drivers/iio/potentiometer/tpl0102.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * tpl0102.c - Support for Texas Instruments digital potentiometers
   4  *
   5  * Copyright (C) 2016, 2018
   6  * Author: Matt Ranostay <matt.ranostay@konsulko.com>
   7  *
   8  * TODO: enable/disable hi-z output control
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/i2c.h>
  13 #include <linux/regmap.h>
  14 #include <linux/iio/iio.h>
  15
  16 struct tpl0102_cfg {
  17         int wipers;
  18         int max_pos;
  19         int kohms;
  20 };
  21
  22 enum tpl0102_type {
  23         CAT5140_503,
  24         CAT5140_104,
  25         TPL0102_104,
  26         TPL0401_103,
  27 };
  28
  29 static const struct tpl0102_cfg tpl0102_cfg[] = {
  30         /* on-semiconductor parts */
  31         [CAT5140_503] = { .wipers = 1, .max_pos = 256, .kohms = 50, },
  32         [CAT5140_104] = { .wipers = 1, .max_pos = 256, .kohms = 100, },
  33         /* ti parts */
  34         [TPL0102_104] = { .wipers = 2, .max_pos = 256, .kohms = 100 },
  35         [TPL0401_103] = { .wipers = 1, .max_pos = 128, .kohms = 10, },
  36 };
  37
  38 struct tpl0102_data {
  39         struct regmap *regmap;
  40         unsigned long devid;
  41 };
  42
  43 static const struct regmap_config tpl0102_regmap_config = {
  44         .reg_bits = 8,
  45         .val_bits = 8,
  46 };
  47
  48 #define TPL0102_CHANNEL(ch) {                                   \
  49         .type = IIO_RESISTANCE,                                 \
  50         .indexed = 1,                                           \
  51         .output = 1,                                            \
  52         .channel = (ch),                                        \
  53         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
  54         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
  55 }
  56
  57 static const struct iio_chan_spec tpl0102_channels[] = {
  58         TPL0102_CHANNEL(0),
  59         TPL0102_CHANNEL(1),
  60 };
  61
  62 static int tpl0102_read_raw(struct iio_dev *indio_dev,
  63                             struct iio_chan_spec const *chan,
  64                             int *val, int *val2, long mask)
  65 {
  66         struct tpl0102_data *data = iio_priv(indio_dev);
  67
  68         switch (mask) {
  69         case IIO_CHAN_INFO_RAW: {
  70                 int ret = regmap_read(data->regmap, chan->channel, val);
  71
  72                 return ret ? ret : IIO_VAL_INT;
  73         }
  74         case IIO_CHAN_INFO_SCALE:
  75                 *val = 1000 * tpl0102_cfg[data->devid].kohms;
  76                 *val2 = tpl0102_cfg[data->devid].max_pos;
  77                 return IIO_VAL_FRACTIONAL;
  78         }
  79
  80         return -EINVAL;
  81 }
  82
  83 static int tpl0102_write_raw(struct iio_dev *indio_dev,
  84                              struct iio_chan_spec const *chan,
  85                              int val, int val2, long mask)
  86 {
  87         struct tpl0102_data *data = iio_priv(indio_dev);
  88
  89         if (mask != IIO_CHAN_INFO_RAW)
  90                 return -EINVAL;
  91
  92         if (val >= tpl0102_cfg[data->devid].max_pos || val < 0)
  93                 return -EINVAL;
  94
  95         return regmap_write(data->regmap, chan->channel, val);
  96 }
  97
  98 static const struct iio_info tpl0102_info = {
  99         .read_raw = tpl0102_read_raw,
 100         .write_raw = tpl0102_write_raw,
 101 };
 102
 103 static int tpl0102_probe(struct i2c_client *client,
 104                          const struct i2c_device_id *id)
 105 {
 106         struct device *dev = &client->dev;
 107         struct tpl0102_data *data;
 108         struct iio_dev *indio_dev;
 109
 110         indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
 111         if (!indio_dev)
 112                 return -ENOMEM;
 113         data = iio_priv(indio_dev);
 114         i2c_set_clientdata(client, indio_dev);
 115
 116         data->devid = id->driver_data;
 117         data->regmap = devm_regmap_init_i2c(client, &tpl0102_regmap_config);
 118         if (IS_ERR(data->regmap)) {
 119                 dev_err(dev, "regmap initialization failed\n");
 120                 return PTR_ERR(data->regmap);
 121         }
 122
 123         indio_dev->dev.parent = dev;
 124         indio_dev->info = &tpl0102_info;
 125         indio_dev->channels = tpl0102_channels;
 126         indio_dev->num_channels = tpl0102_cfg[data->devid].wipers;
 127         indio_dev->name = client->name;
 128
 129         return devm_iio_device_register(dev, indio_dev);
 130 }
 131
 132 static const struct i2c_device_id tpl0102_id[] = {
 133         { "cat5140-503", CAT5140_503 },
 134         { "cat5140-104", CAT5140_104 },
 135         { "tpl0102-104", TPL0102_104 },
 136         { "tpl0401-103", TPL0401_103 },
 137         {}
 138 };
 139 MODULE_DEVICE_TABLE(i2c, tpl0102_id);
 140
 141 static struct i2c_driver tpl0102_driver = {
 142         .driver = {
 143                 .name = "tpl0102",
 144         },
 145         .probe = tpl0102_probe,
 146         .id_table = tpl0102_id,
 147 };
 148
 149 module_i2c_driver(tpl0102_driver);
 150
 151 MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
 152 MODULE_DESCRIPTION("TPL0102 digital potentiometer");
 153 MODULE_LICENSE("GPL");