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13#include <linux/module.h>
14#include <linux/spi/spi.h>
15#include <linux/iio/iio.h>
16#include <linux/regulator/consumer.h>
17
18enum {
19 adc0831,
20 adc0832,
21 adc0834,
22 adc0838,
23};
24
25struct adc0832 {
26 struct spi_device *spi;
27 struct regulator *reg;
28 struct mutex lock;
29 u8 mux_bits;
30
31 u8 tx_buf[2] ____cacheline_aligned;
32 u8 rx_buf[2];
33};
34
35#define ADC0832_VOLTAGE_CHANNEL(chan) \
36 { \
37 .type = IIO_VOLTAGE, \
38 .indexed = 1, \
39 .channel = chan, \
40 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
41 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
42 }
43
44#define ADC0832_VOLTAGE_CHANNEL_DIFF(chan1, chan2) \
45 { \
46 .type = IIO_VOLTAGE, \
47 .indexed = 1, \
48 .channel = (chan1), \
49 .channel2 = (chan2), \
50 .differential = 1, \
51 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
52 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
53 }
54
55static const struct iio_chan_spec adc0831_channels[] = {
56 ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1),
57};
58
59static const struct iio_chan_spec adc0832_channels[] = {
60 ADC0832_VOLTAGE_CHANNEL(0),
61 ADC0832_VOLTAGE_CHANNEL(1),
62 ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1),
63 ADC0832_VOLTAGE_CHANNEL_DIFF(1, 0),
64};
65
66static const struct iio_chan_spec adc0834_channels[] = {
67 ADC0832_VOLTAGE_CHANNEL(0),
68 ADC0832_VOLTAGE_CHANNEL(1),
69 ADC0832_VOLTAGE_CHANNEL(2),
70 ADC0832_VOLTAGE_CHANNEL(3),
71 ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1),
72 ADC0832_VOLTAGE_CHANNEL_DIFF(1, 0),
73 ADC0832_VOLTAGE_CHANNEL_DIFF(2, 3),
74 ADC0832_VOLTAGE_CHANNEL_DIFF(3, 2),
75};
76
77static const struct iio_chan_spec adc0838_channels[] = {
78 ADC0832_VOLTAGE_CHANNEL(0),
79 ADC0832_VOLTAGE_CHANNEL(1),
80 ADC0832_VOLTAGE_CHANNEL(2),
81 ADC0832_VOLTAGE_CHANNEL(3),
82 ADC0832_VOLTAGE_CHANNEL(4),
83 ADC0832_VOLTAGE_CHANNEL(5),
84 ADC0832_VOLTAGE_CHANNEL(6),
85 ADC0832_VOLTAGE_CHANNEL(7),
86 ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1),
87 ADC0832_VOLTAGE_CHANNEL_DIFF(1, 0),
88 ADC0832_VOLTAGE_CHANNEL_DIFF(2, 3),
89 ADC0832_VOLTAGE_CHANNEL_DIFF(3, 2),
90 ADC0832_VOLTAGE_CHANNEL_DIFF(4, 5),
91 ADC0832_VOLTAGE_CHANNEL_DIFF(5, 4),
92 ADC0832_VOLTAGE_CHANNEL_DIFF(6, 7),
93 ADC0832_VOLTAGE_CHANNEL_DIFF(7, 6),
94};
95
96static int adc0831_adc_conversion(struct adc0832 *adc)
97{
98 struct spi_device *spi = adc->spi;
99 int ret;
100
101 ret = spi_read(spi, &adc->rx_buf, 2);
102 if (ret)
103 return ret;
104
105
106
107
108 return (adc->rx_buf[0] << 2 & 0xff) | (adc->rx_buf[1] >> 6);
109}
110
111static int adc0832_adc_conversion(struct adc0832 *adc, int channel,
112 bool differential)
113{
114 struct spi_device *spi = adc->spi;
115 struct spi_transfer xfer = {
116 .tx_buf = adc->tx_buf,
117 .rx_buf = adc->rx_buf,
118 .len = 2,
119 };
120 int ret;
121
122 if (!adc->mux_bits)
123 return adc0831_adc_conversion(adc);
124
125
126 adc->tx_buf[0] = 1 << (adc->mux_bits + 1);
127
128 adc->tx_buf[0] |= differential ? 0 : (1 << adc->mux_bits);
129
130 adc->tx_buf[0] |= (channel % 2) << (adc->mux_bits - 1);
131
132 if (adc->mux_bits > 1)
133 adc->tx_buf[0] |= channel / 2;
134
135
136 adc->tx_buf[0] <<= 1;
137
138 ret = spi_sync_transfer(spi, &xfer, 1);
139 if (ret)
140 return ret;
141
142 return adc->rx_buf[1];
143}
144
145static int adc0832_read_raw(struct iio_dev *iio,
146 struct iio_chan_spec const *channel, int *value,
147 int *shift, long mask)
148{
149 struct adc0832 *adc = iio_priv(iio);
150
151 switch (mask) {
152 case IIO_CHAN_INFO_RAW:
153 mutex_lock(&adc->lock);
154 *value = adc0832_adc_conversion(adc, channel->channel,
155 channel->differential);
156 mutex_unlock(&adc->lock);
157 if (*value < 0)
158 return *value;
159
160 return IIO_VAL_INT;
161 case IIO_CHAN_INFO_SCALE:
162 *value = regulator_get_voltage(adc->reg);
163 if (*value < 0)
164 return *value;
165
166
167 *value /= 1000;
168 *shift = 8;
169
170 return IIO_VAL_FRACTIONAL_LOG2;
171 }
172
173 return -EINVAL;
174}
175
176static const struct iio_info adc0832_info = {
177 .read_raw = adc0832_read_raw,
178 .driver_module = THIS_MODULE,
179};
180
181static int adc0832_probe(struct spi_device *spi)
182{
183 struct iio_dev *indio_dev;
184 struct adc0832 *adc;
185 int ret;
186
187 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
188 if (!indio_dev)
189 return -ENOMEM;
190
191 adc = iio_priv(indio_dev);
192 adc->spi = spi;
193 mutex_init(&adc->lock);
194
195 indio_dev->name = spi_get_device_id(spi)->name;
196 indio_dev->dev.parent = &spi->dev;
197 indio_dev->info = &adc0832_info;
198 indio_dev->modes = INDIO_DIRECT_MODE;
199
200 switch (spi_get_device_id(spi)->driver_data) {
201 case adc0831:
202 adc->mux_bits = 0;
203 indio_dev->channels = adc0831_channels;
204 indio_dev->num_channels = ARRAY_SIZE(adc0831_channels);
205 break;
206 case adc0832:
207 adc->mux_bits = 1;
208 indio_dev->channels = adc0832_channels;
209 indio_dev->num_channels = ARRAY_SIZE(adc0832_channels);
210 break;
211 case adc0834:
212 adc->mux_bits = 2;
213 indio_dev->channels = adc0834_channels;
214 indio_dev->num_channels = ARRAY_SIZE(adc0834_channels);
215 break;
216 case adc0838:
217 adc->mux_bits = 3;
218 indio_dev->channels = adc0838_channels;
219 indio_dev->num_channels = ARRAY_SIZE(adc0838_channels);
220 break;
221 default:
222 return -EINVAL;
223 }
224
225 adc->reg = devm_regulator_get(&spi->dev, "vref");
226 if (IS_ERR(adc->reg))
227 return PTR_ERR(adc->reg);
228
229 ret = regulator_enable(adc->reg);
230 if (ret)
231 return ret;
232
233 spi_set_drvdata(spi, indio_dev);
234
235 ret = iio_device_register(indio_dev);
236 if (ret)
237 regulator_disable(adc->reg);
238
239 return ret;
240}
241
242static int adc0832_remove(struct spi_device *spi)
243{
244 struct iio_dev *indio_dev = spi_get_drvdata(spi);
245 struct adc0832 *adc = iio_priv(indio_dev);
246
247 iio_device_unregister(indio_dev);
248 regulator_disable(adc->reg);
249
250 return 0;
251}
252
253#ifdef CONFIG_OF
254
255static const struct of_device_id adc0832_dt_ids[] = {
256 { .compatible = "ti,adc0831", },
257 { .compatible = "ti,adc0832", },
258 { .compatible = "ti,adc0834", },
259 { .compatible = "ti,adc0838", },
260 {}
261};
262MODULE_DEVICE_TABLE(of, adc0832_dt_ids);
263
264#endif
265
266static const struct spi_device_id adc0832_id[] = {
267 { "adc0831", adc0831 },
268 { "adc0832", adc0832 },
269 { "adc0834", adc0834 },
270 { "adc0838", adc0838 },
271 {}
272};
273MODULE_DEVICE_TABLE(spi, adc0832_id);
274
275static struct spi_driver adc0832_driver = {
276 .driver = {
277 .name = "adc0832",
278 .of_match_table = of_match_ptr(adc0832_dt_ids),
279 },
280 .probe = adc0832_probe,
281 .remove = adc0832_remove,
282 .id_table = adc0832_id,
283};
284module_spi_driver(adc0832_driver);
285
286MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
287MODULE_DESCRIPTION("ADC0831/ADC0832/ADC0834/ADC0838 driver");
288MODULE_LICENSE("GPL v2");
289
