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/dac121c081.pdf
17 */
18
19#include <linux/iio/iio.h>
20#include <linux/i2c.h>
21#include <linux/module.h>
22#include <linux/mod_devicetable.h>
23#include <linux/property.h>
24#include <linux/regulator/consumer.h>
25
26enum chip_id {
27	single_8bit, single_10bit, single_12bit,
28	quad_8bit, quad_10bit, quad_12bit
29};
30
31struct dac5571_spec {
32	u8 num_channels;
33	u8 resolution;
34};
35
36static const struct dac5571_spec dac5571_spec[] = {
37	[single_8bit]  = {.num_channels = 1, .resolution =  8},
38	[single_10bit] = {.num_channels = 1, .resolution = 10},
39	[single_12bit] = {.num_channels = 1, .resolution = 12},
40	[quad_8bit]    = {.num_channels = 4, .resolution =  8},
41	[quad_10bit]   = {.num_channels = 4, .resolution = 10},
42	[quad_12bit]   = {.num_channels = 4, .resolution = 12},
43};
44
45struct dac5571_data {
46	struct i2c_client *client;
47	int id;
48	struct mutex lock;
49	struct regulator *vref;
50	u16 val[4];
51	bool powerdown[4];
52	u8 powerdown_mode[4];
53	struct dac5571_spec const *spec;
54	int (*dac5571_cmd)(struct dac5571_data *data, int channel, u16 val);
55	int (*dac5571_pwrdwn)(struct dac5571_data *data, int channel, u8 pwrdwn);
56	u8 buf[3] __aligned(IIO_DMA_MINALIGN);
57};
58
59#define DAC5571_POWERDOWN(mode)		((mode) + 1)
60#define DAC5571_POWERDOWN_FLAG		BIT(0)
61#define DAC5571_CHANNEL_SELECT		1
62#define DAC5571_LOADMODE_DIRECT		BIT(4)
63#define DAC5571_SINGLE_PWRDWN_BITS	4
64#define DAC5571_QUAD_PWRDWN_BITS	6
65
66static int dac5571_cmd_single(struct dac5571_data *data, int channel, u16 val)
67{
68	unsigned int shift;
69
70	shift = 12 - data->spec->resolution;
71	data->buf[1] = val << shift;
72	data->buf[0] = val >> (8 - shift);
73
74	if (i2c_master_send(data->client, data->buf, 2) != 2)
75		return -EIO;
76
77	return 0;
78}
79
80static int dac5571_cmd_quad(struct dac5571_data *data, int channel, u16 val)
81{
82	unsigned int shift;
83
84	shift = 16 - data->spec->resolution;
85	data->buf[2] = val << shift;
86	data->buf[1] = (val >> (8 - shift));
87	data->buf[0] = (channel << DAC5571_CHANNEL_SELECT) |
88		       DAC5571_LOADMODE_DIRECT;
89
90	if (i2c_master_send(data->client, data->buf, 3) != 3)
91		return -EIO;
92
93	return 0;
94}
95
96static int dac5571_pwrdwn_single(struct dac5571_data *data, int channel, u8 pwrdwn)
97{
98	data->buf[1] = 0;
99	data->buf[0] = pwrdwn << DAC5571_SINGLE_PWRDWN_BITS;
100
101	if (i2c_master_send(data->client, data->buf, 2) != 2)
102		return -EIO;
103
104	return 0;
105}
106
107static int dac5571_pwrdwn_quad(struct dac5571_data *data, int channel, u8 pwrdwn)
108{
109	data->buf[2] = 0;
110	data->buf[1] = pwrdwn << DAC5571_QUAD_PWRDWN_BITS;
111	data->buf[0] = (channel << DAC5571_CHANNEL_SELECT) |
112		       DAC5571_LOADMODE_DIRECT | DAC5571_POWERDOWN_FLAG;
113
114	if (i2c_master_send(data->client, data->buf, 3) != 3)
115		return -EIO;
116
117	return 0;
118}
119
120static const char *const dac5571_powerdown_modes[] = {
121	"1kohm_to_gnd", "100kohm_to_gnd", "three_state",
122};
123
124static int dac5571_get_powerdown_mode(struct iio_dev *indio_dev,
125				      const struct iio_chan_spec *chan)
126{
127	struct dac5571_data *data = iio_priv(indio_dev);
128
129	return data->powerdown_mode[chan->channel];
130}
131
132static int dac5571_set_powerdown_mode(struct iio_dev *indio_dev,
133				      const struct iio_chan_spec *chan,
134				      unsigned int mode)
135{
136	struct dac5571_data *data = iio_priv(indio_dev);
137	int ret = 0;
138
139	if (data->powerdown_mode[chan->channel] == mode)
140		return 0;
141
142	mutex_lock(&data->lock);
143	if (data->powerdown[chan->channel]) {
144		ret = data->dac5571_pwrdwn(data, chan->channel,
145					   DAC5571_POWERDOWN(mode));
146		if (ret)
147			goto out;
148	}
149	data->powerdown_mode[chan->channel] = mode;
150
151 out:
152	mutex_unlock(&data->lock);
153
154	return ret;
155}
156
157static const struct iio_enum dac5571_powerdown_mode = {
158	.items = dac5571_powerdown_modes,
159	.num_items = ARRAY_SIZE(dac5571_powerdown_modes),
160	.get = dac5571_get_powerdown_mode,
161	.set = dac5571_set_powerdown_mode,
162};
163
164static ssize_t dac5571_read_powerdown(struct iio_dev *indio_dev,
165				      uintptr_t private,
166				      const struct iio_chan_spec *chan,
167				      char *buf)
168{
169	struct dac5571_data *data = iio_priv(indio_dev);
170
171	return sysfs_emit(buf, "%d\n", data->powerdown[chan->channel]);
172}
173
174static ssize_t dac5571_write_powerdown(struct iio_dev *indio_dev,
175				       uintptr_t private,
176				       const struct iio_chan_spec *chan,
177				       const char *buf, size_t len)
178{
179	struct dac5571_data *data = iio_priv(indio_dev);
180	bool powerdown;
181	int ret;
182
183	ret = kstrtobool(buf, &powerdown);
184	if (ret)
185		return ret;
186
187	if (data->powerdown[chan->channel] == powerdown)
188		return len;
189
190	mutex_lock(&data->lock);
191	if (powerdown)
192		ret = data->dac5571_pwrdwn(data, chan->channel,
193			    DAC5571_POWERDOWN(data->powerdown_mode[chan->channel]));
194	else
195		ret = data->dac5571_cmd(data, chan->channel,
196				data->val[chan->channel]);
197	if (ret)
198		goto out;
199
200	data->powerdown[chan->channel] = powerdown;
201
202 out:
203	mutex_unlock(&data->lock);
204
205	return ret ? ret : len;
206}
207
208
209static const struct iio_chan_spec_ext_info dac5571_ext_info[] = {
210	{
211		.name	   = "powerdown",
212		.read	   = dac5571_read_powerdown,
213		.write	   = dac5571_write_powerdown,
214		.shared	   = IIO_SEPARATE,
215	},
216	IIO_ENUM("powerdown_mode", IIO_SEPARATE, &dac5571_powerdown_mode),
217	IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE, &dac5571_powerdown_mode),
218	{},
219};
220
221#define dac5571_CHANNEL(chan, name) {				\
222	.type = IIO_VOLTAGE,					\
223	.channel = (chan),					\
224	.address = (chan),					\
225	.indexed = true,					\
226	.output = true,						\
227	.datasheet_name = name,					\
228	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
229	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
230	.ext_info = dac5571_ext_info,				\
231}
232
233static const struct iio_chan_spec dac5571_channels[] = {
234	dac5571_CHANNEL(0, "A"),
235	dac5571_CHANNEL(1, "B"),
236	dac5571_CHANNEL(2, "C"),
237	dac5571_CHANNEL(3, "D"),
238};
239
240static int dac5571_read_raw(struct iio_dev *indio_dev,
241			    struct iio_chan_spec const *chan,
242			    int *val, int *val2, long mask)
243{
244	struct dac5571_data *data = iio_priv(indio_dev);
245	int ret;
246
247	switch (mask) {
248	case IIO_CHAN_INFO_RAW:
249		*val = data->val[chan->channel];
250		return IIO_VAL_INT;
251
252	case IIO_CHAN_INFO_SCALE:
253		ret = regulator_get_voltage(data->vref);
254		if (ret < 0)
255			return ret;
256
257		*val = ret / 1000;
258		*val2 = data->spec->resolution;
259		return IIO_VAL_FRACTIONAL_LOG2;
260
261	default:
262		return -EINVAL;
263	}
264}
265
266static int dac5571_write_raw(struct iio_dev *indio_dev,
267			     struct iio_chan_spec const *chan,
268			     int val, int val2, long mask)
269{
270	struct dac5571_data *data = iio_priv(indio_dev);
271	int ret;
272
273	switch (mask) {
274	case IIO_CHAN_INFO_RAW:
275		if (data->val[chan->channel] == val)
276			return 0;
277
278		if (val >= (1 << data->spec->resolution) || val < 0)
279			return -EINVAL;
280
281		if (data->powerdown[chan->channel])
282			return -EBUSY;
283
284		mutex_lock(&data->lock);
285		ret = data->dac5571_cmd(data, chan->channel, val);
286		if (ret == 0)
287			data->val[chan->channel] = val;
288		mutex_unlock(&data->lock);
289		return ret;
290
291	default:
292		return -EINVAL;
293	}
294}
295
296static int dac5571_write_raw_get_fmt(struct iio_dev *indio_dev,
297				     struct iio_chan_spec const *chan,
298				     long mask)
299{
300	return IIO_VAL_INT;
301}
302
303static const struct iio_info dac5571_info = {
304	.read_raw = dac5571_read_raw,
305	.write_raw = dac5571_write_raw,
306	.write_raw_get_fmt = dac5571_write_raw_get_fmt,
307};
308
309static int dac5571_probe(struct i2c_client *client)
310{
311	const struct i2c_device_id *id = i2c_client_get_device_id(client);
312	struct device *dev = &client->dev;
313	const struct dac5571_spec *spec;
314	struct dac5571_data *data;
315	struct iio_dev *indio_dev;
316	enum chip_id chip_id;
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	if (dev_fwnode(dev))
333		chip_id = (uintptr_t)device_get_match_data(dev);
334	else
335		chip_id = id->driver_data;
336
337	spec = &dac5571_spec[chip_id];
338
339	indio_dev->num_channels = spec->num_channels;
340	data->spec = spec;
341
342	data->vref = devm_regulator_get(dev, "vref");
343	if (IS_ERR(data->vref))
344		return PTR_ERR(data->vref);
345
346	ret = regulator_enable(data->vref);
347	if (ret < 0)
348		return ret;
349
350	mutex_init(&data->lock);
351
352	switch (spec->num_channels) {
353	case 1:
354		data->dac5571_cmd = dac5571_cmd_single;
355		data->dac5571_pwrdwn = dac5571_pwrdwn_single;
356		break;
357	case 4:
358		data->dac5571_cmd = dac5571_cmd_quad;
359		data->dac5571_pwrdwn = dac5571_pwrdwn_quad;
360		break;
361	default:
362		ret = -EINVAL;
363		goto err;
364	}
365
366	for (i = 0; i < spec->num_channels; i++) {
367		ret = data->dac5571_cmd(data, i, 0);
368		if (ret) {
369			dev_err(dev, "failed to initialize channel %d to 0\n", i);
370			goto err;
371		}
372	}
373
374	ret = iio_device_register(indio_dev);
375	if (ret)
376		goto err;
377
378	return 0;
379
380 err:
381	regulator_disable(data->vref);
382	return ret;
383}
384
385static void dac5571_remove(struct i2c_client *i2c)
386{
387	struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
388	struct dac5571_data *data = iio_priv(indio_dev);
389
390	iio_device_unregister(indio_dev);
391	regulator_disable(data->vref);
392}
393
394static const struct of_device_id dac5571_of_id[] = {
395	{.compatible = "ti,dac5571", .data = (void *)single_8bit},
396	{.compatible = "ti,dac6571", .data = (void *)single_10bit},
397	{.compatible = "ti,dac7571", .data = (void *)single_12bit},
398	{.compatible = "ti,dac5574", .data = (void *)quad_8bit},
399	{.compatible = "ti,dac6574", .data = (void *)quad_10bit},
400	{.compatible = "ti,dac7574", .data = (void *)quad_12bit},
401	{.compatible = "ti,dac5573", .data = (void *)quad_8bit},
402	{.compatible = "ti,dac6573", .data = (void *)quad_10bit},
403	{.compatible = "ti,dac7573", .data = (void *)quad_12bit},
404	{.compatible = "ti,dac121c081", .data = (void *)single_12bit},
405	{}
406};
407MODULE_DEVICE_TABLE(of, dac5571_of_id);
408
409static const struct i2c_device_id dac5571_id[] = {
410	{"dac5571", single_8bit},
411	{"dac6571", single_10bit},
412	{"dac7571", single_12bit},
413	{"dac5574", quad_8bit},
414	{"dac6574", quad_10bit},
415	{"dac7574", quad_12bit},
416	{"dac5573", quad_8bit},
417	{"dac6573", quad_10bit},
418	{"dac7573", quad_12bit},
419	{"dac121c081", single_12bit},
420	{}
421};
422MODULE_DEVICE_TABLE(i2c, dac5571_id);
423
424static struct i2c_driver dac5571_driver = {
425	.driver = {
426		   .name = "ti-dac5571",
427		   .of_match_table = dac5571_of_id,
428	},
429	.probe = dac5571_probe,
430	.remove   = dac5571_remove,
431	.id_table = dac5571_id,
432};
433module_i2c_driver(dac5571_driver);
434
435MODULE_AUTHOR("Sean Nyekjaer <sean@geanix.dk>");
436MODULE_DESCRIPTION("Texas Instruments 8/10/12-bit 1/4-channel DAC driver");
437MODULE_LICENSE("GPL v2");
438