drivers/iio/accel/bma220_spi.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * BMA220 Digital triaxial acceleration sensor driver
   4  *
   5  * Copyright (c) 2016,2020 Intel Corporation.
   6  */
   7
   8 #include <linux/bits.h>
   9 #include <linux/kernel.h>
  10 #include <linux/mod_devicetable.h>
  11 #include <linux/module.h>
  12 #include <linux/spi/spi.h>
  13
  14 #include <linux/iio/buffer.h>
  15 #include <linux/iio/iio.h>
  16 #include <linux/iio/sysfs.h>
  17 #include <linux/iio/trigger_consumer.h>
  18 #include <linux/iio/triggered_buffer.h>
  19
  20 #define BMA220_REG_ID                           0x00
  21 #define BMA220_REG_ACCEL_X                      0x02
  22 #define BMA220_REG_ACCEL_Y                      0x03
  23 #define BMA220_REG_ACCEL_Z                      0x04
  24 #define BMA220_REG_RANGE                        0x11
  25 #define BMA220_REG_SUSPEND                      0x18
  26
  27 #define BMA220_CHIP_ID                          0xDD
  28 #define BMA220_READ_MASK                        BIT(7)
  29 #define BMA220_RANGE_MASK                       GENMASK(1, 0)
  30 #define BMA220_SUSPEND_SLEEP                    0xFF
  31 #define BMA220_SUSPEND_WAKE                     0x00
  32
  33 #define BMA220_DEVICE_NAME                      "bma220"
  34
  35 #define BMA220_ACCEL_CHANNEL(index, reg, axis) {                        \
  36         .type = IIO_ACCEL,                                              \
  37         .address = reg,                                                 \
  38         .modified = 1,                                                  \
  39         .channel2 = IIO_MOD_##axis,                                     \
  40         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),                   \
  41         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),           \
  42         .scan_index = index,                                            \
  43         .scan_type = {                                                  \
  44                 .sign = 's',                                            \
  45                 .realbits = 6,                                          \
  46                 .storagebits = 8,                                       \
  47                 .shift = 2,                                             \
  48                 .endianness = IIO_CPU,                                  \
  49         },                                                              \
  50 }
  51
  52 enum bma220_axis {
  53         AXIS_X,
  54         AXIS_Y,
  55         AXIS_Z,
  56 };
  57
  58 static const int bma220_scale_table[][2] = {
  59         {0, 623000}, {1, 248000}, {2, 491000}, {4, 983000},
  60 };
  61
  62 struct bma220_data {
  63         struct spi_device *spi_device;
  64         struct mutex lock;
  65         struct {
  66                 s8 chans[3];
  67                 /* Ensure timestamp is naturally aligned. */
  68                 s64 timestamp __aligned(8);
  69         } scan;
  70         u8 tx_buf[2] __aligned(IIO_DMA_MINALIGN);
  71 };
  72
  73 static const struct iio_chan_spec bma220_channels[] = {
  74         BMA220_ACCEL_CHANNEL(0, BMA220_REG_ACCEL_X, X),
  75         BMA220_ACCEL_CHANNEL(1, BMA220_REG_ACCEL_Y, Y),
  76         BMA220_ACCEL_CHANNEL(2, BMA220_REG_ACCEL_Z, Z),
  77         IIO_CHAN_SOFT_TIMESTAMP(3),
  78 };
  79
  80 static inline int bma220_read_reg(struct spi_device *spi, u8 reg)
  81 {
  82         return spi_w8r8(spi, reg | BMA220_READ_MASK);
  83 }
  84
  85 static const unsigned long bma220_accel_scan_masks[] = {
  86         BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
  87         0
  88 };
  89
  90 static irqreturn_t bma220_trigger_handler(int irq, void *p)
  91 {
  92         int ret;
  93         struct iio_poll_func *pf = p;
  94         struct iio_dev *indio_dev = pf->indio_dev;
  95         struct bma220_data *data = iio_priv(indio_dev);
  96         struct spi_device *spi = data->spi_device;
  97
  98         mutex_lock(&data->lock);
  99         data->tx_buf[0] = BMA220_REG_ACCEL_X | BMA220_READ_MASK;
 100         ret = spi_write_then_read(spi, data->tx_buf, 1, &data->scan.chans,
 101                                   ARRAY_SIZE(bma220_channels) - 1);
 102         if (ret < 0)
 103                 goto err;
 104
 105         iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
 106                                            pf->timestamp);
 107 err:
 108         mutex_unlock(&data->lock);
 109         iio_trigger_notify_done(indio_dev->trig);
 110
 111         return IRQ_HANDLED;
 112 }
 113
 114 static int bma220_read_raw(struct iio_dev *indio_dev,
 115                            struct iio_chan_spec const *chan,
 116                            int *val, int *val2, long mask)
 117 {
 118         int ret;
 119         u8 range_idx;
 120         struct bma220_data *data = iio_priv(indio_dev);
 121
 122         switch (mask) {
 123         case IIO_CHAN_INFO_RAW:
 124                 ret = bma220_read_reg(data->spi_device, chan->address);
 125                 if (ret < 0)
 126                         return -EINVAL;
 127                 *val = sign_extend32(ret >> chan->scan_type.shift,
 128                                      chan->scan_type.realbits - 1);
 129                 return IIO_VAL_INT;
 130         case IIO_CHAN_INFO_SCALE:
 131                 ret = bma220_read_reg(data->spi_device, BMA220_REG_RANGE);
 132                 if (ret < 0)
 133                         return ret;
 134                 range_idx = ret & BMA220_RANGE_MASK;
 135                 *val = bma220_scale_table[range_idx][0];
 136                 *val2 = bma220_scale_table[range_idx][1];
 137                 return IIO_VAL_INT_PLUS_MICRO;
 138         }
 139
 140         return -EINVAL;
 141 }
 142
 143 static int bma220_write_raw(struct iio_dev *indio_dev,
 144                             struct iio_chan_spec const *chan,
 145                             int val, int val2, long mask)
 146 {
 147         int i;
 148         int ret;
 149         int index = -1;
 150         struct bma220_data *data = iio_priv(indio_dev);
 151
 152         switch (mask) {
 153         case IIO_CHAN_INFO_SCALE:
 154                 for (i = 0; i < ARRAY_SIZE(bma220_scale_table); i++)
 155                         if (val == bma220_scale_table[i][0] &&
 156                             val2 == bma220_scale_table[i][1]) {
 157                                 index = i;
 158                                 break;
 159                         }
 160                 if (index < 0)
 161                         return -EINVAL;
 162
 163                 mutex_lock(&data->lock);
 164                 data->tx_buf[0] = BMA220_REG_RANGE;
 165                 data->tx_buf[1] = index;
 166                 ret = spi_write(data->spi_device, data->tx_buf,
 167                                 sizeof(data->tx_buf));
 168                 if (ret < 0)
 169                         dev_err(&data->spi_device->dev,
 170                                 "failed to set measurement range\n");
 171                 mutex_unlock(&data->lock);
 172
 173                 return 0;
 174         }
 175
 176         return -EINVAL;
 177 }
 178
 179 static int bma220_read_avail(struct iio_dev *indio_dev,
 180                              struct iio_chan_spec const *chan,
 181                              const int **vals, int *type, int *length,
 182                              long mask)
 183 {
 184         switch (mask) {
 185         case IIO_CHAN_INFO_SCALE:
 186                 *vals = (int *)bma220_scale_table;
 187                 *type = IIO_VAL_INT_PLUS_MICRO;
 188                 *length = ARRAY_SIZE(bma220_scale_table) * 2;
 189                 return IIO_AVAIL_LIST;
 190         default:
 191                 return -EINVAL;
 192         }
 193 }
 194
 195 static const struct iio_info bma220_info = {
 196         .read_raw               = bma220_read_raw,
 197         .write_raw              = bma220_write_raw,
 198         .read_avail             = bma220_read_avail,
 199 };
 200
 201 static int bma220_init(struct spi_device *spi)
 202 {
 203         int ret;
 204
 205         ret = bma220_read_reg(spi, BMA220_REG_ID);
 206         if (ret != BMA220_CHIP_ID)
 207                 return -ENODEV;
 208
 209         /* Make sure the chip is powered on */
 210         ret = bma220_read_reg(spi, BMA220_REG_SUSPEND);
 211         if (ret == BMA220_SUSPEND_WAKE)
 212                 ret = bma220_read_reg(spi, BMA220_REG_SUSPEND);
 213         if (ret < 0)
 214                 return ret;
 215         if (ret == BMA220_SUSPEND_WAKE)
 216                 return -EBUSY;
 217
 218         return 0;
 219 }
 220
 221 static int bma220_power(struct spi_device *spi, bool up)
 222 {
 223         int i, ret;
 224
 225         /**
 226          * The chip can be suspended/woken up by a simple register read.
 227          * So, we need up to 2 register reads of the suspend register
 228          * to make sure that the device is in the desired state.
 229          */
 230         for (i = 0; i < 2; i++) {
 231                 ret = bma220_read_reg(spi, BMA220_REG_SUSPEND);
 232                 if (ret < 0)
 233                         return ret;
 234
 235                 if (up && ret == BMA220_SUSPEND_SLEEP)
 236                         return 0;
 237
 238                 if (!up && ret == BMA220_SUSPEND_WAKE)
 239                         return 0;
 240         }
 241
 242         return -EBUSY;
 243 }
 244
 245 static void bma220_deinit(void *spi)
 246 {
 247         bma220_power(spi, false);
 248 }
 249
 250 static int bma220_probe(struct spi_device *spi)
 251 {
 252         int ret;
 253         struct iio_dev *indio_dev;
 254         struct bma220_data *data;
 255
 256         indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*data));
 257         if (!indio_dev) {
 258                 dev_err(&spi->dev, "iio allocation failed!\n");
 259                 return -ENOMEM;
 260         }
 261
 262         data = iio_priv(indio_dev);
 263         data->spi_device = spi;
 264         mutex_init(&data->lock);
 265
 266         indio_dev->info = &bma220_info;
 267         indio_dev->name = BMA220_DEVICE_NAME;
 268         indio_dev->modes = INDIO_DIRECT_MODE;
 269         indio_dev->channels = bma220_channels;
 270         indio_dev->num_channels = ARRAY_SIZE(bma220_channels);
 271         indio_dev->available_scan_masks = bma220_accel_scan_masks;
 272
 273         ret = bma220_init(data->spi_device);
 274         if (ret)
 275                 return ret;
 276
 277         ret = devm_add_action_or_reset(&spi->dev, bma220_deinit, spi);
 278         if (ret)
 279                 return ret;
 280
 281         ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
 282                                               iio_pollfunc_store_time,
 283                                               bma220_trigger_handler, NULL);
 284         if (ret < 0) {
 285                 dev_err(&spi->dev, "iio triggered buffer setup failed\n");
 286                 return ret;
 287         }
 288
 289         return devm_iio_device_register(&spi->dev, indio_dev);
 290 }
 291
 292 static int bma220_suspend(struct device *dev)
 293 {
 294         struct spi_device *spi = to_spi_device(dev);
 295
 296         return bma220_power(spi, false);
 297 }
 298
 299 static int bma220_resume(struct device *dev)
 300 {
 301         struct spi_device *spi = to_spi_device(dev);
 302
 303         return bma220_power(spi, true);
 304 }
 305 static DEFINE_SIMPLE_DEV_PM_OPS(bma220_pm_ops, bma220_suspend, bma220_resume);
 306
 307 static const struct spi_device_id bma220_spi_id[] = {
 308         {"bma220", 0},
 309         {}
 310 };
 311
 312 static const struct acpi_device_id bma220_acpi_id[] = {
 313         {"BMA0220", 0},
 314         {}
 315 };
 316 MODULE_DEVICE_TABLE(spi, bma220_spi_id);
 317
 318 static struct spi_driver bma220_driver = {
 319         .driver = {
 320                 .name = "bma220_spi",
 321                 .pm = pm_sleep_ptr(&bma220_pm_ops),
 322                 .acpi_match_table = bma220_acpi_id,
 323         },
 324         .probe =            bma220_probe,
 325         .id_table =         bma220_spi_id,
 326 };
 327 module_spi_driver(bma220_driver);
 328
 329 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
 330 MODULE_DESCRIPTION("BMA220 acceleration sensor driver");
 331 MODULE_LICENSE("GPL v2");