This source file includes following definitions.
- ad7303_write
- ad7303_read_dac_powerdown
- ad7303_write_dac_powerdown
- ad7303_get_vref
- ad7303_read_raw
- ad7303_write_raw
- ad7303_probe
- ad7303_remove
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7
8 #include <linux/err.h>
9 #include <linux/module.h>
10 #include <linux/kernel.h>
11 #include <linux/spi/spi.h>
12 #include <linux/slab.h>
13 #include <linux/sysfs.h>
14 #include <linux/regulator/consumer.h>
15 #include <linux/of.h>
16
17 #include <linux/iio/iio.h>
18 #include <linux/iio/sysfs.h>
19
20 #include <linux/platform_data/ad7303.h>
21
22 #define AD7303_CFG_EXTERNAL_VREF BIT(15)
23 #define AD7303_CFG_POWER_DOWN(ch) BIT(11 + (ch))
24 #define AD7303_CFG_ADDR_OFFSET 10
25
26 #define AD7303_CMD_UPDATE_DAC (0x3 << 8)
27
28
29
30
31
32
33
34
35
36 struct ad7303_state {
37 struct spi_device *spi;
38 uint16_t config;
39 uint8_t dac_cache[2];
40
41 struct regulator *vdd_reg;
42 struct regulator *vref_reg;
43
44
45
46
47
48 __be16 data ____cacheline_aligned;
49 };
50
51 static int ad7303_write(struct ad7303_state *st, unsigned int chan,
52 uint8_t val)
53 {
54 st->data = cpu_to_be16(AD7303_CMD_UPDATE_DAC |
55 (chan << AD7303_CFG_ADDR_OFFSET) |
56 st->config | val);
57
58 return spi_write(st->spi, &st->data, sizeof(st->data));
59 }
60
61 static ssize_t ad7303_read_dac_powerdown(struct iio_dev *indio_dev,
62 uintptr_t private, const struct iio_chan_spec *chan, char *buf)
63 {
64 struct ad7303_state *st = iio_priv(indio_dev);
65
66 return sprintf(buf, "%d\n", (bool)(st->config &
67 AD7303_CFG_POWER_DOWN(chan->channel)));
68 }
69
70 static ssize_t ad7303_write_dac_powerdown(struct iio_dev *indio_dev,
71 uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
72 size_t len)
73 {
74 struct ad7303_state *st = iio_priv(indio_dev);
75 bool pwr_down;
76 int ret;
77
78 ret = strtobool(buf, &pwr_down);
79 if (ret)
80 return ret;
81
82 mutex_lock(&indio_dev->mlock);
83
84 if (pwr_down)
85 st->config |= AD7303_CFG_POWER_DOWN(chan->channel);
86 else
87 st->config &= ~AD7303_CFG_POWER_DOWN(chan->channel);
88
89
90
91 ad7303_write(st, chan->channel, st->dac_cache[chan->channel]);
92
93 mutex_unlock(&indio_dev->mlock);
94 return len;
95 }
96
97 static int ad7303_get_vref(struct ad7303_state *st,
98 struct iio_chan_spec const *chan)
99 {
100 int ret;
101
102 if (st->config & AD7303_CFG_EXTERNAL_VREF)
103 return regulator_get_voltage(st->vref_reg);
104
105 ret = regulator_get_voltage(st->vdd_reg);
106 if (ret < 0)
107 return ret;
108 return ret / 2;
109 }
110
111 static int ad7303_read_raw(struct iio_dev *indio_dev,
112 struct iio_chan_spec const *chan, int *val, int *val2, long info)
113 {
114 struct ad7303_state *st = iio_priv(indio_dev);
115 int vref_uv;
116
117 switch (info) {
118 case IIO_CHAN_INFO_RAW:
119 *val = st->dac_cache[chan->channel];
120 return IIO_VAL_INT;
121 case IIO_CHAN_INFO_SCALE:
122 vref_uv = ad7303_get_vref(st, chan);
123 if (vref_uv < 0)
124 return vref_uv;
125
126 *val = 2 * vref_uv / 1000;
127 *val2 = chan->scan_type.realbits;
128
129 return IIO_VAL_FRACTIONAL_LOG2;
130 default:
131 break;
132 }
133 return -EINVAL;
134 }
135
136 static int ad7303_write_raw(struct iio_dev *indio_dev,
137 struct iio_chan_spec const *chan, int val, int val2, long mask)
138 {
139 struct ad7303_state *st = iio_priv(indio_dev);
140 int ret;
141
142 switch (mask) {
143 case IIO_CHAN_INFO_RAW:
144 if (val >= (1 << chan->scan_type.realbits) || val < 0)
145 return -EINVAL;
146
147 mutex_lock(&indio_dev->mlock);
148 ret = ad7303_write(st, chan->address, val);
149 if (ret == 0)
150 st->dac_cache[chan->channel] = val;
151 mutex_unlock(&indio_dev->mlock);
152 break;
153 default:
154 ret = -EINVAL;
155 }
156
157 return ret;
158 }
159
160 static const struct iio_info ad7303_info = {
161 .read_raw = ad7303_read_raw,
162 .write_raw = ad7303_write_raw,
163 };
164
165 static const struct iio_chan_spec_ext_info ad7303_ext_info[] = {
166 {
167 .name = "powerdown",
168 .read = ad7303_read_dac_powerdown,
169 .write = ad7303_write_dac_powerdown,
170 .shared = IIO_SEPARATE,
171 },
172 { },
173 };
174
175 #define AD7303_CHANNEL(chan) { \
176 .type = IIO_VOLTAGE, \
177 .indexed = 1, \
178 .output = 1, \
179 .channel = (chan), \
180 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
181 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
182 .address = (chan), \
183 .scan_type = { \
184 .sign = 'u', \
185 .realbits = 8, \
186 .storagebits = 8, \
187 .shift = 0, \
188 }, \
189 .ext_info = ad7303_ext_info, \
190 }
191
192 static const struct iio_chan_spec ad7303_channels[] = {
193 AD7303_CHANNEL(0),
194 AD7303_CHANNEL(1),
195 };
196
197 static int ad7303_probe(struct spi_device *spi)
198 {
199 const struct spi_device_id *id = spi_get_device_id(spi);
200 struct iio_dev *indio_dev;
201 struct ad7303_state *st;
202 bool ext_ref;
203 int ret;
204
205 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
206 if (indio_dev == NULL)
207 return -ENOMEM;
208
209 st = iio_priv(indio_dev);
210 spi_set_drvdata(spi, indio_dev);
211
212 st->spi = spi;
213
214 st->vdd_reg = devm_regulator_get(&spi->dev, "Vdd");
215 if (IS_ERR(st->vdd_reg))
216 return PTR_ERR(st->vdd_reg);
217
218 ret = regulator_enable(st->vdd_reg);
219 if (ret)
220 return ret;
221
222 if (spi->dev.of_node) {
223 ext_ref = of_property_read_bool(spi->dev.of_node,
224 "REF-supply");
225 } else {
226 struct ad7303_platform_data *pdata = spi->dev.platform_data;
227 if (pdata && pdata->use_external_ref)
228 ext_ref = true;
229 else
230 ext_ref = false;
231 }
232
233 if (ext_ref) {
234 st->vref_reg = devm_regulator_get(&spi->dev, "REF");
235 if (IS_ERR(st->vref_reg)) {
236 ret = PTR_ERR(st->vref_reg);
237 goto err_disable_vdd_reg;
238 }
239
240 ret = regulator_enable(st->vref_reg);
241 if (ret)
242 goto err_disable_vdd_reg;
243
244 st->config |= AD7303_CFG_EXTERNAL_VREF;
245 }
246
247 indio_dev->dev.parent = &spi->dev;
248 indio_dev->name = id->name;
249 indio_dev->info = &ad7303_info;
250 indio_dev->modes = INDIO_DIRECT_MODE;
251 indio_dev->channels = ad7303_channels;
252 indio_dev->num_channels = ARRAY_SIZE(ad7303_channels);
253
254 ret = iio_device_register(indio_dev);
255 if (ret)
256 goto err_disable_vref_reg;
257
258 return 0;
259
260 err_disable_vref_reg:
261 if (st->vref_reg)
262 regulator_disable(st->vref_reg);
263 err_disable_vdd_reg:
264 regulator_disable(st->vdd_reg);
265 return ret;
266 }
267
268 static int ad7303_remove(struct spi_device *spi)
269 {
270 struct iio_dev *indio_dev = spi_get_drvdata(spi);
271 struct ad7303_state *st = iio_priv(indio_dev);
272
273 iio_device_unregister(indio_dev);
274
275 if (st->vref_reg)
276 regulator_disable(st->vref_reg);
277 regulator_disable(st->vdd_reg);
278
279 return 0;
280 }
281
282 static const struct of_device_id ad7303_spi_of_match[] = {
283 { .compatible = "adi,ad7303", },
284 { },
285 };
286 MODULE_DEVICE_TABLE(of, ad7303_spi_of_match);
287
288 static const struct spi_device_id ad7303_spi_ids[] = {
289 { "ad7303", 0 },
290 {}
291 };
292 MODULE_DEVICE_TABLE(spi, ad7303_spi_ids);
293
294 static struct spi_driver ad7303_driver = {
295 .driver = {
296 .name = "ad7303",
297 .of_match_table = of_match_ptr(ad7303_spi_of_match),
298 },
299 .probe = ad7303_probe,
300 .remove = ad7303_remove,
301 .id_table = ad7303_spi_ids,
302 };
303 module_spi_driver(ad7303_driver);
304
305 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
306 MODULE_DESCRIPTION("Analog Devices AD7303 DAC driver");
307 MODULE_LICENSE("GPL v2");