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9#include <linux/err.h>
10#include <linux/module.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#include <linux/of.h>
17
18#include <linux/iio/iio.h>
19#include <linux/iio/sysfs.h>
20
21#include <linux/platform_data/ad7303.h>
22
23#define AD7303_CFG_EXTERNAL_VREF BIT(15)
24#define AD7303_CFG_POWER_DOWN(ch) BIT(11 + (ch))
25#define AD7303_CFG_ADDR_OFFSET 10
26
27#define AD7303_CMD_UPDATE_DAC (0x3 << 8)
28
29
30
31
32
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
46
47
48
49 __be16 data ____cacheline_aligned;
50};
51
52static int ad7303_write(struct ad7303_state *st, unsigned int chan,
53 uint8_t val)
54{
55 st->data = cpu_to_be16(AD7303_CMD_UPDATE_DAC |
56 (chan << AD7303_CFG_ADDR_OFFSET) |
57 st->config | val);
58
59 return spi_write(st->spi, &st->data, sizeof(st->data));
60}
61
62static ssize_t ad7303_read_dac_powerdown(struct iio_dev *indio_dev,
63 uintptr_t private, const struct iio_chan_spec *chan, char *buf)
64{
65 struct ad7303_state *st = iio_priv(indio_dev);
66
67 return sprintf(buf, "%d\n", (bool)(st->config &
68 AD7303_CFG_POWER_DOWN(chan->channel)));
69}
70
71static ssize_t ad7303_write_dac_powerdown(struct iio_dev *indio_dev,
72 uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
73 size_t len)
74{
75 struct ad7303_state *st = iio_priv(indio_dev);
76 bool pwr_down;
77 int ret;
78
79 ret = strtobool(buf, &pwr_down);
80 if (ret)
81 return ret;
82
83 mutex_lock(&indio_dev->mlock);
84
85 if (pwr_down)
86 st->config |= AD7303_CFG_POWER_DOWN(chan->channel);
87 else
88 st->config &= ~AD7303_CFG_POWER_DOWN(chan->channel);
89
90
91
92 ad7303_write(st, chan->channel, st->dac_cache[chan->channel]);
93
94 mutex_unlock(&indio_dev->mlock);
95 return len;
96}
97
98static int ad7303_get_vref(struct ad7303_state *st,
99 struct iio_chan_spec const *chan)
100{
101 int ret;
102
103 if (st->config & AD7303_CFG_EXTERNAL_VREF)
104 return regulator_get_voltage(st->vref_reg);
105
106 ret = regulator_get_voltage(st->vdd_reg);
107 if (ret < 0)
108 return ret;
109 return ret / 2;
110}
111
112static int ad7303_read_raw(struct iio_dev *indio_dev,
113 struct iio_chan_spec const *chan, int *val, int *val2, long info)
114{
115 struct ad7303_state *st = iio_priv(indio_dev);
116 int vref_uv;
117
118 switch (info) {
119 case IIO_CHAN_INFO_RAW:
120 *val = st->dac_cache[chan->channel];
121 return IIO_VAL_INT;
122 case IIO_CHAN_INFO_SCALE:
123 vref_uv = ad7303_get_vref(st, chan);
124 if (vref_uv < 0)
125 return vref_uv;
126
127 *val = 2 * vref_uv / 1000;
128 *val2 = chan->scan_type.realbits;
129
130 return IIO_VAL_FRACTIONAL_LOG2;
131 default:
132 break;
133 }
134 return -EINVAL;
135}
136
137static int ad7303_write_raw(struct iio_dev *indio_dev,
138 struct iio_chan_spec const *chan, int val, int val2, long mask)
139{
140 struct ad7303_state *st = iio_priv(indio_dev);
141 int ret;
142
143 switch (mask) {
144 case IIO_CHAN_INFO_RAW:
145 if (val >= (1 << chan->scan_type.realbits) || val < 0)
146 return -EINVAL;
147
148 mutex_lock(&indio_dev->mlock);
149 ret = ad7303_write(st, chan->address, val);
150 if (ret == 0)
151 st->dac_cache[chan->channel] = val;
152 mutex_unlock(&indio_dev->mlock);
153 break;
154 default:
155 ret = -EINVAL;
156 }
157
158 return ret;
159}
160
161static const struct iio_info ad7303_info = {
162 .read_raw = ad7303_read_raw,
163 .write_raw = ad7303_write_raw,
164 .driver_module = THIS_MODULE,
165};
166
167static const struct iio_chan_spec_ext_info ad7303_ext_info[] = {
168 {
169 .name = "powerdown",
170 .read = ad7303_read_dac_powerdown,
171 .write = ad7303_write_dac_powerdown,
172 .shared = IIO_SEPARATE,
173 },
174 { },
175};
176
177#define AD7303_CHANNEL(chan) { \
178 .type = IIO_VOLTAGE, \
179 .indexed = 1, \
180 .output = 1, \
181 .channel = (chan), \
182 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
183 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
184 .address = (chan), \
185 .scan_type = { \
186 .sign = 'u', \
187 .realbits = 8, \
188 .storagebits = 8, \
189 .shift = 0, \
190 }, \
191 .ext_info = ad7303_ext_info, \
192}
193
194static const struct iio_chan_spec ad7303_channels[] = {
195 AD7303_CHANNEL(0),
196 AD7303_CHANNEL(1),
197};
198
199static int ad7303_probe(struct spi_device *spi)
200{
201 const struct spi_device_id *id = spi_get_device_id(spi);
202 struct iio_dev *indio_dev;
203 struct ad7303_state *st;
204 bool ext_ref;
205 int ret;
206
207 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
208 if (indio_dev == NULL)
209 return -ENOMEM;
210
211 st = iio_priv(indio_dev);
212 spi_set_drvdata(spi, indio_dev);
213
214 st->spi = spi;
215
216 st->vdd_reg = devm_regulator_get(&spi->dev, "Vdd");
217 if (IS_ERR(st->vdd_reg))
218 return PTR_ERR(st->vdd_reg);
219
220 ret = regulator_enable(st->vdd_reg);
221 if (ret)
222 return ret;
223
224 if (spi->dev.of_node) {
225 ext_ref = of_property_read_bool(spi->dev.of_node,
226 "REF-supply");
227 } else {
228 struct ad7303_platform_data *pdata = spi->dev.platform_data;
229 if (pdata && pdata->use_external_ref)
230 ext_ref = true;
231 else
232 ext_ref = false;
233 }
234
235 if (ext_ref) {
236 st->vref_reg = devm_regulator_get(&spi->dev, "REF");
237 if (IS_ERR(st->vref_reg)) {
238 ret = PTR_ERR(st->vref_reg);
239 goto err_disable_vdd_reg;
240 }
241
242 ret = regulator_enable(st->vref_reg);
243 if (ret)
244 goto err_disable_vdd_reg;
245
246 st->config |= AD7303_CFG_EXTERNAL_VREF;
247 }
248
249 indio_dev->dev.parent = &spi->dev;
250 indio_dev->name = id->name;
251 indio_dev->info = &ad7303_info;
252 indio_dev->modes = INDIO_DIRECT_MODE;
253 indio_dev->channels = ad7303_channels;
254 indio_dev->num_channels = ARRAY_SIZE(ad7303_channels);
255
256 ret = iio_device_register(indio_dev);
257 if (ret)
258 goto err_disable_vref_reg;
259
260 return 0;
261
262err_disable_vref_reg:
263 if (st->vref_reg)
264 regulator_disable(st->vref_reg);
265err_disable_vdd_reg:
266 regulator_disable(st->vdd_reg);
267 return ret;
268}
269
270static int ad7303_remove(struct spi_device *spi)
271{
272 struct iio_dev *indio_dev = spi_get_drvdata(spi);
273 struct ad7303_state *st = iio_priv(indio_dev);
274
275 iio_device_unregister(indio_dev);
276
277 if (st->vref_reg)
278 regulator_disable(st->vref_reg);
279 regulator_disable(st->vdd_reg);
280
281 return 0;
282}
283
284static const struct of_device_id ad7303_spi_of_match[] = {
285 { .compatible = "adi,ad7303", },
286 { },
287};
288MODULE_DEVICE_TABLE(of, ad7303_spi_of_match);
289
290static const struct spi_device_id ad7303_spi_ids[] = {
291 { "ad7303", 0 },
292 {}
293};
294MODULE_DEVICE_TABLE(spi, ad7303_spi_ids);
295
296static struct spi_driver ad7303_driver = {
297 .driver = {
298 .name = "ad7303",
299 .of_match_table = of_match_ptr(ad7303_spi_of_match),
300 },
301 .probe = ad7303_probe,
302 .remove = ad7303_remove,
303 .id_table = ad7303_spi_ids,
304};
305module_spi_driver(ad7303_driver);
306
307MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
308MODULE_DESCRIPTION("Analog Devices AD7303 DAC driver");
309MODULE_LICENSE("GPL v2");
310
