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 * http://www.ti.com/lit/ds/symlink/dac5571.pdf
8 * http://www.ti.com/lit/ds/symlink/dac6571.pdf
9 * http://www.ti.com/lit/ds/symlink/dac7571.pdf
10 * http://www.ti.com/lit/ds/symlink/dac5574.pdf
11 * http://www.ti.com/lit/ds/symlink/dac6574.pdf
12 * http://www.ti.com/lit/ds/symlink/dac7574.pdf
13 * http://www.ti.com/lit/ds/symlink/dac5573.pdf
14 * http://www.ti.com/lit/ds/symlink/dac6573.pdf
15 * http://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/of_device.h>
22 #include <linux/of.h>
23 #include <linux/regulator/consumer.h>
24
25 enum chip_id {
26 single_8bit, single_10bit, single_12bit,
27 quad_8bit, quad_10bit, quad_12bit
28 };
29
30 struct dac5571_spec {
31 u8 num_channels;
32 u8 resolution;
33 };
34
35 static const struct dac5571_spec dac5571_spec[] = {
36 [single_8bit] = {.num_channels = 1, .resolution = 8},
37 [single_10bit] = {.num_channels = 1, .resolution = 10},
38 [single_12bit] = {.num_channels = 1, .resolution = 12},
39 [quad_8bit] = {.num_channels = 4, .resolution = 8},
40 [quad_10bit] = {.num_channels = 4, .resolution = 10},
41 [quad_12bit] = {.num_channels = 4, .resolution = 12},
42 };
43
44 struct dac5571_data {
45 struct i2c_client *client;
46 int id;
47 struct mutex lock;
48 struct regulator *vref;
49 u16 val[4];
50 bool powerdown;
51 u8 powerdown_mode;
52 struct dac5571_spec const *spec;
53 int (*dac5571_cmd)(struct dac5571_data *data, int channel, u16 val);
54 int (*dac5571_pwrdwn)(struct dac5571_data *data, int channel, u8 pwrdwn);
55 u8 buf[3] ____cacheline_aligned;
56 };
57
58 #define DAC5571_POWERDOWN(mode) ((mode) + 1)
59 #define DAC5571_POWERDOWN_FLAG BIT(0)
60 #define DAC5571_CHANNEL_SELECT 1
61 #define DAC5571_LOADMODE_DIRECT BIT(4)
62 #define DAC5571_SINGLE_PWRDWN_BITS 4
63 #define DAC5571_QUAD_PWRDWN_BITS 6
64
dac5571_cmd_single(struct dac5571_data * data,int channel,u16 val)65 static int dac5571_cmd_single(struct dac5571_data *data, int channel, u16 val)
66 {
67 unsigned int shift;
68
69 shift = 12 - data->spec->resolution;
70 data->buf[1] = val << shift;
71 data->buf[0] = val >> (8 - shift);
72
73 if (i2c_master_send(data->client, data->buf, 2) != 2)
74 return -EIO;
75
76 return 0;
77 }
78
dac5571_cmd_quad(struct dac5571_data * data,int channel,u16 val)79 static int dac5571_cmd_quad(struct dac5571_data *data, int channel, u16 val)
80 {
81 unsigned int shift;
82
83 shift = 16 - data->spec->resolution;
84 data->buf[2] = val << shift;
85 data->buf[1] = (val >> (8 - shift));
86 data->buf[0] = (channel << DAC5571_CHANNEL_SELECT) |
87 DAC5571_LOADMODE_DIRECT;
88
89 if (i2c_master_send(data->client, data->buf, 3) != 3)
90 return -EIO;
91
92 return 0;
93 }
94
dac5571_pwrdwn_single(struct dac5571_data * data,int channel,u8 pwrdwn)95 static int dac5571_pwrdwn_single(struct dac5571_data *data, int channel, u8 pwrdwn)
96 {
97 data->buf[1] = 0;
98 data->buf[0] = pwrdwn << DAC5571_SINGLE_PWRDWN_BITS;
99
100 if (i2c_master_send(data->client, data->buf, 2) != 2)
101 return -EIO;
102
103 return 0;
104 }
105
dac5571_pwrdwn_quad(struct dac5571_data * data,int channel,u8 pwrdwn)106 static int dac5571_pwrdwn_quad(struct dac5571_data *data, int channel, u8 pwrdwn)
107 {
108 data->buf[2] = 0;
109 data->buf[1] = pwrdwn << DAC5571_QUAD_PWRDWN_BITS;
110 data->buf[0] = (channel << DAC5571_CHANNEL_SELECT) |
111 DAC5571_LOADMODE_DIRECT | DAC5571_POWERDOWN_FLAG;
112
113 if (i2c_master_send(data->client, data->buf, 3) != 3)
114 return -EIO;
115
116 return 0;
117 }
118
119 static const char *const dac5571_powerdown_modes[] = {
120 "1kohm_to_gnd", "100kohm_to_gnd", "three_state",
121 };
122
dac5571_get_powerdown_mode(struct iio_dev * indio_dev,const struct iio_chan_spec * chan)123 static int dac5571_get_powerdown_mode(struct iio_dev *indio_dev,
124 const struct iio_chan_spec *chan)
125 {
126 struct dac5571_data *data = iio_priv(indio_dev);
127
128 return data->powerdown_mode;
129 }
130
dac5571_set_powerdown_mode(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,unsigned int mode)131 static int dac5571_set_powerdown_mode(struct iio_dev *indio_dev,
132 const struct iio_chan_spec *chan,
133 unsigned int mode)
134 {
135 struct dac5571_data *data = iio_priv(indio_dev);
136 int ret = 0;
137
138 if (data->powerdown_mode == mode)
139 return 0;
140
141 mutex_lock(&data->lock);
142 if (data->powerdown) {
143 ret = data->dac5571_pwrdwn(data, chan->channel,
144 DAC5571_POWERDOWN(mode));
145 if (ret)
146 goto out;
147 }
148 data->powerdown_mode = mode;
149
150 out:
151 mutex_unlock(&data->lock);
152
153 return ret;
154 }
155
156 static const struct iio_enum dac5571_powerdown_mode = {
157 .items = dac5571_powerdown_modes,
158 .num_items = ARRAY_SIZE(dac5571_powerdown_modes),
159 .get = dac5571_get_powerdown_mode,
160 .set = dac5571_set_powerdown_mode,
161 };
162
dac5571_read_powerdown(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,char * buf)163 static ssize_t dac5571_read_powerdown(struct iio_dev *indio_dev,
164 uintptr_t private,
165 const struct iio_chan_spec *chan,
166 char *buf)
167 {
168 struct dac5571_data *data = iio_priv(indio_dev);
169
170 return sprintf(buf, "%d\n", data->powerdown);
171 }
172
dac5571_write_powerdown(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,const char * buf,size_t len)173 static ssize_t dac5571_write_powerdown(struct iio_dev *indio_dev,
174 uintptr_t private,
175 const struct iio_chan_spec *chan,
176 const char *buf, size_t len)
177 {
178 struct dac5571_data *data = iio_priv(indio_dev);
179 bool powerdown;
180 int ret;
181
182 ret = strtobool(buf, &powerdown);
183 if (ret)
184 return ret;
185
186 if (data->powerdown == powerdown)
187 return len;
188
189 mutex_lock(&data->lock);
190 if (powerdown)
191 ret = data->dac5571_pwrdwn(data, chan->channel,
192 DAC5571_POWERDOWN(data->powerdown_mode));
193 else
194 ret = data->dac5571_cmd(data, chan->channel, data->val[0]);
195 if (ret)
196 goto out;
197
198 data->powerdown = powerdown;
199
200 out:
201 mutex_unlock(&data->lock);
202
203 return ret ? ret : len;
204 }
205
206
207 static 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_SHARED_BY_TYPE,
213 },
214 IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE, &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
231 static 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
dac5571_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)238 static 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
dac5571_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)264 static 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)
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
dac5571_write_raw_get_fmt(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,long mask)294 static 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
301 static 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
dac5571_probe(struct i2c_client * client,const struct i2c_device_id * id)307 static 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->dev.parent = dev;
325 indio_dev->dev.of_node = client->dev.of_node;
326 indio_dev->info = &dac5571_info;
327 indio_dev->name = id->name;
328 indio_dev->modes = INDIO_DIRECT_MODE;
329 indio_dev->channels = dac5571_channels;
330
331 spec = &dac5571_spec[id->driver_data];
332 indio_dev->num_channels = spec->num_channels;
333 data->spec = spec;
334
335 data->vref = devm_regulator_get(dev, "vref");
336 if (IS_ERR(data->vref))
337 return PTR_ERR(data->vref);
338
339 ret = regulator_enable(data->vref);
340 if (ret < 0)
341 return ret;
342
343 mutex_init(&data->lock);
344
345 switch (spec->num_channels) {
346 case 1:
347 data->dac5571_cmd = dac5571_cmd_single;
348 data->dac5571_pwrdwn = dac5571_pwrdwn_single;
349 break;
350 case 4:
351 data->dac5571_cmd = dac5571_cmd_quad;
352 data->dac5571_pwrdwn = dac5571_pwrdwn_quad;
353 break;
354 default:
355 ret = -EINVAL;
356 goto err;
357 }
358
359 for (i = 0; i < spec->num_channels; i++) {
360 ret = data->dac5571_cmd(data, i, 0);
361 if (ret) {
362 dev_err(dev, "failed to initialize channel %d to 0\n", i);
363 goto err;
364 }
365 }
366
367 ret = iio_device_register(indio_dev);
368 if (ret)
369 goto err;
370
371 return 0;
372
373 err:
374 regulator_disable(data->vref);
375 return ret;
376 }
377
dac5571_remove(struct i2c_client * i2c)378 static int dac5571_remove(struct i2c_client *i2c)
379 {
380 struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
381 struct dac5571_data *data = iio_priv(indio_dev);
382
383 iio_device_unregister(indio_dev);
384 regulator_disable(data->vref);
385
386 return 0;
387 }
388
389 #ifdef CONFIG_OF
390 static const struct of_device_id dac5571_of_id[] = {
391 {.compatible = "ti,dac5571"},
392 {.compatible = "ti,dac6571"},
393 {.compatible = "ti,dac7571"},
394 {.compatible = "ti,dac5574"},
395 {.compatible = "ti,dac6574"},
396 {.compatible = "ti,dac7574"},
397 {.compatible = "ti,dac5573"},
398 {.compatible = "ti,dac6573"},
399 {.compatible = "ti,dac7573"},
400 {}
401 };
402 MODULE_DEVICE_TABLE(of, dac5571_of_id);
403 #endif
404
405 static const struct i2c_device_id dac5571_id[] = {
406 {"dac5571", single_8bit},
407 {"dac6571", single_10bit},
408 {"dac7571", single_12bit},
409 {"dac5574", quad_8bit},
410 {"dac6574", quad_10bit},
411 {"dac7574", quad_12bit},
412 {"dac5573", quad_8bit},
413 {"dac6573", quad_10bit},
414 {"dac7573", quad_12bit},
415 {}
416 };
417 MODULE_DEVICE_TABLE(i2c, dac5571_id);
418
419 static struct i2c_driver dac5571_driver = {
420 .driver = {
421 .name = "ti-dac5571",
422 .of_match_table = of_match_ptr(dac5571_of_id),
423 },
424 .probe = dac5571_probe,
425 .remove = dac5571_remove,
426 .id_table = dac5571_id,
427 };
428 module_i2c_driver(dac5571_driver);
429
430 MODULE_AUTHOR("Sean Nyekjaer <sean@geanix.dk>");
431 MODULE_DESCRIPTION("Texas Instruments 8/10/12-bit 1/4-channel DAC driver");
432 MODULE_LICENSE("GPL v2");
433