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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * ti-dac082s085.c - Texas Instruments 8/10/12-bit 2/4-channel DAC driver4 *5 * Copyright (C) 2017 KUNBUS GmbH6 *7 * https://www.ti.com/lit/ds/symlink/dac082s085.pdf8 * https://www.ti.com/lit/ds/symlink/dac102s085.pdf9 * https://www.ti.com/lit/ds/symlink/dac122s085.pdf10 * https://www.ti.com/lit/ds/symlink/dac084s085.pdf11 * https://www.ti.com/lit/ds/symlink/dac104s085.pdf12 * https://www.ti.com/lit/ds/symlink/dac124s085.pdf13 */14 15#include <linux/iio/iio.h>16#include <linux/module.h>17#include <linux/mod_devicetable.h>18#include <linux/regulator/consumer.h>19#include <linux/spi/spi.h>20 21enum { dual_8bit, dual_10bit, dual_12bit, quad_8bit, quad_10bit, quad_12bit };22 23struct ti_dac_spec {24 u8 num_channels;25 u8 resolution;26};27 28static const struct ti_dac_spec ti_dac_spec[] = {29 [dual_8bit] = { .num_channels = 2, .resolution = 8 },30 [dual_10bit] = { .num_channels = 2, .resolution = 10 },31 [dual_12bit] = { .num_channels = 2, .resolution = 12 },32 [quad_8bit] = { .num_channels = 4, .resolution = 8 },33 [quad_10bit] = { .num_channels = 4, .resolution = 10 },34 [quad_12bit] = { .num_channels = 4, .resolution = 12 },35};36 37/**38 * struct ti_dac_chip - TI DAC chip39 * @lock: protects write sequences40 * @vref: regulator generating Vref41 * @mesg: SPI message to perform a write42 * @xfer: SPI transfer used by @mesg43 * @val: cached value of each output44 * @powerdown: whether the chip is powered down45 * @powerdown_mode: selected by the user46 * @resolution: resolution of the chip47 * @buf: buffer for @xfer48 */49struct ti_dac_chip {50 struct mutex lock;51 struct regulator *vref;52 struct spi_message mesg;53 struct spi_transfer xfer;54 u16 val[4];55 bool powerdown;56 u8 powerdown_mode;57 u8 resolution;58 u8 buf[2] __aligned(IIO_DMA_MINALIGN);59};60 61#define WRITE_NOT_UPDATE(chan) (0x00 | (chan) << 6)62#define WRITE_AND_UPDATE(chan) (0x10 | (chan) << 6)63#define WRITE_ALL_UPDATE 0x2064#define POWERDOWN(mode) (0x30 | ((mode) + 1) << 6)65 66static int ti_dac_cmd(struct ti_dac_chip *ti_dac, u8 cmd, u16 val)67{68 u8 shift = 12 - ti_dac->resolution;69 70 ti_dac->buf[0] = cmd | (val >> (8 - shift));71 ti_dac->buf[1] = (val << shift) & 0xff;72 return spi_sync(ti_dac->mesg.spi, &ti_dac->mesg);73}74 75static const char * const ti_dac_powerdown_modes[] = {76 "2.5kohm_to_gnd", "100kohm_to_gnd", "three_state",77};78 79static int ti_dac_get_powerdown_mode(struct iio_dev *indio_dev,80 const struct iio_chan_spec *chan)81{82 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);83 84 return ti_dac->powerdown_mode;85}86 87static int ti_dac_set_powerdown_mode(struct iio_dev *indio_dev,88 const struct iio_chan_spec *chan,89 unsigned int mode)90{91 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);92 int ret = 0;93 94 if (ti_dac->powerdown_mode == mode)95 return 0;96 97 mutex_lock(&ti_dac->lock);98 if (ti_dac->powerdown) {99 ret = ti_dac_cmd(ti_dac, POWERDOWN(mode), 0);100 if (ret)101 goto out;102 }103 ti_dac->powerdown_mode = mode;104 105out:106 mutex_unlock(&ti_dac->lock);107 return ret;108}109 110static const struct iio_enum ti_dac_powerdown_mode = {111 .items = ti_dac_powerdown_modes,112 .num_items = ARRAY_SIZE(ti_dac_powerdown_modes),113 .get = ti_dac_get_powerdown_mode,114 .set = ti_dac_set_powerdown_mode,115};116 117static ssize_t ti_dac_read_powerdown(struct iio_dev *indio_dev,118 uintptr_t private,119 const struct iio_chan_spec *chan,120 char *buf)121{122 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);123 124 return sysfs_emit(buf, "%d\n", ti_dac->powerdown);125}126 127static ssize_t ti_dac_write_powerdown(struct iio_dev *indio_dev,128 uintptr_t private,129 const struct iio_chan_spec *chan,130 const char *buf, size_t len)131{132 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);133 bool powerdown;134 int ret;135 136 ret = kstrtobool(buf, &powerdown);137 if (ret)138 return ret;139 140 if (ti_dac->powerdown == powerdown)141 return len;142 143 mutex_lock(&ti_dac->lock);144 if (powerdown)145 ret = ti_dac_cmd(ti_dac, POWERDOWN(ti_dac->powerdown_mode), 0);146 else147 ret = ti_dac_cmd(ti_dac, WRITE_AND_UPDATE(0), ti_dac->val[0]);148 if (!ret)149 ti_dac->powerdown = powerdown;150 mutex_unlock(&ti_dac->lock);151 152 return ret ? ret : len;153}154 155static const struct iio_chan_spec_ext_info ti_dac_ext_info[] = {156 {157 .name = "powerdown",158 .read = ti_dac_read_powerdown,159 .write = ti_dac_write_powerdown,160 .shared = IIO_SHARED_BY_TYPE,161 },162 IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE, &ti_dac_powerdown_mode),163 IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE, &ti_dac_powerdown_mode),164 { },165};166 167#define TI_DAC_CHANNEL(chan) { \168 .type = IIO_VOLTAGE, \169 .channel = (chan), \170 .address = (chan), \171 .indexed = true, \172 .output = true, \173 .datasheet_name = (const char[]){ 'A' + (chan), 0 }, \174 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \175 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \176 .ext_info = ti_dac_ext_info, \177}178 179static const struct iio_chan_spec ti_dac_channels[] = {180 TI_DAC_CHANNEL(0),181 TI_DAC_CHANNEL(1),182 TI_DAC_CHANNEL(2),183 TI_DAC_CHANNEL(3),184};185 186static int ti_dac_read_raw(struct iio_dev *indio_dev,187 struct iio_chan_spec const *chan,188 int *val, int *val2, long mask)189{190 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);191 int ret;192 193 switch (mask) {194 case IIO_CHAN_INFO_RAW:195 *val = ti_dac->val[chan->channel];196 ret = IIO_VAL_INT;197 break;198 199 case IIO_CHAN_INFO_SCALE:200 ret = regulator_get_voltage(ti_dac->vref);201 if (ret < 0)202 return ret;203 204 *val = ret / 1000;205 *val2 = ti_dac->resolution;206 ret = IIO_VAL_FRACTIONAL_LOG2;207 break;208 209 default:210 ret = -EINVAL;211 }212 213 return ret;214}215 216static int ti_dac_write_raw(struct iio_dev *indio_dev,217 struct iio_chan_spec const *chan,218 int val, int val2, long mask)219{220 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);221 int ret;222 223 switch (mask) {224 case IIO_CHAN_INFO_RAW:225 if (ti_dac->val[chan->channel] == val)226 return 0;227 228 if (val >= (1 << ti_dac->resolution) || val < 0)229 return -EINVAL;230 231 if (ti_dac->powerdown)232 return -EBUSY;233 234 mutex_lock(&ti_dac->lock);235 ret = ti_dac_cmd(ti_dac, WRITE_AND_UPDATE(chan->channel), val);236 if (!ret)237 ti_dac->val[chan->channel] = val;238 mutex_unlock(&ti_dac->lock);239 break;240 241 default:242 ret = -EINVAL;243 }244 245 return ret;246}247 248static int ti_dac_write_raw_get_fmt(struct iio_dev *indio_dev,249 struct iio_chan_spec const *chan, long mask)250{251 return IIO_VAL_INT;252}253 254static const struct iio_info ti_dac_info = {255 .read_raw = ti_dac_read_raw,256 .write_raw = ti_dac_write_raw,257 .write_raw_get_fmt = ti_dac_write_raw_get_fmt,258};259 260static int ti_dac_probe(struct spi_device *spi)261{262 struct device *dev = &spi->dev;263 const struct ti_dac_spec *spec;264 struct ti_dac_chip *ti_dac;265 struct iio_dev *indio_dev;266 int ret;267 268 indio_dev = devm_iio_device_alloc(dev, sizeof(*ti_dac));269 if (!indio_dev)270 return -ENOMEM;271 272 indio_dev->info = &ti_dac_info;273 indio_dev->name = spi->modalias;274 indio_dev->modes = INDIO_DIRECT_MODE;275 indio_dev->channels = ti_dac_channels;276 spi_set_drvdata(spi, indio_dev);277 278 ti_dac = iio_priv(indio_dev);279 ti_dac->xfer.tx_buf = &ti_dac->buf;280 ti_dac->xfer.len = sizeof(ti_dac->buf);281 spi_message_init_with_transfers(&ti_dac->mesg, &ti_dac->xfer, 1);282 ti_dac->mesg.spi = spi;283 284 spec = &ti_dac_spec[spi_get_device_id(spi)->driver_data];285 indio_dev->num_channels = spec->num_channels;286 ti_dac->resolution = spec->resolution;287 288 ti_dac->vref = devm_regulator_get(dev, "vref");289 if (IS_ERR(ti_dac->vref))290 return PTR_ERR(ti_dac->vref);291 292 ret = regulator_enable(ti_dac->vref);293 if (ret < 0)294 return ret;295 296 mutex_init(&ti_dac->lock);297 298 ret = ti_dac_cmd(ti_dac, WRITE_ALL_UPDATE, 0);299 if (ret) {300 dev_err(dev, "failed to initialize outputs to 0\n");301 goto err;302 }303 304 ret = iio_device_register(indio_dev);305 if (ret)306 goto err;307 308 return 0;309 310err:311 mutex_destroy(&ti_dac->lock);312 regulator_disable(ti_dac->vref);313 return ret;314}315 316static void ti_dac_remove(struct spi_device *spi)317{318 struct iio_dev *indio_dev = spi_get_drvdata(spi);319 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);320 321 iio_device_unregister(indio_dev);322 mutex_destroy(&ti_dac->lock);323 regulator_disable(ti_dac->vref);324}325 326static const struct of_device_id ti_dac_of_id[] = {327 { .compatible = "ti,dac082s085" },328 { .compatible = "ti,dac102s085" },329 { .compatible = "ti,dac122s085" },330 { .compatible = "ti,dac084s085" },331 { .compatible = "ti,dac104s085" },332 { .compatible = "ti,dac124s085" },333 { }334};335MODULE_DEVICE_TABLE(of, ti_dac_of_id);336 337static const struct spi_device_id ti_dac_spi_id[] = {338 { "dac082s085", dual_8bit },339 { "dac102s085", dual_10bit },340 { "dac122s085", dual_12bit },341 { "dac084s085", quad_8bit },342 { "dac104s085", quad_10bit },343 { "dac124s085", quad_12bit },344 { }345};346MODULE_DEVICE_TABLE(spi, ti_dac_spi_id);347 348static struct spi_driver ti_dac_driver = {349 .driver = {350 .name = "ti-dac082s085",351 .of_match_table = ti_dac_of_id,352 },353 .probe = ti_dac_probe,354 .remove = ti_dac_remove,355 .id_table = ti_dac_spi_id,356};357module_spi_driver(ti_dac_driver);358 359MODULE_AUTHOR("Lukas Wunner <lukas@wunner.de>");360MODULE_DESCRIPTION("Texas Instruments 8/10/12-bit 2/4-channel DAC driver");361MODULE_LICENSE("GPL v2");362