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