drivers/iio/accel/da280.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /**
   3  * IIO driver for the MiraMEMS DA280 3-axis accelerometer and
   4  * IIO driver for the MiraMEMS DA226 2-axis accelerometer
   5  *
   6  * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/i2c.h>
  11 #include <linux/acpi.h>
  12 #include <linux/iio/iio.h>
  13 #include <linux/iio/sysfs.h>
  14 #include <linux/byteorder/generic.h>
  15
  16 #define DA280_REG_CHIP_ID               0x01
  17 #define DA280_REG_ACC_X_LSB             0x02
  18 #define DA280_REG_ACC_Y_LSB             0x04
  19 #define DA280_REG_ACC_Z_LSB             0x06
  20 #define DA280_REG_MODE_BW               0x11
  21
  22 #define DA280_CHIP_ID                   0x13
  23 #define DA280_MODE_ENABLE               0x1e
  24 #define DA280_MODE_DISABLE              0x9e
  25
  26 enum da280_chipset { da226, da280 };
  27
  28 /*
  29  * a value of + or -4096 corresponds to + or - 1G
  30  * scale = 9.81 / 4096 = 0.002395019
  31  */
  32
  33 static const int da280_nscale = 2395019;
  34
  35 #define DA280_CHANNEL(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 }
  43
  44 static const struct iio_chan_spec da280_channels[] = {
  45         DA280_CHANNEL(DA280_REG_ACC_X_LSB, X),
  46         DA280_CHANNEL(DA280_REG_ACC_Y_LSB, Y),
  47         DA280_CHANNEL(DA280_REG_ACC_Z_LSB, Z),
  48 };
  49
  50 struct da280_data {
  51         struct i2c_client *client;
  52 };
  53
  54 static int da280_enable(struct i2c_client *client, bool enable)
  55 {
  56         u8 data = enable ? DA280_MODE_ENABLE : DA280_MODE_DISABLE;
  57
  58         return i2c_smbus_write_byte_data(client, DA280_REG_MODE_BW, data);
  59 }
  60
  61 static int da280_read_raw(struct iio_dev *indio_dev,
  62                                 struct iio_chan_spec const *chan,
  63                                 int *val, int *val2, long mask)
  64 {
  65         struct da280_data *data = iio_priv(indio_dev);
  66         int ret;
  67
  68         switch (mask) {
  69         case IIO_CHAN_INFO_RAW:
  70                 ret = i2c_smbus_read_word_data(data->client, chan->address);
  71                 if (ret < 0)
  72                         return ret;
  73                 /*
  74                  * Values are 14 bits, stored as 16 bits with the 2
  75                  * least significant bits always 0.
  76                  */
  77                 *val = (short)ret >> 2;
  78                 return IIO_VAL_INT;
  79         case IIO_CHAN_INFO_SCALE:
  80                 *val = 0;
  81                 *val2 = da280_nscale;
  82                 return IIO_VAL_INT_PLUS_NANO;
  83         default:
  84                 return -EINVAL;
  85         }
  86 }
  87
  88 static const struct iio_info da280_info = {
  89         .read_raw       = da280_read_raw,
  90 };
  91
  92 static enum da280_chipset da280_match_acpi_device(struct device *dev)
  93 {
  94         const struct acpi_device_id *id;
  95
  96         id = acpi_match_device(dev->driver->acpi_match_table, dev);
  97         if (!id)
  98                 return -EINVAL;
  99
 100         return (enum da280_chipset) id->driver_data;
 101 }
 102
 103 static int da280_probe(struct i2c_client *client,
 104                         const struct i2c_device_id *id)
 105 {
 106         int ret;
 107         struct iio_dev *indio_dev;
 108         struct da280_data *data;
 109         enum da280_chipset chip;
 110
 111         ret = i2c_smbus_read_byte_data(client, DA280_REG_CHIP_ID);
 112         if (ret != DA280_CHIP_ID)
 113                 return (ret < 0) ? ret : -ENODEV;
 114
 115         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 116         if (!indio_dev)
 117                 return -ENOMEM;
 118
 119         data = iio_priv(indio_dev);
 120         data->client = client;
 121         i2c_set_clientdata(client, indio_dev);
 122
 123         indio_dev->dev.parent = &client->dev;
 124         indio_dev->info = &da280_info;
 125         indio_dev->modes = INDIO_DIRECT_MODE;
 126         indio_dev->channels = da280_channels;
 127
 128         if (ACPI_HANDLE(&client->dev)) {
 129                 chip = da280_match_acpi_device(&client->dev);
 130         } else {
 131                 chip = id->driver_data;
 132         }
 133
 134         if (chip == da226) {
 135                 indio_dev->name = "da226";
 136                 indio_dev->num_channels = 2;
 137         } else {
 138                 indio_dev->name = "da280";
 139                 indio_dev->num_channels = 3;
 140         }
 141
 142         ret = da280_enable(client, true);
 143         if (ret < 0)
 144                 return ret;
 145
 146         ret = iio_device_register(indio_dev);
 147         if (ret < 0) {
 148                 dev_err(&client->dev, "device_register failed\n");
 149                 da280_enable(client, false);
 150         }
 151
 152         return ret;
 153 }
 154
 155 static int da280_remove(struct i2c_client *client)
 156 {
 157         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 158
 159         iio_device_unregister(indio_dev);
 160
 161         return da280_enable(client, false);
 162 }
 163
 164 #ifdef CONFIG_PM_SLEEP
 165 static int da280_suspend(struct device *dev)
 166 {
 167         return da280_enable(to_i2c_client(dev), false);
 168 }
 169
 170 static int da280_resume(struct device *dev)
 171 {
 172         return da280_enable(to_i2c_client(dev), true);
 173 }
 174 #endif
 175
 176 static SIMPLE_DEV_PM_OPS(da280_pm_ops, da280_suspend, da280_resume);
 177
 178 static const struct acpi_device_id da280_acpi_match[] = {
 179         {"MIRAACC", da280},
 180         {},
 181 };
 182 MODULE_DEVICE_TABLE(acpi, da280_acpi_match);
 183
 184 static const struct i2c_device_id da280_i2c_id[] = {
 185         { "da226", da226 },
 186         { "da280", da280 },
 187         {}
 188 };
 189 MODULE_DEVICE_TABLE(i2c, da280_i2c_id);
 190
 191 static struct i2c_driver da280_driver = {
 192         .driver = {
 193                 .name = "da280",
 194                 .acpi_match_table = ACPI_PTR(da280_acpi_match),
 195                 .pm = &da280_pm_ops,
 196         },
 197         .probe          = da280_probe,
 198         .remove         = da280_remove,
 199         .id_table       = da280_i2c_id,
 200 };
 201
 202 module_i2c_driver(da280_driver);
 203
 204 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
 205 MODULE_DESCRIPTION("MiraMEMS DA280 3-Axis Accelerometer driver");
 206 MODULE_LICENSE("GPL v2");