1 // SPDX-License-Identifier: GPL-2.0-only
3 * ti-dac082s085.c - Texas Instruments 8/10/12-bit 2/4-channel DAC driver
5 * Copyright (C) 2017 KUNBUS GmbH
7 * http://www.ti.com/lit/ds/symlink/dac082s085.pdf
8 * http://www.ti.com/lit/ds/symlink/dac102s085.pdf
9 * http://www.ti.com/lit/ds/symlink/dac122s085.pdf
10 * http://www.ti.com/lit/ds/symlink/dac084s085.pdf
11 * http://www.ti.com/lit/ds/symlink/dac104s085.pdf
12 * http://www.ti.com/lit/ds/symlink/dac124s085.pdf
15 #include <linux/iio/iio.h>
16 #include <linux/module.h>
17 #include <linux/regulator/consumer.h>
18 #include <linux/spi/spi.h>
20 enum { dual_8bit, dual_10bit, dual_12bit, quad_8bit, quad_10bit, quad_12bit };
27 static const struct ti_dac_spec ti_dac_spec[] = {
28 [dual_8bit] = { .num_channels = 2, .resolution = 8 },
29 [dual_10bit] = { .num_channels = 2, .resolution = 10 },
30 [dual_12bit] = { .num_channels = 2, .resolution = 12 },
31 [quad_8bit] = { .num_channels = 4, .resolution = 8 },
32 [quad_10bit] = { .num_channels = 4, .resolution = 10 },
33 [quad_12bit] = { .num_channels = 4, .resolution = 12 },
37 * struct ti_dac_chip - TI DAC chip
38 * @lock: protects write sequences
39 * @vref: regulator generating Vref
40 * @mesg: SPI message to perform a write
41 * @xfer: SPI transfer used by @mesg
42 * @val: cached value of each output
43 * @powerdown: whether the chip is powered down
44 * @powerdown_mode: selected by the user
45 * @resolution: resolution of the chip
46 * @buf: buffer for @xfer
50 struct regulator *vref;
51 struct spi_message mesg;
52 struct spi_transfer xfer;
57 u8 buf[2] ____cacheline_aligned;
60 #define WRITE_NOT_UPDATE(chan) (0x00 | (chan) << 6)
61 #define WRITE_AND_UPDATE(chan) (0x10 | (chan) << 6)
62 #define WRITE_ALL_UPDATE 0x20
63 #define POWERDOWN(mode) (0x30 | ((mode) + 1) << 6)
65 static int ti_dac_cmd(struct ti_dac_chip *ti_dac, u8 cmd, u16 val)
67 u8 shift = 12 - ti_dac->resolution;
69 ti_dac->buf[0] = cmd | (val >> (8 - shift));
70 ti_dac->buf[1] = (val << shift) & 0xff;
71 return spi_sync(ti_dac->mesg.spi, &ti_dac->mesg);
74 static const char * const ti_dac_powerdown_modes[] = {
75 "2.5kohm_to_gnd", "100kohm_to_gnd", "three_state",
78 static int ti_dac_get_powerdown_mode(struct iio_dev *indio_dev,
79 const struct iio_chan_spec *chan)
81 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
83 return ti_dac->powerdown_mode;
86 static int ti_dac_set_powerdown_mode(struct iio_dev *indio_dev,
87 const struct iio_chan_spec *chan,
90 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
93 if (ti_dac->powerdown_mode == mode)
96 mutex_lock(&ti_dac->lock);
97 if (ti_dac->powerdown) {
98 ret = ti_dac_cmd(ti_dac, POWERDOWN(mode), 0);
102 ti_dac->powerdown_mode = mode;
105 mutex_unlock(&ti_dac->lock);
109 static const struct iio_enum ti_dac_powerdown_mode = {
110 .items = ti_dac_powerdown_modes,
111 .num_items = ARRAY_SIZE(ti_dac_powerdown_modes),
112 .get = ti_dac_get_powerdown_mode,
113 .set = ti_dac_set_powerdown_mode,
116 static ssize_t ti_dac_read_powerdown(struct iio_dev *indio_dev,
118 const struct iio_chan_spec *chan,
121 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
123 return sprintf(buf, "%d\n", ti_dac->powerdown);
126 static ssize_t ti_dac_write_powerdown(struct iio_dev *indio_dev,
128 const struct iio_chan_spec *chan,
129 const char *buf, size_t len)
131 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
135 ret = strtobool(buf, &powerdown);
139 if (ti_dac->powerdown == powerdown)
142 mutex_lock(&ti_dac->lock);
144 ret = ti_dac_cmd(ti_dac, POWERDOWN(ti_dac->powerdown_mode), 0);
146 ret = ti_dac_cmd(ti_dac, WRITE_AND_UPDATE(0), ti_dac->val[0]);
148 ti_dac->powerdown = powerdown;
149 mutex_unlock(&ti_dac->lock);
151 return ret ? ret : len;
154 static const struct iio_chan_spec_ext_info ti_dac_ext_info[] = {
157 .read = ti_dac_read_powerdown,
158 .write = ti_dac_write_powerdown,
159 .shared = IIO_SHARED_BY_TYPE,
161 IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE, &ti_dac_powerdown_mode),
162 IIO_ENUM_AVAILABLE("powerdown_mode", &ti_dac_powerdown_mode),
166 #define TI_DAC_CHANNEL(chan) { \
167 .type = IIO_VOLTAGE, \
172 .datasheet_name = (const char[]){ 'A' + (chan), 0 }, \
173 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
174 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
175 .ext_info = ti_dac_ext_info, \
178 static const struct iio_chan_spec ti_dac_channels[] = {
185 static int ti_dac_read_raw(struct iio_dev *indio_dev,
186 struct iio_chan_spec const *chan,
187 int *val, int *val2, long mask)
189 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
193 case IIO_CHAN_INFO_RAW:
194 *val = ti_dac->val[chan->channel];
198 case IIO_CHAN_INFO_SCALE:
199 ret = regulator_get_voltage(ti_dac->vref);
204 *val2 = ti_dac->resolution;
205 ret = IIO_VAL_FRACTIONAL_LOG2;
215 static int ti_dac_write_raw(struct iio_dev *indio_dev,
216 struct iio_chan_spec const *chan,
217 int val, int val2, long mask)
219 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
223 case IIO_CHAN_INFO_RAW:
224 if (ti_dac->val[chan->channel] == val)
227 if (val >= (1 << ti_dac->resolution) || val < 0)
230 if (ti_dac->powerdown)
233 mutex_lock(&ti_dac->lock);
234 ret = ti_dac_cmd(ti_dac, WRITE_AND_UPDATE(chan->channel), val);
236 ti_dac->val[chan->channel] = val;
237 mutex_unlock(&ti_dac->lock);
247 static int ti_dac_write_raw_get_fmt(struct iio_dev *indio_dev,
248 struct iio_chan_spec const *chan, long mask)
253 static const struct iio_info ti_dac_info = {
254 .read_raw = ti_dac_read_raw,
255 .write_raw = ti_dac_write_raw,
256 .write_raw_get_fmt = ti_dac_write_raw_get_fmt,
259 static int ti_dac_probe(struct spi_device *spi)
261 struct device *dev = &spi->dev;
262 const struct ti_dac_spec *spec;
263 struct ti_dac_chip *ti_dac;
264 struct iio_dev *indio_dev;
267 indio_dev = devm_iio_device_alloc(dev, sizeof(*ti_dac));
271 indio_dev->dev.parent = dev;
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);
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;
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;
288 ti_dac->vref = devm_regulator_get(dev, "vref");
289 if (IS_ERR(ti_dac->vref))
290 return PTR_ERR(ti_dac->vref);
292 ret = regulator_enable(ti_dac->vref);
296 mutex_init(&ti_dac->lock);
298 ret = ti_dac_cmd(ti_dac, WRITE_ALL_UPDATE, 0);
300 dev_err(dev, "failed to initialize outputs to 0\n");
304 ret = iio_device_register(indio_dev);
311 mutex_destroy(&ti_dac->lock);
312 regulator_disable(ti_dac->vref);
316 static int ti_dac_remove(struct spi_device *spi)
318 struct iio_dev *indio_dev = spi_get_drvdata(spi);
319 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
321 iio_device_unregister(indio_dev);
322 mutex_destroy(&ti_dac->lock);
323 regulator_disable(ti_dac->vref);
329 static const struct of_device_id ti_dac_of_id[] = {
330 { .compatible = "ti,dac082s085" },
331 { .compatible = "ti,dac102s085" },
332 { .compatible = "ti,dac122s085" },
333 { .compatible = "ti,dac084s085" },
334 { .compatible = "ti,dac104s085" },
335 { .compatible = "ti,dac124s085" },
338 MODULE_DEVICE_TABLE(of, ti_dac_of_id);
341 static const struct spi_device_id ti_dac_spi_id[] = {
342 { "dac082s085", dual_8bit },
343 { "dac102s085", dual_10bit },
344 { "dac122s085", dual_12bit },
345 { "dac084s085", quad_8bit },
346 { "dac104s085", quad_10bit },
347 { "dac124s085", quad_12bit },
350 MODULE_DEVICE_TABLE(spi, ti_dac_spi_id);
352 static struct spi_driver ti_dac_driver = {
354 .name = "ti-dac082s085",
355 .of_match_table = of_match_ptr(ti_dac_of_id),
357 .probe = ti_dac_probe,
358 .remove = ti_dac_remove,
359 .id_table = ti_dac_spi_id,
361 module_spi_driver(ti_dac_driver);
363 MODULE_AUTHOR("Lukas Wunner <lukas@wunner.de>");
364 MODULE_DESCRIPTION("Texas Instruments 8/10/12-bit 2/4-channel DAC driver");
365 MODULE_LICENSE("GPL v2");