drivers/iio/adc/ti-adc128s052.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2014 Angelo Compagnucci <angelo.compagnucci@gmail.com>
   4  *
   5  * Driver for Texas Instruments' ADC128S052, ADC122S021 and ADC124S021 ADC chip.
   6  * Datasheets can be found here:
   7  * https://www.ti.com/lit/ds/symlink/adc128s052.pdf
   8  * https://www.ti.com/lit/ds/symlink/adc122s021.pdf
   9  * https://www.ti.com/lit/ds/symlink/adc124s021.pdf
  10  */
  11
  12 #include <linux/acpi.h>
  13 #include <linux/err.h>
  14 #include <linux/spi/spi.h>
  15 #include <linux/module.h>
  16 #include <linux/mod_devicetable.h>
  17 #include <linux/iio/iio.h>
  18 #include <linux/property.h>
  19 #include <linux/regulator/consumer.h>
  20
  21 struct adc128_configuration {
  22         const struct iio_chan_spec      *channels;
  23         u8                              num_channels;
  24 };
  25
  26 struct adc128 {
  27         struct spi_device *spi;
  28
  29         struct regulator *reg;
  30         struct mutex lock;
  31
  32         u8 buffer[2] __aligned(IIO_DMA_MINALIGN);
  33 };
  34
  35 static int adc128_adc_conversion(struct adc128 *adc, u8 channel)
  36 {
  37         int ret;
  38
  39         mutex_lock(&adc->lock);
  40
  41         adc->buffer[0] = channel << 3;
  42         adc->buffer[1] = 0;
  43
  44         ret = spi_write(adc->spi, &adc->buffer, 2);
  45         if (ret < 0) {
  46                 mutex_unlock(&adc->lock);
  47                 return ret;
  48         }
  49
  50         ret = spi_read(adc->spi, &adc->buffer, 2);
  51
  52         mutex_unlock(&adc->lock);
  53
  54         if (ret < 0)
  55                 return ret;
  56
  57         return ((adc->buffer[0] << 8 | adc->buffer[1]) & 0xFFF);
  58 }
  59
  60 static int adc128_read_raw(struct iio_dev *indio_dev,
  61                            struct iio_chan_spec const *channel, int *val,
  62                            int *val2, long mask)
  63 {
  64         struct adc128 *adc = iio_priv(indio_dev);
  65         int ret;
  66
  67         switch (mask) {
  68         case IIO_CHAN_INFO_RAW:
  69
  70                 ret = adc128_adc_conversion(adc, channel->channel);
  71                 if (ret < 0)
  72                         return ret;
  73
  74                 *val = ret;
  75                 return IIO_VAL_INT;
  76
  77         case IIO_CHAN_INFO_SCALE:
  78
  79                 ret = regulator_get_voltage(adc->reg);
  80                 if (ret < 0)
  81                         return ret;
  82
  83                 *val = ret / 1000;
  84                 *val2 = 12;
  85                 return IIO_VAL_FRACTIONAL_LOG2;
  86
  87         default:
  88                 return -EINVAL;
  89         }
  90
  91 }
  92
  93 #define ADC128_VOLTAGE_CHANNEL(num)     \
  94         { \
  95                 .type = IIO_VOLTAGE, \
  96                 .indexed = 1, \
  97                 .channel = (num), \
  98                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
  99                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
 100         }
 101
 102 static const struct iio_chan_spec adc128s052_channels[] = {
 103         ADC128_VOLTAGE_CHANNEL(0),
 104         ADC128_VOLTAGE_CHANNEL(1),
 105         ADC128_VOLTAGE_CHANNEL(2),
 106         ADC128_VOLTAGE_CHANNEL(3),
 107         ADC128_VOLTAGE_CHANNEL(4),
 108         ADC128_VOLTAGE_CHANNEL(5),
 109         ADC128_VOLTAGE_CHANNEL(6),
 110         ADC128_VOLTAGE_CHANNEL(7),
 111 };
 112
 113 static const struct iio_chan_spec adc122s021_channels[] = {
 114         ADC128_VOLTAGE_CHANNEL(0),
 115         ADC128_VOLTAGE_CHANNEL(1),
 116 };
 117
 118 static const struct iio_chan_spec adc124s021_channels[] = {
 119         ADC128_VOLTAGE_CHANNEL(0),
 120         ADC128_VOLTAGE_CHANNEL(1),
 121         ADC128_VOLTAGE_CHANNEL(2),
 122         ADC128_VOLTAGE_CHANNEL(3),
 123 };
 124
 125 static const struct adc128_configuration adc128_config[] = {
 126         { adc128s052_channels, ARRAY_SIZE(adc128s052_channels) },
 127         { adc122s021_channels, ARRAY_SIZE(adc122s021_channels) },
 128         { adc124s021_channels, ARRAY_SIZE(adc124s021_channels) },
 129 };
 130
 131 static const struct iio_info adc128_info = {
 132         .read_raw = adc128_read_raw,
 133 };
 134
 135 static void adc128_disable_regulator(void *reg)
 136 {
 137         regulator_disable(reg);
 138 }
 139
 140 static int adc128_probe(struct spi_device *spi)
 141 {
 142         struct iio_dev *indio_dev;
 143         unsigned int config;
 144         struct adc128 *adc;
 145         int ret;
 146
 147         if (dev_fwnode(&spi->dev))
 148                 config = (unsigned long) device_get_match_data(&spi->dev);
 149         else
 150                 config = spi_get_device_id(spi)->driver_data;
 151
 152         indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
 153         if (!indio_dev)
 154                 return -ENOMEM;
 155
 156         adc = iio_priv(indio_dev);
 157         adc->spi = spi;
 158
 159         indio_dev->name = spi_get_device_id(spi)->name;
 160         indio_dev->modes = INDIO_DIRECT_MODE;
 161         indio_dev->info = &adc128_info;
 162
 163         indio_dev->channels = adc128_config[config].channels;
 164         indio_dev->num_channels = adc128_config[config].num_channels;
 165
 166         adc->reg = devm_regulator_get(&spi->dev, "vref");
 167         if (IS_ERR(adc->reg))
 168                 return PTR_ERR(adc->reg);
 169
 170         ret = regulator_enable(adc->reg);
 171         if (ret < 0)
 172                 return ret;
 173         ret = devm_add_action_or_reset(&spi->dev, adc128_disable_regulator,
 174                                        adc->reg);
 175         if (ret)
 176                 return ret;
 177
 178         mutex_init(&adc->lock);
 179
 180         return devm_iio_device_register(&spi->dev, indio_dev);
 181 }
 182
 183 static const struct of_device_id adc128_of_match[] = {
 184         { .compatible = "ti,adc128s052", },
 185         { .compatible = "ti,adc122s021", },
 186         { .compatible = "ti,adc122s051", },
 187         { .compatible = "ti,adc122s101", },
 188         { .compatible = "ti,adc124s021", },
 189         { .compatible = "ti,adc124s051", },
 190         { .compatible = "ti,adc124s101", },
 191         { /* sentinel */ },
 192 };
 193 MODULE_DEVICE_TABLE(of, adc128_of_match);
 194
 195 static const struct spi_device_id adc128_id[] = {
 196         { "adc128s052", 0 },    /* index into adc128_config */
 197         { "adc122s021", 1 },
 198         { "adc122s051", 1 },
 199         { "adc122s101", 1 },
 200         { "adc124s021", 2 },
 201         { "adc124s051", 2 },
 202         { "adc124s101", 2 },
 203         { }
 204 };
 205 MODULE_DEVICE_TABLE(spi, adc128_id);
 206
 207 #ifdef CONFIG_ACPI
 208 static const struct acpi_device_id adc128_acpi_match[] = {
 209         { "AANT1280", 2 }, /* ADC124S021 compatible ACPI ID */
 210         { }
 211 };
 212 MODULE_DEVICE_TABLE(acpi, adc128_acpi_match);
 213 #endif
 214
 215 static struct spi_driver adc128_driver = {
 216         .driver = {
 217                 .name = "adc128s052",
 218                 .of_match_table = adc128_of_match,
 219                 .acpi_match_table = ACPI_PTR(adc128_acpi_match),
 220         },
 221         .probe = adc128_probe,
 222         .id_table = adc128_id,
 223 };
 224 module_spi_driver(adc128_driver);
 225
 226 MODULE_AUTHOR("Angelo Compagnucci <angelo.compagnucci@gmail.com>");
 227 MODULE_DESCRIPTION("Texas Instruments ADC128S052");
 228 MODULE_LICENSE("GPL v2");