drivers/iio/adc/max77541-adc.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (c) 2022 Analog Devices, Inc.
   4  * ADI MAX77541 ADC Driver with IIO interface
   5  */
   6
   7 #include <linux/bitfield.h>
   8 #include <linux/iio/iio.h>
   9 #include <linux/mod_devicetable.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/regmap.h>
  12 #include <linux/units.h>
  13
  14 #include <linux/mfd/max77541.h>
  15
  16 enum max77541_adc_range {
  17         LOW_RANGE,
  18         MID_RANGE,
  19         HIGH_RANGE,
  20 };
  21
  22 enum max77541_adc_channel {
  23         MAX77541_ADC_VSYS_V,
  24         MAX77541_ADC_VOUT1_V,
  25         MAX77541_ADC_VOUT2_V,
  26         MAX77541_ADC_TEMP,
  27 };
  28
  29 static int max77541_adc_offset(struct iio_dev *indio_dev,
  30                                struct iio_chan_spec const *chan,
  31                                int *val, int *val2)
  32 {
  33         switch (chan->channel) {
  34         case MAX77541_ADC_TEMP:
  35                 *val = DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS, 1725);
  36                 return IIO_VAL_INT;
  37         default:
  38                 return -EINVAL;
  39         }
  40 }
  41
  42 static int max77541_adc_scale(struct iio_dev *indio_dev,
  43                               struct iio_chan_spec const *chan,
  44                               int *val, int *val2)
  45 {
  46         struct regmap **regmap = iio_priv(indio_dev);
  47         unsigned int reg_val;
  48         int ret;
  49
  50         switch (chan->channel) {
  51         case MAX77541_ADC_VSYS_V:
  52                 *val = 25;
  53                 return IIO_VAL_INT;
  54         case MAX77541_ADC_VOUT1_V:
  55         case MAX77541_ADC_VOUT2_V:
  56                 ret = regmap_read(*regmap, MAX77541_REG_M2_CFG1, &reg_val);
  57                 if (ret)
  58                         return ret;
  59
  60                 reg_val = FIELD_GET(MAX77541_BITS_MX_CFG1_RNG, reg_val);
  61                 switch (reg_val) {
  62                 case LOW_RANGE:
  63                         *val = 6;
  64                         *val2 = 250000;
  65                         break;
  66                 case MID_RANGE:
  67                         *val = 12;
  68                         *val2 = 500000;
  69                         break;
  70                 case HIGH_RANGE:
  71                         *val = 25;
  72                         return IIO_VAL_INT;
  73                 default:
  74                         return -EINVAL;
  75                 }
  76
  77                 return IIO_VAL_INT_PLUS_MICRO;
  78         case MAX77541_ADC_TEMP:
  79                 *val = 1725;
  80                 return IIO_VAL_INT;
  81         default:
  82                 return -EINVAL;
  83         }
  84 }
  85
  86 static int max77541_adc_raw(struct iio_dev *indio_dev,
  87                             struct iio_chan_spec const *chan,
  88                             int *val)
  89 {
  90         struct regmap **regmap = iio_priv(indio_dev);
  91         int ret;
  92
  93         ret = regmap_read(*regmap, chan->address, val);
  94         if (ret)
  95                 return ret;
  96
  97         return IIO_VAL_INT;
  98 }
  99
 100 #define MAX77541_ADC_CHANNEL_V(_channel, _name, _type, _reg) \
 101         {                                                       \
 102                 .type = _type,                                  \
 103                 .indexed = 1,                                   \
 104                 .channel = _channel,                            \
 105                 .address = _reg,                                \
 106                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |  \
 107                                       BIT(IIO_CHAN_INFO_SCALE), \
 108                 .datasheet_name = _name,                        \
 109         }
 110
 111 #define MAX77541_ADC_CHANNEL_TEMP(_channel, _name, _type, _reg) \
 112         {                                                       \
 113                 .type = _type,                                  \
 114                 .indexed = 1,                                   \
 115                 .channel = _channel,                            \
 116                 .address = _reg,                                \
 117                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |  \
 118                                       BIT(IIO_CHAN_INFO_SCALE) |\
 119                                       BIT(IIO_CHAN_INFO_OFFSET),\
 120                 .datasheet_name = _name,                        \
 121         }
 122
 123 static const struct iio_chan_spec max77541_adc_channels[] = {
 124         MAX77541_ADC_CHANNEL_V(MAX77541_ADC_VSYS_V, "vsys_v", IIO_VOLTAGE,
 125                                MAX77541_REG_ADC_DATA_CH1),
 126         MAX77541_ADC_CHANNEL_V(MAX77541_ADC_VOUT1_V, "vout1_v", IIO_VOLTAGE,
 127                                MAX77541_REG_ADC_DATA_CH2),
 128         MAX77541_ADC_CHANNEL_V(MAX77541_ADC_VOUT2_V, "vout2_v", IIO_VOLTAGE,
 129                                MAX77541_REG_ADC_DATA_CH3),
 130         MAX77541_ADC_CHANNEL_TEMP(MAX77541_ADC_TEMP, "temp", IIO_TEMP,
 131                                   MAX77541_REG_ADC_DATA_CH6),
 132 };
 133
 134 static int max77541_adc_read_raw(struct iio_dev *indio_dev,
 135                                  struct iio_chan_spec const *chan,
 136                                  int *val, int *val2, long mask)
 137 {
 138         switch (mask) {
 139         case IIO_CHAN_INFO_OFFSET:
 140                 return max77541_adc_offset(indio_dev, chan, val, val2);
 141         case IIO_CHAN_INFO_SCALE:
 142                 return max77541_adc_scale(indio_dev, chan, val, val2);
 143         case IIO_CHAN_INFO_RAW:
 144                 return max77541_adc_raw(indio_dev, chan, val);
 145         default:
 146                 return -EINVAL;
 147         }
 148 }
 149
 150 static const struct iio_info max77541_adc_info = {
 151         .read_raw = max77541_adc_read_raw,
 152 };
 153
 154 static int max77541_adc_probe(struct platform_device *pdev)
 155 {
 156         struct device *dev = &pdev->dev;
 157         struct iio_dev *indio_dev;
 158         struct regmap **regmap;
 159
 160         indio_dev = devm_iio_device_alloc(dev, sizeof(*regmap));
 161         if (!indio_dev)
 162                 return -ENOMEM;
 163
 164         regmap = iio_priv(indio_dev);
 165
 166         *regmap = dev_get_regmap(dev->parent, NULL);
 167         indio_dev->modes = INDIO_DIRECT_MODE;
 168
 169         indio_dev->name = "max77541";
 170         indio_dev->info = &max77541_adc_info;
 171         indio_dev->channels = max77541_adc_channels;
 172         indio_dev->num_channels = ARRAY_SIZE(max77541_adc_channels);
 173
 174         return devm_iio_device_register(dev, indio_dev);
 175 }
 176
 177 static const struct platform_device_id max77541_adc_platform_id[] = {
 178         { "max77541-adc" },
 179         { /* sentinel */ }
 180 };
 181 MODULE_DEVICE_TABLE(platform, max77541_adc_platform_id);
 182
 183 static struct platform_driver max77541_adc_driver = {
 184         .driver = {
 185                 .name = "max77541-adc",
 186         },
 187         .probe = max77541_adc_probe,
 188         .id_table = max77541_adc_platform_id,
 189 };
 190 module_platform_driver(max77541_adc_driver);
 191
 192 MODULE_AUTHOR("Okan Sahin <Okan.Sahin@analog.com>");
 193 MODULE_DESCRIPTION("MAX77541 ADC driver");
 194 MODULE_LICENSE("GPL");