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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/*
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};
96
97#define AD8801_CHANNEL(chan) { \
98 .type = IIO_VOLTAGE, \
99 .indexed = 1, \
100 .output = 1, \
101 .channel = chan, \
102 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
103 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
104 BIT(IIO_CHAN_INFO_OFFSET), \
105}
106
107static const struct iio_chan_spec ad8801_channels[] = {
108 AD8801_CHANNEL(0),
109 AD8801_CHANNEL(1),
110 AD8801_CHANNEL(2),
111 AD8801_CHANNEL(3),
112 AD8801_CHANNEL(4),
113 AD8801_CHANNEL(5),
114 AD8801_CHANNEL(6),
115 AD8801_CHANNEL(7),
116};
117
118static int ad8801_probe(struct spi_device *spi)
119{
120 struct iio_dev *indio_dev;
121 struct ad8801_state *state;
122 const struct spi_device_id *id;
123 int ret;
124
125 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*state));
126 if (indio_dev == NULL)
127 return -ENOMEM;
128
129 state = iio_priv(indio_dev);
130 state->spi = spi;
131 id = spi_get_device_id(spi);
132
133 state->vrefh_reg = devm_regulator_get(&spi->dev, "vrefh");
134 if (IS_ERR(state->vrefh_reg)) {
135 dev_err(&spi->dev, "Vrefh regulator not specified\n");
136 return PTR_ERR(state->vrefh_reg);
137 }
138
139 ret = regulator_enable(state->vrefh_reg);
140 if (ret) {
141 dev_err(&spi->dev, "Failed to enable vrefh regulator: %d\n",
142 ret);
143 return ret;
144 }
145
146 ret = regulator_get_voltage(state->vrefh_reg);
147 if (ret < 0) {
148 dev_err(&spi->dev, "Failed to read vrefh regulator: %d\n",
149 ret);
150 goto error_disable_vrefh_reg;
151 }
152 state->vrefh_mv = ret / 1000;
153
154 if (id->driver_data == ID_AD8803) {
155 state->vrefl_reg = devm_regulator_get(&spi->dev, "vrefl");
156 if (IS_ERR(state->vrefl_reg)) {
157 dev_err(&spi->dev, "Vrefl regulator not specified\n");
158 ret = PTR_ERR(state->vrefl_reg);
159 goto error_disable_vrefh_reg;
160 }
161
162 ret = regulator_enable(state->vrefl_reg);
163 if (ret) {
164 dev_err(&spi->dev, "Failed to enable vrefl regulator: %d\n",
165 ret);
166 goto error_disable_vrefh_reg;
167 }
168
169 ret = regulator_get_voltage(state->vrefl_reg);
170 if (ret < 0) {
171 dev_err(&spi->dev, "Failed to read vrefl regulator: %d\n",
172 ret);
173 goto error_disable_vrefl_reg;
174 }
175 state->vrefl_mv = ret / 1000;
176 } else {
177 state->vrefl_mv = 0;
178 state->vrefl_reg = NULL;
179 }
180
181 spi_set_drvdata(spi, indio_dev);
182 indio_dev->dev.parent = &spi->dev;
183 indio_dev->info = &ad8801_info;
184 indio_dev->modes = INDIO_DIRECT_MODE;
185 indio_dev->channels = ad8801_channels;
186 indio_dev->num_channels = ARRAY_SIZE(ad8801_channels);
187 indio_dev->name = id->name;
188
189 ret = iio_device_register(indio_dev);
190 if (ret) {
191 dev_err(&spi->dev, "Failed to register iio device: %d\n",
192 ret);
193 goto error_disable_vrefl_reg;
194 }
195
196 return 0;
197
198error_disable_vrefl_reg:
199 if (state->vrefl_reg)
200 regulator_disable(state->vrefl_reg);
201error_disable_vrefh_reg:
202 regulator_disable(state->vrefh_reg);
203 return ret;
204}
205
206static int ad8801_remove(struct spi_device *spi)
207{
208 struct iio_dev *indio_dev = spi_get_drvdata(spi);
209 struct ad8801_state *state = iio_priv(indio_dev);
210
211 iio_device_unregister(indio_dev);
212 if (state->vrefl_reg)
213 regulator_disable(state->vrefl_reg);
214 regulator_disable(state->vrefh_reg);
215
216 return 0;
217}
218
219static const struct spi_device_id ad8801_ids[] = {
220 {"ad8801", ID_AD8801},
221 {"ad8803", ID_AD8803},
222 {}
223};
224MODULE_DEVICE_TABLE(spi, ad8801_ids);
225
226static struct spi_driver ad8801_driver = {
227 .driver = {
228 .name = "ad8801",
229 },
230 .probe = ad8801_probe,
231 .remove = ad8801_remove,
232 .id_table = ad8801_ids,
233};
234module_spi_driver(ad8801_driver);
235
236MODULE_AUTHOR("Gwenhael Goavec-Merou <gwenhael.goavec-merou@trabucayre.com>");
237MODULE_DESCRIPTION("Analog Devices AD8801/AD8803 DAC");
238MODULE_LICENSE("GPL v2");