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NFS: Don't clear desc->pg_moreio in nfs_do_recoalesce()
[linux/fpc-iii.git] / drivers / iio / adc / max1027.c
blob44bf815adb6c0d4edd9162fca82b4aaa1dd95d81
1 /*
2 * iio/adc/max1027.c
3 * Copyright (C) 2014 Philippe Reynes
4 *
5 * based on linux/drivers/iio/ad7923.c
6 * Copyright 2011 Analog Devices Inc (from AD7923 Driver)
7 * Copyright 2012 CS Systemes d'Information
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 * max1027.c
14 *
15 * Partial support for max1027 and similar chips.
16 */
17
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/spi/spi.h>
21 #include <linux/delay.h>
22
23 #include <linux/iio/iio.h>
24 #include <linux/iio/buffer.h>
25 #include <linux/iio/trigger.h>
26 #include <linux/iio/trigger_consumer.h>
27 #include <linux/iio/triggered_buffer.h>
28
29 #define MAX1027_CONV_REG BIT(7)
30 #define MAX1027_SETUP_REG BIT(6)
31 #define MAX1027_AVG_REG BIT(5)
32 #define MAX1027_RST_REG BIT(4)
33
34 /* conversion register */
35 #define MAX1027_TEMP BIT(0)
36 #define MAX1027_SCAN_0_N (0x00 << 1)
37 #define MAX1027_SCAN_N_M (0x01 << 1)
38 #define MAX1027_SCAN_N (0x02 << 1)
39 #define MAX1027_NOSCAN (0x03 << 1)
40 #define MAX1027_CHAN(n) ((n) << 3)
41
42 /* setup register */
43 #define MAX1027_UNIPOLAR 0x02
44 #define MAX1027_BIPOLAR 0x03
45 #define MAX1027_REF_MODE0 (0x00 << 2)
46 #define MAX1027_REF_MODE1 (0x01 << 2)
47 #define MAX1027_REF_MODE2 (0x02 << 2)
48 #define MAX1027_REF_MODE3 (0x03 << 2)
49 #define MAX1027_CKS_MODE0 (0x00 << 4)
50 #define MAX1027_CKS_MODE1 (0x01 << 4)
51 #define MAX1027_CKS_MODE2 (0x02 << 4)
52 #define MAX1027_CKS_MODE3 (0x03 << 4)
53
54 /* averaging register */
55 #define MAX1027_NSCAN_4 0x00
56 #define MAX1027_NSCAN_8 0x01
57 #define MAX1027_NSCAN_12 0x02
58 #define MAX1027_NSCAN_16 0x03
59 #define MAX1027_NAVG_4 (0x00 << 2)
60 #define MAX1027_NAVG_8 (0x01 << 2)
61 #define MAX1027_NAVG_16 (0x02 << 2)
62 #define MAX1027_NAVG_32 (0x03 << 2)
63 #define MAX1027_AVG_EN BIT(4)
64
65 enum max1027_id {
66 max1027,
67 max1029,
68 max1031,
69 };
70
71 static const struct spi_device_id max1027_id[] = {
72 {"max1027", max1027},
73 {"max1029", max1029},
74 {"max1031", max1031},
75 {}
76 };
77 MODULE_DEVICE_TABLE(spi, max1027_id);
78
79 #ifdef CONFIG_OF
80 static const struct of_device_id max1027_adc_dt_ids[] = {
81 { .compatible = "maxim,max1027" },
82 { .compatible = "maxim,max1029" },
83 { .compatible = "maxim,max1031" },
84 {},
85 };
86 MODULE_DEVICE_TABLE(of, max1027_adc_dt_ids);
87 #endif
88
89 #define MAX1027_V_CHAN(index) \
90 { \
91 .type = IIO_VOLTAGE, \
92 .indexed = 1, \
93 .channel = index, \
94 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
95 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
96 .scan_index = index + 1, \
97 .scan_type = { \
98 .sign = 'u', \
99 .realbits = 10, \
100 .storagebits = 16, \
101 .shift = 2, \
102 .endianness = IIO_BE, \
103 }, \
104 }
105
106 #define MAX1027_T_CHAN \
107 { \
108 .type = IIO_TEMP, \
109 .channel = 0, \
110 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
111 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
112 .scan_index = 0, \
113 .scan_type = { \
114 .sign = 'u', \
115 .realbits = 12, \
116 .storagebits = 16, \
117 .endianness = IIO_BE, \
118 }, \
119 }
120
121 static const struct iio_chan_spec max1027_channels[] = {
122 MAX1027_T_CHAN,
123 MAX1027_V_CHAN(0),
124 MAX1027_V_CHAN(1),
125 MAX1027_V_CHAN(2),
126 MAX1027_V_CHAN(3),
127 MAX1027_V_CHAN(4),
128 MAX1027_V_CHAN(5),
129 MAX1027_V_CHAN(6),
130 MAX1027_V_CHAN(7)
131 };
132
133 static const struct iio_chan_spec max1029_channels[] = {
134 MAX1027_T_CHAN,
135 MAX1027_V_CHAN(0),
136 MAX1027_V_CHAN(1),
137 MAX1027_V_CHAN(2),
138 MAX1027_V_CHAN(3),
139 MAX1027_V_CHAN(4),
140 MAX1027_V_CHAN(5),
141 MAX1027_V_CHAN(6),
142 MAX1027_V_CHAN(7),
143 MAX1027_V_CHAN(8),
144 MAX1027_V_CHAN(9),
145 MAX1027_V_CHAN(10),
146 MAX1027_V_CHAN(11)
147 };
148
149 static const struct iio_chan_spec max1031_channels[] = {
150 MAX1027_T_CHAN,
151 MAX1027_V_CHAN(0),
152 MAX1027_V_CHAN(1),
153 MAX1027_V_CHAN(2),
154 MAX1027_V_CHAN(3),
155 MAX1027_V_CHAN(4),
156 MAX1027_V_CHAN(5),
157 MAX1027_V_CHAN(6),
158 MAX1027_V_CHAN(7),
159 MAX1027_V_CHAN(8),
160 MAX1027_V_CHAN(9),
161 MAX1027_V_CHAN(10),
162 MAX1027_V_CHAN(11),
163 MAX1027_V_CHAN(12),
164 MAX1027_V_CHAN(13),
165 MAX1027_V_CHAN(14),
166 MAX1027_V_CHAN(15)
167 };
168
169 static const unsigned long max1027_available_scan_masks[] = {
170 0x000001ff,
171 0x00000000,
172 };
173
174 static const unsigned long max1029_available_scan_masks[] = {
175 0x00001fff,
176 0x00000000,
177 };
178
179 static const unsigned long max1031_available_scan_masks[] = {
180 0x0001ffff,
181 0x00000000,
182 };
183
184 struct max1027_chip_info {
185 const struct iio_chan_spec *channels;
186 unsigned int num_channels;
187 const unsigned long *available_scan_masks;
188 };
189
190 static const struct max1027_chip_info max1027_chip_info_tbl[] = {
191 [max1027] = {
192 .channels = max1027_channels,
193 .num_channels = ARRAY_SIZE(max1027_channels),
194 .available_scan_masks = max1027_available_scan_masks,
195 },
196 [max1029] = {
197 .channels = max1029_channels,
198 .num_channels = ARRAY_SIZE(max1029_channels),
199 .available_scan_masks = max1029_available_scan_masks,
200 },
201 [max1031] = {
202 .channels = max1031_channels,
203 .num_channels = ARRAY_SIZE(max1031_channels),
204 .available_scan_masks = max1031_available_scan_masks,
205 },
206 };
207
208 struct max1027_state {
209 const struct max1027_chip_info *info;
210 struct spi_device *spi;
211 struct iio_trigger *trig;
212 __be16 *buffer;
213 struct mutex lock;
214
215 u8 reg ____cacheline_aligned;
216 };
217
218 static int max1027_read_single_value(struct iio_dev *indio_dev,
219 struct iio_chan_spec const *chan,
220 int *val)
221 {
222 int ret;
223 struct max1027_state *st = iio_priv(indio_dev);
224
225 if (iio_buffer_enabled(indio_dev)) {
226 dev_warn(&indio_dev->dev, "trigger mode already enabled");
227 return -EBUSY;
228 }
229
230 /* Start acquisition on conversion register write */
231 st->reg = MAX1027_SETUP_REG | MAX1027_REF_MODE2 | MAX1027_CKS_MODE2;
232 ret = spi_write(st->spi, &st->reg, 1);
233 if (ret < 0) {
234 dev_err(&indio_dev->dev,
235 "Failed to configure setup register\n");
236 return ret;
237 }
238
239 /* Configure conversion register with the requested chan */
240 st->reg = MAX1027_CONV_REG | MAX1027_CHAN(chan->channel) |
241 MAX1027_NOSCAN | !!(chan->type == IIO_TEMP);
242 ret = spi_write(st->spi, &st->reg, 1);
243 if (ret < 0) {
244 dev_err(&indio_dev->dev,
245 "Failed to configure conversion register\n");
246 return ret;
247 }
248
249 /*
250 * For an unknown reason, when we use the mode "10" (write
251 * conversion register), the interrupt doesn't occur every time.
252 * So we just wait 1 ms.
253 */
254 mdelay(1);
255
256 /* Read result */
257 ret = spi_read(st->spi, st->buffer, (chan->type == IIO_TEMP) ? 4 : 2);
258 if (ret < 0)
259 return ret;
260
261 *val = be16_to_cpu(st->buffer[0]);
262
263 return IIO_VAL_INT;
264 }
265
266 static int max1027_read_raw(struct iio_dev *indio_dev,
267 struct iio_chan_spec const *chan,
268 int *val, int *val2, long mask)
269 {
270 int ret = 0;
271 struct max1027_state *st = iio_priv(indio_dev);
272
273 mutex_lock(&st->lock);
274
275 switch (mask) {
276 case IIO_CHAN_INFO_RAW:
277 ret = max1027_read_single_value(indio_dev, chan, val);
278 break;
279 case IIO_CHAN_INFO_SCALE:
280 switch (chan->type) {
281 case IIO_TEMP:
282 *val = 1;
283 *val2 = 8;
284 ret = IIO_VAL_FRACTIONAL;
285 break;
286 case IIO_VOLTAGE:
287 *val = 2500;
288 *val2 = 10;
289 ret = IIO_VAL_FRACTIONAL_LOG2;
290 break;
291 default:
292 ret = -EINVAL;
293 break;
294 }
295 break;
296 default:
297 ret = -EINVAL;
298 break;
299 }
300
301 mutex_unlock(&st->lock);
302
303 return ret;
304 }
305
306 static int max1027_debugfs_reg_access(struct iio_dev *indio_dev,
307 unsigned reg, unsigned writeval,
308 unsigned *readval)
309 {
310 struct max1027_state *st = iio_priv(indio_dev);
311 u8 *val = (u8 *)st->buffer;
312
313 if (readval != NULL)
314 return -EINVAL;
315
316 *val = (u8)writeval;
317 return spi_write(st->spi, val, 1);
318 }
319
320 static int max1027_validate_trigger(struct iio_dev *indio_dev,
321 struct iio_trigger *trig)
322 {
323 struct max1027_state *st = iio_priv(indio_dev);
324
325 if (st->trig != trig)
326 return -EINVAL;
327
328 return 0;
329 }
330
331 static int max1027_set_trigger_state(struct iio_trigger *trig, bool state)
332 {
333 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
334 struct max1027_state *st = iio_priv(indio_dev);
335 int ret;
336
337 if (state) {
338 /* Start acquisition on cnvst */
339 st->reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE0 |
340 MAX1027_REF_MODE2;
341 ret = spi_write(st->spi, &st->reg, 1);
342 if (ret < 0)
343 return ret;
344
345 /* Scan from 0 to max */
346 st->reg = MAX1027_CONV_REG | MAX1027_CHAN(0) |
347 MAX1027_SCAN_N_M | MAX1027_TEMP;
348 ret = spi_write(st->spi, &st->reg, 1);
349 if (ret < 0)
350 return ret;
351 } else {
352 /* Start acquisition on conversion register write */
353 st->reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE2 |
354 MAX1027_REF_MODE2;
355 ret = spi_write(st->spi, &st->reg, 1);
356 if (ret < 0)
357 return ret;
358 }
359
360 return 0;
361 }
362
363 static int max1027_validate_device(struct iio_trigger *trig,
364 struct iio_dev *indio_dev)
365 {
366 struct iio_dev *indio = iio_trigger_get_drvdata(trig);
367
368 if (indio != indio_dev)
369 return -EINVAL;
370
371 return 0;
372 }
373
374 static irqreturn_t max1027_trigger_handler(int irq, void *private)
375 {
376 struct iio_poll_func *pf = (struct iio_poll_func *)private;
377 struct iio_dev *indio_dev = pf->indio_dev;
378 struct max1027_state *st = iio_priv(indio_dev);
379
380 pr_debug("%s(irq=%d, private=0x%p)\n", __func__, irq, private);
381
382 /* fill buffer with all channel */
383 spi_read(st->spi, st->buffer, indio_dev->masklength * 2);
384
385 iio_push_to_buffers(indio_dev, st->buffer);
386
387 iio_trigger_notify_done(indio_dev->trig);
388
389 return IRQ_HANDLED;
390 }
391
392 static const struct iio_trigger_ops max1027_trigger_ops = {
393 .owner = THIS_MODULE,
394 .validate_device = &max1027_validate_device,
395 .set_trigger_state = &max1027_set_trigger_state,
396 };
397
398 static const struct iio_info max1027_info = {
399 .driver_module = THIS_MODULE,
400 .read_raw = &max1027_read_raw,
401 .validate_trigger = &max1027_validate_trigger,
402 .debugfs_reg_access = &max1027_debugfs_reg_access,
403 };
404
405 static int max1027_probe(struct spi_device *spi)
406 {
407 int ret;
408 struct iio_dev *indio_dev;
409 struct max1027_state *st;
410
411 pr_debug("%s: probe(spi = 0x%p)\n", __func__, spi);
412
413 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
414 if (indio_dev == NULL) {
415 pr_err("Can't allocate iio device\n");
416 return -ENOMEM;
417 }
418
419 spi_set_drvdata(spi, indio_dev);
420
421 st = iio_priv(indio_dev);
422 st->spi = spi;
423 st->info = &max1027_chip_info_tbl[spi_get_device_id(spi)->driver_data];
424
425 mutex_init(&st->lock);
426
427 indio_dev->name = spi_get_device_id(spi)->name;
428 indio_dev->dev.parent = &spi->dev;
429 indio_dev->info = &max1027_info;
430 indio_dev->modes = INDIO_DIRECT_MODE;
431 indio_dev->channels = st->info->channels;
432 indio_dev->num_channels = st->info->num_channels;
433 indio_dev->available_scan_masks = st->info->available_scan_masks;
434
435 st->buffer = devm_kmalloc(&indio_dev->dev,
436 indio_dev->num_channels * 2,
437 GFP_KERNEL);
438 if (st->buffer == NULL) {
439 dev_err(&indio_dev->dev, "Can't allocate buffer\n");
440 return -ENOMEM;
441 }
442
443 ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
444 &max1027_trigger_handler, NULL);
445 if (ret < 0) {
446 dev_err(&indio_dev->dev, "Failed to setup buffer\n");
447 return ret;
448 }
449
450 st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-trigger",
451 indio_dev->name);
452 if (st->trig == NULL) {
453 ret = -ENOMEM;
454 dev_err(&indio_dev->dev, "Failed to allocate iio trigger\n");
455 goto fail_trigger_alloc;
456 }
457
458 st->trig->ops = &max1027_trigger_ops;
459 st->trig->dev.parent = &spi->dev;
460 iio_trigger_set_drvdata(st->trig, indio_dev);
461 iio_trigger_register(st->trig);
462
463 ret = devm_request_threaded_irq(&spi->dev, spi->irq,
464 iio_trigger_generic_data_rdy_poll,
465 NULL,
466 IRQF_TRIGGER_FALLING,
467 spi->dev.driver->name, st->trig);
468 if (ret < 0) {
469 dev_err(&indio_dev->dev, "Failed to allocate IRQ.\n");
470 goto fail_dev_register;
471 }
472
473 /* Disable averaging */
474 st->reg = MAX1027_AVG_REG;
475 ret = spi_write(st->spi, &st->reg, 1);
476 if (ret < 0) {
477 dev_err(&indio_dev->dev, "Failed to configure averaging register\n");
478 goto fail_dev_register;
479 }
480
481 ret = iio_device_register(indio_dev);
482 if (ret < 0) {
483 dev_err(&indio_dev->dev, "Failed to register iio device\n");
484 goto fail_dev_register;
485 }
486
487 return 0;
488
489 fail_dev_register:
490 fail_trigger_alloc:
491 iio_triggered_buffer_cleanup(indio_dev);
492
493 return ret;
494 }
495
496 static int max1027_remove(struct spi_device *spi)
497 {
498 struct iio_dev *indio_dev = spi_get_drvdata(spi);
499
500 pr_debug("%s: remove(spi = 0x%p)\n", __func__, spi);
501
502 iio_device_unregister(indio_dev);
503 iio_triggered_buffer_cleanup(indio_dev);
504
505 return 0;
506 }
507
508 static struct spi_driver max1027_driver = {
509 .driver = {
510 .name = "max1027",
511 .owner = THIS_MODULE,
512 },
513 .probe = max1027_probe,
514 .remove = max1027_remove,
515 .id_table = max1027_id,
516 };
517 module_spi_driver(max1027_driver);
518
519 MODULE_AUTHOR("Philippe Reynes <tremyfr@yahoo.fr>");
520 MODULE_DESCRIPTION("MAX1027/MAX1029/MAX1031 ADC");
521 MODULE_LICENSE("GPL v2");
Linux with added FPC-III support