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1// SPDX-License-Identifier: GPL-2.02/*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.pdf8 * https://www.ti.com/lit/ds/symlink/adc122s021.pdf9 * https://www.ti.com/lit/ds/symlink/adc124s021.pdf10 */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 20struct adc128_configuration {21 const struct iio_chan_spec *channels;22 u8 num_channels;23};24 25struct 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 34static 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 59static 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 101static 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 112static const struct iio_chan_spec adc122s021_channels[] = {113 ADC128_VOLTAGE_CHANNEL(0),114 ADC128_VOLTAGE_CHANNEL(1),115};116 117static 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 124static 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 130static const struct iio_info adc128_info = {131 .read_raw = adc128_read_raw,132};133 134static void adc128_disable_regulator(void *reg)135{136 regulator_disable(reg);137}138 139static 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 179static 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};189MODULE_DEVICE_TABLE(of, adc128_of_match);190 191static 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};201MODULE_DEVICE_TABLE(spi, adc128_id);202 203static const struct acpi_device_id adc128_acpi_match[] = {204 { "AANT1280", (kernel_ulong_t)&adc128_config[2] },205 { }206};207MODULE_DEVICE_TABLE(acpi, adc128_acpi_match);208 209static 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};218module_spi_driver(adc128_driver);219 220MODULE_AUTHOR("Angelo Compagnucci <angelo.compagnucci@gmail.com>");221MODULE_DESCRIPTION("Texas Instruments ADC128S052");222MODULE_LICENSE("GPL v2");223