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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * IIO DAC driver for Analog Devices AD8801 DAC4 *5 * Copyright (C) 2016 Gwenhael Goavec-Merou6 */7 8#include <linux/iio/iio.h>9#include <linux/module.h>10#include <linux/regulator/consumer.h>11#include <linux/spi/spi.h>12#include <linux/sysfs.h>13 14#define AD8801_CFG_ADDR_OFFSET 815 16enum ad8801_device_ids {17 ID_AD8801,18 ID_AD8803,19};20 21struct ad8801_state {22 struct spi_device *spi;23 unsigned char dac_cache[8]; /* Value write on each channel */24 unsigned int vrefh_mv;25 unsigned int vrefl_mv;26 struct regulator *vrefh_reg;27 struct regulator *vrefl_reg;28 29 __be16 data __aligned(IIO_DMA_MINALIGN);30};31 32static int ad8801_spi_write(struct ad8801_state *state,33 u8 channel, unsigned char value)34{35 state->data = cpu_to_be16((channel << AD8801_CFG_ADDR_OFFSET) | value);36 return spi_write(state->spi, &state->data, sizeof(state->data));37}38 39static int ad8801_write_raw(struct iio_dev *indio_dev,40 struct iio_chan_spec const *chan, int val, int val2, long mask)41{42 struct ad8801_state *state = iio_priv(indio_dev);43 int ret;44 45 switch (mask) {46 case IIO_CHAN_INFO_RAW:47 if (val >= 256 || val < 0)48 return -EINVAL;49 50 ret = ad8801_spi_write(state, chan->channel, val);51 if (ret == 0)52 state->dac_cache[chan->channel] = val;53 break;54 default:55 ret = -EINVAL;56 }57 58 return ret;59}60 61static int ad8801_read_raw(struct iio_dev *indio_dev,62 struct iio_chan_spec const *chan, int *val, int *val2, long info)63{64 struct ad8801_state *state = iio_priv(indio_dev);65 66 switch (info) {67 case IIO_CHAN_INFO_RAW:68 *val = state->dac_cache[chan->channel];69 return IIO_VAL_INT;70 case IIO_CHAN_INFO_SCALE:71 *val = state->vrefh_mv - state->vrefl_mv;72 *val2 = 8;73 return IIO_VAL_FRACTIONAL_LOG2;74 case IIO_CHAN_INFO_OFFSET:75 *val = state->vrefl_mv;76 return IIO_VAL_INT;77 default:78 return -EINVAL;79 }80 81 return -EINVAL;82}83 84static const struct iio_info ad8801_info = {85 .read_raw = ad8801_read_raw,86 .write_raw = ad8801_write_raw,87};88 89#define AD8801_CHANNEL(chan) { \90 .type = IIO_VOLTAGE, \91 .indexed = 1, \92 .output = 1, \93 .channel = chan, \94 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \95 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \96 BIT(IIO_CHAN_INFO_OFFSET), \97}98 99static const struct iio_chan_spec ad8801_channels[] = {100 AD8801_CHANNEL(0),101 AD8801_CHANNEL(1),102 AD8801_CHANNEL(2),103 AD8801_CHANNEL(3),104 AD8801_CHANNEL(4),105 AD8801_CHANNEL(5),106 AD8801_CHANNEL(6),107 AD8801_CHANNEL(7),108};109 110static int ad8801_probe(struct spi_device *spi)111{112 struct iio_dev *indio_dev;113 struct ad8801_state *state;114 const struct spi_device_id *id;115 int ret;116 117 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*state));118 if (indio_dev == NULL)119 return -ENOMEM;120 121 state = iio_priv(indio_dev);122 state->spi = spi;123 id = spi_get_device_id(spi);124 125 state->vrefh_reg = devm_regulator_get(&spi->dev, "vrefh");126 if (IS_ERR(state->vrefh_reg))127 return dev_err_probe(&spi->dev, PTR_ERR(state->vrefh_reg),128 "Vrefh regulator not specified\n");129 130 ret = regulator_enable(state->vrefh_reg);131 if (ret) {132 dev_err(&spi->dev, "Failed to enable vrefh regulator: %d\n",133 ret);134 return ret;135 }136 137 ret = regulator_get_voltage(state->vrefh_reg);138 if (ret < 0) {139 dev_err(&spi->dev, "Failed to read vrefh regulator: %d\n",140 ret);141 goto error_disable_vrefh_reg;142 }143 state->vrefh_mv = ret / 1000;144 145 if (id->driver_data == ID_AD8803) {146 state->vrefl_reg = devm_regulator_get(&spi->dev, "vrefl");147 if (IS_ERR(state->vrefl_reg)) {148 ret = dev_err_probe(&spi->dev, PTR_ERR(state->vrefl_reg),149 "Vrefl regulator not specified\n");150 goto error_disable_vrefh_reg;151 }152 153 ret = regulator_enable(state->vrefl_reg);154 if (ret) {155 dev_err(&spi->dev, "Failed to enable vrefl regulator: %d\n",156 ret);157 goto error_disable_vrefh_reg;158 }159 160 ret = regulator_get_voltage(state->vrefl_reg);161 if (ret < 0) {162 dev_err(&spi->dev, "Failed to read vrefl regulator: %d\n",163 ret);164 goto error_disable_vrefl_reg;165 }166 state->vrefl_mv = ret / 1000;167 } else {168 state->vrefl_mv = 0;169 state->vrefl_reg = NULL;170 }171 172 spi_set_drvdata(spi, indio_dev);173 indio_dev->info = &ad8801_info;174 indio_dev->modes = INDIO_DIRECT_MODE;175 indio_dev->channels = ad8801_channels;176 indio_dev->num_channels = ARRAY_SIZE(ad8801_channels);177 indio_dev->name = id->name;178 179 ret = iio_device_register(indio_dev);180 if (ret) {181 dev_err(&spi->dev, "Failed to register iio device: %d\n",182 ret);183 goto error_disable_vrefl_reg;184 }185 186 return 0;187 188error_disable_vrefl_reg:189 if (state->vrefl_reg)190 regulator_disable(state->vrefl_reg);191error_disable_vrefh_reg:192 regulator_disable(state->vrefh_reg);193 return ret;194}195 196static void ad8801_remove(struct spi_device *spi)197{198 struct iio_dev *indio_dev = spi_get_drvdata(spi);199 struct ad8801_state *state = iio_priv(indio_dev);200 201 iio_device_unregister(indio_dev);202 if (state->vrefl_reg)203 regulator_disable(state->vrefl_reg);204 regulator_disable(state->vrefh_reg);205}206 207static const struct spi_device_id ad8801_ids[] = {208 {"ad8801", ID_AD8801},209 {"ad8803", ID_AD8803},210 {}211};212MODULE_DEVICE_TABLE(spi, ad8801_ids);213 214static struct spi_driver ad8801_driver = {215 .driver = {216 .name = "ad8801",217 },218 .probe = ad8801_probe,219 .remove = ad8801_remove,220 .id_table = ad8801_ids,221};222module_spi_driver(ad8801_driver);223 224MODULE_AUTHOR("Gwenhael Goavec-Merou <gwenhael.goavec-merou@trabucayre.com>");225MODULE_DESCRIPTION("Analog Devices AD8801/AD8803 DAC");226MODULE_LICENSE("GPL v2");227