drivers/iio/accel/mma7660.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Freescale MMA7660FC 3-Axis Accelerometer
   4  *
   5  * Copyright (c) 2016, Intel Corporation.
   6  *
   7  * IIO driver for Freescale MMA7660FC; 7-bit I2C address: 0x4c.
   8  */
   9
  10 #include <linux/i2c.h>
  11 #include <linux/mod_devicetable.h>
  12 #include <linux/module.h>
  13 #include <linux/iio/iio.h>
  14 #include <linux/iio/sysfs.h>
  15
  16 #define MMA7660_DRIVER_NAME     "mma7660"
  17
  18 #define MMA7660_REG_XOUT        0x00
  19 #define MMA7660_REG_YOUT        0x01
  20 #define MMA7660_REG_ZOUT        0x02
  21 #define MMA7660_REG_OUT_BIT_ALERT       BIT(6)
  22
  23 #define MMA7660_REG_MODE        0x07
  24 #define MMA7660_REG_MODE_BIT_MODE       BIT(0)
  25 #define MMA7660_REG_MODE_BIT_TON        BIT(2)
  26
  27 #define MMA7660_I2C_READ_RETRIES        5
  28
  29 /*
  30  * The accelerometer has one measurement range:
  31  *
  32  * -1.5g - +1.5g (6-bit, signed)
  33  *
  34  * scale = (1.5 + 1.5) * 9.81 / (2^6 - 1)       = 0.467142857
  35  */
  36
  37 #define MMA7660_SCALE_AVAIL     "0.467142857"
  38
  39 static const int mma7660_nscale = 467142857;
  40
  41 enum mma7660_mode {
  42         MMA7660_MODE_STANDBY,
  43         MMA7660_MODE_ACTIVE
  44 };
  45
  46 struct mma7660_data {
  47         struct i2c_client *client;
  48         struct mutex lock;
  49         enum mma7660_mode mode;
  50         struct iio_mount_matrix orientation;
  51 };
  52
  53 static const struct iio_mount_matrix *
  54 mma7660_get_mount_matrix(const struct iio_dev *indio_dev,
  55                         const struct iio_chan_spec *chan)
  56 {
  57         struct mma7660_data *data = iio_priv(indio_dev);
  58
  59         return &data->orientation;
  60 }
  61
  62 static const struct iio_chan_spec_ext_info mma7660_ext_info[] = {
  63         IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, mma7660_get_mount_matrix),
  64         { }
  65 };
  66
  67 static IIO_CONST_ATTR(in_accel_scale_available, MMA7660_SCALE_AVAIL);
  68
  69 static struct attribute *mma7660_attributes[] = {
  70         &iio_const_attr_in_accel_scale_available.dev_attr.attr,
  71         NULL,
  72 };
  73
  74 static const struct attribute_group mma7660_attribute_group = {
  75         .attrs = mma7660_attributes
  76 };
  77
  78 #define MMA7660_CHANNEL(reg, axis) {    \
  79         .type = IIO_ACCEL,      \
  80         .address = reg, \
  81         .modified = 1,  \
  82         .channel2 = IIO_MOD_##axis,     \
  83         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),   \
  84         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
  85         .ext_info = mma7660_ext_info,                           \
  86 }
  87
  88 static const struct iio_chan_spec mma7660_channels[] = {
  89         MMA7660_CHANNEL(MMA7660_REG_XOUT, X),
  90         MMA7660_CHANNEL(MMA7660_REG_YOUT, Y),
  91         MMA7660_CHANNEL(MMA7660_REG_ZOUT, Z),
  92 };
  93
  94 static int mma7660_set_mode(struct mma7660_data *data,
  95                                 enum mma7660_mode mode)
  96 {
  97         int ret;
  98         struct i2c_client *client = data->client;
  99
 100         if (mode == data->mode)
 101                 return 0;
 102
 103         ret = i2c_smbus_read_byte_data(client, MMA7660_REG_MODE);
 104         if (ret < 0) {
 105                 dev_err(&client->dev, "failed to read sensor mode\n");
 106                 return ret;
 107         }
 108
 109         if (mode == MMA7660_MODE_ACTIVE) {
 110                 ret &= ~MMA7660_REG_MODE_BIT_TON;
 111                 ret |= MMA7660_REG_MODE_BIT_MODE;
 112         } else {
 113                 ret &= ~MMA7660_REG_MODE_BIT_TON;
 114                 ret &= ~MMA7660_REG_MODE_BIT_MODE;
 115         }
 116
 117         ret = i2c_smbus_write_byte_data(client, MMA7660_REG_MODE, ret);
 118         if (ret < 0) {
 119                 dev_err(&client->dev, "failed to change sensor mode\n");
 120                 return ret;
 121         }
 122
 123         data->mode = mode;
 124
 125         return ret;
 126 }
 127
 128 static int mma7660_read_accel(struct mma7660_data *data, u8 address)
 129 {
 130         int ret, retries = MMA7660_I2C_READ_RETRIES;
 131         struct i2c_client *client = data->client;
 132
 133         /*
 134          * Read data. If the Alert bit is set, the register was read at
 135          * the same time as the device was attempting to update the content.
 136          * The solution is to read the register again. Do this only
 137          * MMA7660_I2C_READ_RETRIES times to avoid spending too much time
 138          * in the kernel.
 139          */
 140         do {
 141                 ret = i2c_smbus_read_byte_data(client, address);
 142                 if (ret < 0) {
 143                         dev_err(&client->dev, "register read failed\n");
 144                         return ret;
 145                 }
 146         } while (retries-- > 0 && ret & MMA7660_REG_OUT_BIT_ALERT);
 147
 148         if (ret & MMA7660_REG_OUT_BIT_ALERT) {
 149                 dev_err(&client->dev, "all register read retries failed\n");
 150                 return -ETIMEDOUT;
 151         }
 152
 153         return ret;
 154 }
 155
 156 static int mma7660_read_raw(struct iio_dev *indio_dev,
 157                                 struct iio_chan_spec const *chan,
 158                                 int *val, int *val2, long mask)
 159 {
 160         struct mma7660_data *data = iio_priv(indio_dev);
 161         int ret;
 162
 163         switch (mask) {
 164         case IIO_CHAN_INFO_RAW:
 165                 mutex_lock(&data->lock);
 166                 ret = mma7660_read_accel(data, chan->address);
 167                 mutex_unlock(&data->lock);
 168                 if (ret < 0)
 169                         return ret;
 170                 *val = sign_extend32(ret, 5);
 171                 return IIO_VAL_INT;
 172         case IIO_CHAN_INFO_SCALE:
 173                 *val = 0;
 174                 *val2 = mma7660_nscale;
 175                 return IIO_VAL_INT_PLUS_NANO;
 176         default:
 177                 return -EINVAL;
 178         }
 179
 180         return -EINVAL;
 181 }
 182
 183 static const struct iio_info mma7660_info = {
 184         .read_raw               = mma7660_read_raw,
 185         .attrs                  = &mma7660_attribute_group,
 186 };
 187
 188 static int mma7660_probe(struct i2c_client *client)
 189 {
 190         int ret;
 191         struct iio_dev *indio_dev;
 192         struct mma7660_data *data;
 193
 194         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 195         if (!indio_dev) {
 196                 dev_err(&client->dev, "iio allocation failed!\n");
 197                 return -ENOMEM;
 198         }
 199
 200         data = iio_priv(indio_dev);
 201         data->client = client;
 202         i2c_set_clientdata(client, indio_dev);
 203         mutex_init(&data->lock);
 204         data->mode = MMA7660_MODE_STANDBY;
 205
 206         ret = iio_read_mount_matrix(&client->dev, &data->orientation);
 207         if (ret)
 208                 return ret;
 209
 210         indio_dev->info = &mma7660_info;
 211         indio_dev->name = MMA7660_DRIVER_NAME;
 212         indio_dev->modes = INDIO_DIRECT_MODE;
 213         indio_dev->channels = mma7660_channels;
 214         indio_dev->num_channels = ARRAY_SIZE(mma7660_channels);
 215
 216         ret = mma7660_set_mode(data, MMA7660_MODE_ACTIVE);
 217         if (ret < 0)
 218                 return ret;
 219
 220         ret = iio_device_register(indio_dev);
 221         if (ret < 0) {
 222                 dev_err(&client->dev, "device_register failed\n");
 223                 mma7660_set_mode(data, MMA7660_MODE_STANDBY);
 224         }
 225
 226         return ret;
 227 }
 228
 229 static void mma7660_remove(struct i2c_client *client)
 230 {
 231         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 232         int ret;
 233
 234         iio_device_unregister(indio_dev);
 235
 236         ret = mma7660_set_mode(iio_priv(indio_dev), MMA7660_MODE_STANDBY);
 237         if (ret)
 238                 dev_warn(&client->dev, "Failed to put device in stand-by mode (%pe), ignoring\n",
 239                          ERR_PTR(ret));
 240 }
 241
 242 static int mma7660_suspend(struct device *dev)
 243 {
 244         struct mma7660_data *data;
 245
 246         data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
 247
 248         return mma7660_set_mode(data, MMA7660_MODE_STANDBY);
 249 }
 250
 251 static int mma7660_resume(struct device *dev)
 252 {
 253         struct mma7660_data *data;
 254
 255         data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
 256
 257         return mma7660_set_mode(data, MMA7660_MODE_ACTIVE);
 258 }
 259
 260 static DEFINE_SIMPLE_DEV_PM_OPS(mma7660_pm_ops, mma7660_suspend,
 261                                 mma7660_resume);
 262
 263 static const struct i2c_device_id mma7660_i2c_id[] = {
 264         { "mma7660" },
 265         {}
 266 };
 267 MODULE_DEVICE_TABLE(i2c, mma7660_i2c_id);
 268
 269 static const struct of_device_id mma7660_of_match[] = {
 270         { .compatible = "fsl,mma7660" },
 271         { }
 272 };
 273 MODULE_DEVICE_TABLE(of, mma7660_of_match);
 274
 275 static const struct acpi_device_id mma7660_acpi_id[] = {
 276         {"MMA7660", 0},
 277         {}
 278 };
 279
 280 MODULE_DEVICE_TABLE(acpi, mma7660_acpi_id);
 281
 282 static struct i2c_driver mma7660_driver = {
 283         .driver = {
 284                 .name = "mma7660",
 285                 .pm = pm_sleep_ptr(&mma7660_pm_ops),
 286                 .of_match_table = mma7660_of_match,
 287                 .acpi_match_table = mma7660_acpi_id,
 288         },
 289         .probe          = mma7660_probe,
 290         .remove         = mma7660_remove,
 291         .id_table       = mma7660_i2c_id,
 292 };
 293
 294 module_i2c_driver(mma7660_driver);
 295
 296 MODULE_AUTHOR("Constantin Musca <constantin.musca@intel.com>");
 297 MODULE_DESCRIPTION("Freescale MMA7660FC 3-Axis Accelerometer driver");
 298 MODULE_LICENSE("GPL v2");