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10#include <linux/module.h>
11#include <linux/spi/spi.h>
12#include <linux/iio/iio.h>
13#include <linux/regulator/consumer.h>
14#include <linux/iio/buffer.h>
15#include <linux/iio/trigger.h>
16#include <linux/iio/triggered_buffer.h>
17#include <linux/iio/trigger_consumer.h>
18
19enum {
20 adc0831,
21 adc0832,
22 adc0834,
23 adc0838,
24};
25
26struct adc0832 {
27 struct spi_device *spi;
28 struct regulator *reg;
29 struct mutex lock;
30 u8 mux_bits;
31
32 u8 tx_buf[2] ____cacheline_aligned;
33 u8 rx_buf[2];
34};
35
36#define ADC0832_VOLTAGE_CHANNEL(chan) \
37 { \
38 .type = IIO_VOLTAGE, \
39 .indexed = 1, \
40 .channel = chan, \
41 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
42 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
43 .scan_index = chan, \
44 .scan_type = { \
45 .sign = 'u', \
46 .realbits = 8, \
47 .storagebits = 8, \
48 }, \
49 }
50
51#define ADC0832_VOLTAGE_CHANNEL_DIFF(chan1, chan2, si) \
52 { \
53 .type = IIO_VOLTAGE, \
54 .indexed = 1, \
55 .channel = (chan1), \
56 .channel2 = (chan2), \
57 .differential = 1, \
58 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
59 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
60 .scan_index = si, \
61 .scan_type = { \
62 .sign = 'u', \
63 .realbits = 8, \
64 .storagebits = 8, \
65 }, \
66 }
67
68static const struct iio_chan_spec adc0831_channels[] = {
69 ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1, 0),
70 IIO_CHAN_SOFT_TIMESTAMP(1),
71};
72
73static const struct iio_chan_spec adc0832_channels[] = {
74 ADC0832_VOLTAGE_CHANNEL(0),
75 ADC0832_VOLTAGE_CHANNEL(1),
76 ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1, 2),
77 ADC0832_VOLTAGE_CHANNEL_DIFF(1, 0, 3),
78 IIO_CHAN_SOFT_TIMESTAMP(4),
79};
80
81static const struct iio_chan_spec adc0834_channels[] = {
82 ADC0832_VOLTAGE_CHANNEL(0),
83 ADC0832_VOLTAGE_CHANNEL(1),
84 ADC0832_VOLTAGE_CHANNEL(2),
85 ADC0832_VOLTAGE_CHANNEL(3),
86 ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1, 4),
87 ADC0832_VOLTAGE_CHANNEL_DIFF(1, 0, 5),
88 ADC0832_VOLTAGE_CHANNEL_DIFF(2, 3, 6),
89 ADC0832_VOLTAGE_CHANNEL_DIFF(3, 2, 7),
90 IIO_CHAN_SOFT_TIMESTAMP(8),
91};
92
93static const struct iio_chan_spec adc0838_channels[] = {
94 ADC0832_VOLTAGE_CHANNEL(0),
95 ADC0832_VOLTAGE_CHANNEL(1),
96 ADC0832_VOLTAGE_CHANNEL(2),
97 ADC0832_VOLTAGE_CHANNEL(3),
98 ADC0832_VOLTAGE_CHANNEL(4),
99 ADC0832_VOLTAGE_CHANNEL(5),
100 ADC0832_VOLTAGE_CHANNEL(6),
101 ADC0832_VOLTAGE_CHANNEL(7),
102 ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1, 8),
103 ADC0832_VOLTAGE_CHANNEL_DIFF(1, 0, 9),
104 ADC0832_VOLTAGE_CHANNEL_DIFF(2, 3, 10),
105 ADC0832_VOLTAGE_CHANNEL_DIFF(3, 2, 11),
106 ADC0832_VOLTAGE_CHANNEL_DIFF(4, 5, 12),
107 ADC0832_VOLTAGE_CHANNEL_DIFF(5, 4, 13),
108 ADC0832_VOLTAGE_CHANNEL_DIFF(6, 7, 14),
109 ADC0832_VOLTAGE_CHANNEL_DIFF(7, 6, 15),
110 IIO_CHAN_SOFT_TIMESTAMP(16),
111};
112
113static int adc0831_adc_conversion(struct adc0832 *adc)
114{
115 struct spi_device *spi = adc->spi;
116 int ret;
117
118 ret = spi_read(spi, &adc->rx_buf, 2);
119 if (ret)
120 return ret;
121
122
123
124
125 return (adc->rx_buf[0] << 2 & 0xff) | (adc->rx_buf[1] >> 6);
126}
127
128static int adc0832_adc_conversion(struct adc0832 *adc, int channel,
129 bool differential)
130{
131 struct spi_device *spi = adc->spi;
132 struct spi_transfer xfer = {
133 .tx_buf = adc->tx_buf,
134 .rx_buf = adc->rx_buf,
135 .len = 2,
136 };
137 int ret;
138
139 if (!adc->mux_bits)
140 return adc0831_adc_conversion(adc);
141
142
143 adc->tx_buf[0] = 1 << (adc->mux_bits + 1);
144
145 adc->tx_buf[0] |= differential ? 0 : (1 << adc->mux_bits);
146
147 adc->tx_buf[0] |= (channel % 2) << (adc->mux_bits - 1);
148
149 if (adc->mux_bits > 1)
150 adc->tx_buf[0] |= channel / 2;
151
152
153 adc->tx_buf[0] <<= 1;
154
155 ret = spi_sync_transfer(spi, &xfer, 1);
156 if (ret)
157 return ret;
158
159 return adc->rx_buf[1];
160}
161
162static int adc0832_read_raw(struct iio_dev *iio,
163 struct iio_chan_spec const *channel, int *value,
164 int *shift, long mask)
165{
166 struct adc0832 *adc = iio_priv(iio);
167
168 switch (mask) {
169 case IIO_CHAN_INFO_RAW:
170 mutex_lock(&adc->lock);
171 *value = adc0832_adc_conversion(adc, channel->channel,
172 channel->differential);
173 mutex_unlock(&adc->lock);
174 if (*value < 0)
175 return *value;
176
177 return IIO_VAL_INT;
178 case IIO_CHAN_INFO_SCALE:
179 *value = regulator_get_voltage(adc->reg);
180 if (*value < 0)
181 return *value;
182
183
184 *value /= 1000;
185 *shift = 8;
186
187 return IIO_VAL_FRACTIONAL_LOG2;
188 }
189
190 return -EINVAL;
191}
192
193static const struct iio_info adc0832_info = {
194 .read_raw = adc0832_read_raw,
195};
196
197static irqreturn_t adc0832_trigger_handler(int irq, void *p)
198{
199 struct iio_poll_func *pf = p;
200 struct iio_dev *indio_dev = pf->indio_dev;
201 struct adc0832 *adc = iio_priv(indio_dev);
202 u8 data[24] = { };
203 int scan_index;
204 int i = 0;
205
206 mutex_lock(&adc->lock);
207
208 for_each_set_bit(scan_index, indio_dev->active_scan_mask,
209 indio_dev->masklength) {
210 const struct iio_chan_spec *scan_chan =
211 &indio_dev->channels[scan_index];
212 int ret = adc0832_adc_conversion(adc, scan_chan->channel,
213 scan_chan->differential);
214 if (ret < 0) {
215 dev_warn(&adc->spi->dev,
216 "failed to get conversion data\n");
217 goto out;
218 }
219
220 data[i] = ret;
221 i++;
222 }
223 iio_push_to_buffers_with_timestamp(indio_dev, data,
224 iio_get_time_ns(indio_dev));
225out:
226 mutex_unlock(&adc->lock);
227
228 iio_trigger_notify_done(indio_dev->trig);
229
230 return IRQ_HANDLED;
231}
232
233static int adc0832_probe(struct spi_device *spi)
234{
235 struct iio_dev *indio_dev;
236 struct adc0832 *adc;
237 int ret;
238
239 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
240 if (!indio_dev)
241 return -ENOMEM;
242
243 adc = iio_priv(indio_dev);
244 adc->spi = spi;
245 mutex_init(&adc->lock);
246
247 indio_dev->name = spi_get_device_id(spi)->name;
248 indio_dev->dev.parent = &spi->dev;
249 indio_dev->dev.of_node = spi->dev.of_node;
250 indio_dev->info = &adc0832_info;
251 indio_dev->modes = INDIO_DIRECT_MODE;
252
253 switch (spi_get_device_id(spi)->driver_data) {
254 case adc0831:
255 adc->mux_bits = 0;
256 indio_dev->channels = adc0831_channels;
257 indio_dev->num_channels = ARRAY_SIZE(adc0831_channels);
258 break;
259 case adc0832:
260 adc->mux_bits = 1;
261 indio_dev->channels = adc0832_channels;
262 indio_dev->num_channels = ARRAY_SIZE(adc0832_channels);
263 break;
264 case adc0834:
265 adc->mux_bits = 2;
266 indio_dev->channels = adc0834_channels;
267 indio_dev->num_channels = ARRAY_SIZE(adc0834_channels);
268 break;
269 case adc0838:
270 adc->mux_bits = 3;
271 indio_dev->channels = adc0838_channels;
272 indio_dev->num_channels = ARRAY_SIZE(adc0838_channels);
273 break;
274 default:
275 return -EINVAL;
276 }
277
278 adc->reg = devm_regulator_get(&spi->dev, "vref");
279 if (IS_ERR(adc->reg))
280 return PTR_ERR(adc->reg);
281
282 ret = regulator_enable(adc->reg);
283 if (ret)
284 return ret;
285
286 spi_set_drvdata(spi, indio_dev);
287
288 ret = iio_triggered_buffer_setup(indio_dev, NULL,
289 adc0832_trigger_handler, NULL);
290 if (ret)
291 goto err_reg_disable;
292
293 ret = iio_device_register(indio_dev);
294 if (ret)
295 goto err_buffer_cleanup;
296
297 return 0;
298err_buffer_cleanup:
299 iio_triggered_buffer_cleanup(indio_dev);
300err_reg_disable:
301 regulator_disable(adc->reg);
302
303 return ret;
304}
305
306static int adc0832_remove(struct spi_device *spi)
307{
308 struct iio_dev *indio_dev = spi_get_drvdata(spi);
309 struct adc0832 *adc = iio_priv(indio_dev);
310
311 iio_device_unregister(indio_dev);
312 iio_triggered_buffer_cleanup(indio_dev);
313 regulator_disable(adc->reg);
314
315 return 0;
316}
317
318#ifdef CONFIG_OF
319
320static const struct of_device_id adc0832_dt_ids[] = {
321 { .compatible = "ti,adc0831", },
322 { .compatible = "ti,adc0832", },
323 { .compatible = "ti,adc0834", },
324 { .compatible = "ti,adc0838", },
325 {}
326};
327MODULE_DEVICE_TABLE(of, adc0832_dt_ids);
328
329#endif
330
331static const struct spi_device_id adc0832_id[] = {
332 { "adc0831", adc0831 },
333 { "adc0832", adc0832 },
334 { "adc0834", adc0834 },
335 { "adc0838", adc0838 },
336 {}
337};
338MODULE_DEVICE_TABLE(spi, adc0832_id);
339
340static struct spi_driver adc0832_driver = {
341 .driver = {
342 .name = "adc0832",
343 .of_match_table = of_match_ptr(adc0832_dt_ids),
344 },
345 .probe = adc0832_probe,
346 .remove = adc0832_remove,
347 .id_table = adc0832_id,
348};
349module_spi_driver(adc0832_driver);
350
351MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
352MODULE_DESCRIPTION("ADC0831/ADC0832/ADC0834/ADC0838 driver");
353MODULE_LICENSE("GPL v2");
354
