1 // SPDX-License-Identifier: GPL-2.0+
3 * lmp91000.c - Support for Texas Instruments digital potentiostats
5 * Copyright (C) 2016, 2018
6 * Author: Matt Ranostay <matt.ranostay@konsulko.com>
8 * TODO: bias voltage + polarity control, and multiple chip support
11 #include <linux/module.h>
12 #include <linux/i2c.h>
13 #include <linux/delay.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>
23 #define LMP91000_REG_LOCK 0x01
24 #define LMP91000_REG_TIACN 0x10
25 #define LMP91000_REG_TIACN_GAIN_SHIFT 2
27 #define LMP91000_REG_REFCN 0x11
28 #define LMP91000_REG_REFCN_EXT_REF 0x20
29 #define LMP91000_REG_REFCN_50_ZERO 0x80
31 #define LMP91000_REG_MODECN 0x12
32 #define LMP91000_REG_MODECN_3LEAD 0x03
33 #define LMP91000_REG_MODECN_TEMP 0x07
35 #define LMP91000_DRV_NAME "lmp91000"
37 static const int lmp91000_tia_gain[] = { 0, 2750, 3500, 7000, 14000, 35000,
40 static const int lmp91000_rload[] = { 10, 33, 50, 100 };
42 #define LMP91000_TEMP_BASE -40
44 static 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 };
59 static const struct regmap_config lmp91000_regmap_config = {
64 struct lmp91000_data {
65 struct regmap *regmap;
68 struct iio_trigger *trig;
69 struct iio_cb_buffer *cb_buffer;
70 struct iio_channel *adc_chan;
72 struct completion completion;
74 /* 64-bit data + 64-bit naturally aligned timestamp */
75 u32 buffer[4] __aligned(8);
78 static const struct iio_chan_spec lmp91000_channels[] = {
79 { /* chemical channel mV */
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),
93 IIO_CHAN_SOFT_TIMESTAMP(1),
94 { /* temperature channel mV */
97 .address = LMP91000_REG_MODECN_TEMP,
98 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
103 static int lmp91000_read(struct lmp91000_data *data, int channel, int *val)
107 ret = regmap_read(data->regmap, LMP91000_REG_MODECN, &state);
111 ret = regmap_write(data->regmap, LMP91000_REG_MODECN, channel);
115 /* delay till first temperature reading is complete */
116 if ((state != channel) && (channel == LMP91000_REG_MODECN_TEMP))
117 usleep_range(3000, 4000);
119 data->chan_select = channel != LMP91000_REG_MODECN_3LEAD;
121 iio_trigger_poll_chained(data->trig);
123 ret = wait_for_completion_timeout(&data->completion, HZ);
124 reinit_completion(&data->completion);
129 *val = data->buffer[data->chan_select];
134 static irqreturn_t lmp91000_buffer_handler(int irq, void *private)
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);
141 memset(data->buffer, 0, sizeof(data->buffer));
143 ret = lmp91000_read(data, LMP91000_REG_MODECN_3LEAD, &val);
145 data->buffer[0] = val;
146 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
147 iio_get_time_ns(indio_dev));
150 iio_trigger_notify_done(indio_dev->trig);
155 static int lmp91000_read_raw(struct iio_dev *indio_dev,
156 struct iio_chan_spec const *chan,
157 int *val, int *val2, long mask)
159 struct lmp91000_data *data = iio_priv(indio_dev);
162 case IIO_CHAN_INFO_RAW:
163 case IIO_CHAN_INFO_PROCESSED: {
164 int ret = iio_channel_start_all_cb(data->cb_buffer);
169 ret = lmp91000_read(data, chan->address, val);
171 iio_channel_stop_all_cb(data->cb_buffer);
176 if (mask == IIO_CHAN_INFO_PROCESSED) {
179 ret = iio_convert_raw_to_processed(data->adc_chan,
184 for (i = 0; i < ARRAY_SIZE(lmp91000_temp_lut); i++)
185 if (lmp91000_temp_lut[i] < tmp)
188 *val = (LMP91000_TEMP_BASE + i) * 1000;
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);
201 static const struct iio_info lmp91000_info = {
202 .read_raw = lmp91000_read_raw,
205 static int lmp91000_read_config(struct lmp91000_data *data)
207 struct device *dev = data->dev;
208 struct device_node *np = dev->of_node;
209 unsigned int reg, val;
212 ret = of_property_read_u32(np, "ti,tia-gain-ohm", &val);
214 if (of_property_read_bool(np, "ti,external-tia-resistor"))
217 dev_err(dev, "no ti,tia-gain-ohm defined");
223 for (i = 0; i < ARRAY_SIZE(lmp91000_tia_gain); i++) {
224 if (lmp91000_tia_gain[i] == val) {
225 reg = i << LMP91000_REG_TIACN_GAIN_SHIFT;
232 dev_err(dev, "invalid ti,tia-gain-ohm %d\n", val);
236 ret = of_property_read_u32(np, "ti,rload-ohm", &val);
239 dev_info(dev, "no ti,rload-ohm defined, default to %d\n", val);
243 for (i = 0; i < ARRAY_SIZE(lmp91000_rload); i++) {
244 if (lmp91000_rload[i] == val) {
252 dev_err(dev, "invalid ti,rload-ohm %d\n", val);
256 regmap_write(data->regmap, LMP91000_REG_LOCK, 0);
257 regmap_write(data->regmap, LMP91000_REG_TIACN, reg);
258 regmap_write(data->regmap, LMP91000_REG_REFCN, LMP91000_REG_REFCN_EXT_REF
259 | LMP91000_REG_REFCN_50_ZERO);
260 regmap_write(data->regmap, LMP91000_REG_LOCK, 1);
265 static int lmp91000_buffer_cb(const void *val, void *private)
267 struct iio_dev *indio_dev = private;
268 struct lmp91000_data *data = iio_priv(indio_dev);
270 data->buffer[data->chan_select] = *((int *)val);
271 complete_all(&data->completion);
276 static const struct iio_trigger_ops lmp91000_trigger_ops = {
280 static int lmp91000_buffer_preenable(struct iio_dev *indio_dev)
282 struct lmp91000_data *data = iio_priv(indio_dev);
284 return iio_channel_start_all_cb(data->cb_buffer);
287 static int lmp91000_buffer_predisable(struct iio_dev *indio_dev)
289 struct lmp91000_data *data = iio_priv(indio_dev);
291 iio_channel_stop_all_cb(data->cb_buffer);
296 static const struct iio_buffer_setup_ops lmp91000_buffer_setup_ops = {
297 .preenable = lmp91000_buffer_preenable,
298 .postenable = iio_triggered_buffer_postenable,
299 .predisable = lmp91000_buffer_predisable,
302 static int lmp91000_probe(struct i2c_client *client,
303 const struct i2c_device_id *id)
305 struct device *dev = &client->dev;
306 struct lmp91000_data *data;
307 struct iio_dev *indio_dev;
310 indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
314 indio_dev->info = &lmp91000_info;
315 indio_dev->channels = lmp91000_channels;
316 indio_dev->num_channels = ARRAY_SIZE(lmp91000_channels);
317 indio_dev->name = LMP91000_DRV_NAME;
318 indio_dev->dev.parent = &client->dev;
319 indio_dev->modes = INDIO_DIRECT_MODE;
320 i2c_set_clientdata(client, indio_dev);
322 data = iio_priv(indio_dev);
324 data->regmap = devm_regmap_init_i2c(client, &lmp91000_regmap_config);
325 if (IS_ERR(data->regmap)) {
326 dev_err(dev, "regmap initialization failed.\n");
327 return PTR_ERR(data->regmap);
330 data->trig = devm_iio_trigger_alloc(data->dev, "%s-mux%d",
331 indio_dev->name, indio_dev->id);
333 dev_err(dev, "cannot allocate iio trigger.\n");
337 data->trig->ops = &lmp91000_trigger_ops;
338 data->trig->dev.parent = dev;
339 init_completion(&data->completion);
341 ret = lmp91000_read_config(data);
345 ret = iio_trigger_set_immutable(iio_channel_cb_get_iio_dev(data->cb_buffer),
348 dev_err(dev, "cannot set immutable trigger.\n");
352 ret = iio_trigger_register(data->trig);
354 dev_err(dev, "cannot register iio trigger.\n");
358 ret = iio_triggered_buffer_setup(indio_dev, NULL,
359 &lmp91000_buffer_handler,
360 &lmp91000_buffer_setup_ops);
362 goto error_unreg_trigger;
364 data->cb_buffer = iio_channel_get_all_cb(dev, &lmp91000_buffer_cb,
367 if (IS_ERR(data->cb_buffer)) {
368 if (PTR_ERR(data->cb_buffer) == -ENODEV)
371 ret = PTR_ERR(data->cb_buffer);
373 goto error_unreg_buffer;
376 data->adc_chan = iio_channel_cb_get_channels(data->cb_buffer);
378 ret = iio_device_register(indio_dev);
380 goto error_unreg_cb_buffer;
384 error_unreg_cb_buffer:
385 iio_channel_release_all_cb(data->cb_buffer);
388 iio_triggered_buffer_cleanup(indio_dev);
391 iio_trigger_unregister(data->trig);
396 static int lmp91000_remove(struct i2c_client *client)
398 struct iio_dev *indio_dev = i2c_get_clientdata(client);
399 struct lmp91000_data *data = iio_priv(indio_dev);
401 iio_device_unregister(indio_dev);
403 iio_channel_stop_all_cb(data->cb_buffer);
404 iio_channel_release_all_cb(data->cb_buffer);
406 iio_triggered_buffer_cleanup(indio_dev);
407 iio_trigger_unregister(data->trig);
412 static const struct of_device_id lmp91000_of_match[] = {
413 { .compatible = "ti,lmp91000", },
414 { .compatible = "ti,lmp91002", },
417 MODULE_DEVICE_TABLE(of, lmp91000_of_match);
419 static const struct i2c_device_id lmp91000_id[] = {
424 MODULE_DEVICE_TABLE(i2c, lmp91000_id);
426 static struct i2c_driver lmp91000_driver = {
428 .name = LMP91000_DRV_NAME,
429 .of_match_table = of_match_ptr(lmp91000_of_match),
431 .probe = lmp91000_probe,
432 .remove = lmp91000_remove,
433 .id_table = lmp91000_id,
435 module_i2c_driver(lmp91000_driver);
437 MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
438 MODULE_DESCRIPTION("LMP91000 digital potentiostat");
439 MODULE_LICENSE("GPL");