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