_buf[2] ____cacheline_aligned;
  81 };
  82
  83 static const struct iio_chan_spec bma220_channels[] = {
  84         BMA220_ACCEL_CHANNEL(0, BMA220_REG_ACCEL_X, X),
  85         BMA220_ACCEL_CHANNEL(1, BMA220_REG_ACCEL_Y, Y),
  86         BMA220_ACCEL_CHANNEL(2, BMA220_REG_ACCEL_Z, Z),
  87         IIO_CHAN_SOFT_TIMESTAMP(3),
  88 };
  89
  90 static inline int bma220_read_reg(struct spi_device *spi, u8 reg)
  91 {
  92         return spi_w8r8(spi, reg | BMA220_READ_MASK);
  93 }
  94
  95 static const unsigned long bma220_accel_scan_masks[] = {
  96         BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
  97         0
  98 };
  99
 100 static irqreturn_t bma220_trigger_handler(int irq, void *p)
 101 {
 102         int ret;
 103         struct iio_poll_func *pf = p;
 104         struct iio_dev *indio_dev = pf->indio_dev;
 105         struct bma220_data *data = iio_priv(indio_dev);
 106         struct spi_device *spi = data->spi_device;
 107
 108         mutex_lock(&data->lock);
 109         data->tx_buf[0] = BMA220_REG_ACCEL_X | BMA220_READ_MASK;
 110         ret = spi_write_then_read(spi, data->tx_buf, 1, data->buffer,
 111                                   ARRAY_SIZE(bma220_channels) - 1);
 112         if (ret < 0)
 113                 goto err;
 114
 115         iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
 116                                            pf->timestamp);
 117 err:
 118         mutex_unlock(&data->lock);
 119         iio_trigger_notify_done(indio_dev->trig);
 120
 121         return IRQ_HANDLED;
 122 }
 123
 124 static int bma220_read_raw(struct iio_dev *indio_dev,
 125                            struct iio_chan_spec const *chan,
 126                            int *val, int *val2, long mask)
 127 {
 128         int ret;
 129         u8 range_idx;
 130         struct bma220_data *data = iio_priv(indio_dev);
 131
 132         switch (mask) {
 133         case IIO_CHAN_INFO_RAW:
 134                 ret = bma220_read_reg(data->spi_device, chan->address);
 135                 if (ret < 0)
 136                         return -EINVAL;
 137                 *val = sign_extend32(ret >> BMA220_DATA_SHIFT, 5);
 138                 return IIO_VAL_INT;
 139         case IIO_CHAN_INFO_SCALE:
 140                 ret = bma220_read_reg(data->spi_device, BMA220_REG_RANGE);
 141                 if (ret < 0)
 142                         return ret;
 143                 range_idx = ret & BMA220_RANGE_MASK;
 144                 *val = bma220_scale_table[range_idx][0];
 145                 *val2 = bma220_scale_table[range_idx][1];
 146                 return IIO_VAL_INT_PLUS_MICRO;
 147         }
 148
 149         return -EINVAL;
 150 }
 151
 152 static int bma220_write_raw(struct iio_dev *indio_dev,
 153                             struct iio_chan_spec const *chan,
 154                             int val, int val2, long mask)
 155 {
 156         int i;
 157         int ret;
 158         int index = -1;
 159         struct bma220_data *data = iio_priv(indio_dev);
 160
 161         switch (mask) {
 162         case IIO_CHAN_INFO_SCALE:
 163                 for (i = 0; i < ARRAY_SIZE(bma220_scale_table); i++)
 164                         if (val == bma220_scale_table[i][0] &&
 165                             val2 == bma220_scale_table[i][1]) {
 166                                 index = i;
 167                                 break;
 168                         }
 169                 if (index < 0)
 170                         return -EINVAL;
 171
 172                 mutex_lock(&data->lock);
 173                 data->tx_buf[0] = BMA220_REG_RANGE;
 174                 data->tx_buf[1] = index;
 175                 ret = spi_write(data->spi_device, data->tx_buf,
 176                                 sizeof(data->tx_buf));
 177                 if (ret < 0)
 178                         dev_err(&data->spi_device->dev,
 179                                 "failed to set measurement range\n");
 180                 mutex_unlock(&data->lock);
 181
 182                 return 0;
 183         }
 184
 185         return -EINVAL;
 186 }
 187
 188 static const struct iio_info bma220_info = {
 189         .read_raw               = bma220_read_raw,
 190         .write_raw              = bma220_write_raw,
 191         .attrs                  = &bma220_attribute_group,
 192 };
 193
 194 static int bma220_init(struct spi_device *spi)
 195 {
 196         int ret;
 197
 198         ret = bma220_read_reg(spi, BMA220_REG_ID);
 199         if (ret != BMA220_CHIP_ID)
 200                 return -ENODEV;
 201
 202         /* Make sure the chip is powered on */
 203         ret = bma220_read_reg(spi, BMA220_REG_SUSPEND);
 204         if (ret < 0)
 205                 return ret;
 206         else if (ret == BMA220_SUSPEND_WAKE)
 207                 return bma220_read_reg(spi, BMA220_REG_SUSPEND);
 208
 209         return 0;
 210 }
 211
 212 static int bma220_deinit(struct spi_device *spi)
 213 {
 214         int ret;
 215
 216         /* Make sure the chip is powered off */
 217         ret = bma220_read_reg(spi, BMA220_REG_SUSPEND);
 218         if (ret < 0)
 219                 return ret;
 220         else if (ret == BMA220_SUSPEND_SLEEP)
 221                 return bma220_read_reg(spi, BMA220_REG_SUSPEND);
 222
 223         return 0;
 224 }
 225
 226 static int bma220_probe(struct spi_device *spi)
 227 {
 228         int ret;
 229         struct iio_dev *indio_dev;
 230         struct bma220_data *data;
 231
 232         indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*data));
 233         if (!indio_dev) {
 234                 dev_err(&spi->dev, "iio allocation failed!\n");
 235                 return -ENOMEM;
 236         }
 237
 238         data = iio_priv(indio_dev);
 239         data->spi_device = spi;
 240         spi_set_drvdata(spi, indio_dev);
 241         mutex_init(&data->lock);
 242
 243         indio_dev->dev.parent = &spi->dev;
 244         indio_dev->info = &bma220_info;
 245         indio_dev->name = BMA220_DEVICE_NAME;
 246         indio_dev->modes = INDIO_DIRECT_MODE;
 247         indio_dev->channels = bma220_channels;
 248         indio_dev->num_channels = ARRAY_SIZE(bma220_channels);
 249         indio_dev->available_scan_masks = bma220_accel_scan_masks;
 250
 251         ret = bma220_init(data->spi_device);
 252         if (ret < 0)
 253                 return ret;
 254
 255         ret = iio_triggered_buffer_setup(indio_dev, iio_pollfunc_store_time,
 256                                          bma220_trigger_handler, NULL);
 257         if (ret < 0) {
 258                 dev_err(&spi->dev, "iio triggered buffer setup failed\n");
 259                 goto err_suspend;
 260         }
 261
 262         ret = iio_device_register(indio_dev);
 263         if (ret < 0) {
 264                 dev_err(&spi->dev, "iio_device_register failed\n");
 265                 iio_triggered_buffer_cleanup(indio_dev);
 266                 goto err_suspend;
 267         }
 268
 269         return 0;
 270
 271 err_suspend:
 272         return bma220_deinit(spi);
 273 }
 274
 275 static int bma220_remove(struct spi_device *spi)
 276 {
 277         struct iio_dev *indio_dev = spi_get_drvdata(spi);
 278
 279         iio_device_unregister(indio_dev);
 280         iio_triggered_buffer_cleanup(indio_dev);
 281
 282         return bma220_deinit(spi);
 283 }
 284
 285 #ifdef CONFIG_PM_SLEEP
 286 static int bma220_suspend(struct device *dev)
 287 {
 288         struct bma220_data *data =
 289                         iio_priv(spi_get_drvdata(to_spi_device(dev)));
 290
 291         /* The chip can be suspended/woken up by a simple register read. */
 292         return bma220_read_reg(data->spi_device, BMA220_REG_SUSPEND);
 293 }
 294
 295 static int bma220_resume(struct device *dev)
 296 {
 297         struct bma220_data *data =
 298                         iio_priv(spi_get_drvdata(to_spi_device(dev)));
 299
 300         return bma220_read_reg(data->spi_device, BMA220_REG_SUSPEND);
 301 }
 302
 303 static SIMPLE_DEV_PM_OPS(bma220_pm_ops, bma220_suspend, bma220_resume);
 304
 305 #define BMA220_PM_OPS (&bma220_pm_ops)
 306 #else
 307 #define BMA220_PM_OPS NULL
 308 #endif
 309
 310 static const struct spi_device_id bma220_spi_id[] = {
 311         {"bma220", 0},
 312         {}
 313 };
 314
 315 static const struct acpi_device_id bma220_acpi_id[] = {
 316         {"BMA0220", 0},
 317         {}
 318 };
 319
 320 MODULE_DEVICE_TABLE(spi, bma220_spi_id);
 321
 322 static struct spi_driver bma220_driver = {
 323         .driver = {
 324                 .name = "bma220_spi",
 325                 .pm = BMA220_PM_OPS,
 326                 .acpi_match_table = ACPI_PTR(bma220_acpi_id),
 327         },
 328         .probe =            bma220_probe,
 329         .remove =           bma220_remove,
 330         .id_table =         bma220_spi_id,
 331 };
 332
 333 module_spi_driver(bma220_driver);
 334
 335 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
 336 MODULE_DESCRIPTION("BMA220 acceleration sensor driver");
 337 MODULE_LICENSE("GPL v2");