ti-dac5571.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * ti-dac5571.c - Texas Instruments 8/10/12-bit 1/4-channel DAC driver
  4 *
  5 * Copyright (C) 2018 Prevas A/S
  6 *
  7 * https://www.ti.com/lit/ds/symlink/dac5571.pdf
  8 * https://www.ti.com/lit/ds/symlink/dac6571.pdf
  9 * https://www.ti.com/lit/ds/symlink/dac7571.pdf
 10 * https://www.ti.com/lit/ds/symlink/dac5574.pdf
 11 * https://www.ti.com/lit/ds/symlink/dac6574.pdf
 12 * https://www.ti.com/lit/ds/symlink/dac7574.pdf
 13 * https://www.ti.com/lit/ds/symlink/dac5573.pdf
 14 * https://www.ti.com/lit/ds/symlink/dac6573.pdf
 15 * https://www.ti.com/lit/ds/symlink/dac7573.pdf
 16 * https://www.ti.com/lit/ds/symlink/dac081c081.pdf
 17 * https://www.ti.com/lit/ds/symlink/dac121c081.pdf
 18 */
 19
 20#include <linux/iio/iio.h>
 21#include <linux/i2c.h>
 22#include <linux/module.h>
 23#include <linux/mod_devicetable.h>
 24#include <linux/property.h>
 25#include <linux/regulator/consumer.h>
 26
 27enum chip_id {
 28	single_8bit, single_10bit, single_12bit,
 29	quad_8bit, quad_10bit, quad_12bit
 30};
 31
 32struct dac5571_spec {
 33	u8 num_channels;
 34	u8 resolution;
 35};
 36
 37static const struct dac5571_spec dac5571_spec[] = {
 38	[single_8bit]  = {.num_channels = 1, .resolution =  8},
 39	[single_10bit] = {.num_channels = 1, .resolution = 10},
 40	[single_12bit] = {.num_channels = 1, .resolution = 12},
 41	[quad_8bit]    = {.num_channels = 4, .resolution =  8},
 42	[quad_10bit]   = {.num_channels = 4, .resolution = 10},
 43	[quad_12bit]   = {.num_channels = 4, .resolution = 12},
 44};
 45
 46struct dac5571_data {
 47	struct i2c_client *client;
 48	int id;
 49	struct mutex lock;
 50	struct regulator *vref;
 51	u16 val[4];
 52	bool powerdown[4];
 53	u8 powerdown_mode[4];
 54	struct dac5571_spec const *spec;
 55	int (*dac5571_cmd)(struct dac5571_data *data, int channel, u16 val);
 56	int (*dac5571_pwrdwn)(struct dac5571_data *data, int channel, u8 pwrdwn);
 57	u8 buf[3] __aligned(IIO_DMA_MINALIGN);
 58};
 59
 60#define DAC5571_POWERDOWN(mode)		((mode) + 1)
 61#define DAC5571_POWERDOWN_FLAG		BIT(0)
 62#define DAC5571_CHANNEL_SELECT		1
 63#define DAC5571_LOADMODE_DIRECT		BIT(4)
 64#define DAC5571_SINGLE_PWRDWN_BITS	4
 65#define DAC5571_QUAD_PWRDWN_BITS	6
 66
 67static int dac5571_cmd_single(struct dac5571_data *data, int channel, u16 val)
 68{
 69	unsigned int shift;
 70
 71	shift = 12 - data->spec->resolution;
 72	data->buf[1] = val << shift;
 73	data->buf[0] = val >> (8 - shift);
 74
 75	if (i2c_master_send(data->client, data->buf, 2) != 2)
 76		return -EIO;
 77
 78	return 0;
 79}
 80
 81static int dac5571_cmd_quad(struct dac5571_data *data, int channel, u16 val)
 82{
 83	unsigned int shift;
 84
 85	shift = 16 - data->spec->resolution;
 86	data->buf[2] = val << shift;
 87	data->buf[1] = (val >> (8 - shift));
 88	data->buf[0] = (channel << DAC5571_CHANNEL_SELECT) |
 89		       DAC5571_LOADMODE_DIRECT;
 90
 91	if (i2c_master_send(data->client, data->buf, 3) != 3)
 92		return -EIO;
 93
 94	return 0;
 95}
 96
 97static int dac5571_pwrdwn_single(struct dac5571_data *data, int channel, u8 pwrdwn)
 98{
 99	data->buf[1] = 0;
100	data->buf[0] = pwrdwn << DAC5571_SINGLE_PWRDWN_BITS;
101
102	if (i2c_master_send(data->client, data->buf, 2) != 2)
103		return -EIO;
104
105	return 0;
106}
107
108static int dac5571_pwrdwn_quad(struct dac5571_data *data, int channel, u8 pwrdwn)
109{
110	data->buf[2] = 0;
111	data->buf[1] = pwrdwn << DAC5571_QUAD_PWRDWN_BITS;
112	data->buf[0] = (channel << DAC5571_CHANNEL_SELECT) |
113		       DAC5571_LOADMODE_DIRECT | DAC5571_POWERDOWN_FLAG;
114
115	if (i2c_master_send(data->client, data->buf, 3) != 3)
116		return -EIO;
117
118	return 0;
119}
120
121static const char *const dac5571_powerdown_modes[] = {
122	"1kohm_to_gnd", "100kohm_to_gnd", "three_state",
123};
124
125static int dac5571_get_powerdown_mode(struct iio_dev *indio_dev,
126				      const struct iio_chan_spec *chan)
127{
128	struct dac5571_data *data = iio_priv(indio_dev);
129
130	return data->powerdown_mode[chan->channel];
131}
132
133static int dac5571_set_powerdown_mode(struct iio_dev *indio_dev,
134				      const struct iio_chan_spec *chan,
135				      unsigned int mode)
136{
137	struct dac5571_data *data = iio_priv(indio_dev);
138	int ret = 0;
139
140	if (data->powerdown_mode[chan->channel] == mode)
141		return 0;
142
143	mutex_lock(&data->lock);
144	if (data->powerdown[chan->channel]) {
145		ret = data->dac5571_pwrdwn(data, chan->channel,
146					   DAC5571_POWERDOWN(mode));
147		if (ret)
148			goto out;
149	}
150	data->powerdown_mode[chan->channel] = mode;
151
152 out:
153	mutex_unlock(&data->lock);
154
155	return ret;
156}
157
158static const struct iio_enum dac5571_powerdown_mode = {
159	.items = dac5571_powerdown_modes,
160	.num_items = ARRAY_SIZE(dac5571_powerdown_modes),
161	.get = dac5571_get_powerdown_mode,
162	.set = dac5571_set_powerdown_mode,
163};
164
165static ssize_t dac5571_read_powerdown(struct iio_dev *indio_dev,
166				      uintptr_t private,
167				      const struct iio_chan_spec *chan,
168				      char *buf)
169{
170	struct dac5571_data *data = iio_priv(indio_dev);
171
172	return sysfs_emit(buf, "%d\n", data->powerdown[chan->channel]);
173}
174
175static ssize_t dac5571_write_powerdown(struct iio_dev *indio_dev,
176				       uintptr_t private,
177				       const struct iio_chan_spec *chan,
178				       const char *buf, size_t len)
179{
180	struct dac5571_data *data = iio_priv(indio_dev);
181	bool powerdown;
182	int ret;
183
184	ret = kstrtobool(buf, &powerdown);
185	if (ret)
186		return ret;
187
188	if (data->powerdown[chan->channel] == powerdown)
189		return len;
190
191	mutex_lock(&data->lock);
192	if (powerdown)
193		ret = data->dac5571_pwrdwn(data, chan->channel,
194			    DAC5571_POWERDOWN(data->powerdown_mode[chan->channel]));
195	else
196		ret = data->dac5571_cmd(data, chan->channel,
197				data->val[chan->channel]);
198	if (ret)
199		goto out;
200
201	data->powerdown[chan->channel] = powerdown;
202
203 out:
204	mutex_unlock(&data->lock);
205
206	return ret ? ret : len;
207}
208
209
210static const struct iio_chan_spec_ext_info dac5571_ext_info[] = {
211	{
212		.name	   = "powerdown",
213		.read	   = dac5571_read_powerdown,
214		.write	   = dac5571_write_powerdown,
215		.shared	   = IIO_SEPARATE,
216	},
217	IIO_ENUM("powerdown_mode", IIO_SEPARATE, &dac5571_powerdown_mode),
218	IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE, &dac5571_powerdown_mode),
219	{ }
220};
221
222#define dac5571_CHANNEL(chan, name) {				\
223	.type = IIO_VOLTAGE,					\
224	.channel = (chan),					\
225	.address = (chan),					\
226	.indexed = true,					\
227	.output = true,						\
228	.datasheet_name = name,					\
229	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
230	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
231	.ext_info = dac5571_ext_info,				\
232}
233
234static const struct iio_chan_spec dac5571_channels[] = {
235	dac5571_CHANNEL(0, "A"),
236	dac5571_CHANNEL(1, "B"),
237	dac5571_CHANNEL(2, "C"),
238	dac5571_CHANNEL(3, "D"),
239};
240
241static int dac5571_read_raw(struct iio_dev *indio_dev,
242			    struct iio_chan_spec const *chan,
243			    int *val, int *val2, long mask)
244{
245	struct dac5571_data *data = iio_priv(indio_dev);
246	int ret;
247
248	switch (mask) {
249	case IIO_CHAN_INFO_RAW:
250		*val = data->val[chan->channel];
251		return IIO_VAL_INT;
252
253	case IIO_CHAN_INFO_SCALE:
254		ret = regulator_get_voltage(data->vref);
255		if (ret < 0)
256			return ret;
257
258		*val = ret / 1000;
259		*val2 = data->spec->resolution;
260		return IIO_VAL_FRACTIONAL_LOG2;
261
262	default:
263		return -EINVAL;
264	}
265}
266
267static int dac5571_write_raw(struct iio_dev *indio_dev,
268			     struct iio_chan_spec const *chan,
269			     int val, int val2, long mask)
270{
271	struct dac5571_data *data = iio_priv(indio_dev);
272	int ret;
273
274	switch (mask) {
275	case IIO_CHAN_INFO_RAW:
276		if (data->val[chan->channel] == val)
277			return 0;
278
279		if (val >= (1 << data->spec->resolution) || val < 0)
280			return -EINVAL;
281
282		if (data->powerdown[chan->channel])
283			return -EBUSY;
284
285		mutex_lock(&data->lock);
286		ret = data->dac5571_cmd(data, chan->channel, val);
287		if (ret == 0)
288			data->val[chan->channel] = val;
289		mutex_unlock(&data->lock);
290		return ret;
291
292	default:
293		return -EINVAL;
294	}
295}
296
297static int dac5571_write_raw_get_fmt(struct iio_dev *indio_dev,
298				     struct iio_chan_spec const *chan,
299				     long mask)
300{
301	return IIO_VAL_INT;
302}
303
304static const struct iio_info dac5571_info = {
305	.read_raw = dac5571_read_raw,
306	.write_raw = dac5571_write_raw,
307	.write_raw_get_fmt = dac5571_write_raw_get_fmt,
308};
309
310static int dac5571_probe(struct i2c_client *client)
311{
312	const struct i2c_device_id *id = i2c_client_get_device_id(client);
313	struct device *dev = &client->dev;
314	const struct dac5571_spec *spec;
315	struct dac5571_data *data;
316	struct iio_dev *indio_dev;
317	int ret, i;
318
319	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
320	if (!indio_dev)
321		return -ENOMEM;
322
323	data = iio_priv(indio_dev);
324	i2c_set_clientdata(client, indio_dev);
325	data->client = client;
326
327	indio_dev->info = &dac5571_info;
328	indio_dev->name = id->name;
329	indio_dev->modes = INDIO_DIRECT_MODE;
330	indio_dev->channels = dac5571_channels;
331
332	spec = i2c_get_match_data(client);
333
334	indio_dev->num_channels = spec->num_channels;
335	data->spec = spec;
336
337	data->vref = devm_regulator_get(dev, "vref");
338	if (IS_ERR(data->vref))
339		return PTR_ERR(data->vref);
340
341	ret = regulator_enable(data->vref);
342	if (ret < 0)
343		return ret;
344
345	mutex_init(&data->lock);
346
347	switch (spec->num_channels) {
348	case 1:
349		data->dac5571_cmd = dac5571_cmd_single;
350		data->dac5571_pwrdwn = dac5571_pwrdwn_single;
351		break;
352	case 4:
353		data->dac5571_cmd = dac5571_cmd_quad;
354		data->dac5571_pwrdwn = dac5571_pwrdwn_quad;
355		break;
356	default:
357		ret = -EINVAL;
358		goto err;
359	}
360
361	for (i = 0; i < spec->num_channels; i++) {
362		ret = data->dac5571_cmd(data, i, 0);
363		if (ret) {
364			dev_err(dev, "failed to initialize channel %d to 0\n", i);
365			goto err;
366		}
367	}
368
369	ret = iio_device_register(indio_dev);
370	if (ret)
371		goto err;
372
373	return 0;
374
375 err:
376	regulator_disable(data->vref);
377	return ret;
378}
379
380static void dac5571_remove(struct i2c_client *i2c)
381{
382	struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
383	struct dac5571_data *data = iio_priv(indio_dev);
384
385	iio_device_unregister(indio_dev);
386	regulator_disable(data->vref);
387}
388
389static const struct of_device_id dac5571_of_id[] = {
390	{.compatible = "ti,dac081c081", .data = &dac5571_spec[single_8bit] },
391	{.compatible = "ti,dac121c081", .data = &dac5571_spec[single_12bit] },
392	{.compatible = "ti,dac5571", .data = &dac5571_spec[single_8bit] },
393	{.compatible = "ti,dac6571", .data = &dac5571_spec[single_10bit] },
394	{.compatible = "ti,dac7571", .data = &dac5571_spec[single_12bit] },
395	{.compatible = "ti,dac5574", .data = &dac5571_spec[quad_8bit] },
396	{.compatible = "ti,dac6574", .data = &dac5571_spec[quad_10bit] },
397	{.compatible = "ti,dac7574", .data = &dac5571_spec[quad_12bit] },
398	{.compatible = "ti,dac5573", .data = &dac5571_spec[quad_8bit] },
399	{.compatible = "ti,dac6573", .data = &dac5571_spec[quad_10bit] },
400	{.compatible = "ti,dac7573", .data = &dac5571_spec[quad_12bit] },
401	{ }
402};
403MODULE_DEVICE_TABLE(of, dac5571_of_id);
404
405static const struct i2c_device_id dac5571_id[] = {
406	{"dac081c081", (kernel_ulong_t)&dac5571_spec[single_8bit] },
407	{"dac121c081", (kernel_ulong_t)&dac5571_spec[single_12bit] },
408	{"dac5571", (kernel_ulong_t)&dac5571_spec[single_8bit] },
409	{"dac6571", (kernel_ulong_t)&dac5571_spec[single_10bit] },
410	{"dac7571", (kernel_ulong_t)&dac5571_spec[single_12bit] },
411	{"dac5574", (kernel_ulong_t)&dac5571_spec[quad_8bit] },
412	{"dac6574", (kernel_ulong_t)&dac5571_spec[quad_10bit] },
413	{"dac7574", (kernel_ulong_t)&dac5571_spec[quad_12bit] },
414	{"dac5573", (kernel_ulong_t)&dac5571_spec[quad_8bit] },
415	{"dac6573", (kernel_ulong_t)&dac5571_spec[quad_10bit] },
416	{"dac7573", (kernel_ulong_t)&dac5571_spec[quad_12bit] },
417	{ }
418};
419MODULE_DEVICE_TABLE(i2c, dac5571_id);
420
421static struct i2c_driver dac5571_driver = {
422	.driver = {
423		   .name = "ti-dac5571",
424		   .of_match_table = dac5571_of_id,
425	},
426	.probe = dac5571_probe,
427	.remove   = dac5571_remove,
428	.id_table = dac5571_id,
429};
430module_i2c_driver(dac5571_driver);
431
432MODULE_AUTHOR("Sean Nyekjaer <sean@geanix.dk>");
433MODULE_DESCRIPTION("Texas Instruments 8/10/12-bit 1/4-channel DAC driver");
434MODULE_LICENSE("GPL v2");