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  1/*
  2 * IIO DAC driver for Analog Devices AD8801 DAC
  3 *
  4 * Copyright (C) 2016 Gwenhael Goavec-Merou
  5 * This program is free software; you can redistribute it and/or modify
  6 * it under the terms of the GNU General Public License, version 2, as
  7 * published by the Free Software Foundation.
  8 *
  9 * This program is distributed in the hope that it will be useful, but
 10 * WITHOUT ANY WARRANTY; without even the implied warranty of
 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 12 * General Public License for more details.
 13 *
 14 */
 15
 16#include <linux/iio/iio.h>
 17#include <linux/module.h>
 18#include <linux/regulator/consumer.h>
 19#include <linux/spi/spi.h>
 20#include <linux/sysfs.h>
 21
 22#define AD8801_CFG_ADDR_OFFSET 8
 23
 24enum ad8801_device_ids {
 25	ID_AD8801,
 26	ID_AD8803,
 27};
 28
 29struct ad8801_state {
 30	struct spi_device *spi;
 31	unsigned char dac_cache[8]; /* Value write on each channel */
 32	unsigned int vrefh_mv;
 33	unsigned int vrefl_mv;
 34	struct regulator *vrefh_reg;
 35	struct regulator *vrefl_reg;
 36
 37	__be16 data ____cacheline_aligned;
 38};
 39
 40static int ad8801_spi_write(struct ad8801_state *state,
 41	u8 channel, unsigned char value)
 42{
 43	state->data = cpu_to_be16((channel << AD8801_CFG_ADDR_OFFSET) | value);
 44	return spi_write(state->spi, &state->data, sizeof(state->data));
 45}
 46
 47static int ad8801_write_raw(struct iio_dev *indio_dev,
 48	struct iio_chan_spec const *chan, int val, int val2, long mask)
 49{
 50	struct ad8801_state *state = iio_priv(indio_dev);
 51	int ret;
 52
 53	switch (mask) {
 54	case IIO_CHAN_INFO_RAW:
 55		if (val >= 256 || val < 0)
 56			return -EINVAL;
 57
 58		ret = ad8801_spi_write(state, chan->channel, val);
 59		if (ret == 0)
 60			state->dac_cache[chan->channel] = val;
 61		break;
 62	default:
 63		ret = -EINVAL;
 64	}
 65
 66	return ret;
 67}
 68
 69static int ad8801_read_raw(struct iio_dev *indio_dev,
 70	struct iio_chan_spec const *chan, int *val, int *val2, long info)
 71{
 72	struct ad8801_state *state = iio_priv(indio_dev);
 73
 74	switch (info) {
 75	case IIO_CHAN_INFO_RAW:
 76		*val = state->dac_cache[chan->channel];
 77		return IIO_VAL_INT;
 78	case IIO_CHAN_INFO_SCALE:
 79		*val = state->vrefh_mv - state->vrefl_mv;
 80		*val2 = 8;
 81		return IIO_VAL_FRACTIONAL_LOG2;
 82	case IIO_CHAN_INFO_OFFSET:
 83		*val = state->vrefl_mv;
 84		return IIO_VAL_INT;
 85	default:
 86		return -EINVAL;
 87	}
 88
 89	return -EINVAL;
 90}
 91
 92static const struct iio_info ad8801_info = {
 93	.read_raw = ad8801_read_raw,
 94	.write_raw = ad8801_write_raw,
 95	.driver_module = THIS_MODULE,
 96};
 97
 98#define AD8801_CHANNEL(chan) {		\
 99	.type = IIO_VOLTAGE,			\
100	.indexed = 1,				\
101	.output = 1,				\
102	.channel = chan,			\
103	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
104	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |	\
105		BIT(IIO_CHAN_INFO_OFFSET), \
106}
107
108static const struct iio_chan_spec ad8801_channels[] = {
109	AD8801_CHANNEL(0),
110	AD8801_CHANNEL(1),
111	AD8801_CHANNEL(2),
112	AD8801_CHANNEL(3),
113	AD8801_CHANNEL(4),
114	AD8801_CHANNEL(5),
115	AD8801_CHANNEL(6),
116	AD8801_CHANNEL(7),
117};
118
119static int ad8801_probe(struct spi_device *spi)
120{
121	struct iio_dev *indio_dev;
122	struct ad8801_state *state;
123	const struct spi_device_id *id;
124	int ret;
125
126	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*state));
127	if (indio_dev == NULL)
128		return -ENOMEM;
129
130	state = iio_priv(indio_dev);
131	state->spi = spi;
132	id = spi_get_device_id(spi);
133
134	state->vrefh_reg = devm_regulator_get(&spi->dev, "vrefh");
135	if (IS_ERR(state->vrefh_reg)) {
136		dev_err(&spi->dev, "Vrefh regulator not specified\n");
137		return PTR_ERR(state->vrefh_reg);
138	}
139
140	ret = regulator_enable(state->vrefh_reg);
141	if (ret) {
142		dev_err(&spi->dev, "Failed to enable vrefh regulator: %d\n",
143				ret);
144		return ret;
145	}
146
147	ret = regulator_get_voltage(state->vrefh_reg);
148	if (ret < 0) {
149		dev_err(&spi->dev, "Failed to read vrefh regulator: %d\n",
150				ret);
151		goto error_disable_vrefh_reg;
152	}
153	state->vrefh_mv = ret / 1000;
154
155	if (id->driver_data == ID_AD8803) {
156		state->vrefl_reg = devm_regulator_get(&spi->dev, "vrefl");
157		if (IS_ERR(state->vrefl_reg)) {
158			dev_err(&spi->dev, "Vrefl regulator not specified\n");
159			ret = PTR_ERR(state->vrefl_reg);
160			goto error_disable_vrefh_reg;
161		}
162
163		ret = regulator_enable(state->vrefl_reg);
164		if (ret) {
165			dev_err(&spi->dev, "Failed to enable vrefl regulator: %d\n",
166					ret);
167			goto error_disable_vrefh_reg;
168		}
169
170		ret = regulator_get_voltage(state->vrefl_reg);
171		if (ret < 0) {
172			dev_err(&spi->dev, "Failed to read vrefl regulator: %d\n",
173					ret);
174			goto error_disable_vrefl_reg;
175		}
176		state->vrefl_mv = ret / 1000;
177	} else {
178		state->vrefl_mv = 0;
179		state->vrefl_reg = NULL;
180	}
181
182	spi_set_drvdata(spi, indio_dev);
183	indio_dev->dev.parent = &spi->dev;
184	indio_dev->info = &ad8801_info;
185	indio_dev->modes = INDIO_DIRECT_MODE;
186	indio_dev->channels = ad8801_channels;
187	indio_dev->num_channels = ARRAY_SIZE(ad8801_channels);
188	indio_dev->name = id->name;
189
190	ret = iio_device_register(indio_dev);
191	if (ret) {
192		dev_err(&spi->dev, "Failed to register iio device: %d\n",
193				ret);
194		goto error_disable_vrefl_reg;
195	}
196
197	return 0;
198
199error_disable_vrefl_reg:
200	if (state->vrefl_reg)
201		regulator_disable(state->vrefl_reg);
202error_disable_vrefh_reg:
203	regulator_disable(state->vrefh_reg);
204	return ret;
205}
206
207static int ad8801_remove(struct spi_device *spi)
208{
209	struct iio_dev *indio_dev = spi_get_drvdata(spi);
210	struct ad8801_state *state = iio_priv(indio_dev);
211
212	iio_device_unregister(indio_dev);
213	if (state->vrefl_reg)
214		regulator_disable(state->vrefl_reg);
215	regulator_disable(state->vrefh_reg);
216
217	return 0;
218}
219
220static const struct spi_device_id ad8801_ids[] = {
221	{"ad8801", ID_AD8801},
222	{"ad8803", ID_AD8803},
223	{}
224};
225MODULE_DEVICE_TABLE(spi, ad8801_ids);
226
227static struct spi_driver ad8801_driver = {
228	.driver = {
229		.name	= "ad8801",
230	},
231	.probe		= ad8801_probe,
232	.remove		= ad8801_remove,
233	.id_table	= ad8801_ids,
234};
235module_spi_driver(ad8801_driver);
236
237MODULE_AUTHOR("Gwenhael Goavec-Merou <gwenhael.goavec-merou@trabucayre.com>");
238MODULE_DESCRIPTION("Analog Devices AD8801/AD8803 DAC");
239MODULE_LICENSE("GPL v2");
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * IIO DAC driver for Analog Devices AD8801 DAC
  4 *
  5 * Copyright (C) 2016 Gwenhael Goavec-Merou
  6 */
  7
  8#include <linux/iio/iio.h>
  9#include <linux/module.h>
 10#include <linux/regulator/consumer.h>
 11#include <linux/spi/spi.h>
 12#include <linux/sysfs.h>
 13
 14#define AD8801_CFG_ADDR_OFFSET 8
 15
 16enum ad8801_device_ids {
 17	ID_AD8801,
 18	ID_AD8803,
 19};
 20
 21struct ad8801_state {
 22	struct spi_device *spi;
 23	unsigned char dac_cache[8]; /* Value write on each channel */
 24	unsigned int vrefh_mv;
 25	unsigned int vrefl_mv;
 26	struct regulator *vrefh_reg;
 27	struct regulator *vrefl_reg;
 28
 29	__be16 data ____cacheline_aligned;
 30};
 31
 32static int ad8801_spi_write(struct ad8801_state *state,
 33	u8 channel, unsigned char value)
 34{
 35	state->data = cpu_to_be16((channel << AD8801_CFG_ADDR_OFFSET) | value);
 36	return spi_write(state->spi, &state->data, sizeof(state->data));
 37}
 38
 39static int ad8801_write_raw(struct iio_dev *indio_dev,
 40	struct iio_chan_spec const *chan, int val, int val2, long mask)
 41{
 42	struct ad8801_state *state = iio_priv(indio_dev);
 43	int ret;
 44
 45	switch (mask) {
 46	case IIO_CHAN_INFO_RAW:
 47		if (val >= 256 || val < 0)
 48			return -EINVAL;
 49
 50		ret = ad8801_spi_write(state, chan->channel, val);
 51		if (ret == 0)
 52			state->dac_cache[chan->channel] = val;
 53		break;
 54	default:
 55		ret = -EINVAL;
 56	}
 57
 58	return ret;
 59}
 60
 61static int ad8801_read_raw(struct iio_dev *indio_dev,
 62	struct iio_chan_spec const *chan, int *val, int *val2, long info)
 63{
 64	struct ad8801_state *state = iio_priv(indio_dev);
 65
 66	switch (info) {
 67	case IIO_CHAN_INFO_RAW:
 68		*val = state->dac_cache[chan->channel];
 69		return IIO_VAL_INT;
 70	case IIO_CHAN_INFO_SCALE:
 71		*val = state->vrefh_mv - state->vrefl_mv;
 72		*val2 = 8;
 73		return IIO_VAL_FRACTIONAL_LOG2;
 74	case IIO_CHAN_INFO_OFFSET:
 75		*val = state->vrefl_mv;
 76		return IIO_VAL_INT;
 77	default:
 78		return -EINVAL;
 79	}
 80
 81	return -EINVAL;
 82}
 83
 84static const struct iio_info ad8801_info = {
 85	.read_raw = ad8801_read_raw,
 86	.write_raw = ad8801_write_raw,
 87};
 88
 89#define AD8801_CHANNEL(chan) {		\
 90	.type = IIO_VOLTAGE,			\
 91	.indexed = 1,				\
 92	.output = 1,				\
 93	.channel = chan,			\
 94	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
 95	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |	\
 96		BIT(IIO_CHAN_INFO_OFFSET), \
 97}
 98
 99static const struct iio_chan_spec ad8801_channels[] = {
100	AD8801_CHANNEL(0),
101	AD8801_CHANNEL(1),
102	AD8801_CHANNEL(2),
103	AD8801_CHANNEL(3),
104	AD8801_CHANNEL(4),
105	AD8801_CHANNEL(5),
106	AD8801_CHANNEL(6),
107	AD8801_CHANNEL(7),
108};
109
110static int ad8801_probe(struct spi_device *spi)
111{
112	struct iio_dev *indio_dev;
113	struct ad8801_state *state;
114	const struct spi_device_id *id;
115	int ret;
116
117	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*state));
118	if (indio_dev == NULL)
119		return -ENOMEM;
120
121	state = iio_priv(indio_dev);
122	state->spi = spi;
123	id = spi_get_device_id(spi);
124
125	state->vrefh_reg = devm_regulator_get(&spi->dev, "vrefh");
126	if (IS_ERR(state->vrefh_reg)) {
127		dev_err(&spi->dev, "Vrefh regulator not specified\n");
128		return PTR_ERR(state->vrefh_reg);
129	}
130
131	ret = regulator_enable(state->vrefh_reg);
132	if (ret) {
133		dev_err(&spi->dev, "Failed to enable vrefh regulator: %d\n",
134				ret);
135		return ret;
136	}
137
138	ret = regulator_get_voltage(state->vrefh_reg);
139	if (ret < 0) {
140		dev_err(&spi->dev, "Failed to read vrefh regulator: %d\n",
141				ret);
142		goto error_disable_vrefh_reg;
143	}
144	state->vrefh_mv = ret / 1000;
145
146	if (id->driver_data == ID_AD8803) {
147		state->vrefl_reg = devm_regulator_get(&spi->dev, "vrefl");
148		if (IS_ERR(state->vrefl_reg)) {
149			dev_err(&spi->dev, "Vrefl regulator not specified\n");
150			ret = PTR_ERR(state->vrefl_reg);
151			goto error_disable_vrefh_reg;
152		}
153
154		ret = regulator_enable(state->vrefl_reg);
155		if (ret) {
156			dev_err(&spi->dev, "Failed to enable vrefl regulator: %d\n",
157					ret);
158			goto error_disable_vrefh_reg;
159		}
160
161		ret = regulator_get_voltage(state->vrefl_reg);
162		if (ret < 0) {
163			dev_err(&spi->dev, "Failed to read vrefl regulator: %d\n",
164					ret);
165			goto error_disable_vrefl_reg;
166		}
167		state->vrefl_mv = ret / 1000;
168	} else {
169		state->vrefl_mv = 0;
170		state->vrefl_reg = NULL;
171	}
172
173	spi_set_drvdata(spi, indio_dev);
174	indio_dev->dev.parent = &spi->dev;
175	indio_dev->info = &ad8801_info;
176	indio_dev->modes = INDIO_DIRECT_MODE;
177	indio_dev->channels = ad8801_channels;
178	indio_dev->num_channels = ARRAY_SIZE(ad8801_channels);
179	indio_dev->name = id->name;
180
181	ret = iio_device_register(indio_dev);
182	if (ret) {
183		dev_err(&spi->dev, "Failed to register iio device: %d\n",
184				ret);
185		goto error_disable_vrefl_reg;
186	}
187
188	return 0;
189
190error_disable_vrefl_reg:
191	if (state->vrefl_reg)
192		regulator_disable(state->vrefl_reg);
193error_disable_vrefh_reg:
194	regulator_disable(state->vrefh_reg);
195	return ret;
196}
197
198static int ad8801_remove(struct spi_device *spi)
199{
200	struct iio_dev *indio_dev = spi_get_drvdata(spi);
201	struct ad8801_state *state = iio_priv(indio_dev);
202
203	iio_device_unregister(indio_dev);
204	if (state->vrefl_reg)
205		regulator_disable(state->vrefl_reg);
206	regulator_disable(state->vrefh_reg);
207
208	return 0;
209}
210
211static const struct spi_device_id ad8801_ids[] = {
212	{"ad8801", ID_AD8801},
213	{"ad8803", ID_AD8803},
214	{}
215};
216MODULE_DEVICE_TABLE(spi, ad8801_ids);
217
218static struct spi_driver ad8801_driver = {
219	.driver = {
220		.name	= "ad8801",
221	},
222	.probe		= ad8801_probe,
223	.remove		= ad8801_remove,
224	.id_table	= ad8801_ids,
225};
226module_spi_driver(ad8801_driver);
227
228MODULE_AUTHOR("Gwenhael Goavec-Merou <gwenhael.goavec-merou@trabucayre.com>");
229MODULE_DESCRIPTION("Analog Devices AD8801/AD8803 DAC");
230MODULE_LICENSE("GPL v2");