[linux-2.6-block.git] / drivers / iio / potentiostat / lmp91000.c

/*
 * lmp91000.c - Support for Texas Instruments digital potentiostats
 *
 * Copyright (C) 2016 Matt Ranostay <mranostay@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * TODO: bias voltage + polarity control, and multiple chip support
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/regmap.h>
#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include <linux/iio/consumer.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>

#define LMP91000_REG_LOCK		0x01
#define LMP91000_REG_TIACN		0x10
#define LMP91000_REG_TIACN_GAIN_SHIFT	2

#define LMP91000_REG_REFCN		0x11
#define LMP91000_REG_REFCN_EXT_REF	0x20
#define LMP91000_REG_REFCN_50_ZERO	0x80

#define LMP91000_REG_MODECN		0x12
#define LMP91000_REG_MODECN_3LEAD	0x03
#define LMP91000_REG_MODECN_TEMP	0x07

#define LMP91000_DRV_NAME	"lmp91000"

static const int lmp91000_tia_gain[] = { 0, 2750, 3500, 7000, 14000, 35000,
					 120000, 350000 };

static const int lmp91000_rload[] = { 10, 33, 50, 100 };

#define LMP91000_TEMP_BASE	-40

static const u16 lmp91000_temp_lut[] = {
	1875, 1867, 1860, 1852, 1844, 1836, 1828, 1821, 1813, 1805,
	1797, 1789, 1782, 1774, 1766, 1758, 1750, 1742, 1734, 1727,
	1719, 1711, 1703, 1695, 1687, 1679, 1671, 1663, 1656, 1648,
	1640, 1632, 1624, 1616, 1608, 1600, 1592, 1584, 1576, 1568,
	1560, 1552, 1544, 1536, 1528, 1520, 1512, 1504, 1496, 1488,
	1480, 1472, 1464, 1456, 1448, 1440, 1432, 1424, 1415, 1407,
	1399, 1391, 1383, 1375, 1367, 1359, 1351, 1342, 1334, 1326,
	1318, 1310, 1302, 1293, 1285, 1277, 1269, 1261, 1253, 1244,
	1236, 1228, 1220, 1212, 1203, 1195, 1187, 1179, 1170, 1162,
	1154, 1146, 1137, 1129, 1121, 1112, 1104, 1096, 1087, 1079,
	1071, 1063, 1054, 1046, 1038, 1029, 1021, 1012, 1004,  996,
	 987,  979,  971,  962,  954,  945,  937,  929,  920,  912,
	 903,  895,  886,  878,  870,  861 };

static const struct regmap_config lmp91000_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
};

struct lmp91000_data {
	struct regmap *regmap;
	struct device *dev;

	struct iio_trigger *trig;
	struct iio_cb_buffer *cb_buffer;
	struct iio_channel *adc_chan;

	struct completion completion;
	u8 chan_select;

	u32 buffer[4]; /* 64-bit data + 64-bit timestamp */
};

static const struct iio_chan_spec lmp91000_channels[] = {
	{ /* chemical channel mV */
		.type = IIO_VOLTAGE,
		.channel = 0,
		.address = LMP91000_REG_MODECN_3LEAD,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
				      BIT(IIO_CHAN_INFO_OFFSET) |
				      BIT(IIO_CHAN_INFO_SCALE),
		.scan_index = 0,
		.scan_type = {
			.sign = 's',
			.realbits = 32,
			.storagebits = 32,
		},
	},
	IIO_CHAN_SOFT_TIMESTAMP(1),
	{ /* temperature channel mV */
		.type = IIO_TEMP,
		.channel = 1,
		.address = LMP91000_REG_MODECN_TEMP,
		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
		.scan_index = -1,
	},
};

static int lmp91000_read(struct lmp91000_data *data, int channel, int *val)
{
	int state, ret;

	ret = regmap_read(data->regmap, LMP91000_REG_MODECN, &state);
	if (ret)
		return -EINVAL;

	ret = regmap_write(data->regmap, LMP91000_REG_MODECN, channel);
	if (ret)
		return -EINVAL;

	/* delay till first temperature reading is complete */
	if ((state != channel) && (channel == LMP91000_REG_MODECN_TEMP))
		usleep_range(3000, 4000);

	data->chan_select = channel != LMP91000_REG_MODECN_3LEAD;

	iio_trigger_poll_chained(data->trig);

	ret = wait_for_completion_timeout(&data->completion, HZ);
	reinit_completion(&data->completion);

	if (!ret)
		return -ETIMEDOUT;

	*val = data->buffer[data->chan_select];

	return 0;
}

static irqreturn_t lmp91000_buffer_handler(int irq, void *private)
{
	struct iio_poll_func *pf = private;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct lmp91000_data *data = iio_priv(indio_dev);
	int ret, val;

	memset(data->buffer, 0, sizeof(data->buffer));

	ret = lmp91000_read(data, LMP91000_REG_MODECN_3LEAD, &val);
	if (!ret) {
		data->buffer[0] = val;
		iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
						   iio_get_time_ns(indio_dev));
	}

	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
}

static int lmp91000_read_raw(struct iio_dev *indio_dev,
			     struct iio_chan_spec const *chan,
			     int *val, int *val2, long mask)
{
	struct lmp91000_data *data = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
	case IIO_CHAN_INFO_PROCESSED: {
		int ret = iio_channel_start_all_cb(data->cb_buffer);

		if (ret)
			return ret;

		ret = lmp91000_read(data, chan->address, val);

		iio_channel_stop_all_cb(data->cb_buffer);

		if (ret)
			return ret;

		if (mask == IIO_CHAN_INFO_PROCESSED) {
			int tmp, i;

			ret = iio_convert_raw_to_processed(data->adc_chan,
							   *val, &tmp, 1);
			if (ret)
				return ret;

			for (i = 0; i < ARRAY_SIZE(lmp91000_temp_lut); i++)
				if (lmp91000_temp_lut[i] < tmp)
					break;

			*val = (LMP91000_TEMP_BASE + i) * 1000;
		}
		return IIO_VAL_INT;
	}
	case IIO_CHAN_INFO_OFFSET:
		return iio_read_channel_offset(data->adc_chan, val, val2);
	case IIO_CHAN_INFO_SCALE:
		return iio_read_channel_scale(data->adc_chan, val, val2);
	}

	return -EINVAL;
}

static const struct iio_info lmp91000_info = {
	.driver_module = THIS_MODULE,
	.read_raw = lmp91000_read_raw,
};

static int lmp91000_read_config(struct lmp91000_data *data)
{
	struct device *dev = data->dev;
	struct device_node *np = dev->of_node;
	unsigned int reg, val;
	int i, ret;

	ret = of_property_read_u32(np, "ti,tia-gain-ohm", &val);
	if (ret) {
		if (of_property_read_bool(np, "ti,external-tia-resistor"))
			val = 0;
		else {
			dev_err(dev, "no ti,tia-gain-ohm defined");
			return ret;
		}
	}

	ret = -EINVAL;
	for (i = 0; i < ARRAY_SIZE(lmp91000_tia_gain); i++) {
		if (lmp91000_tia_gain[i] == val) {
			reg = i << LMP91000_REG_TIACN_GAIN_SHIFT;
			ret = 0;
			break;
		}
	}

	if (ret) {
		dev_err(dev, "invalid ti,tia-gain-ohm %d\n", val);
		return ret;
	}

	ret = of_property_read_u32(np, "ti,rload-ohm", &val);
	if (ret) {
		val = 100;
		dev_info(dev, "no ti,rload-ohm defined, default to %d\n", val);
	}

	ret = -EINVAL;
	for (i = 0; i < ARRAY_SIZE(lmp91000_rload); i++) {
		if (lmp91000_rload[i] == val) {
			reg |= i;
			ret = 0;
			break;
		}
	}

	if (ret) {
		dev_err(dev, "invalid ti,rload-ohm %d\n", val);
		return ret;
	}

	regmap_write(data->regmap, LMP91000_REG_LOCK, 0);
	regmap_write(data->regmap, LMP91000_REG_TIACN, reg);
	regmap_write(data->regmap, LMP91000_REG_REFCN, LMP91000_REG_REFCN_EXT_REF
					| LMP91000_REG_REFCN_50_ZERO);
	regmap_write(data->regmap, LMP91000_REG_LOCK, 1);

	return 0;
}

static int lmp91000_buffer_cb(const void *val, void *private)
{
	struct iio_dev *indio_dev = private;
	struct lmp91000_data *data = iio_priv(indio_dev);

	data->buffer[data->chan_select] = *((int *)val);
	complete_all(&data->completion);

	return 0;
}

static const struct iio_trigger_ops lmp91000_trigger_ops = {
	.owner = THIS_MODULE,
};


static int lmp91000_buffer_preenable(struct iio_dev *indio_dev)
{
	struct lmp91000_data *data = iio_priv(indio_dev);

	return iio_channel_start_all_cb(data->cb_buffer);
}

static int lmp91000_buffer_predisable(struct iio_dev *indio_dev)
{
	struct lmp91000_data *data = iio_priv(indio_dev);

	iio_channel_stop_all_cb(data->cb_buffer);

	return 0;
}

static const struct iio_buffer_setup_ops lmp91000_buffer_setup_ops = {
	.preenable = lmp91000_buffer_preenable,
	.postenable = iio_triggered_buffer_postenable,
	.predisable = lmp91000_buffer_predisable,
};

static int lmp91000_probe(struct i2c_client *client,
			  const struct i2c_device_id *id)
{
	struct device *dev = &client->dev;
	struct lmp91000_data *data;
	struct iio_dev *indio_dev;
	int ret;

	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
	if (!indio_dev)
		return -ENOMEM;

	indio_dev->info = &lmp91000_info;
	indio_dev->channels = lmp91000_channels;
	indio_dev->num_channels = ARRAY_SIZE(lmp91000_channels);
	indio_dev->name = LMP91000_DRV_NAME;
	indio_dev->dev.parent = &client->dev;
	indio_dev->modes = INDIO_DIRECT_MODE;
	i2c_set_clientdata(client, indio_dev);

	data = iio_priv(indio_dev);
	data->dev = dev;
	data->regmap = devm_regmap_init_i2c(client, &lmp91000_regmap_config);
	if (IS_ERR(data->regmap)) {
		dev_err(dev, "regmap initialization failed.\n");
		return PTR_ERR(data->regmap);
	}

	data->trig = devm_iio_trigger_alloc(data->dev, "%s-mux%d",
					    indio_dev->name, indio_dev->id);
	if (!data->trig) {
		dev_err(dev, "cannot allocate iio trigger.\n");
		return -ENOMEM;
	}

	data->trig->ops = &lmp91000_trigger_ops;
	data->trig->dev.parent = dev;
	init_completion(&data->completion);

	ret = lmp91000_read_config(data);
	if (ret)
		return ret;

	ret = iio_trigger_set_immutable(iio_channel_cb_get_iio_dev(data->cb_buffer),
					data->trig);
	if (ret) {
		dev_err(dev, "cannot set immutable trigger.\n");
		return ret;
	}

	ret = iio_trigger_register(data->trig);
	if (ret) {
		dev_err(dev, "cannot register iio trigger.\n");
		return ret;
	}

	ret = iio_triggered_buffer_setup(indio_dev, NULL,
					 &lmp91000_buffer_handler,
					 &lmp91000_buffer_setup_ops);
	if (ret)
		goto error_unreg_trigger;

	data->cb_buffer = iio_channel_get_all_cb(dev, &lmp91000_buffer_cb,
						 indio_dev);

	if (IS_ERR(data->cb_buffer)) {
		if (PTR_ERR(data->cb_buffer) == -ENODEV)
			ret = -EPROBE_DEFER;
		else
			ret = PTR_ERR(data->cb_buffer);

		goto error_unreg_buffer;
	}

	data->adc_chan = iio_channel_cb_get_channels(data->cb_buffer);

	ret = iio_device_register(indio_dev);
	if (ret)
		goto error_unreg_cb_buffer;

	return 0;

error_unreg_cb_buffer:
	iio_channel_release_all_cb(data->cb_buffer);

error_unreg_buffer:
	iio_triggered_buffer_cleanup(indio_dev);

error_unreg_trigger:
	iio_trigger_unregister(data->trig);

	return ret;
}

static int lmp91000_remove(struct i2c_client *client)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);
	struct lmp91000_data *data = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);

	iio_channel_stop_all_cb(data->cb_buffer);
	iio_channel_release_all_cb(data->cb_buffer);

	iio_triggered_buffer_cleanup(indio_dev);
	iio_trigger_unregister(data->trig);

	return 0;
}

static const struct of_device_id lmp91000_of_match[] = {
	{ .compatible = "ti,lmp91000", },
	{ },
};
MODULE_DEVICE_TABLE(of, lmp91000_of_match);

static const struct i2c_device_id lmp91000_id[] = {
	{ "lmp91000", 0 },
	{}
};
MODULE_DEVICE_TABLE(i2c, lmp91000_id);

static struct i2c_driver lmp91000_driver = {
	.driver = {
		.name = LMP91000_DRV_NAME,
		.of_match_table = of_match_ptr(lmp91000_of_match),
	},
	.probe = lmp91000_probe,
	.remove = lmp91000_remove,
	.id_table = lmp91000_id,
};
module_i2c_driver(lmp91000_driver);

MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
MODULE_DESCRIPTION("LMP91000 digital potentiostat");
MODULE_LICENSE("GPL");
Commit	Line	Data
67e17300 MR	1	/*
	2	* lmp91000.c - Support for Texas Instruments digital potentiostats
	3	*
	4	* Copyright (C) 2016 Matt Ranostay <mranostay@gmail.com>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* TODO: bias voltage + polarity control, and multiple chip support
	17	*/
	18
	19	#include <linux/module.h>
	20	#include <linux/i2c.h>
	21	#include <linux/delay.h>
	22	#include <linux/of.h>
	23	#include <linux/regmap.h>
	24	#include <linux/iio/iio.h>
	25	#include <linux/iio/buffer.h>
	26	#include <linux/iio/consumer.h>
	27	#include <linux/iio/trigger.h>
	28	#include <linux/iio/trigger_consumer.h>
	29	#include <linux/iio/triggered_buffer.h>
	30
	31	#define LMP91000_REG_LOCK 0x01
	32	#define LMP91000_REG_TIACN 0x10
	33	#define LMP91000_REG_TIACN_GAIN_SHIFT 2
	34
	35	#define LMP91000_REG_REFCN 0x11
	36	#define LMP91000_REG_REFCN_EXT_REF 0x20
	37	#define LMP91000_REG_REFCN_50_ZERO 0x80
	38
	39	#define LMP91000_REG_MODECN 0x12
	40	#define LMP91000_REG_MODECN_3LEAD 0x03
	41	#define LMP91000_REG_MODECN_TEMP 0x07
	42
	43	#define LMP91000_DRV_NAME "lmp91000"
	44
	45	static const int lmp91000_tia_gain[] = { 0, 2750, 3500, 7000, 14000, 35000,
	46	120000, 350000 };
	47
	48	static const int lmp91000_rload[] = { 10, 33, 50, 100 };
	49
	50	#define LMP91000_TEMP_BASE -40
	51
	52	static const u16 lmp91000_temp_lut[] = {
	53	1875, 1867, 1860, 1852, 1844, 1836, 1828, 1821, 1813, 1805,
	54	1797, 1789, 1782, 1774, 1766, 1758, 1750, 1742, 1734, 1727,
	55	1719, 1711, 1703, 1695, 1687, 1679, 1671, 1663, 1656, 1648,
	56	1640, 1632, 1624, 1616, 1608, 1600, 1592, 1584, 1576, 1568,
	57	1560, 1552, 1544, 1536, 1528, 1520, 1512, 1504, 1496, 1488,
	58	1480, 1472, 1464, 1456, 1448, 1440, 1432, 1424, 1415, 1407,
	59	1399, 1391, 1383, 1375, 1367, 1359, 1351, 1342, 1334, 1326,
	60	1318, 1310, 1302, 1293, 1285, 1277, 1269, 1261, 1253, 1244,
	61	1236, 1228, 1220, 1212, 1203, 1195, 1187, 1179, 1170, 1162,
	62	1154, 1146, 1137, 1129, 1121, 1112, 1104, 1096, 1087, 1079,
	63	1071, 1063, 1054, 1046, 1038, 1029, 1021, 1012, 1004, 996,
	64	987, 979, 971, 962, 954, 945, 937, 929, 920, 912,
65	903, 895, 886, 878, 870, 861 };
66
67	static const struct regmap_config lmp91000_regmap_config = {
68	.reg_bits = 8,
69	.val_bits = 8,
70	};
71
72	struct lmp91000_data {
73	struct regmap *regmap;
74	struct device *dev;
75
76	struct iio_trigger *trig;
77	struct iio_cb_buffer *cb_buffer;
78	struct iio_channel *adc_chan;
79
80	struct completion completion;
81	u8 chan_select;
82
83	u32 buffer[4]; /* 64-bit data + 64-bit timestamp */
84	};
85
86	static const struct iio_chan_spec lmp91000_channels[] = {
87	{ /* chemical channel mV */
88	.type = IIO_VOLTAGE,
89	.channel = 0,
90	.address = LMP91000_REG_MODECN_3LEAD,
91	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \|
92	BIT(IIO_CHAN_INFO_OFFSET) \|
93	BIT(IIO_CHAN_INFO_SCALE),
94	.scan_index = 0,
95	.scan_type = {
96	.sign = 's',
97	.realbits = 32,
98	.storagebits = 32,
99	},
100	},
101	IIO_CHAN_SOFT_TIMESTAMP(1),
102	{ /* temperature channel mV */
103	.type = IIO_TEMP,
104	.channel = 1,
105	.address = LMP91000_REG_MODECN_TEMP,
106	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
107	.scan_index = -1,
108	},
109	};
110
111	static int lmp91000_read(struct lmp91000_data data, int channel, int val)
112	{
113	int state, ret;
114
115	ret = regmap_read(data->regmap, LMP91000_REG_MODECN, &state);
116	if (ret)
117	return -EINVAL;
118
119	ret = regmap_write(data->regmap, LMP91000_REG_MODECN, channel);
120	if (ret)
121	return -EINVAL;
122
123	/* delay till first temperature reading is complete */
124	if ((state != channel) && (channel == LMP91000_REG_MODECN_TEMP))
125	usleep_range(3000, 4000);
126
127	data->chan_select = channel != LMP91000_REG_MODECN_3LEAD;
128
129	iio_trigger_poll_chained(data->trig);
130
131	ret = wait_for_completion_timeout(&data->completion, HZ);
132	reinit_completion(&data->completion);
133
134	if (!ret)
135	return -ETIMEDOUT;
136
137	*val = data->buffer[data->chan_select];
138
139	return 0;
140	}
141
142	static irqreturn_t lmp91000_buffer_handler(int irq, void *private)
143	{
144	struct iio_poll_func *pf = private;
145	struct iio_dev *indio_dev = pf->indio_dev;
146	struct lmp91000_data *data = iio_priv(indio_dev);
147	int ret, val;
148
149	memset(data->buffer, 0, sizeof(data->buffer));
150
151	ret = lmp91000_read(data, LMP91000_REG_MODECN_3LEAD, &val);
152	if (!ret) {
153	data->buffer[0] = val;
154	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
155	iio_get_time_ns(indio_dev));
156	}
157
158	iio_trigger_notify_done(indio_dev->trig);
159
160	return IRQ_HANDLED;
161	}
162
163	static int lmp91000_read_raw(struct iio_dev *indio_dev,
164	struct iio_chan_spec const *chan,
165	int val, int val2, long mask)
166	{
167	struct lmp91000_data *data = iio_priv(indio_dev);
168
169	switch (mask) {
170	case IIO_CHAN_INFO_RAW:
171	case IIO_CHAN_INFO_PROCESSED: {
172	int ret = iio_channel_start_all_cb(data->cb_buffer);
173
174	if (ret)
175	return ret;
176
177	ret = lmp91000_read(data, chan->address, val);
178
179	iio_channel_stop_all_cb(data->cb_buffer);
180
181	if (ret)
182	return ret;
183
184	if (mask == IIO_CHAN_INFO_PROCESSED) {
185	int tmp, i;
186
187	ret = iio_convert_raw_to_processed(data->adc_chan,
188	*val, &tmp, 1);
189	if (ret)
190	return ret;
191
192	for (i = 0; i < ARRAY_SIZE(lmp91000_temp_lut); i++)
193	if (lmp91000_temp_lut[i] < tmp)
194	break;
195
196	val = (LMP91000_TEMP_BASE + i) 1000;
197	}
198	return IIO_VAL_INT;
199	}
200	case IIO_CHAN_INFO_OFFSET:
201	return iio_read_channel_offset(data->adc_chan, val, val2);
202	case IIO_CHAN_INFO_SCALE:
203	return iio_read_channel_scale(data->adc_chan, val, val2);
204	}
205
206	return -EINVAL;
207	}
208
209	static const struct iio_info lmp91000_info = {
210	.driver_module = THIS_MODULE,
211	.read_raw = lmp91000_read_raw,
212	};
213
214	static int lmp91000_read_config(struct lmp91000_data *data)
215	{
216	struct device *dev = data->dev;
217	struct device_node *np = dev->of_node;
218	unsigned int reg, val;
219	int i, ret;
220
221	ret = of_property_read_u32(np, "ti,tia-gain-ohm", &val);
222	if (ret) {
223	if (of_property_read_bool(np, "ti,external-tia-resistor"))
224	val = 0;
225	else {
226	dev_err(dev, "no ti,tia-gain-ohm defined");
227	return ret;
228	}
229	}
230
231	ret = -EINVAL;
232	for (i = 0; i < ARRAY_SIZE(lmp91000_tia_gain); i++) {
233	if (lmp91000_tia_gain[i] == val) {
234	reg = i << LMP91000_REG_TIACN_GAIN_SHIFT;
235	ret = 0;
236	break;
237	}
238	}
239
240	if (ret) {
241	dev_err(dev, "invalid ti,tia-gain-ohm %d\n", val);
242	return ret;
243	}
244
245	ret = of_property_read_u32(np, "ti,rload-ohm", &val);
246	if (ret) {
247	val = 100;
248	dev_info(dev, "no ti,rload-ohm defined, default to %d\n", val);
249	}
250
251	ret = -EINVAL;
252	for (i = 0; i < ARRAY_SIZE(lmp91000_rload); i++) {
253	if (lmp91000_rload[i] == val) {
254	reg \|= i;
255	ret = 0;
256	break;
257	}
258	}
259
260	if (ret) {
261	dev_err(dev, "invalid ti,rload-ohm %d\n", val);
262	return ret;
263	}
264
265	regmap_write(data->regmap, LMP91000_REG_LOCK, 0);
266	regmap_write(data->regmap, LMP91000_REG_TIACN, reg);
267	regmap_write(data->regmap, LMP91000_REG_REFCN, LMP91000_REG_REFCN_EXT_REF
268	\| LMP91000_REG_REFCN_50_ZERO);
269	regmap_write(data->regmap, LMP91000_REG_LOCK, 1);
270
271	return 0;
272	}
273
274	static int lmp91000_buffer_cb(const void val, void private)
275	{
276	struct iio_dev *indio_dev = private;
277	struct lmp91000_data *data = iio_priv(indio_dev);
278
279	data->buffer[data->chan_select] = ((int )val);
280	complete_all(&data->completion);
281
282	return 0;
283	}
284
285	static const struct iio_trigger_ops lmp91000_trigger_ops = {
286	.owner = THIS_MODULE,
287	};
288
289
290	static int lmp91000_buffer_preenable(struct iio_dev *indio_dev)
291	{
292	struct lmp91000_data *data = iio_priv(indio_dev);
293
294	return iio_channel_start_all_cb(data->cb_buffer);
295	}
296
297	static int lmp91000_buffer_predisable(struct iio_dev *indio_dev)
298	{
299	struct lmp91000_data *data = iio_priv(indio_dev);
300
301	iio_channel_stop_all_cb(data->cb_buffer);
302
303	return 0;
304	}
305
306	static const struct iio_buffer_setup_ops lmp91000_buffer_setup_ops = {
307	.preenable = lmp91000_buffer_preenable,
308	.postenable = iio_triggered_buffer_postenable,
309	.predisable = lmp91000_buffer_predisable,
310	};
311
312	static int lmp91000_probe(struct i2c_client *client,
313	const struct i2c_device_id *id)
314	{
315	struct device *dev = &client->dev;
316	struct lmp91000_data *data;
317	struct iio_dev *indio_dev;
318	int ret;
319
320	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
321	if (!indio_dev)
322	return -ENOMEM;
323
324	indio_dev->info = &lmp91000_info;
325	indio_dev->channels = lmp91000_channels;
326	indio_dev->num_channels = ARRAY_SIZE(lmp91000_channels);
327	indio_dev->name = LMP91000_DRV_NAME;
e78c1f57	328	indio_dev->dev.parent = &client->dev;
67e17300 MR	329	indio_dev->modes = INDIO_DIRECT_MODE;
	330	i2c_set_clientdata(client, indio_dev);
	331
	332	data = iio_priv(indio_dev);
	333	data->dev = dev;
	334	data->regmap = devm_regmap_init_i2c(client, &lmp91000_regmap_config);
	335	if (IS_ERR(data->regmap)) {
	336	dev_err(dev, "regmap initialization failed.\n");
	337	return PTR_ERR(data->regmap);
	338	}
	339
	340	data->trig = devm_iio_trigger_alloc(data->dev, "%s-mux%d",
	341	indio_dev->name, indio_dev->id);
	342	if (!data->trig) {
	343	dev_err(dev, "cannot allocate iio trigger.\n");
	344	return -ENOMEM;
	345	}
	346
	347	data->trig->ops = &lmp91000_trigger_ops;
	348	data->trig->dev.parent = dev;
	349	init_completion(&data->completion);
	350
	351	ret = lmp91000_read_config(data);
	352	if (ret)
	353	return ret;
	354
	355	ret = iio_trigger_set_immutable(iio_channel_cb_get_iio_dev(data->cb_buffer),
	356	data->trig);
	357	if (ret) {
	358	dev_err(dev, "cannot set immutable trigger.\n");
	359	return ret;
	360	}
	361
	362	ret = iio_trigger_register(data->trig);
	363	if (ret) {
	364	dev_err(dev, "cannot register iio trigger.\n");
	365	return ret;
	366	}
	367
	368	ret = iio_triggered_buffer_setup(indio_dev, NULL,
	369	&lmp91000_buffer_handler,
	370	&lmp91000_buffer_setup_ops);
	371	if (ret)
	372	goto error_unreg_trigger;
	373
	374	data->cb_buffer = iio_channel_get_all_cb(dev, &lmp91000_buffer_cb,
	375	indio_dev);
	376
	377	if (IS_ERR(data->cb_buffer)) {
	378	if (PTR_ERR(data->cb_buffer) == -ENODEV)
	379	ret = -EPROBE_DEFER;
	380	else
	381	ret = PTR_ERR(data->cb_buffer);
	382
	383	goto error_unreg_buffer;
	384	}
	385
	386	data->adc_chan = iio_channel_cb_get_channels(data->cb_buffer);
	387
	388	ret = iio_device_register(indio_dev);
	389	if (ret)
	390	goto error_unreg_cb_buffer;
	391
	392	return 0;
393
394	error_unreg_cb_buffer:
395	iio_channel_release_all_cb(data->cb_buffer);
396
397	error_unreg_buffer:
398	iio_triggered_buffer_cleanup(indio_dev);
399
400	error_unreg_trigger:
401	iio_trigger_unregister(data->trig);
402
403	return ret;
404	}
405
406	static int lmp91000_remove(struct i2c_client *client)
407	{
408	struct iio_dev *indio_dev = i2c_get_clientdata(client);
409	struct lmp91000_data *data = iio_priv(indio_dev);
410
411	iio_device_unregister(indio_dev);
412
413	iio_channel_stop_all_cb(data->cb_buffer);
414	iio_channel_release_all_cb(data->cb_buffer);
415
416	iio_triggered_buffer_cleanup(indio_dev);
417	iio_trigger_unregister(data->trig);
418
419	return 0;
420	}
421
422	static const struct of_device_id lmp91000_of_match[] = {
423	{ .compatible = "ti,lmp91000", },
424	{ },
425	};
426	MODULE_DEVICE_TABLE(of, lmp91000_of_match);
427
428	static const struct i2c_device_id lmp91000_id[] = {
429	{ "lmp91000", 0 },
430	{}
431	};
432	MODULE_DEVICE_TABLE(i2c, lmp91000_id);
433
434	static struct i2c_driver lmp91000_driver = {
435	.driver = {
436	.name = LMP91000_DRV_NAME,
437	.of_match_table = of_match_ptr(lmp91000_of_match),
438	},
439	.probe = lmp91000_probe,
440	.remove = lmp91000_remove,
441	.id_table = lmp91000_id,
442	};
443	module_i2c_driver(lmp91000_driver);
444
445	MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
446	MODULE_DESCRIPTION("LMP91000 digital potentiostat");
447	MODULE_LICENSE("GPL");