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1// SPDX-License-Identifier: GPL-2.02/* ti-dac7311.c - Texas Instruments 8/10/12-bit 1-channel DAC driver3 *4 * Copyright (C) 2018 CMC NV5 *6 * https://www.ti.com/lit/ds/symlink/dac7311.pdf7 */8 9#include <linux/iio/iio.h>10#include <linux/module.h>11#include <linux/regulator/consumer.h>12#include <linux/spi/spi.h>13 14enum {15 ID_DAC5311 = 0,16 ID_DAC6311,17 ID_DAC7311,18};19 20enum {21 POWER_1KOHM_TO_GND = 0,22 POWER_100KOHM_TO_GND,23 POWER_TRI_STATE,24};25 26struct ti_dac_spec {27 u8 resolution;28};29 30static const struct ti_dac_spec ti_dac_spec[] = {31 [ID_DAC5311] = { .resolution = 8 },32 [ID_DAC6311] = { .resolution = 10 },33 [ID_DAC7311] = { .resolution = 12 },34};35 36/**37 * struct ti_dac_chip - TI DAC chip38 * @lock: protects write sequences39 * @vref: regulator generating Vref40 * @spi: SPI device to send data to the device41 * @val: cached value42 * @powerdown: whether the chip is powered down43 * @powerdown_mode: selected by the user44 * @resolution: resolution of the chip45 * @buf: buffer for transfer data46 */47struct ti_dac_chip {48 struct mutex lock;49 struct regulator *vref;50 struct spi_device *spi;51 u16 val;52 bool powerdown;53 u8 powerdown_mode;54 u8 resolution;55 u8 buf[2] __aligned(IIO_DMA_MINALIGN);56};57 58static u8 ti_dac_get_power(struct ti_dac_chip *ti_dac, bool powerdown)59{60 if (powerdown)61 return ti_dac->powerdown_mode + 1;62 63 return 0;64}65 66static int ti_dac_cmd(struct ti_dac_chip *ti_dac, u8 power, u16 val)67{68 u8 shift = 14 - ti_dac->resolution;69 70 ti_dac->buf[0] = (val << shift) & 0xFF;71 ti_dac->buf[1] = (power << 6) | (val >> (8 - shift));72 return spi_write(ti_dac->spi, ti_dac->buf, 2);73}74 75static const char * const ti_dac_powerdown_modes[] = {76 "1kohm_to_gnd",77 "100kohm_to_gnd",78 "three_state",79};80 81static int ti_dac_get_powerdown_mode(struct iio_dev *indio_dev,82 const struct iio_chan_spec *chan)83{84 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);85 86 return ti_dac->powerdown_mode;87}88 89static int ti_dac_set_powerdown_mode(struct iio_dev *indio_dev,90 const struct iio_chan_spec *chan,91 unsigned int mode)92{93 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);94 95 ti_dac->powerdown_mode = mode;96 return 0;97}98 99static const struct iio_enum ti_dac_powerdown_mode = {100 .items = ti_dac_powerdown_modes,101 .num_items = ARRAY_SIZE(ti_dac_powerdown_modes),102 .get = ti_dac_get_powerdown_mode,103 .set = ti_dac_set_powerdown_mode,104};105 106static ssize_t ti_dac_read_powerdown(struct iio_dev *indio_dev,107 uintptr_t private,108 const struct iio_chan_spec *chan,109 char *buf)110{111 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);112 113 return sysfs_emit(buf, "%d\n", ti_dac->powerdown);114}115 116static ssize_t ti_dac_write_powerdown(struct iio_dev *indio_dev,117 uintptr_t private,118 const struct iio_chan_spec *chan,119 const char *buf, size_t len)120{121 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);122 bool powerdown;123 u8 power;124 int ret;125 126 ret = kstrtobool(buf, &powerdown);127 if (ret)128 return ret;129 130 power = ti_dac_get_power(ti_dac, powerdown);131 132 mutex_lock(&ti_dac->lock);133 ret = ti_dac_cmd(ti_dac, power, 0);134 if (!ret)135 ti_dac->powerdown = powerdown;136 mutex_unlock(&ti_dac->lock);137 138 return ret ? ret : len;139}140 141static const struct iio_chan_spec_ext_info ti_dac_ext_info[] = {142 {143 .name = "powerdown",144 .read = ti_dac_read_powerdown,145 .write = ti_dac_write_powerdown,146 .shared = IIO_SHARED_BY_TYPE,147 },148 IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE, &ti_dac_powerdown_mode),149 IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE, &ti_dac_powerdown_mode),150 { },151};152 153#define TI_DAC_CHANNEL(chan) { \154 .type = IIO_VOLTAGE, \155 .channel = (chan), \156 .output = true, \157 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \158 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \159 .ext_info = ti_dac_ext_info, \160}161 162static const struct iio_chan_spec ti_dac_channels[] = {163 TI_DAC_CHANNEL(0),164};165 166static int ti_dac_read_raw(struct iio_dev *indio_dev,167 struct iio_chan_spec const *chan,168 int *val, int *val2, long mask)169{170 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);171 int ret;172 173 switch (mask) {174 case IIO_CHAN_INFO_RAW:175 *val = ti_dac->val;176 return IIO_VAL_INT;177 178 case IIO_CHAN_INFO_SCALE:179 ret = regulator_get_voltage(ti_dac->vref);180 if (ret < 0)181 return ret;182 183 *val = ret / 1000;184 *val2 = ti_dac->resolution;185 return IIO_VAL_FRACTIONAL_LOG2;186 }187 188 return -EINVAL;189}190 191static int ti_dac_write_raw(struct iio_dev *indio_dev,192 struct iio_chan_spec const *chan,193 int val, int val2, long mask)194{195 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);196 u8 power = ti_dac_get_power(ti_dac, ti_dac->powerdown);197 int ret;198 199 switch (mask) {200 case IIO_CHAN_INFO_RAW:201 if (ti_dac->val == val)202 return 0;203 204 if (val >= (1 << ti_dac->resolution) || val < 0)205 return -EINVAL;206 207 if (ti_dac->powerdown)208 return -EBUSY;209 210 mutex_lock(&ti_dac->lock);211 ret = ti_dac_cmd(ti_dac, power, val);212 if (!ret)213 ti_dac->val = val;214 mutex_unlock(&ti_dac->lock);215 break;216 217 default:218 ret = -EINVAL;219 }220 221 return ret;222}223 224static int ti_dac_write_raw_get_fmt(struct iio_dev *indio_dev,225 struct iio_chan_spec const *chan, long mask)226{227 return IIO_VAL_INT;228}229 230static const struct iio_info ti_dac_info = {231 .read_raw = ti_dac_read_raw,232 .write_raw = ti_dac_write_raw,233 .write_raw_get_fmt = ti_dac_write_raw_get_fmt,234};235 236static int ti_dac_probe(struct spi_device *spi)237{238 struct device *dev = &spi->dev;239 const struct ti_dac_spec *spec;240 struct ti_dac_chip *ti_dac;241 struct iio_dev *indio_dev;242 int ret;243 244 indio_dev = devm_iio_device_alloc(dev, sizeof(*ti_dac));245 if (!indio_dev) {246 dev_err(dev, "can not allocate iio device\n");247 return -ENOMEM;248 }249 250 spi->mode = SPI_MODE_1;251 spi->bits_per_word = 16;252 ret = spi_setup(spi);253 if (ret < 0)254 return dev_err_probe(dev, ret, "spi_setup failed\n");255 256 indio_dev->info = &ti_dac_info;257 indio_dev->name = spi_get_device_id(spi)->name;258 indio_dev->modes = INDIO_DIRECT_MODE;259 indio_dev->channels = ti_dac_channels;260 spi_set_drvdata(spi, indio_dev);261 262 ti_dac = iio_priv(indio_dev);263 ti_dac->powerdown = false;264 ti_dac->spi = spi;265 266 spec = &ti_dac_spec[spi_get_device_id(spi)->driver_data];267 indio_dev->num_channels = 1;268 ti_dac->resolution = spec->resolution;269 270 ti_dac->vref = devm_regulator_get(dev, "vref");271 if (IS_ERR(ti_dac->vref))272 return dev_err_probe(dev, PTR_ERR(ti_dac->vref),273 "error to get regulator\n");274 275 ret = regulator_enable(ti_dac->vref);276 if (ret < 0) {277 dev_err(dev, "can not enable regulator\n");278 return ret;279 }280 281 mutex_init(&ti_dac->lock);282 283 ret = iio_device_register(indio_dev);284 if (ret) {285 dev_err(dev, "fail to register iio device: %d\n", ret);286 goto err;287 }288 289 return 0;290 291err:292 mutex_destroy(&ti_dac->lock);293 regulator_disable(ti_dac->vref);294 return ret;295}296 297static void ti_dac_remove(struct spi_device *spi)298{299 struct iio_dev *indio_dev = spi_get_drvdata(spi);300 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);301 302 iio_device_unregister(indio_dev);303 mutex_destroy(&ti_dac->lock);304 regulator_disable(ti_dac->vref);305}306 307static const struct of_device_id ti_dac_of_id[] = {308 { .compatible = "ti,dac5311" },309 { .compatible = "ti,dac6311" },310 { .compatible = "ti,dac7311" },311 { }312};313MODULE_DEVICE_TABLE(of, ti_dac_of_id);314 315static const struct spi_device_id ti_dac_spi_id[] = {316 { "dac5311", ID_DAC5311 },317 { "dac6311", ID_DAC6311 },318 { "dac7311", ID_DAC7311 },319 { }320};321MODULE_DEVICE_TABLE(spi, ti_dac_spi_id);322 323static struct spi_driver ti_dac_driver = {324 .driver = {325 .name = "ti-dac7311",326 .of_match_table = ti_dac_of_id,327 },328 .probe = ti_dac_probe,329 .remove = ti_dac_remove,330 .id_table = ti_dac_spi_id,331};332module_spi_driver(ti_dac_driver);333 334MODULE_AUTHOR("Charles-Antoine Couret <charles-antoine.couret@essensium.com>");335MODULE_DESCRIPTION("Texas Instruments 8/10/12-bit 1-channel DAC driver");336MODULE_LICENSE("GPL v2");337