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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Maxim MAX55224 * Dual, Ultra-Low-Power 10-Bit, Voltage-Output DACs5 *6 * Copyright 2022 Timesys Corp.7 */8 9#include <linux/device.h>10#include <linux/kernel.h>11#include <linux/module.h>12#include <linux/mod_devicetable.h>13#include <linux/regmap.h>14#include <linux/regulator/consumer.h>15#include <linux/slab.h>16#include <linux/spi/spi.h>17 18#include <linux/iio/iio.h>19 20#define MAX5522_MAX_ADDR 1521#define MAX5522_CTRL_NONE 022#define MAX5522_CTRL_LOAD_IN_A 923#define MAX5522_CTRL_LOAD_IN_B 1024 25#define MAX5522_REG_DATA(x) ((x) + MAX5522_CTRL_LOAD_IN_A)26 27struct max5522_chip_info {28 const char *name;29 const struct iio_chan_spec *channels;30 unsigned int num_channels;31};32 33struct max5522_state {34 struct regmap *regmap;35 const struct max5522_chip_info *chip_info;36 unsigned short dac_cache[2];37 struct regulator *vrefin_reg;38};39 40#define MAX5522_CHANNEL(chan) { \41 .type = IIO_VOLTAGE, \42 .indexed = 1, \43 .output = 1, \44 .channel = chan, \45 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \46 BIT(IIO_CHAN_INFO_SCALE), \47 .scan_type = { \48 .sign = 'u', \49 .realbits = 10, \50 .storagebits = 16, \51 .shift = 2, \52 } \53}54 55static const struct iio_chan_spec max5522_channels[] = {56 MAX5522_CHANNEL(0),57 MAX5522_CHANNEL(1),58};59 60enum max5522_type {61 ID_MAX5522,62};63 64static const struct max5522_chip_info max5522_chip_info_tbl[] = {65 [ID_MAX5522] = {66 .name = "max5522",67 .channels = max5522_channels,68 .num_channels = 2,69 },70};71 72static inline int max5522_info_to_reg(struct iio_chan_spec const *chan)73{74 return MAX5522_REG_DATA(chan->channel);75}76 77static int max5522_read_raw(struct iio_dev *indio_dev,78 struct iio_chan_spec const *chan,79 int *val, int *val2, long info)80{81 struct max5522_state *state = iio_priv(indio_dev);82 int ret;83 84 switch (info) {85 case IIO_CHAN_INFO_RAW:86 *val = state->dac_cache[chan->channel];87 return IIO_VAL_INT;88 case IIO_CHAN_INFO_SCALE:89 ret = regulator_get_voltage(state->vrefin_reg);90 if (ret < 0)91 return -EINVAL;92 *val = ret / 1000;93 *val2 = 10;94 return IIO_VAL_FRACTIONAL_LOG2;95 default:96 return -EINVAL;97 }98 99 return -EINVAL;100}101 102static int max5522_write_raw(struct iio_dev *indio_dev,103 struct iio_chan_spec const *chan,104 int val, int val2, long info)105{106 struct max5522_state *state = iio_priv(indio_dev);107 int rval;108 109 if (val > 1023 || val < 0)110 return -EINVAL;111 112 rval = regmap_write(state->regmap, max5522_info_to_reg(chan),113 val << chan->scan_type.shift);114 if (rval < 0)115 return rval;116 117 state->dac_cache[chan->channel] = val;118 119 return 0;120}121 122static const struct iio_info max5522_info = {123 .read_raw = max5522_read_raw,124 .write_raw = max5522_write_raw,125};126 127static const struct regmap_config max5522_regmap_config = {128 .reg_bits = 4,129 .val_bits = 12,130 .max_register = MAX5522_MAX_ADDR,131};132 133static int max5522_spi_probe(struct spi_device *spi)134{135 struct iio_dev *indio_dev;136 struct max5522_state *state;137 int ret;138 139 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*state));140 if (indio_dev == NULL) {141 dev_err(&spi->dev, "failed to allocate iio device\n");142 return -ENOMEM;143 }144 145 state = iio_priv(indio_dev);146 state->chip_info = spi_get_device_match_data(spi);147 if (!state->chip_info)148 return -EINVAL;149 150 state->vrefin_reg = devm_regulator_get(&spi->dev, "vrefin");151 if (IS_ERR(state->vrefin_reg))152 return dev_err_probe(&spi->dev, PTR_ERR(state->vrefin_reg),153 "Vrefin regulator not specified\n");154 155 ret = regulator_enable(state->vrefin_reg);156 if (ret) {157 return dev_err_probe(&spi->dev, ret,158 "Failed to enable vref regulators\n");159 }160 161 state->regmap = devm_regmap_init_spi(spi, &max5522_regmap_config);162 163 if (IS_ERR(state->regmap))164 return PTR_ERR(state->regmap);165 166 indio_dev->info = &max5522_info;167 indio_dev->modes = INDIO_DIRECT_MODE;168 indio_dev->channels = max5522_channels;169 indio_dev->num_channels = ARRAY_SIZE(max5522_channels);170 indio_dev->name = max5522_chip_info_tbl[ID_MAX5522].name;171 172 return devm_iio_device_register(&spi->dev, indio_dev);173}174 175static const struct spi_device_id max5522_ids[] = {176 { "max5522", (kernel_ulong_t)&max5522_chip_info_tbl[ID_MAX5522] },177 {}178};179MODULE_DEVICE_TABLE(spi, max5522_ids);180 181static const struct of_device_id max5522_of_match[] = {182 {183 .compatible = "maxim,max5522",184 .data = &max5522_chip_info_tbl[ID_MAX5522],185 },186 {}187};188MODULE_DEVICE_TABLE(of, max5522_of_match);189 190static struct spi_driver max5522_spi_driver = {191 .driver = {192 .name = "max5522",193 .of_match_table = max5522_of_match,194 },195 .probe = max5522_spi_probe,196 .id_table = max5522_ids,197};198module_spi_driver(max5522_spi_driver);199 200MODULE_AUTHOR("Angelo Dureghello <angelo.dureghello@timesys.com");201MODULE_DESCRIPTION("MAX5522 DAC driver");202MODULE_LICENSE("GPL");203