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11#include <linux/module.h>
12#include <linux/i2c.h>
13#include <linux/delay.h>
14#include <linux/of.h>
15#include <linux/regmap.h>
16#include <linux/iio/iio.h>
17#include <linux/iio/buffer.h>
18#include <linux/iio/consumer.h>
19#include <linux/iio/trigger.h>
20#include <linux/iio/trigger_consumer.h>
21#include <linux/iio/triggered_buffer.h>
22
23#define LMP91000_REG_LOCK 0x01
24#define LMP91000_REG_TIACN 0x10
25#define LMP91000_REG_TIACN_GAIN_SHIFT 2
26
27#define LMP91000_REG_REFCN 0x11
28#define LMP91000_REG_REFCN_EXT_REF 0x20
29#define LMP91000_REG_REFCN_50_ZERO 0x80
30
31#define LMP91000_REG_MODECN 0x12
32#define LMP91000_REG_MODECN_3LEAD 0x03
33#define LMP91000_REG_MODECN_TEMP 0x07
34
35#define LMP91000_DRV_NAME "lmp91000"
36
37static const int lmp91000_tia_gain[] = { 0, 2750, 3500, 7000, 14000, 35000,
38 120000, 350000 };
39
40static const int lmp91000_rload[] = { 10, 33, 50, 100 };
41
42#define LMP91000_TEMP_BASE -40
43
44static const u16 lmp91000_temp_lut[] = {
45 1875, 1867, 1860, 1852, 1844, 1836, 1828, 1821, 1813, 1805,
46 1797, 1789, 1782, 1774, 1766, 1758, 1750, 1742, 1734, 1727,
47 1719, 1711, 1703, 1695, 1687, 1679, 1671, 1663, 1656, 1648,
48 1640, 1632, 1624, 1616, 1608, 1600, 1592, 1584, 1576, 1568,
49 1560, 1552, 1544, 1536, 1528, 1520, 1512, 1504, 1496, 1488,
50 1480, 1472, 1464, 1456, 1448, 1440, 1432, 1424, 1415, 1407,
51 1399, 1391, 1383, 1375, 1367, 1359, 1351, 1342, 1334, 1326,
52 1318, 1310, 1302, 1293, 1285, 1277, 1269, 1261, 1253, 1244,
53 1236, 1228, 1220, 1212, 1203, 1195, 1187, 1179, 1170, 1162,
54 1154, 1146, 1137, 1129, 1121, 1112, 1104, 1096, 1087, 1079,
55 1071, 1063, 1054, 1046, 1038, 1029, 1021, 1012, 1004, 996,
56 987, 979, 971, 962, 954, 945, 937, 929, 920, 912,
57 903, 895, 886, 878, 870, 861 };
58
59static const struct regmap_config lmp91000_regmap_config = {
60 .reg_bits = 8,
61 .val_bits = 8,
62};
63
64struct lmp91000_data {
65 struct regmap *regmap;
66 struct device *dev;
67
68 struct iio_trigger *trig;
69 struct iio_cb_buffer *cb_buffer;
70 struct iio_channel *adc_chan;
71
72 struct completion completion;
73 u8 chan_select;
74
75 u32 buffer[4];
76};
77
78static const struct iio_chan_spec lmp91000_channels[] = {
79 {
80 .type = IIO_VOLTAGE,
81 .channel = 0,
82 .address = LMP91000_REG_MODECN_3LEAD,
83 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
84 BIT(IIO_CHAN_INFO_OFFSET) |
85 BIT(IIO_CHAN_INFO_SCALE),
86 .scan_index = 0,
87 .scan_type = {
88 .sign = 's',
89 .realbits = 32,
90 .storagebits = 32,
91 },
92 },
93 IIO_CHAN_SOFT_TIMESTAMP(1),
94 {
95 .type = IIO_TEMP,
96 .channel = 1,
97 .address = LMP91000_REG_MODECN_TEMP,
98 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
99 .scan_index = -1,
100 },
101};
102
103static int lmp91000_read(struct lmp91000_data *data, int channel, int *val)
104{
105 int state, ret;
106
107 ret = regmap_read(data->regmap, LMP91000_REG_MODECN, &state);
108 if (ret)
109 return -EINVAL;
110
111 ret = regmap_write(data->regmap, LMP91000_REG_MODECN, channel);
112 if (ret)
113 return -EINVAL;
114
115
116 if (state != channel && channel == LMP91000_REG_MODECN_TEMP)
117 usleep_range(3000, 4000);
118
119 data->chan_select = channel != LMP91000_REG_MODECN_3LEAD;
120
121 iio_trigger_poll_chained(data->trig);
122
123 ret = wait_for_completion_timeout(&data->completion, HZ);
124 reinit_completion(&data->completion);
125
126 if (!ret)
127 return -ETIMEDOUT;
128
129 *val = data->buffer[data->chan_select];
130
131 return 0;
132}
133
134static irqreturn_t lmp91000_buffer_handler(int irq, void *private)
135{
136 struct iio_poll_func *pf = private;
137 struct iio_dev *indio_dev = pf->indio_dev;
138 struct lmp91000_data *data = iio_priv(indio_dev);
139 int ret, val;
140
141 memset(data->buffer, 0, sizeof(data->buffer));
142
143 ret = lmp91000_read(data, LMP91000_REG_MODECN_3LEAD, &val);
144 if (!ret) {
145 data->buffer[0] = val;
146 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
147 iio_get_time_ns(indio_dev));
148 }
149
150 iio_trigger_notify_done(indio_dev->trig);
151
152 return IRQ_HANDLED;
153}
154
155static int lmp91000_read_raw(struct iio_dev *indio_dev,
156 struct iio_chan_spec const *chan,
157 int *val, int *val2, long mask)
158{
159 struct lmp91000_data *data = iio_priv(indio_dev);
160
161 switch (mask) {
162 case IIO_CHAN_INFO_RAW:
163 case IIO_CHAN_INFO_PROCESSED: {
164 int ret = iio_channel_start_all_cb(data->cb_buffer);
165
166 if (ret)
167 return ret;
168
169 ret = lmp91000_read(data, chan->address, val);
170
171 iio_channel_stop_all_cb(data->cb_buffer);
172
173 if (ret)
174 return ret;
175
176 if (mask == IIO_CHAN_INFO_PROCESSED) {
177 int tmp, i;
178
179 ret = iio_convert_raw_to_processed(data->adc_chan,
180 *val, &tmp, 1);
181 if (ret)
182 return ret;
183
184 for (i = 0; i < ARRAY_SIZE(lmp91000_temp_lut); i++)
185 if (lmp91000_temp_lut[i] < tmp)
186 break;
187
188 *val = (LMP91000_TEMP_BASE + i) * 1000;
189 }
190 return IIO_VAL_INT;
191 }
192 case IIO_CHAN_INFO_OFFSET:
193 return iio_read_channel_offset(data->adc_chan, val, val2);
194 case IIO_CHAN_INFO_SCALE:
195 return iio_read_channel_scale(data->adc_chan, val, val2);
196 }
197
198 return -EINVAL;
199}
200
201static const struct iio_info lmp91000_info = {
202 .read_raw = lmp91000_read_raw,
203};
204
205static int lmp91000_read_config(struct lmp91000_data *data)
206{
207 struct device *dev = data->dev;
208 struct device_node *np = dev->of_node;
209 unsigned int reg, val;
210 int i, ret;
211
212 ret = of_property_read_u32(np, "ti,tia-gain-ohm", &val);
213 if (ret) {
214 if (!of_property_read_bool(np, "ti,external-tia-resistor")) {
215 dev_err(dev, "no ti,tia-gain-ohm defined and external resistor not specified\n");
216 return ret;
217 }
218 val = 0;
219 }
220
221 ret = -EINVAL;
222 for (i = 0; i < ARRAY_SIZE(lmp91000_tia_gain); i++) {
223 if (lmp91000_tia_gain[i] == val) {
224 reg = i << LMP91000_REG_TIACN_GAIN_SHIFT;
225 ret = 0;
226 break;
227 }
228 }
229
230 if (ret) {
231 dev_err(dev, "invalid ti,tia-gain-ohm %d\n", val);
232 return ret;
233 }
234
235 ret = of_property_read_u32(np, "ti,rload-ohm", &val);
236 if (ret) {
237 val = 100;
238 dev_info(dev, "no ti,rload-ohm defined, default to %d\n", val);
239 }
240
241 ret = -EINVAL;
242 for (i = 0; i < ARRAY_SIZE(lmp91000_rload); i++) {
243 if (lmp91000_rload[i] == val) {
244 reg |= i;
245 ret = 0;
246 break;
247 }
248 }
249
250 if (ret) {
251 dev_err(dev, "invalid ti,rload-ohm %d\n", val);
252 return ret;
253 }
254
255 regmap_write(data->regmap, LMP91000_REG_LOCK, 0);
256 regmap_write(data->regmap, LMP91000_REG_TIACN, reg);
257 regmap_write(data->regmap, LMP91000_REG_REFCN,
258 LMP91000_REG_REFCN_EXT_REF | LMP91000_REG_REFCN_50_ZERO);
259 regmap_write(data->regmap, LMP91000_REG_LOCK, 1);
260
261 return 0;
262}
263
264static int lmp91000_buffer_cb(const void *val, void *private)
265{
266 struct iio_dev *indio_dev = private;
267 struct lmp91000_data *data = iio_priv(indio_dev);
268
269 data->buffer[data->chan_select] = *((int *)val);
270 complete_all(&data->completion);
271
272 return 0;
273}
274
275static const struct iio_trigger_ops lmp91000_trigger_ops = {
276};
277
278static int lmp91000_buffer_preenable(struct iio_dev *indio_dev)
279{
280 struct lmp91000_data *data = iio_priv(indio_dev);
281
282 return iio_channel_start_all_cb(data->cb_buffer);
283}
284
285static int lmp91000_buffer_predisable(struct iio_dev *indio_dev)
286{
287 struct lmp91000_data *data = iio_priv(indio_dev);
288
289 iio_channel_stop_all_cb(data->cb_buffer);
290
291 return 0;
292}
293
294static const struct iio_buffer_setup_ops lmp91000_buffer_setup_ops = {
295 .preenable = lmp91000_buffer_preenable,
296 .postenable = iio_triggered_buffer_postenable,
297 .predisable = lmp91000_buffer_predisable,
298};
299
300static int lmp91000_probe(struct i2c_client *client,
301 const struct i2c_device_id *id)
302{
303 struct device *dev = &client->dev;
304 struct lmp91000_data *data;
305 struct iio_dev *indio_dev;
306 int ret;
307
308 indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
309 if (!indio_dev)
310 return -ENOMEM;
311
312 indio_dev->info = &lmp91000_info;
313 indio_dev->channels = lmp91000_channels;
314 indio_dev->num_channels = ARRAY_SIZE(lmp91000_channels);
315 indio_dev->name = LMP91000_DRV_NAME;
316 indio_dev->dev.parent = &client->dev;
317 indio_dev->modes = INDIO_DIRECT_MODE;
318 i2c_set_clientdata(client, indio_dev);
319
320 data = iio_priv(indio_dev);
321 data->dev = dev;
322 data->regmap = devm_regmap_init_i2c(client, &lmp91000_regmap_config);
323 if (IS_ERR(data->regmap)) {
324 dev_err(dev, "regmap initialization failed.\n");
325 return PTR_ERR(data->regmap);
326 }
327
328 data->trig = devm_iio_trigger_alloc(data->dev, "%s-mux%d",
329 indio_dev->name, indio_dev->id);
330 if (!data->trig) {
331 dev_err(dev, "cannot allocate iio trigger.\n");
332 return -ENOMEM;
333 }
334
335 data->trig->ops = &lmp91000_trigger_ops;
336 data->trig->dev.parent = dev;
337 init_completion(&data->completion);
338
339 ret = lmp91000_read_config(data);
340 if (ret)
341 return ret;
342
343 ret = iio_trigger_set_immutable(iio_channel_cb_get_iio_dev(data->cb_buffer),
344 data->trig);
345 if (ret) {
346 dev_err(dev, "cannot set immutable trigger.\n");
347 return ret;
348 }
349
350 ret = iio_trigger_register(data->trig);
351 if (ret) {
352 dev_err(dev, "cannot register iio trigger.\n");
353 return ret;
354 }
355
356 ret = iio_triggered_buffer_setup(indio_dev, NULL,
357 &lmp91000_buffer_handler,
358 &lmp91000_buffer_setup_ops);
359 if (ret)
360 goto error_unreg_trigger;
361
362 data->cb_buffer = iio_channel_get_all_cb(dev, &lmp91000_buffer_cb,
363 indio_dev);
364
365 if (IS_ERR(data->cb_buffer)) {
366 if (PTR_ERR(data->cb_buffer) == -ENODEV)
367 ret = -EPROBE_DEFER;
368 else
369 ret = PTR_ERR(data->cb_buffer);
370
371 goto error_unreg_buffer;
372 }
373
374 data->adc_chan = iio_channel_cb_get_channels(data->cb_buffer);
375
376 ret = iio_device_register(indio_dev);
377 if (ret)
378 goto error_unreg_cb_buffer;
379
380 return 0;
381
382error_unreg_cb_buffer:
383 iio_channel_release_all_cb(data->cb_buffer);
384
385error_unreg_buffer:
386 iio_triggered_buffer_cleanup(indio_dev);
387
388error_unreg_trigger:
389 iio_trigger_unregister(data->trig);
390
391 return ret;
392}
393
394static int lmp91000_remove(struct i2c_client *client)
395{
396 struct iio_dev *indio_dev = i2c_get_clientdata(client);
397 struct lmp91000_data *data = iio_priv(indio_dev);
398
399 iio_device_unregister(indio_dev);
400
401 iio_channel_stop_all_cb(data->cb_buffer);
402 iio_channel_release_all_cb(data->cb_buffer);
403
404 iio_triggered_buffer_cleanup(indio_dev);
405 iio_trigger_unregister(data->trig);
406
407 return 0;
408}
409
410static const struct of_device_id lmp91000_of_match[] = {
411 { .compatible = "ti,lmp91000", },
412 { .compatible = "ti,lmp91002", },
413 { },
414};
415MODULE_DEVICE_TABLE(of, lmp91000_of_match);
416
417static const struct i2c_device_id lmp91000_id[] = {
418 { "lmp91000", 0 },
419 { "lmp91002", 0 },
420 {}
421};
422MODULE_DEVICE_TABLE(i2c, lmp91000_id);
423
424static struct i2c_driver lmp91000_driver = {
425 .driver = {
426 .name = LMP91000_DRV_NAME,
427 .of_match_table = of_match_ptr(lmp91000_of_match),
428 },
429 .probe = lmp91000_probe,
430 .remove = lmp91000_remove,
431 .id_table = lmp91000_id,
432};
433module_i2c_driver(lmp91000_driver);
434
435MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
436MODULE_DESCRIPTION("LMP91000 digital potentiostat");
437MODULE_LICENSE("GPL");
438
