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8#include <linux/err.h>
9#include <linux/module.h>
10#include <linux/mod_devicetable.h>
11#include <linux/kernel.h>
12#include <linux/spi/spi.h>
13#include <linux/slab.h>
14#include <linux/sysfs.h>
15#include <linux/regulator/consumer.h>
16
17#include <linux/iio/iio.h>
18#include <linux/iio/sysfs.h>
19
20#define AD7303_CFG_EXTERNAL_VREF BIT(15)
21#define AD7303_CFG_POWER_DOWN(ch) BIT(11 + (ch))
22#define AD7303_CFG_ADDR_OFFSET 10
23
24#define AD7303_CMD_UPDATE_DAC (0x3 << 8)
25
26
27
28
29
30
31
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33
34
35
36
37struct ad7303_state {
38 struct spi_device *spi;
39 uint16_t config;
40 uint8_t dac_cache[2];
41
42 struct regulator *vdd_reg;
43 struct regulator *vref_reg;
44
45 struct mutex lock;
46
47
48
49
50 __be16 data ____cacheline_aligned;
51};
52
53static int ad7303_write(struct ad7303_state *st, unsigned int chan,
54 uint8_t val)
55{
56 st->data = cpu_to_be16(AD7303_CMD_UPDATE_DAC |
57 (chan << AD7303_CFG_ADDR_OFFSET) |
58 st->config | val);
59
60 return spi_write(st->spi, &st->data, sizeof(st->data));
61}
62
63static ssize_t ad7303_read_dac_powerdown(struct iio_dev *indio_dev,
64 uintptr_t private, const struct iio_chan_spec *chan, char *buf)
65{
66 struct ad7303_state *st = iio_priv(indio_dev);
67
68 return sysfs_emit(buf, "%d\n", (bool)(st->config &
69 AD7303_CFG_POWER_DOWN(chan->channel)));
70}
71
72static ssize_t ad7303_write_dac_powerdown(struct iio_dev *indio_dev,
73 uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
74 size_t len)
75{
76 struct ad7303_state *st = iio_priv(indio_dev);
77 bool pwr_down;
78 int ret;
79
80 ret = strtobool(buf, &pwr_down);
81 if (ret)
82 return ret;
83
84 mutex_lock(&st->lock);
85
86 if (pwr_down)
87 st->config |= AD7303_CFG_POWER_DOWN(chan->channel);
88 else
89 st->config &= ~AD7303_CFG_POWER_DOWN(chan->channel);
90
91
92
93 ad7303_write(st, chan->channel, st->dac_cache[chan->channel]);
94
95 mutex_unlock(&st->lock);
96 return len;
97}
98
99static int ad7303_get_vref(struct ad7303_state *st,
100 struct iio_chan_spec const *chan)
101{
102 int ret;
103
104 if (st->config & AD7303_CFG_EXTERNAL_VREF)
105 return regulator_get_voltage(st->vref_reg);
106
107 ret = regulator_get_voltage(st->vdd_reg);
108 if (ret < 0)
109 return ret;
110 return ret / 2;
111}
112
113static int ad7303_read_raw(struct iio_dev *indio_dev,
114 struct iio_chan_spec const *chan, int *val, int *val2, long info)
115{
116 struct ad7303_state *st = iio_priv(indio_dev);
117 int vref_uv;
118
119 switch (info) {
120 case IIO_CHAN_INFO_RAW:
121 mutex_lock(&st->lock);
122 *val = st->dac_cache[chan->channel];
123 mutex_unlock(&st->lock);
124 return IIO_VAL_INT;
125 case IIO_CHAN_INFO_SCALE:
126 vref_uv = ad7303_get_vref(st, chan);
127 if (vref_uv < 0)
128 return vref_uv;
129
130 *val = 2 * vref_uv / 1000;
131 *val2 = chan->scan_type.realbits;
132
133 return IIO_VAL_FRACTIONAL_LOG2;
134 default:
135 break;
136 }
137 return -EINVAL;
138}
139
140static int ad7303_write_raw(struct iio_dev *indio_dev,
141 struct iio_chan_spec const *chan, int val, int val2, long mask)
142{
143 struct ad7303_state *st = iio_priv(indio_dev);
144 int ret;
145
146 switch (mask) {
147 case IIO_CHAN_INFO_RAW:
148 if (val >= (1 << chan->scan_type.realbits) || val < 0)
149 return -EINVAL;
150
151 mutex_lock(&st->lock);
152 ret = ad7303_write(st, chan->address, val);
153 if (ret == 0)
154 st->dac_cache[chan->channel] = val;
155 mutex_unlock(&st->lock);
156 break;
157 default:
158 ret = -EINVAL;
159 }
160
161 return ret;
162}
163
164static const struct iio_info ad7303_info = {
165 .read_raw = ad7303_read_raw,
166 .write_raw = ad7303_write_raw,
167};
168
169static const struct iio_chan_spec_ext_info ad7303_ext_info[] = {
170 {
171 .name = "powerdown",
172 .read = ad7303_read_dac_powerdown,
173 .write = ad7303_write_dac_powerdown,
174 .shared = IIO_SEPARATE,
175 },
176 { },
177};
178
179#define AD7303_CHANNEL(chan) { \
180 .type = IIO_VOLTAGE, \
181 .indexed = 1, \
182 .output = 1, \
183 .channel = (chan), \
184 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
185 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
186 .address = (chan), \
187 .scan_type = { \
188 .sign = 'u', \
189 .realbits = 8, \
190 .storagebits = 8, \
191 .shift = 0, \
192 }, \
193 .ext_info = ad7303_ext_info, \
194}
195
196static const struct iio_chan_spec ad7303_channels[] = {
197 AD7303_CHANNEL(0),
198 AD7303_CHANNEL(1),
199};
200
201static int ad7303_probe(struct spi_device *spi)
202{
203 const struct spi_device_id *id = spi_get_device_id(spi);
204 struct iio_dev *indio_dev;
205 struct ad7303_state *st;
206 int ret;
207
208 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
209 if (indio_dev == NULL)
210 return -ENOMEM;
211
212 st = iio_priv(indio_dev);
213 spi_set_drvdata(spi, indio_dev);
214
215 st->spi = spi;
216
217 mutex_init(&st->lock);
218
219 st->vdd_reg = devm_regulator_get(&spi->dev, "Vdd");
220 if (IS_ERR(st->vdd_reg))
221 return PTR_ERR(st->vdd_reg);
222
223 ret = regulator_enable(st->vdd_reg);
224 if (ret)
225 return ret;
226
227 st->vref_reg = devm_regulator_get_optional(&spi->dev, "REF");
228 if (IS_ERR(st->vref_reg)) {
229 ret = PTR_ERR(st->vref_reg);
230 if (ret != -ENODEV)
231 goto err_disable_vdd_reg;
232 st->vref_reg = NULL;
233 }
234
235 if (st->vref_reg) {
236 ret = regulator_enable(st->vref_reg);
237 if (ret)
238 goto err_disable_vdd_reg;
239
240 st->config |= AD7303_CFG_EXTERNAL_VREF;
241 }
242
243 indio_dev->name = id->name;
244 indio_dev->info = &ad7303_info;
245 indio_dev->modes = INDIO_DIRECT_MODE;
246 indio_dev->channels = ad7303_channels;
247 indio_dev->num_channels = ARRAY_SIZE(ad7303_channels);
248
249 ret = iio_device_register(indio_dev);
250 if (ret)
251 goto err_disable_vref_reg;
252
253 return 0;
254
255err_disable_vref_reg:
256 if (st->vref_reg)
257 regulator_disable(st->vref_reg);
258err_disable_vdd_reg:
259 regulator_disable(st->vdd_reg);
260 return ret;
261}
262
263static int ad7303_remove(struct spi_device *spi)
264{
265 struct iio_dev *indio_dev = spi_get_drvdata(spi);
266 struct ad7303_state *st = iio_priv(indio_dev);
267
268 iio_device_unregister(indio_dev);
269
270 if (st->vref_reg)
271 regulator_disable(st->vref_reg);
272 regulator_disable(st->vdd_reg);
273
274 return 0;
275}
276
277static const struct of_device_id ad7303_spi_of_match[] = {
278 { .compatible = "adi,ad7303", },
279 { },
280};
281MODULE_DEVICE_TABLE(of, ad7303_spi_of_match);
282
283static const struct spi_device_id ad7303_spi_ids[] = {
284 { "ad7303", 0 },
285 {}
286};
287MODULE_DEVICE_TABLE(spi, ad7303_spi_ids);
288
289static struct spi_driver ad7303_driver = {
290 .driver = {
291 .name = "ad7303",
292 .of_match_table = ad7303_spi_of_match,
293 },
294 .probe = ad7303_probe,
295 .remove = ad7303_remove,
296 .id_table = ad7303_spi_ids,
297};
298module_spi_driver(ad7303_driver);
299
300MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
301MODULE_DESCRIPTION("Analog Devices AD7303 DAC driver");
302MODULE_LICENSE("GPL v2");
303
