This source file includes following definitions.
- max1118_read
- max1118_get_vref_mV
- max1118_read_raw
- max1118_trigger_handler
- max1118_probe
- max1118_remove
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20 #include <linux/module.h>
21 #include <linux/spi/spi.h>
22 #include <linux/iio/iio.h>
23 #include <linux/iio/buffer.h>
24 #include <linux/iio/triggered_buffer.h>
25 #include <linux/iio/trigger_consumer.h>
26 #include <linux/regulator/consumer.h>
27
28 enum max1118_id {
29 max1117,
30 max1118,
31 max1119,
32 };
33
34 struct max1118 {
35 struct spi_device *spi;
36 struct mutex lock;
37 struct regulator *reg;
38
39 u8 data ____cacheline_aligned;
40 };
41
42 #define MAX1118_CHANNEL(ch) \
43 { \
44 .type = IIO_VOLTAGE, \
45 .indexed = 1, \
46 .channel = (ch), \
47 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
48 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
49 .scan_index = ch, \
50 .scan_type = { \
51 .sign = 'u', \
52 .realbits = 8, \
53 .storagebits = 8, \
54 }, \
55 }
56
57 static const struct iio_chan_spec max1118_channels[] = {
58 MAX1118_CHANNEL(0),
59 MAX1118_CHANNEL(1),
60 IIO_CHAN_SOFT_TIMESTAMP(2),
61 };
62
63 static int max1118_read(struct spi_device *spi, int channel)
64 {
65 struct iio_dev *indio_dev = spi_get_drvdata(spi);
66 struct max1118 *adc = iio_priv(indio_dev);
67 struct spi_transfer xfers[] = {
68
69
70
71
72 {
73 .len = 0,
74 .delay_usecs = 1,
75 .cs_change = 1,
76 },
77
78
79
80
81
82 {
83 .len = 0,
84 .delay_usecs = 8,
85 },
86 {
87 .rx_buf = &adc->data,
88 .len = 1,
89 },
90 };
91 int ret;
92
93 if (channel == 0)
94 ret = spi_sync_transfer(spi, xfers + 1, 2);
95 else
96 ret = spi_sync_transfer(spi, xfers, 3);
97
98 if (ret)
99 return ret;
100
101 return adc->data;
102 }
103
104 static int max1118_get_vref_mV(struct spi_device *spi)
105 {
106 struct iio_dev *indio_dev = spi_get_drvdata(spi);
107 struct max1118 *adc = iio_priv(indio_dev);
108 const struct spi_device_id *id = spi_get_device_id(spi);
109 int vref_uV;
110
111 switch (id->driver_data) {
112 case max1117:
113 return 2048;
114 case max1119:
115 return 4096;
116 case max1118:
117 vref_uV = regulator_get_voltage(adc->reg);
118 if (vref_uV < 0)
119 return vref_uV;
120 return vref_uV / 1000;
121 }
122
123 return -ENODEV;
124 }
125
126 static int max1118_read_raw(struct iio_dev *indio_dev,
127 struct iio_chan_spec const *chan,
128 int *val, int *val2, long mask)
129 {
130 struct max1118 *adc = iio_priv(indio_dev);
131
132 switch (mask) {
133 case IIO_CHAN_INFO_RAW:
134 mutex_lock(&adc->lock);
135 *val = max1118_read(adc->spi, chan->channel);
136 mutex_unlock(&adc->lock);
137 if (*val < 0)
138 return *val;
139
140 return IIO_VAL_INT;
141 case IIO_CHAN_INFO_SCALE:
142 *val = max1118_get_vref_mV(adc->spi);
143 if (*val < 0)
144 return *val;
145 *val2 = 8;
146
147 return IIO_VAL_FRACTIONAL_LOG2;
148 }
149
150 return -EINVAL;
151 }
152
153 static const struct iio_info max1118_info = {
154 .read_raw = max1118_read_raw,
155 };
156
157 static irqreturn_t max1118_trigger_handler(int irq, void *p)
158 {
159 struct iio_poll_func *pf = p;
160 struct iio_dev *indio_dev = pf->indio_dev;
161 struct max1118 *adc = iio_priv(indio_dev);
162 u8 data[16] = { };
163 int scan_index;
164 int i = 0;
165
166 mutex_lock(&adc->lock);
167
168 for_each_set_bit(scan_index, indio_dev->active_scan_mask,
169 indio_dev->masklength) {
170 const struct iio_chan_spec *scan_chan =
171 &indio_dev->channels[scan_index];
172 int ret = max1118_read(adc->spi, scan_chan->channel);
173
174 if (ret < 0) {
175 dev_warn(&adc->spi->dev,
176 "failed to get conversion data\n");
177 goto out;
178 }
179
180 data[i] = ret;
181 i++;
182 }
183 iio_push_to_buffers_with_timestamp(indio_dev, data,
184 iio_get_time_ns(indio_dev));
185 out:
186 mutex_unlock(&adc->lock);
187
188 iio_trigger_notify_done(indio_dev->trig);
189
190 return IRQ_HANDLED;
191 }
192
193 static int max1118_probe(struct spi_device *spi)
194 {
195 struct iio_dev *indio_dev;
196 struct max1118 *adc;
197 const struct spi_device_id *id = spi_get_device_id(spi);
198 int ret;
199
200 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
201 if (!indio_dev)
202 return -ENOMEM;
203
204 adc = iio_priv(indio_dev);
205 adc->spi = spi;
206 mutex_init(&adc->lock);
207
208 if (id->driver_data == max1118) {
209 adc->reg = devm_regulator_get(&spi->dev, "vref");
210 if (IS_ERR(adc->reg)) {
211 dev_err(&spi->dev, "failed to get vref regulator\n");
212 return PTR_ERR(adc->reg);
213 }
214 ret = regulator_enable(adc->reg);
215 if (ret)
216 return ret;
217 }
218
219 spi_set_drvdata(spi, indio_dev);
220
221 indio_dev->name = spi_get_device_id(spi)->name;
222 indio_dev->dev.parent = &spi->dev;
223 indio_dev->info = &max1118_info;
224 indio_dev->modes = INDIO_DIRECT_MODE;
225 indio_dev->channels = max1118_channels;
226 indio_dev->num_channels = ARRAY_SIZE(max1118_channels);
227
228
229
230
231
232
233
234 max1118_read(spi, 0);
235
236 ret = iio_triggered_buffer_setup(indio_dev, NULL,
237 max1118_trigger_handler, NULL);
238 if (ret)
239 goto err_reg_disable;
240
241 ret = iio_device_register(indio_dev);
242 if (ret)
243 goto err_buffer_cleanup;
244
245 return 0;
246
247 err_buffer_cleanup:
248 iio_triggered_buffer_cleanup(indio_dev);
249 err_reg_disable:
250 if (id->driver_data == max1118)
251 regulator_disable(adc->reg);
252
253 return ret;
254 }
255
256 static int max1118_remove(struct spi_device *spi)
257 {
258 struct iio_dev *indio_dev = spi_get_drvdata(spi);
259 struct max1118 *adc = iio_priv(indio_dev);
260 const struct spi_device_id *id = spi_get_device_id(spi);
261
262 iio_device_unregister(indio_dev);
263 iio_triggered_buffer_cleanup(indio_dev);
264 if (id->driver_data == max1118)
265 return regulator_disable(adc->reg);
266
267 return 0;
268 }
269
270 static const struct spi_device_id max1118_id[] = {
271 { "max1117", max1117 },
272 { "max1118", max1118 },
273 { "max1119", max1119 },
274 {}
275 };
276 MODULE_DEVICE_TABLE(spi, max1118_id);
277
278 #ifdef CONFIG_OF
279
280 static const struct of_device_id max1118_dt_ids[] = {
281 { .compatible = "maxim,max1117" },
282 { .compatible = "maxim,max1118" },
283 { .compatible = "maxim,max1119" },
284 {},
285 };
286 MODULE_DEVICE_TABLE(of, max1118_dt_ids);
287
288 #endif
289
290 static struct spi_driver max1118_spi_driver = {
291 .driver = {
292 .name = "max1118",
293 .of_match_table = of_match_ptr(max1118_dt_ids),
294 },
295 .probe = max1118_probe,
296 .remove = max1118_remove,
297 .id_table = max1118_id,
298 };
299 module_spi_driver(max1118_spi_driver);
300
301 MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
302 MODULE_DESCRIPTION("MAXIM MAX1117/MAX1118/MAX1119 ADCs driver");
303 MODULE_LICENSE("GPL v2");