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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 ret ? ret : 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 },
173 { },
174};
175
176#define AD7303_CHANNEL(chan) { \
177 .type = IIO_VOLTAGE, \
178 .indexed = 1, \
179 .output = 1, \
180 .channel = (chan), \
181 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
182 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
183 .address = (chan), \
184 .scan_type = { \
185 .sign = 'u', \
186 .realbits = '8', \
187 .storagebits = '8', \
188 .shift = '0', \
189 }, \
190 .ext_info = ad7303_ext_info, \
191}
192
193static const struct iio_chan_spec ad7303_channels[] = {
194 AD7303_CHANNEL(0),
195 AD7303_CHANNEL(1),
196};
197
198static int ad7303_probe(struct spi_device *spi)
199{
200 const struct spi_device_id *id = spi_get_device_id(spi);
201 struct iio_dev *indio_dev;
202 struct ad7303_state *st;
203 bool ext_ref;
204 int ret;
205
206 indio_dev = iio_device_alloc(sizeof(*st));
207 if (indio_dev == NULL)
208 return -ENOMEM;
209
210 st = iio_priv(indio_dev);
211 spi_set_drvdata(spi, indio_dev);
212
213 st->spi = spi;
214
215 st->vdd_reg = regulator_get(&spi->dev, "Vdd");
216 if (IS_ERR(st->vdd_reg)) {
217 ret = PTR_ERR(st->vdd_reg);
218 goto err_free;
219 }
220
221 ret = regulator_enable(st->vdd_reg);
222 if (ret)
223 goto err_put_vdd_reg;
224
225 if (spi->dev.of_node) {
226 ext_ref = of_property_read_bool(spi->dev.of_node,
227 "REF-supply");
228 } else {
229 struct ad7303_platform_data *pdata = spi->dev.platform_data;
230 if (pdata && pdata->use_external_ref)
231 ext_ref = true;
232 else
233 ext_ref = false;
234 }
235
236 if (ext_ref) {
237 st->vref_reg = regulator_get(&spi->dev, "REF");
238 if (IS_ERR(st->vref_reg)) {
239 ret = PTR_ERR(st->vref_reg);
240 goto err_disable_vdd_reg;
241 }
242
243 ret = regulator_enable(st->vref_reg);
244 if (ret)
245 goto err_put_vref_reg;
246
247 st->config |= AD7303_CFG_EXTERNAL_VREF;
248 }
249
250 indio_dev->dev.parent = &spi->dev;
251 indio_dev->name = id->name;
252 indio_dev->info = &ad7303_info;
253 indio_dev->modes = INDIO_DIRECT_MODE;
254 indio_dev->channels = ad7303_channels;
255 indio_dev->num_channels = ARRAY_SIZE(ad7303_channels);
256
257 ret = iio_device_register(indio_dev);
258 if (ret)
259 goto err_disable_vref_reg;
260
261 return 0;
262
263err_disable_vref_reg:
264 if (st->vref_reg)
265 regulator_disable(st->vref_reg);
266err_put_vref_reg:
267 if (st->vref_reg)
268 regulator_put(st->vref_reg);
269err_disable_vdd_reg:
270 regulator_disable(st->vdd_reg);
271err_put_vdd_reg:
272 regulator_put(st->vdd_reg);
273err_free:
274 iio_device_free(indio_dev);
275
276 return ret;
277}
278
279static int ad7303_remove(struct spi_device *spi)
280{
281 struct iio_dev *indio_dev = spi_get_drvdata(spi);
282 struct ad7303_state *st = iio_priv(indio_dev);
283
284 iio_device_unregister(indio_dev);
285
286 if (st->vref_reg) {
287 regulator_disable(st->vref_reg);
288 regulator_put(st->vref_reg);
289 }
290 regulator_disable(st->vdd_reg);
291 regulator_put(st->vdd_reg);
292
293 iio_device_free(indio_dev);
294
295 return 0;
296}
297
298static const struct spi_device_id ad7303_spi_ids[] = {
299 { "ad7303", 0 },
300 {}
301};
302MODULE_DEVICE_TABLE(spi, ad7303_spi_ids);
303
304static struct spi_driver ad7303_driver = {
305 .driver = {
306 .name = "ad7303",
307 .owner = THIS_MODULE,
308 },
309 .probe = ad7303_probe,
310 .remove = ad7303_remove,
311 .id_table = ad7303_spi_ids,
312};
313module_spi_driver(ad7303_driver);
314
315MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
316MODULE_DESCRIPTION("Analog Devices AD7303 DAC driver");
317MODULE_LICENSE("GPL v2");
318
