This source file includes following definitions.
- ti_dac_cmd
- ti_dac_get_powerdown_mode
- ti_dac_set_powerdown_mode
- ti_dac_read_powerdown
- ti_dac_write_powerdown
- ti_dac_read_raw
- ti_dac_write_raw
- ti_dac_write_raw_get_fmt
- ti_dac_probe
- ti_dac_remove
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15 #include <linux/iio/iio.h>
16 #include <linux/module.h>
17 #include <linux/regulator/consumer.h>
18 #include <linux/spi/spi.h>
19
20 enum { dual_8bit, dual_10bit, dual_12bit, quad_8bit, quad_10bit, quad_12bit };
21
22 struct ti_dac_spec {
23 u8 num_channels;
24 u8 resolution;
25 };
26
27 static const struct ti_dac_spec ti_dac_spec[] = {
28 [dual_8bit] = { .num_channels = 2, .resolution = 8 },
29 [dual_10bit] = { .num_channels = 2, .resolution = 10 },
30 [dual_12bit] = { .num_channels = 2, .resolution = 12 },
31 [quad_8bit] = { .num_channels = 4, .resolution = 8 },
32 [quad_10bit] = { .num_channels = 4, .resolution = 10 },
33 [quad_12bit] = { .num_channels = 4, .resolution = 12 },
34 };
35
36
37
38
39
40
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42
43
44
45
46
47
48 struct ti_dac_chip {
49 struct mutex lock;
50 struct regulator *vref;
51 struct spi_message mesg;
52 struct spi_transfer xfer;
53 u16 val[4];
54 bool powerdown;
55 u8 powerdown_mode;
56 u8 resolution;
57 u8 buf[2] ____cacheline_aligned;
58 };
59
60 #define WRITE_NOT_UPDATE(chan) (0x00 | (chan) << 6)
61 #define WRITE_AND_UPDATE(chan) (0x10 | (chan) << 6)
62 #define WRITE_ALL_UPDATE 0x20
63 #define POWERDOWN(mode) (0x30 | ((mode) + 1) << 6)
64
65 static int ti_dac_cmd(struct ti_dac_chip *ti_dac, u8 cmd, u16 val)
66 {
67 u8 shift = 12 - ti_dac->resolution;
68
69 ti_dac->buf[0] = cmd | (val >> (8 - shift));
70 ti_dac->buf[1] = (val << shift) & 0xff;
71 return spi_sync(ti_dac->mesg.spi, &ti_dac->mesg);
72 }
73
74 static const char * const ti_dac_powerdown_modes[] = {
75 "2.5kohm_to_gnd", "100kohm_to_gnd", "three_state",
76 };
77
78 static int ti_dac_get_powerdown_mode(struct iio_dev *indio_dev,
79 const struct iio_chan_spec *chan)
80 {
81 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
82
83 return ti_dac->powerdown_mode;
84 }
85
86 static int ti_dac_set_powerdown_mode(struct iio_dev *indio_dev,
87 const struct iio_chan_spec *chan,
88 unsigned int mode)
89 {
90 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
91 int ret = 0;
92
93 if (ti_dac->powerdown_mode == mode)
94 return 0;
95
96 mutex_lock(&ti_dac->lock);
97 if (ti_dac->powerdown) {
98 ret = ti_dac_cmd(ti_dac, POWERDOWN(mode), 0);
99 if (ret)
100 goto out;
101 }
102 ti_dac->powerdown_mode = mode;
103
104 out:
105 mutex_unlock(&ti_dac->lock);
106 return ret;
107 }
108
109 static const struct iio_enum ti_dac_powerdown_mode = {
110 .items = ti_dac_powerdown_modes,
111 .num_items = ARRAY_SIZE(ti_dac_powerdown_modes),
112 .get = ti_dac_get_powerdown_mode,
113 .set = ti_dac_set_powerdown_mode,
114 };
115
116 static ssize_t ti_dac_read_powerdown(struct iio_dev *indio_dev,
117 uintptr_t private,
118 const struct iio_chan_spec *chan,
119 char *buf)
120 {
121 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
122
123 return sprintf(buf, "%d\n", ti_dac->powerdown);
124 }
125
126 static ssize_t ti_dac_write_powerdown(struct iio_dev *indio_dev,
127 uintptr_t private,
128 const struct iio_chan_spec *chan,
129 const char *buf, size_t len)
130 {
131 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
132 bool powerdown;
133 int ret;
134
135 ret = strtobool(buf, &powerdown);
136 if (ret)
137 return ret;
138
139 if (ti_dac->powerdown == powerdown)
140 return len;
141
142 mutex_lock(&ti_dac->lock);
143 if (powerdown)
144 ret = ti_dac_cmd(ti_dac, POWERDOWN(ti_dac->powerdown_mode), 0);
145 else
146 ret = ti_dac_cmd(ti_dac, WRITE_AND_UPDATE(0), ti_dac->val[0]);
147 if (!ret)
148 ti_dac->powerdown = powerdown;
149 mutex_unlock(&ti_dac->lock);
150
151 return ret ? ret : len;
152 }
153
154 static const struct iio_chan_spec_ext_info ti_dac_ext_info[] = {
155 {
156 .name = "powerdown",
157 .read = ti_dac_read_powerdown,
158 .write = ti_dac_write_powerdown,
159 .shared = IIO_SHARED_BY_TYPE,
160 },
161 IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE, &ti_dac_powerdown_mode),
162 IIO_ENUM_AVAILABLE("powerdown_mode", &ti_dac_powerdown_mode),
163 { },
164 };
165
166 #define TI_DAC_CHANNEL(chan) { \
167 .type = IIO_VOLTAGE, \
168 .channel = (chan), \
169 .address = (chan), \
170 .indexed = true, \
171 .output = true, \
172 .datasheet_name = (const char[]){ 'A' + (chan), 0 }, \
173 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
174 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
175 .ext_info = ti_dac_ext_info, \
176 }
177
178 static const struct iio_chan_spec ti_dac_channels[] = {
179 TI_DAC_CHANNEL(0),
180 TI_DAC_CHANNEL(1),
181 TI_DAC_CHANNEL(2),
182 TI_DAC_CHANNEL(3),
183 };
184
185 static int ti_dac_read_raw(struct iio_dev *indio_dev,
186 struct iio_chan_spec const *chan,
187 int *val, int *val2, long mask)
188 {
189 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
190 int ret;
191
192 switch (mask) {
193 case IIO_CHAN_INFO_RAW:
194 *val = ti_dac->val[chan->channel];
195 ret = IIO_VAL_INT;
196 break;
197
198 case IIO_CHAN_INFO_SCALE:
199 ret = regulator_get_voltage(ti_dac->vref);
200 if (ret < 0)
201 return ret;
202
203 *val = ret / 1000;
204 *val2 = ti_dac->resolution;
205 ret = IIO_VAL_FRACTIONAL_LOG2;
206 break;
207
208 default:
209 ret = -EINVAL;
210 }
211
212 return ret;
213 }
214
215 static int ti_dac_write_raw(struct iio_dev *indio_dev,
216 struct iio_chan_spec const *chan,
217 int val, int val2, long mask)
218 {
219 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
220 int ret;
221
222 switch (mask) {
223 case IIO_CHAN_INFO_RAW:
224 if (ti_dac->val[chan->channel] == val)
225 return 0;
226
227 if (val >= (1 << ti_dac->resolution) || val < 0)
228 return -EINVAL;
229
230 if (ti_dac->powerdown)
231 return -EBUSY;
232
233 mutex_lock(&ti_dac->lock);
234 ret = ti_dac_cmd(ti_dac, WRITE_AND_UPDATE(chan->channel), val);
235 if (!ret)
236 ti_dac->val[chan->channel] = val;
237 mutex_unlock(&ti_dac->lock);
238 break;
239
240 default:
241 ret = -EINVAL;
242 }
243
244 return ret;
245 }
246
247 static int ti_dac_write_raw_get_fmt(struct iio_dev *indio_dev,
248 struct iio_chan_spec const *chan, long mask)
249 {
250 return IIO_VAL_INT;
251 }
252
253 static const struct iio_info ti_dac_info = {
254 .read_raw = ti_dac_read_raw,
255 .write_raw = ti_dac_write_raw,
256 .write_raw_get_fmt = ti_dac_write_raw_get_fmt,
257 };
258
259 static int ti_dac_probe(struct spi_device *spi)
260 {
261 struct device *dev = &spi->dev;
262 const struct ti_dac_spec *spec;
263 struct ti_dac_chip *ti_dac;
264 struct iio_dev *indio_dev;
265 int ret;
266
267 indio_dev = devm_iio_device_alloc(dev, sizeof(*ti_dac));
268 if (!indio_dev)
269 return -ENOMEM;
270
271 indio_dev->dev.parent = dev;
272 indio_dev->info = &ti_dac_info;
273 indio_dev->name = spi->modalias;
274 indio_dev->modes = INDIO_DIRECT_MODE;
275 indio_dev->channels = ti_dac_channels;
276 spi_set_drvdata(spi, indio_dev);
277
278 ti_dac = iio_priv(indio_dev);
279 ti_dac->xfer.tx_buf = &ti_dac->buf;
280 ti_dac->xfer.len = sizeof(ti_dac->buf);
281 spi_message_init_with_transfers(&ti_dac->mesg, &ti_dac->xfer, 1);
282 ti_dac->mesg.spi = spi;
283
284 spec = &ti_dac_spec[spi_get_device_id(spi)->driver_data];
285 indio_dev->num_channels = spec->num_channels;
286 ti_dac->resolution = spec->resolution;
287
288 ti_dac->vref = devm_regulator_get(dev, "vref");
289 if (IS_ERR(ti_dac->vref))
290 return PTR_ERR(ti_dac->vref);
291
292 ret = regulator_enable(ti_dac->vref);
293 if (ret < 0)
294 return ret;
295
296 mutex_init(&ti_dac->lock);
297
298 ret = ti_dac_cmd(ti_dac, WRITE_ALL_UPDATE, 0);
299 if (ret) {
300 dev_err(dev, "failed to initialize outputs to 0\n");
301 goto err;
302 }
303
304 ret = iio_device_register(indio_dev);
305 if (ret)
306 goto err;
307
308 return 0;
309
310 err:
311 mutex_destroy(&ti_dac->lock);
312 regulator_disable(ti_dac->vref);
313 return ret;
314 }
315
316 static int ti_dac_remove(struct spi_device *spi)
317 {
318 struct iio_dev *indio_dev = spi_get_drvdata(spi);
319 struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
320
321 iio_device_unregister(indio_dev);
322 mutex_destroy(&ti_dac->lock);
323 regulator_disable(ti_dac->vref);
324
325 return 0;
326 }
327
328 #ifdef CONFIG_OF
329 static const struct of_device_id ti_dac_of_id[] = {
330 { .compatible = "ti,dac082s085" },
331 { .compatible = "ti,dac102s085" },
332 { .compatible = "ti,dac122s085" },
333 { .compatible = "ti,dac084s085" },
334 { .compatible = "ti,dac104s085" },
335 { .compatible = "ti,dac124s085" },
336 { }
337 };
338 MODULE_DEVICE_TABLE(of, ti_dac_of_id);
339 #endif
340
341 static const struct spi_device_id ti_dac_spi_id[] = {
342 { "dac082s085", dual_8bit },
343 { "dac102s085", dual_10bit },
344 { "dac122s085", dual_12bit },
345 { "dac084s085", quad_8bit },
346 { "dac104s085", quad_10bit },
347 { "dac124s085", quad_12bit },
348 { }
349 };
350 MODULE_DEVICE_TABLE(spi, ti_dac_spi_id);
351
352 static struct spi_driver ti_dac_driver = {
353 .driver = {
354 .name = "ti-dac082s085",
355 .of_match_table = of_match_ptr(ti_dac_of_id),
356 },
357 .probe = ti_dac_probe,
358 .remove = ti_dac_remove,
359 .id_table = ti_dac_spi_id,
360 };
361 module_spi_driver(ti_dac_driver);
362
363 MODULE_AUTHOR("Lukas Wunner <lukas@wunner.de>");
364 MODULE_DESCRIPTION("Texas Instruments 8/10/12-bit 2/4-channel DAC driver");
365 MODULE_LICENSE("GPL v2");