drivers/iio/light/al3010.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * AL3010 - Dyna Image Ambient Light Sensor
   4  *
   5  * Copyright (c) 2014, Intel Corporation.
   6  * Copyright (c) 2016, Dyna-Image Corp.
   7  * Copyright (c) 2020, David Heidelberg, Michał Mirosław, Dmitry Osipenko
   8  *
   9  * IIO driver for AL3010 (7-bit I2C slave address 0x1C).
  10  *
  11  * TODO: interrupt support, thresholds
  12  * When the driver will get support for interrupt handling, then interrupt
  13  * will need to be disabled before turning sensor OFF in order to avoid
  14  * potential races with the interrupt handling.
  15  */
  16
  17 #include <linux/bitfield.h>
  18 #include <linux/i2c.h>
  19 #include <linux/module.h>
  20 #include <linux/of.h>
  21
  22 #include <linux/iio/iio.h>
  23 #include <linux/iio/sysfs.h>
  24
  25 #define AL3010_DRV_NAME "al3010"
  26
  27 #define AL3010_REG_SYSTEM               0x00
  28 #define AL3010_REG_DATA_LOW             0x0c
  29 #define AL3010_REG_CONFIG               0x10
  30
  31 #define AL3010_CONFIG_DISABLE           0x00
  32 #define AL3010_CONFIG_ENABLE            0x01
  33
  34 #define AL3010_GAIN_MASK                GENMASK(6,4)
  35
  36 #define AL3010_SCALE_AVAILABLE "1.1872 0.2968 0.0742 0.018"
  37
  38 enum al3xxxx_range {
  39         AL3XXX_RANGE_1, /* 77806 lx */
  40         AL3XXX_RANGE_2, /* 19542 lx */
  41         AL3XXX_RANGE_3, /*  4863 lx */
  42         AL3XXX_RANGE_4  /*  1216 lx */
  43 };
  44
  45 static const int al3010_scales[][2] = {
  46         {0, 1187200}, {0, 296800}, {0, 74200}, {0, 18600}
  47 };
  48
  49 struct al3010_data {
  50         struct i2c_client *client;
  51 };
  52
  53 static const struct iio_chan_spec al3010_channels[] = {
  54         {
  55                 .type   = IIO_LIGHT,
  56                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
  57                                       BIT(IIO_CHAN_INFO_SCALE),
  58         }
  59 };
  60
  61 static IIO_CONST_ATTR(in_illuminance_scale_available, AL3010_SCALE_AVAILABLE);
  62
  63 static struct attribute *al3010_attributes[] = {
  64         &iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
  65         NULL,
  66 };
  67
  68 static const struct attribute_group al3010_attribute_group = {
  69         .attrs = al3010_attributes,
  70 };
  71
  72 static int al3010_set_pwr(struct i2c_client *client, bool pwr)
  73 {
  74         u8 val = pwr ? AL3010_CONFIG_ENABLE : AL3010_CONFIG_DISABLE;
  75         return i2c_smbus_write_byte_data(client, AL3010_REG_SYSTEM, val);
  76 }
  77
  78 static void al3010_set_pwr_off(void *_data)
  79 {
  80         struct al3010_data *data = _data;
  81
  82         al3010_set_pwr(data->client, false);
  83 }
  84
  85 static int al3010_init(struct al3010_data *data)
  86 {
  87         int ret;
  88
  89         ret = al3010_set_pwr(data->client, true);
  90
  91         if (ret < 0)
  92                 return ret;
  93
  94         ret = i2c_smbus_write_byte_data(data->client, AL3010_REG_CONFIG,
  95                                         FIELD_PREP(AL3010_GAIN_MASK,
  96                                                    AL3XXX_RANGE_3));
  97         if (ret < 0)
  98                 return ret;
  99
 100         return 0;
 101 }
 102
 103 static int al3010_read_raw(struct iio_dev *indio_dev,
 104                            struct iio_chan_spec const *chan, int *val,
 105                            int *val2, long mask)
 106 {
 107         struct al3010_data *data = iio_priv(indio_dev);
 108         int ret;
 109
 110         switch (mask) {
 111         case IIO_CHAN_INFO_RAW:
 112                 /*
 113                  * ALS ADC value is stored in two adjacent registers:
 114                  * - low byte of output is stored at AL3010_REG_DATA_LOW
 115                  * - high byte of output is stored at AL3010_REG_DATA_LOW + 1
 116                  */
 117                 ret = i2c_smbus_read_word_data(data->client,
 118                                                AL3010_REG_DATA_LOW);
 119                 if (ret < 0)
 120                         return ret;
 121                 *val = ret;
 122                 return IIO_VAL_INT;
 123         case IIO_CHAN_INFO_SCALE:
 124                 ret = i2c_smbus_read_byte_data(data->client,
 125                                                AL3010_REG_CONFIG);
 126                 if (ret < 0)
 127                         return ret;
 128
 129                 ret = FIELD_GET(AL3010_GAIN_MASK, ret);
 130                 *val = al3010_scales[ret][0];
 131                 *val2 = al3010_scales[ret][1];
 132
 133                 return IIO_VAL_INT_PLUS_MICRO;
 134         }
 135         return -EINVAL;
 136 }
 137
 138 static int al3010_write_raw(struct iio_dev *indio_dev,
 139                             struct iio_chan_spec const *chan, int val,
 140                             int val2, long mask)
 141 {
 142         struct al3010_data *data = iio_priv(indio_dev);
 143         int i;
 144
 145         switch (mask) {
 146         case IIO_CHAN_INFO_SCALE:
 147                 for (i = 0; i < ARRAY_SIZE(al3010_scales); i++) {
 148                         if (val != al3010_scales[i][0] ||
 149                             val2 != al3010_scales[i][1])
 150                                 continue;
 151
 152                         return i2c_smbus_write_byte_data(data->client,
 153                                         AL3010_REG_CONFIG,
 154                                         FIELD_PREP(AL3010_GAIN_MASK, i));
 155                 }
 156                 break;
 157         }
 158         return -EINVAL;
 159 }
 160
 161 static const struct iio_info al3010_info = {
 162         .read_raw       = al3010_read_raw,
 163         .write_raw      = al3010_write_raw,
 164         .attrs          = &al3010_attribute_group,
 165 };
 166
 167 static int al3010_probe(struct i2c_client *client,
 168                         const struct i2c_device_id *id)
 169 {
 170         struct al3010_data *data;
 171         struct iio_dev *indio_dev;
 172         int ret;
 173
 174         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 175         if (!indio_dev)
 176                 return -ENOMEM;
 177
 178         data = iio_priv(indio_dev);
 179         i2c_set_clientdata(client, indio_dev);
 180         data->client = client;
 181
 182         indio_dev->info = &al3010_info;
 183         indio_dev->name = AL3010_DRV_NAME;
 184         indio_dev->channels = al3010_channels;
 185         indio_dev->num_channels = ARRAY_SIZE(al3010_channels);
 186         indio_dev->modes = INDIO_DIRECT_MODE;
 187
 188         ret = al3010_init(data);
 189         if (ret < 0) {
 190                 dev_err(&client->dev, "al3010 chip init failed\n");
 191                 return ret;
 192         }
 193
 194         ret = devm_add_action_or_reset(&client->dev,
 195                                         al3010_set_pwr_off,
 196                                         data);
 197         if (ret < 0)
 198                 return ret;
 199
 200         return devm_iio_device_register(&client->dev, indio_dev);
 201 }
 202
 203 static int __maybe_unused al3010_suspend(struct device *dev)
 204 {
 205         return al3010_set_pwr(to_i2c_client(dev), false);
 206 }
 207
 208 static int __maybe_unused al3010_resume(struct device *dev)
 209 {
 210         return al3010_set_pwr(to_i2c_client(dev), true);
 211 }
 212
 213 static SIMPLE_DEV_PM_OPS(al3010_pm_ops, al3010_suspend, al3010_resume);
 214
 215 static const struct i2c_device_id al3010_id[] = {
 216         {"al3010", },
 217         {}
 218 };
 219 MODULE_DEVICE_TABLE(i2c, al3010_id);
 220
 221 static const struct of_device_id al3010_of_match[] = {
 222         { .compatible = "dynaimage,al3010", },
 223         {},
 224 };
 225 MODULE_DEVICE_TABLE(of, al3010_of_match);
 226
 227 static struct i2c_driver al3010_driver = {
 228         .driver = {
 229                 .name = AL3010_DRV_NAME,
 230                 .of_match_table = al3010_of_match,
 231                 .pm = &al3010_pm_ops,
 232         },
 233         .probe          = al3010_probe,
 234         .id_table       = al3010_id,
 235 };
 236 module_i2c_driver(al3010_driver);
 237
 238 MODULE_AUTHOR("Daniel Baluta <daniel.baluta@nxp.com>");
 239 MODULE_AUTHOR("David Heidelberg <david@ixit.cz>");
 240 MODULE_DESCRIPTION("AL3010 Ambient Light Sensor driver");
 241 MODULE_LICENSE("GPL v2");