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131497ac RR |
1 | /* |
2 | * AD5721, AD5721R, AD5761, AD5761R, Voltage Output Digital to Analog Converter | |
3 | * | |
4 | * Copyright 2016 Qtechnology A/S | |
5 | * 2016 Ricardo Ribalda <[email protected]> | |
6 | * | |
7 | * Licensed under the GPL-2. | |
8 | */ | |
9 | #include <linux/kernel.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/spi/spi.h> | |
12 | #include <linux/bitops.h> | |
13 | #include <linux/iio/iio.h> | |
14 | #include <linux/iio/sysfs.h> | |
15 | #include <linux/regulator/consumer.h> | |
16 | #include <linux/platform_data/ad5761.h> | |
17 | ||
18 | #define AD5761_ADDR(addr) ((addr & 0xf) << 16) | |
19 | #define AD5761_ADDR_NOOP 0x0 | |
20 | #define AD5761_ADDR_DAC_WRITE 0x3 | |
21 | #define AD5761_ADDR_CTRL_WRITE_REG 0x4 | |
22 | #define AD5761_ADDR_SW_DATA_RESET 0x7 | |
23 | #define AD5761_ADDR_DAC_READ 0xb | |
24 | #define AD5761_ADDR_CTRL_READ_REG 0xc | |
25 | #define AD5761_ADDR_SW_FULL_RESET 0xf | |
26 | ||
27 | #define AD5761_CTRL_USE_INTVREF BIT(5) | |
28 | #define AD5761_CTRL_ETS BIT(6) | |
29 | ||
30 | /** | |
31 | * struct ad5761_chip_info - chip specific information | |
32 | * @int_vref: Value of the internal reference voltage in mV - 0 if external | |
33 | * reference voltage is used | |
34 | * @channel: channel specification | |
35 | */ | |
36 | ||
37 | struct ad5761_chip_info { | |
38 | unsigned long int_vref; | |
39 | const struct iio_chan_spec channel; | |
40 | }; | |
41 | ||
42 | struct ad5761_range_params { | |
43 | int m; | |
44 | int c; | |
45 | }; | |
46 | ||
47 | enum ad5761_supported_device_ids { | |
48 | ID_AD5721, | |
49 | ID_AD5721R, | |
50 | ID_AD5761, | |
51 | ID_AD5761R, | |
52 | }; | |
53 | ||
54 | /** | |
55 | * struct ad5761_state - driver instance specific data | |
56 | * @spi: spi_device | |
57 | * @vref_reg: reference voltage regulator | |
58 | * @use_intref: true when the internal voltage reference is used | |
59 | * @vref: actual voltage reference in mVolts | |
60 | * @range: output range mode used | |
61 | * @data: cache aligned spi buffer | |
62 | */ | |
63 | struct ad5761_state { | |
64 | struct spi_device *spi; | |
65 | struct regulator *vref_reg; | |
66 | ||
67 | bool use_intref; | |
68 | int vref; | |
69 | enum ad5761_voltage_range range; | |
70 | ||
71 | /* | |
72 | * DMA (thus cache coherency maintenance) requires the | |
73 | * transfer buffers to live in their own cache lines. | |
74 | */ | |
75 | union { | |
76 | __be32 d32; | |
77 | u8 d8[4]; | |
78 | } data[3] ____cacheline_aligned; | |
79 | }; | |
80 | ||
81 | static const struct ad5761_range_params ad5761_range_params[] = { | |
82 | [AD5761_VOLTAGE_RANGE_M10V_10V] = { | |
83 | .m = 80, | |
84 | .c = 40, | |
85 | }, | |
86 | [AD5761_VOLTAGE_RANGE_0V_10V] = { | |
87 | .m = 40, | |
88 | .c = 0, | |
89 | }, | |
90 | [AD5761_VOLTAGE_RANGE_M5V_5V] = { | |
91 | .m = 40, | |
92 | .c = 20, | |
93 | }, | |
94 | [AD5761_VOLTAGE_RANGE_0V_5V] = { | |
95 | .m = 20, | |
96 | .c = 0, | |
97 | }, | |
98 | [AD5761_VOLTAGE_RANGE_M2V5_7V5] = { | |
99 | .m = 40, | |
100 | .c = 10, | |
101 | }, | |
102 | [AD5761_VOLTAGE_RANGE_M3V_3V] = { | |
103 | .m = 24, | |
104 | .c = 12, | |
105 | }, | |
106 | [AD5761_VOLTAGE_RANGE_0V_16V] = { | |
107 | .m = 64, | |
108 | .c = 0, | |
109 | }, | |
110 | [AD5761_VOLTAGE_RANGE_0V_20V] = { | |
111 | .m = 80, | |
112 | .c = 0, | |
113 | }, | |
114 | }; | |
115 | ||
116 | static int _ad5761_spi_write(struct ad5761_state *st, u8 addr, u16 val) | |
117 | { | |
118 | st->data[0].d32 = cpu_to_be32(AD5761_ADDR(addr) | val); | |
119 | ||
120 | return spi_write(st->spi, &st->data[0].d8[1], 3); | |
121 | } | |
122 | ||
123 | static int ad5761_spi_write(struct iio_dev *indio_dev, u8 addr, u16 val) | |
124 | { | |
125 | struct ad5761_state *st = iio_priv(indio_dev); | |
126 | int ret; | |
127 | ||
128 | mutex_lock(&indio_dev->mlock); | |
129 | ret = _ad5761_spi_write(st, addr, val); | |
130 | mutex_unlock(&indio_dev->mlock); | |
131 | ||
132 | return ret; | |
133 | } | |
134 | ||
135 | static int _ad5761_spi_read(struct ad5761_state *st, u8 addr, u16 *val) | |
136 | { | |
137 | int ret; | |
138 | struct spi_transfer xfers[] = { | |
139 | { | |
140 | .tx_buf = &st->data[0].d8[1], | |
141 | .bits_per_word = 8, | |
142 | .len = 3, | |
143 | .cs_change = true, | |
144 | }, { | |
145 | .tx_buf = &st->data[1].d8[1], | |
146 | .rx_buf = &st->data[2].d8[1], | |
147 | .bits_per_word = 8, | |
148 | .len = 3, | |
149 | }, | |
150 | }; | |
151 | ||
152 | st->data[0].d32 = cpu_to_be32(AD5761_ADDR(addr)); | |
153 | st->data[1].d32 = cpu_to_be32(AD5761_ADDR(AD5761_ADDR_NOOP)); | |
154 | ||
155 | ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers)); | |
156 | ||
157 | *val = be32_to_cpu(st->data[2].d32); | |
158 | ||
159 | return ret; | |
160 | } | |
161 | ||
162 | static int ad5761_spi_read(struct iio_dev *indio_dev, u8 addr, u16 *val) | |
163 | { | |
164 | struct ad5761_state *st = iio_priv(indio_dev); | |
165 | int ret; | |
166 | ||
167 | mutex_lock(&indio_dev->mlock); | |
168 | ret = _ad5761_spi_read(st, addr, val); | |
169 | mutex_unlock(&indio_dev->mlock); | |
170 | ||
171 | return ret; | |
172 | } | |
173 | ||
174 | static int ad5761_spi_set_range(struct ad5761_state *st, | |
175 | enum ad5761_voltage_range range) | |
176 | { | |
177 | u16 aux; | |
178 | int ret; | |
179 | ||
180 | aux = (range & 0x7) | AD5761_CTRL_ETS; | |
181 | ||
182 | if (st->use_intref) | |
183 | aux |= AD5761_CTRL_USE_INTVREF; | |
184 | ||
185 | ret = _ad5761_spi_write(st, AD5761_ADDR_SW_FULL_RESET, 0); | |
186 | if (ret) | |
187 | return ret; | |
188 | ||
189 | ret = _ad5761_spi_write(st, AD5761_ADDR_CTRL_WRITE_REG, aux); | |
190 | if (ret) | |
191 | return ret; | |
192 | ||
193 | st->range = range; | |
194 | ||
195 | return 0; | |
196 | } | |
197 | ||
198 | static int ad5761_read_raw(struct iio_dev *indio_dev, | |
199 | struct iio_chan_spec const *chan, | |
200 | int *val, | |
201 | int *val2, | |
202 | long mask) | |
203 | { | |
204 | struct ad5761_state *st; | |
205 | int ret; | |
206 | u16 aux; | |
207 | ||
208 | switch (mask) { | |
209 | case IIO_CHAN_INFO_RAW: | |
210 | ret = ad5761_spi_read(indio_dev, AD5761_ADDR_DAC_READ, &aux); | |
211 | if (ret) | |
212 | return ret; | |
213 | *val = aux >> chan->scan_type.shift; | |
214 | return IIO_VAL_INT; | |
215 | case IIO_CHAN_INFO_SCALE: | |
216 | st = iio_priv(indio_dev); | |
217 | *val = st->vref * ad5761_range_params[st->range].m; | |
218 | *val /= 10; | |
219 | *val2 = chan->scan_type.realbits; | |
220 | return IIO_VAL_FRACTIONAL_LOG2; | |
221 | case IIO_CHAN_INFO_OFFSET: | |
222 | st = iio_priv(indio_dev); | |
223 | *val = -(1 << chan->scan_type.realbits); | |
224 | *val *= ad5761_range_params[st->range].c; | |
225 | *val /= ad5761_range_params[st->range].m; | |
226 | return IIO_VAL_INT; | |
227 | default: | |
228 | return -EINVAL; | |
229 | } | |
230 | } | |
231 | ||
232 | static int ad5761_write_raw(struct iio_dev *indio_dev, | |
233 | struct iio_chan_spec const *chan, | |
234 | int val, | |
235 | int val2, | |
236 | long mask) | |
237 | { | |
238 | u16 aux; | |
239 | ||
240 | if (mask != IIO_CHAN_INFO_RAW) | |
241 | return -EINVAL; | |
242 | ||
243 | if (val2 || (val << chan->scan_type.shift) > 0xffff || val < 0) | |
244 | return -EINVAL; | |
245 | ||
246 | aux = val << chan->scan_type.shift; | |
247 | ||
248 | return ad5761_spi_write(indio_dev, AD5761_ADDR_DAC_WRITE, aux); | |
249 | } | |
250 | ||
251 | static const struct iio_info ad5761_info = { | |
252 | .read_raw = &ad5761_read_raw, | |
253 | .write_raw = &ad5761_write_raw, | |
131497ac RR |
254 | }; |
255 | ||
256 | #define AD5761_CHAN(_bits) { \ | |
257 | .type = IIO_VOLTAGE, \ | |
258 | .output = 1, \ | |
259 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ | |
260 | .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ | |
261 | BIT(IIO_CHAN_INFO_OFFSET), \ | |
262 | .scan_type = { \ | |
263 | .sign = 'u', \ | |
264 | .realbits = (_bits), \ | |
265 | .storagebits = 16, \ | |
266 | .shift = 16 - (_bits), \ | |
267 | }, \ | |
268 | } | |
269 | ||
270 | static const struct ad5761_chip_info ad5761_chip_infos[] = { | |
271 | [ID_AD5721] = { | |
272 | .int_vref = 0, | |
273 | .channel = AD5761_CHAN(12), | |
274 | }, | |
275 | [ID_AD5721R] = { | |
276 | .int_vref = 2500, | |
277 | .channel = AD5761_CHAN(12), | |
278 | }, | |
279 | [ID_AD5761] = { | |
280 | .int_vref = 0, | |
281 | .channel = AD5761_CHAN(16), | |
282 | }, | |
283 | [ID_AD5761R] = { | |
284 | .int_vref = 2500, | |
285 | .channel = AD5761_CHAN(16), | |
286 | }, | |
287 | }; | |
288 | ||
289 | static int ad5761_get_vref(struct ad5761_state *st, | |
290 | const struct ad5761_chip_info *chip_info) | |
291 | { | |
292 | int ret; | |
293 | ||
294 | st->vref_reg = devm_regulator_get_optional(&st->spi->dev, "vref"); | |
295 | if (PTR_ERR(st->vref_reg) == -ENODEV) { | |
296 | /* Use Internal regulator */ | |
297 | if (!chip_info->int_vref) { | |
298 | dev_err(&st->spi->dev, | |
299 | "Voltage reference not found\n"); | |
300 | return -EIO; | |
301 | } | |
302 | ||
303 | st->use_intref = true; | |
304 | st->vref = chip_info->int_vref; | |
305 | return 0; | |
306 | } | |
307 | ||
308 | if (IS_ERR(st->vref_reg)) { | |
309 | dev_err(&st->spi->dev, | |
310 | "Error getting voltage reference regulator\n"); | |
311 | return PTR_ERR(st->vref_reg); | |
312 | } | |
313 | ||
314 | ret = regulator_enable(st->vref_reg); | |
315 | if (ret) { | |
316 | dev_err(&st->spi->dev, | |
317 | "Failed to enable voltage reference\n"); | |
318 | return ret; | |
319 | } | |
320 | ||
321 | ret = regulator_get_voltage(st->vref_reg); | |
322 | if (ret < 0) { | |
323 | dev_err(&st->spi->dev, | |
324 | "Failed to get voltage reference value\n"); | |
325 | goto disable_regulator_vref; | |
326 | } | |
327 | ||
328 | if (ret < 2000000 || ret > 3000000) { | |
329 | dev_warn(&st->spi->dev, | |
330 | "Invalid external voltage ref. value %d uV\n", ret); | |
331 | ret = -EIO; | |
332 | goto disable_regulator_vref; | |
333 | } | |
334 | ||
335 | st->vref = ret / 1000; | |
336 | st->use_intref = false; | |
337 | ||
338 | return 0; | |
339 | ||
340 | disable_regulator_vref: | |
341 | regulator_disable(st->vref_reg); | |
342 | st->vref_reg = NULL; | |
343 | return ret; | |
344 | } | |
345 | ||
346 | static int ad5761_probe(struct spi_device *spi) | |
347 | { | |
348 | struct iio_dev *iio_dev; | |
349 | struct ad5761_state *st; | |
350 | int ret; | |
351 | const struct ad5761_chip_info *chip_info = | |
352 | &ad5761_chip_infos[spi_get_device_id(spi)->driver_data]; | |
353 | enum ad5761_voltage_range voltage_range = AD5761_VOLTAGE_RANGE_0V_5V; | |
354 | struct ad5761_platform_data *pdata = dev_get_platdata(&spi->dev); | |
355 | ||
356 | iio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); | |
357 | if (!iio_dev) | |
358 | return -ENOMEM; | |
359 | ||
360 | st = iio_priv(iio_dev); | |
361 | ||
362 | st->spi = spi; | |
363 | spi_set_drvdata(spi, iio_dev); | |
364 | ||
365 | ret = ad5761_get_vref(st, chip_info); | |
366 | if (ret) | |
367 | return ret; | |
368 | ||
369 | if (pdata) | |
370 | voltage_range = pdata->voltage_range; | |
371 | ||
372 | ret = ad5761_spi_set_range(st, voltage_range); | |
373 | if (ret) | |
374 | goto disable_regulator_err; | |
375 | ||
376 | iio_dev->dev.parent = &spi->dev; | |
377 | iio_dev->info = &ad5761_info; | |
378 | iio_dev->modes = INDIO_DIRECT_MODE; | |
379 | iio_dev->channels = &chip_info->channel; | |
380 | iio_dev->num_channels = 1; | |
381 | iio_dev->name = spi_get_device_id(st->spi)->name; | |
382 | ret = iio_device_register(iio_dev); | |
383 | if (ret) | |
384 | goto disable_regulator_err; | |
385 | ||
386 | return 0; | |
387 | ||
388 | disable_regulator_err: | |
389 | if (!IS_ERR_OR_NULL(st->vref_reg)) | |
390 | regulator_disable(st->vref_reg); | |
391 | ||
392 | return ret; | |
393 | } | |
394 | ||
395 | static int ad5761_remove(struct spi_device *spi) | |
396 | { | |
397 | struct iio_dev *iio_dev = spi_get_drvdata(spi); | |
398 | struct ad5761_state *st = iio_priv(iio_dev); | |
399 | ||
400 | iio_device_unregister(iio_dev); | |
401 | ||
402 | if (!IS_ERR_OR_NULL(st->vref_reg)) | |
403 | regulator_disable(st->vref_reg); | |
404 | ||
405 | return 0; | |
406 | } | |
407 | ||
408 | static const struct spi_device_id ad5761_id[] = { | |
409 | {"ad5721", ID_AD5721}, | |
410 | {"ad5721r", ID_AD5721R}, | |
411 | {"ad5761", ID_AD5761}, | |
412 | {"ad5761r", ID_AD5761R}, | |
413 | {} | |
414 | }; | |
415 | MODULE_DEVICE_TABLE(spi, ad5761_id); | |
416 | ||
417 | static struct spi_driver ad5761_driver = { | |
418 | .driver = { | |
419 | .name = "ad5761", | |
420 | }, | |
421 | .probe = ad5761_probe, | |
422 | .remove = ad5761_remove, | |
423 | .id_table = ad5761_id, | |
424 | }; | |
425 | module_spi_driver(ad5761_driver); | |
426 | ||
427 | MODULE_AUTHOR("Ricardo Ribalda <[email protected]>"); | |
428 | MODULE_DESCRIPTION("Analog Devices AD5721, AD5721R, AD5761, AD5761R driver"); | |
429 | MODULE_LICENSE("GPL v2"); |