drivers/iio/adc/mp2629_adc.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * MP2629 Driver for ADC
   4  *
   5  * Copyright 2020 Monolithic Power Systems, Inc
   6  *
   7  * Author: Saravanan Sekar <sravanhome@gmail.com>
   8  */
   9
  10 #include <linux/iio/driver.h>
  11 #include <linux/iio/iio.h>
  12 #include <linux/iio/machine.h>
  13 #include <linux/mfd/mp2629.h>
  14 #include <linux/module.h>
  15 #include <linux/mutex.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/regmap.h>
  18
  19 #define MP2629_REG_ADC_CTRL             0x03
  20 #define MP2629_REG_BATT_VOLT            0x0e
  21 #define MP2629_REG_SYSTEM_VOLT          0x0f
  22 #define MP2629_REG_INPUT_VOLT           0x11
  23 #define MP2629_REG_BATT_CURRENT         0x12
  24 #define MP2629_REG_INPUT_CURRENT        0x13
  25
  26 #define MP2629_ADC_START                BIT(7)
  27 #define MP2629_ADC_CONTINUOUS           BIT(6)
  28
  29 #define MP2629_MAP(_mp, _mpc) IIO_MAP(#_mp, "mp2629_charger", "mp2629-"_mpc)
  30
  31 #define MP2629_ADC_CHAN(_ch, _type) {                           \
  32         .type = _type,                                          \
  33         .indexed = 1,                                           \
  34         .datasheet_name = #_ch,                                 \
  35         .channel = MP2629_ ## _ch,                              \
  36         .address = MP2629_REG_ ## _ch,                          \
  37         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
  38         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
  39 }
  40
  41 struct mp2629_adc {
  42         struct regmap *regmap;
  43         struct device *dev;
  44 };
  45
  46 static struct iio_chan_spec mp2629_channels[] = {
  47         MP2629_ADC_CHAN(BATT_VOLT, IIO_VOLTAGE),
  48         MP2629_ADC_CHAN(SYSTEM_VOLT, IIO_VOLTAGE),
  49         MP2629_ADC_CHAN(INPUT_VOLT, IIO_VOLTAGE),
  50         MP2629_ADC_CHAN(BATT_CURRENT, IIO_CURRENT),
  51         MP2629_ADC_CHAN(INPUT_CURRENT, IIO_CURRENT)
  52 };
  53
  54 static struct iio_map mp2629_adc_maps[] = {
  55         MP2629_MAP(BATT_VOLT, "batt-volt"),
  56         MP2629_MAP(SYSTEM_VOLT, "system-volt"),
  57         MP2629_MAP(INPUT_VOLT, "input-volt"),
  58         MP2629_MAP(BATT_CURRENT, "batt-current"),
  59         MP2629_MAP(INPUT_CURRENT, "input-current")
  60 };
  61
  62 static int mp2629_read_raw(struct iio_dev *indio_dev,
  63                         struct iio_chan_spec const *chan,
  64                         int *val, int *val2, long mask)
  65 {
  66         struct mp2629_adc *info = iio_priv(indio_dev);
  67         unsigned int rval;
  68         int ret;
  69
  70         switch (mask) {
  71         case IIO_CHAN_INFO_RAW:
  72                 ret = regmap_read(info->regmap, chan->address, &rval);
  73                 if (ret)
  74                         return ret;
  75
  76                 if (chan->address == MP2629_INPUT_VOLT)
  77                         rval &= GENMASK(6, 0);
  78                 *val = rval;
  79                 return IIO_VAL_INT;
  80
  81         case IIO_CHAN_INFO_SCALE:
  82                 switch (chan->channel) {
  83                 case MP2629_BATT_VOLT:
  84                 case MP2629_SYSTEM_VOLT:
  85                         *val = 20;
  86                         return IIO_VAL_INT;
  87
  88                 case MP2629_INPUT_VOLT:
  89                         *val = 60;
  90                         return IIO_VAL_INT;
  91
  92                 case MP2629_BATT_CURRENT:
  93                         *val = 175;
  94                         *val2 = 10;
  95                         return IIO_VAL_FRACTIONAL;
  96
  97                 case MP2629_INPUT_CURRENT:
  98                         *val = 133;
  99                         *val2 = 10;
 100                         return IIO_VAL_FRACTIONAL;
 101
 102                 default:
 103                         return -EINVAL;
 104                 }
 105
 106         default:
 107                 return -EINVAL;
 108         }
 109 }
 110
 111 static const struct iio_info mp2629_adc_info = {
 112         .read_raw = &mp2629_read_raw,
 113 };
 114
 115 static int mp2629_adc_probe(struct platform_device *pdev)
 116 {
 117         struct device *dev = &pdev->dev;
 118         struct mp2629_data *ddata = dev_get_drvdata(dev->parent);
 119         struct mp2629_adc *info;
 120         struct iio_dev *indio_dev;
 121         int ret;
 122
 123         indio_dev = devm_iio_device_alloc(dev, sizeof(*info));
 124         if (!indio_dev)
 125                 return -ENOMEM;
 126
 127         info = iio_priv(indio_dev);
 128         info->regmap = ddata->regmap;
 129         info->dev = dev;
 130         platform_set_drvdata(pdev, indio_dev);
 131
 132         ret = regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
 133                                 MP2629_ADC_START | MP2629_ADC_CONTINUOUS,
 134                                 MP2629_ADC_START | MP2629_ADC_CONTINUOUS);
 135         if (ret) {
 136                 dev_err(dev, "adc enable fail: %d\n", ret);
 137                 return ret;
 138         }
 139
 140         ret = iio_map_array_register(indio_dev, mp2629_adc_maps);
 141         if (ret) {
 142                 dev_err(dev, "IIO maps register fail: %d\n", ret);
 143                 goto fail_disable;
 144         }
 145
 146         indio_dev->name = "mp2629-adc";
 147         indio_dev->dev.parent = dev;
 148         indio_dev->channels = mp2629_channels;
 149         indio_dev->num_channels = ARRAY_SIZE(mp2629_channels);
 150         indio_dev->modes = INDIO_DIRECT_MODE;
 151         indio_dev->info = &mp2629_adc_info;
 152
 153         ret = iio_device_register(indio_dev);
 154         if (ret) {
 155                 dev_err(dev, "IIO device register fail: %d\n", ret);
 156                 goto fail_map_unregister;
 157         }
 158
 159         return 0;
 160
 161 fail_map_unregister:
 162         iio_map_array_unregister(indio_dev);
 163
 164 fail_disable:
 165         regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
 166                                          MP2629_ADC_CONTINUOUS, 0);
 167         regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
 168                                          MP2629_ADC_START, 0);
 169
 170         return ret;
 171 }
 172
 173 static int mp2629_adc_remove(struct platform_device *pdev)
 174 {
 175         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 176         struct mp2629_adc *info = iio_priv(indio_dev);
 177
 178         iio_device_unregister(indio_dev);
 179
 180         iio_map_array_unregister(indio_dev);
 181
 182         regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
 183                                          MP2629_ADC_CONTINUOUS, 0);
 184         regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
 185                                          MP2629_ADC_START, 0);
 186
 187         return 0;
 188 }
 189
 190 static const struct of_device_id mp2629_adc_of_match[] = {
 191         { .compatible = "mps,mp2629_adc"},
 192         {}
 193 };
 194 MODULE_DEVICE_TABLE(of, mp2629_adc_of_match);
 195
 196 static struct platform_driver mp2629_adc_driver = {
 197         .driver = {
 198                 .name = "mp2629_adc",
 199                 .of_match_table = mp2629_adc_of_match,
 200         },
 201         .probe          = mp2629_adc_probe,
 202         .remove         = mp2629_adc_remove,
 203 };
 204 module_platform_driver(mp2629_adc_driver);
 205
 206 MODULE_AUTHOR("Saravanan Sekar <sravanhome@gmail.com>");
 207 MODULE_DESCRIPTION("MP2629 ADC driver");
 208 MODULE_LICENSE("GPL");