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af300848 LPC |
1 | /* |
2 | * Support code for Analog Devices Sigma-Delta ADCs | |
3 | * | |
4 | * Copyright 2012 Analog Devices Inc. | |
5 | * Author: Lars-Peter Clausen <lars@metafoo.de> | |
6 | * | |
7 | * Licensed under the GPL-2. | |
8 | */ | |
9 | ||
10 | #include <linux/interrupt.h> | |
11 | #include <linux/device.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/spi/spi.h> | |
15 | #include <linux/err.h> | |
16 | #include <linux/module.h> | |
17 | ||
18 | #include <linux/iio/iio.h> | |
19 | #include <linux/iio/sysfs.h> | |
20 | #include <linux/iio/buffer.h> | |
21 | #include <linux/iio/trigger.h> | |
22 | #include <linux/iio/trigger_consumer.h> | |
23 | #include <linux/iio/triggered_buffer.h> | |
24 | #include <linux/iio/adc/ad_sigma_delta.h> | |
25 | ||
26 | #include <asm/unaligned.h> | |
27 | ||
28 | ||
29 | #define AD_SD_COMM_CHAN_MASK 0x3 | |
30 | ||
31 | #define AD_SD_REG_COMM 0x00 | |
32 | #define AD_SD_REG_DATA 0x03 | |
33 | ||
34 | /** | |
35 | * ad_sd_set_comm() - Set communications register | |
36 | * | |
37 | * @sigma_delta: The sigma delta device | |
38 | * @comm: New value for the communications register | |
39 | */ | |
40 | void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm) | |
41 | { | |
42 | /* Some variants use the lower two bits of the communications register | |
43 | * to select the channel */ | |
44 | sigma_delta->comm = comm & AD_SD_COMM_CHAN_MASK; | |
45 | } | |
46 | EXPORT_SYMBOL_GPL(ad_sd_set_comm); | |
47 | ||
48 | /** | |
49 | * ad_sd_write_reg() - Write a register | |
50 | * | |
51 | * @sigma_delta: The sigma delta device | |
52 | * @reg: Address of the register | |
53 | * @size: Size of the register (0-3) | |
54 | * @val: Value to write to the register | |
55 | * | |
56 | * Returns 0 on success, an error code otherwise. | |
57 | **/ | |
58 | int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg, | |
59 | unsigned int size, unsigned int val) | |
60 | { | |
61 | uint8_t *data = sigma_delta->data; | |
62 | struct spi_transfer t = { | |
63 | .tx_buf = data, | |
64 | .len = size + 1, | |
65 | .cs_change = sigma_delta->bus_locked, | |
66 | }; | |
67 | struct spi_message m; | |
68 | int ret; | |
69 | ||
70 | data[0] = (reg << sigma_delta->info->addr_shift) | sigma_delta->comm; | |
71 | ||
72 | switch (size) { | |
73 | case 3: | |
74 | data[1] = val >> 16; | |
75 | data[2] = val >> 8; | |
76 | data[3] = val; | |
77 | break; | |
78 | case 2: | |
79 | put_unaligned_be16(val, &data[1]); | |
80 | break; | |
81 | case 1: | |
82 | data[1] = val; | |
83 | break; | |
84 | case 0: | |
85 | break; | |
86 | default: | |
87 | return -EINVAL; | |
88 | } | |
89 | ||
90 | spi_message_init(&m); | |
91 | spi_message_add_tail(&t, &m); | |
92 | ||
93 | if (sigma_delta->bus_locked) | |
94 | ret = spi_sync_locked(sigma_delta->spi, &m); | |
95 | else | |
96 | ret = spi_sync(sigma_delta->spi, &m); | |
97 | ||
98 | return ret; | |
99 | } | |
100 | EXPORT_SYMBOL_GPL(ad_sd_write_reg); | |
101 | ||
102 | static int ad_sd_read_reg_raw(struct ad_sigma_delta *sigma_delta, | |
103 | unsigned int reg, unsigned int size, uint8_t *val) | |
104 | { | |
105 | uint8_t *data = sigma_delta->data; | |
106 | int ret; | |
107 | struct spi_transfer t[] = { | |
108 | { | |
109 | .tx_buf = data, | |
110 | .len = 1, | |
111 | }, { | |
112 | .rx_buf = val, | |
113 | .len = size, | |
114 | .cs_change = sigma_delta->bus_locked, | |
115 | }, | |
116 | }; | |
117 | struct spi_message m; | |
118 | ||
119 | spi_message_init(&m); | |
120 | ||
121 | if (sigma_delta->info->has_registers) { | |
122 | data[0] = reg << sigma_delta->info->addr_shift; | |
123 | data[0] |= sigma_delta->info->read_mask; | |
124 | spi_message_add_tail(&t[0], &m); | |
125 | } | |
126 | spi_message_add_tail(&t[1], &m); | |
127 | ||
128 | if (sigma_delta->bus_locked) | |
129 | ret = spi_sync_locked(sigma_delta->spi, &m); | |
130 | else | |
131 | ret = spi_sync(sigma_delta->spi, &m); | |
132 | ||
133 | return ret; | |
134 | } | |
135 | ||
136 | /** | |
137 | * ad_sd_read_reg() - Read a register | |
138 | * | |
139 | * @sigma_delta: The sigma delta device | |
140 | * @reg: Address of the register | |
141 | * @size: Size of the register (1-4) | |
142 | * @val: Read value | |
143 | * | |
144 | * Returns 0 on success, an error code otherwise. | |
145 | **/ | |
146 | int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, | |
147 | unsigned int reg, unsigned int size, unsigned int *val) | |
148 | { | |
149 | int ret; | |
150 | ||
151 | ret = ad_sd_read_reg_raw(sigma_delta, reg, size, sigma_delta->data); | |
152 | if (ret < 0) | |
153 | goto out; | |
154 | ||
155 | switch (size) { | |
156 | case 4: | |
157 | *val = get_unaligned_be32(sigma_delta->data); | |
158 | break; | |
159 | case 3: | |
160 | *val = (sigma_delta->data[0] << 16) | | |
161 | (sigma_delta->data[1] << 8) | | |
162 | sigma_delta->data[2]; | |
163 | break; | |
164 | case 2: | |
165 | *val = get_unaligned_be16(sigma_delta->data); | |
166 | break; | |
167 | case 1: | |
168 | *val = sigma_delta->data[0]; | |
169 | break; | |
170 | default: | |
171 | ret = -EINVAL; | |
172 | break; | |
173 | } | |
174 | ||
175 | out: | |
176 | return ret; | |
177 | } | |
178 | EXPORT_SYMBOL_GPL(ad_sd_read_reg); | |
179 | ||
180 | static int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta, | |
181 | unsigned int mode, unsigned int channel) | |
182 | { | |
183 | int ret; | |
184 | ||
185 | ret = ad_sigma_delta_set_channel(sigma_delta, channel); | |
186 | if (ret) | |
187 | return ret; | |
188 | ||
189 | spi_bus_lock(sigma_delta->spi->master); | |
190 | sigma_delta->bus_locked = true; | |
16735d02 | 191 | reinit_completion(&sigma_delta->completion); |
af300848 LPC |
192 | |
193 | ret = ad_sigma_delta_set_mode(sigma_delta, mode); | |
194 | if (ret < 0) | |
195 | goto out; | |
196 | ||
197 | sigma_delta->irq_dis = false; | |
198 | enable_irq(sigma_delta->spi->irq); | |
199 | ret = wait_for_completion_timeout(&sigma_delta->completion, 2*HZ); | |
200 | if (ret == 0) { | |
201 | sigma_delta->irq_dis = true; | |
202 | disable_irq_nosync(sigma_delta->spi->irq); | |
203 | ret = -EIO; | |
204 | } else { | |
205 | ret = 0; | |
206 | } | |
207 | out: | |
208 | sigma_delta->bus_locked = false; | |
209 | spi_bus_unlock(sigma_delta->spi->master); | |
210 | ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE); | |
211 | ||
212 | return ret; | |
213 | } | |
214 | ||
215 | /** | |
216 | * ad_sd_calibrate_all() - Performs channel calibration | |
217 | * @sigma_delta: The sigma delta device | |
218 | * @cb: Array of channels and calibration type to perform | |
219 | * @n: Number of items in cb | |
220 | * | |
221 | * Returns 0 on success, an error code otherwise. | |
222 | **/ | |
223 | int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta, | |
224 | const struct ad_sd_calib_data *cb, unsigned int n) | |
225 | { | |
226 | unsigned int i; | |
227 | int ret; | |
228 | ||
229 | for (i = 0; i < n; i++) { | |
230 | ret = ad_sd_calibrate(sigma_delta, cb[i].mode, cb[i].channel); | |
231 | if (ret) | |
232 | return ret; | |
233 | } | |
234 | ||
235 | return 0; | |
236 | } | |
237 | EXPORT_SYMBOL_GPL(ad_sd_calibrate_all); | |
238 | ||
239 | /** | |
240 | * ad_sigma_delta_single_conversion() - Performs a single data conversion | |
241 | * @indio_dev: The IIO device | |
242 | * @chan: The conversion is done for this channel | |
243 | * @val: Pointer to the location where to store the read value | |
244 | * | |
245 | * Returns: 0 on success, an error value otherwise. | |
246 | */ | |
247 | int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev, | |
248 | const struct iio_chan_spec *chan, int *val) | |
249 | { | |
250 | struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); | |
251 | unsigned int sample, raw_sample; | |
252 | int ret = 0; | |
253 | ||
254 | if (iio_buffer_enabled(indio_dev)) | |
255 | return -EBUSY; | |
256 | ||
257 | mutex_lock(&indio_dev->mlock); | |
258 | ad_sigma_delta_set_channel(sigma_delta, chan->address); | |
259 | ||
260 | spi_bus_lock(sigma_delta->spi->master); | |
261 | sigma_delta->bus_locked = true; | |
16735d02 | 262 | reinit_completion(&sigma_delta->completion); |
af300848 LPC |
263 | |
264 | ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_SINGLE); | |
265 | ||
266 | sigma_delta->irq_dis = false; | |
267 | enable_irq(sigma_delta->spi->irq); | |
268 | ret = wait_for_completion_interruptible_timeout( | |
269 | &sigma_delta->completion, HZ); | |
270 | ||
271 | sigma_delta->bus_locked = false; | |
272 | spi_bus_unlock(sigma_delta->spi->master); | |
273 | ||
274 | if (ret == 0) | |
275 | ret = -EIO; | |
276 | if (ret < 0) | |
277 | goto out; | |
278 | ||
279 | ret = ad_sd_read_reg(sigma_delta, AD_SD_REG_DATA, | |
280 | DIV_ROUND_UP(chan->scan_type.realbits + chan->scan_type.shift, 8), | |
281 | &raw_sample); | |
282 | ||
283 | out: | |
284 | if (!sigma_delta->irq_dis) { | |
285 | disable_irq_nosync(sigma_delta->spi->irq); | |
286 | sigma_delta->irq_dis = true; | |
287 | } | |
288 | ||
289 | ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE); | |
290 | mutex_unlock(&indio_dev->mlock); | |
291 | ||
292 | if (ret) | |
293 | return ret; | |
294 | ||
295 | sample = raw_sample >> chan->scan_type.shift; | |
296 | sample &= (1 << chan->scan_type.realbits) - 1; | |
297 | *val = sample; | |
298 | ||
299 | ret = ad_sigma_delta_postprocess_sample(sigma_delta, raw_sample); | |
300 | if (ret) | |
301 | return ret; | |
302 | ||
303 | return IIO_VAL_INT; | |
304 | } | |
305 | EXPORT_SYMBOL_GPL(ad_sigma_delta_single_conversion); | |
306 | ||
307 | static int ad_sd_buffer_postenable(struct iio_dev *indio_dev) | |
308 | { | |
309 | struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); | |
310 | unsigned int channel; | |
311 | int ret; | |
312 | ||
313 | ret = iio_triggered_buffer_postenable(indio_dev); | |
314 | if (ret < 0) | |
315 | return ret; | |
316 | ||
317 | channel = find_first_bit(indio_dev->active_scan_mask, | |
318 | indio_dev->masklength); | |
319 | ret = ad_sigma_delta_set_channel(sigma_delta, | |
320 | indio_dev->channels[channel].address); | |
321 | if (ret) | |
322 | goto err_predisable; | |
323 | ||
324 | spi_bus_lock(sigma_delta->spi->master); | |
325 | sigma_delta->bus_locked = true; | |
326 | ret = ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_CONTINUOUS); | |
327 | if (ret) | |
328 | goto err_unlock; | |
329 | ||
330 | sigma_delta->irq_dis = false; | |
331 | enable_irq(sigma_delta->spi->irq); | |
332 | ||
333 | return 0; | |
334 | ||
335 | err_unlock: | |
336 | spi_bus_unlock(sigma_delta->spi->master); | |
337 | err_predisable: | |
338 | ||
339 | return ret; | |
340 | } | |
341 | ||
342 | static int ad_sd_buffer_postdisable(struct iio_dev *indio_dev) | |
343 | { | |
344 | struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); | |
345 | ||
16735d02 | 346 | reinit_completion(&sigma_delta->completion); |
af300848 LPC |
347 | wait_for_completion_timeout(&sigma_delta->completion, HZ); |
348 | ||
349 | if (!sigma_delta->irq_dis) { | |
350 | disable_irq_nosync(sigma_delta->spi->irq); | |
351 | sigma_delta->irq_dis = true; | |
352 | } | |
353 | ||
354 | ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE); | |
355 | ||
356 | sigma_delta->bus_locked = false; | |
357 | return spi_bus_unlock(sigma_delta->spi->master); | |
358 | } | |
359 | ||
360 | static irqreturn_t ad_sd_trigger_handler(int irq, void *p) | |
361 | { | |
362 | struct iio_poll_func *pf = p; | |
363 | struct iio_dev *indio_dev = pf->indio_dev; | |
364 | struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); | |
365 | unsigned int reg_size; | |
366 | uint8_t data[16]; | |
367 | int ret; | |
368 | ||
369 | memset(data, 0x00, 16); | |
370 | ||
af300848 LPC |
371 | reg_size = indio_dev->channels[0].scan_type.realbits + |
372 | indio_dev->channels[0].scan_type.shift; | |
373 | reg_size = DIV_ROUND_UP(reg_size, 8); | |
374 | ||
375 | switch (reg_size) { | |
376 | case 4: | |
377 | case 2: | |
378 | case 1: | |
379 | ret = ad_sd_read_reg_raw(sigma_delta, AD_SD_REG_DATA, | |
380 | reg_size, &data[0]); | |
381 | break; | |
382 | case 3: | |
383 | /* We store 24 bit samples in a 32 bit word. Keep the upper | |
384 | * byte set to zero. */ | |
385 | ret = ad_sd_read_reg_raw(sigma_delta, AD_SD_REG_DATA, | |
386 | reg_size, &data[1]); | |
387 | break; | |
388 | } | |
389 | ||
a1be505f | 390 | iio_push_to_buffers_with_timestamp(indio_dev, data, pf->timestamp); |
af300848 LPC |
391 | |
392 | iio_trigger_notify_done(indio_dev->trig); | |
393 | sigma_delta->irq_dis = false; | |
394 | enable_irq(sigma_delta->spi->irq); | |
395 | ||
396 | return IRQ_HANDLED; | |
397 | } | |
398 | ||
399 | static const struct iio_buffer_setup_ops ad_sd_buffer_setup_ops = { | |
af300848 LPC |
400 | .postenable = &ad_sd_buffer_postenable, |
401 | .predisable = &iio_triggered_buffer_predisable, | |
402 | .postdisable = &ad_sd_buffer_postdisable, | |
403 | .validate_scan_mask = &iio_validate_scan_mask_onehot, | |
404 | }; | |
405 | ||
406 | static irqreturn_t ad_sd_data_rdy_trig_poll(int irq, void *private) | |
407 | { | |
408 | struct ad_sigma_delta *sigma_delta = private; | |
409 | ||
410 | complete(&sigma_delta->completion); | |
411 | disable_irq_nosync(irq); | |
412 | sigma_delta->irq_dis = true; | |
398fd22b | 413 | iio_trigger_poll(sigma_delta->trig); |
af300848 LPC |
414 | |
415 | return IRQ_HANDLED; | |
416 | } | |
417 | ||
418 | /** | |
419 | * ad_sd_validate_trigger() - validate_trigger callback for ad_sigma_delta devices | |
420 | * @indio_dev: The IIO device | |
421 | * @trig: The new trigger | |
422 | * | |
423 | * Returns: 0 if the 'trig' matches the trigger registered by the ad_sigma_delta | |
424 | * device, -EINVAL otherwise. | |
425 | */ | |
426 | int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig) | |
427 | { | |
428 | struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); | |
429 | ||
430 | if (sigma_delta->trig != trig) | |
431 | return -EINVAL; | |
432 | ||
433 | return 0; | |
434 | } | |
435 | EXPORT_SYMBOL_GPL(ad_sd_validate_trigger); | |
436 | ||
437 | static const struct iio_trigger_ops ad_sd_trigger_ops = { | |
438 | .owner = THIS_MODULE, | |
439 | }; | |
440 | ||
441 | static int ad_sd_probe_trigger(struct iio_dev *indio_dev) | |
442 | { | |
443 | struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); | |
444 | int ret; | |
445 | ||
446 | sigma_delta->trig = iio_trigger_alloc("%s-dev%d", indio_dev->name, | |
447 | indio_dev->id); | |
448 | if (sigma_delta->trig == NULL) { | |
449 | ret = -ENOMEM; | |
450 | goto error_ret; | |
451 | } | |
452 | sigma_delta->trig->ops = &ad_sd_trigger_ops; | |
453 | init_completion(&sigma_delta->completion); | |
454 | ||
455 | ret = request_irq(sigma_delta->spi->irq, | |
456 | ad_sd_data_rdy_trig_poll, | |
457 | IRQF_TRIGGER_LOW, | |
458 | indio_dev->name, | |
459 | sigma_delta); | |
460 | if (ret) | |
461 | goto error_free_trig; | |
462 | ||
463 | if (!sigma_delta->irq_dis) { | |
464 | sigma_delta->irq_dis = true; | |
465 | disable_irq_nosync(sigma_delta->spi->irq); | |
466 | } | |
467 | sigma_delta->trig->dev.parent = &sigma_delta->spi->dev; | |
1e9663c6 | 468 | iio_trigger_set_drvdata(sigma_delta->trig, sigma_delta); |
af300848 LPC |
469 | |
470 | ret = iio_trigger_register(sigma_delta->trig); | |
471 | if (ret) | |
472 | goto error_free_irq; | |
473 | ||
474 | /* select default trigger */ | |
9e5846be | 475 | indio_dev->trig = iio_trigger_get(sigma_delta->trig); |
af300848 LPC |
476 | |
477 | return 0; | |
478 | ||
479 | error_free_irq: | |
480 | free_irq(sigma_delta->spi->irq, sigma_delta); | |
481 | error_free_trig: | |
482 | iio_trigger_free(sigma_delta->trig); | |
483 | error_ret: | |
484 | return ret; | |
485 | } | |
486 | ||
487 | static void ad_sd_remove_trigger(struct iio_dev *indio_dev) | |
488 | { | |
489 | struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); | |
490 | ||
491 | iio_trigger_unregister(sigma_delta->trig); | |
492 | free_irq(sigma_delta->spi->irq, sigma_delta); | |
493 | iio_trigger_free(sigma_delta->trig); | |
494 | } | |
495 | ||
496 | /** | |
497 | * ad_sd_setup_buffer_and_trigger() - | |
498 | * @indio_dev: The IIO device | |
499 | */ | |
500 | int ad_sd_setup_buffer_and_trigger(struct iio_dev *indio_dev) | |
501 | { | |
502 | int ret; | |
503 | ||
504 | ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time, | |
505 | &ad_sd_trigger_handler, &ad_sd_buffer_setup_ops); | |
506 | if (ret) | |
507 | return ret; | |
508 | ||
509 | ret = ad_sd_probe_trigger(indio_dev); | |
510 | if (ret) { | |
511 | iio_triggered_buffer_cleanup(indio_dev); | |
512 | return ret; | |
513 | } | |
514 | ||
515 | return 0; | |
516 | } | |
517 | EXPORT_SYMBOL_GPL(ad_sd_setup_buffer_and_trigger); | |
518 | ||
519 | /** | |
520 | * ad_sd_cleanup_buffer_and_trigger() - | |
521 | * @indio_dev: The IIO device | |
522 | */ | |
523 | void ad_sd_cleanup_buffer_and_trigger(struct iio_dev *indio_dev) | |
524 | { | |
525 | ad_sd_remove_trigger(indio_dev); | |
526 | iio_triggered_buffer_cleanup(indio_dev); | |
527 | } | |
528 | EXPORT_SYMBOL_GPL(ad_sd_cleanup_buffer_and_trigger); | |
529 | ||
530 | /** | |
531 | * ad_sd_init() - Initializes a ad_sigma_delta struct | |
532 | * @sigma_delta: The ad_sigma_delta device | |
533 | * @indio_dev: The IIO device which the Sigma Delta device is used for | |
534 | * @spi: The SPI device for the ad_sigma_delta device | |
535 | * @info: Device specific callbacks and options | |
536 | * | |
537 | * This function needs to be called before any other operations are performed on | |
538 | * the ad_sigma_delta struct. | |
539 | */ | |
540 | int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev, | |
541 | struct spi_device *spi, const struct ad_sigma_delta_info *info) | |
542 | { | |
543 | sigma_delta->spi = spi; | |
544 | sigma_delta->info = info; | |
545 | iio_device_set_drvdata(indio_dev, sigma_delta); | |
546 | ||
547 | return 0; | |
548 | } | |
549 | EXPORT_SYMBOL_GPL(ad_sd_init); | |
550 | ||
551 | MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); | |
552 | MODULE_DESCRIPTION("Analog Devices Sigma-Delta ADCs"); | |
553 | MODULE_LICENSE("GPL v2"); |