drm/nouveau: warn when moving a pinned object
[firefly-linux-kernel-4.4.55.git] / drivers / iio / adc / ad7291.c
1 /*
2  * AD7291 8-Channel, I2C, 12-Bit SAR ADC with Temperature Sensor
3  *
4  * Copyright 2010-2011 Analog Devices Inc.
5  *
6  * Licensed under the GPL-2 or later.
7  */
8
9 #include <linux/device.h>
10 #include <linux/err.h>
11 #include <linux/i2c.h>
12 #include <linux/interrupt.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/mutex.h>
16 #include <linux/regulator/consumer.h>
17 #include <linux/slab.h>
18 #include <linux/sysfs.h>
19
20 #include <linux/iio/iio.h>
21 #include <linux/iio/sysfs.h>
22 #include <linux/iio/events.h>
23
24 #include <linux/platform_data/ad7291.h>
25
26 /*
27  * Simplified handling
28  *
29  * If no events enabled - single polled channel read
30  * If event enabled direct reads disable unless channel
31  * is in the read mask.
32  *
33  * The noise-delayed bit as per datasheet suggestion is always enabled.
34  */
35
36 /*
37  * AD7291 registers definition
38  */
39 #define AD7291_COMMAND                  0x00
40 #define AD7291_VOLTAGE                  0x01
41 #define AD7291_T_SENSE                  0x02
42 #define AD7291_T_AVERAGE                0x03
43 #define AD7291_DATA_HIGH(x)             ((x) * 3 + 0x4)
44 #define AD7291_DATA_LOW(x)              ((x) * 3 + 0x5)
45 #define AD7291_HYST(x)                  ((x) * 3 + 0x6)
46 #define AD7291_VOLTAGE_ALERT_STATUS     0x1F
47 #define AD7291_T_ALERT_STATUS           0x20
48
49 #define AD7291_BITS                     12
50 #define AD7291_VOLTAGE_LIMIT_COUNT      8
51
52
53 /*
54  * AD7291 command
55  */
56 #define AD7291_AUTOCYCLE                BIT(0)
57 #define AD7291_RESET                    BIT(1)
58 #define AD7291_ALERT_CLEAR              BIT(2)
59 #define AD7291_ALERT_POLARITY           BIT(3)
60 #define AD7291_EXT_REF                  BIT(4)
61 #define AD7291_NOISE_DELAY              BIT(5)
62 #define AD7291_T_SENSE_MASK             BIT(7)
63 #define AD7291_VOLTAGE_MASK             GENMASK(15, 8)
64 #define AD7291_VOLTAGE_OFFSET           8
65
66 /*
67  * AD7291 value masks
68  */
69 #define AD7291_VALUE_MASK               GENMASK(11, 0)
70
71 /*
72  * AD7291 alert register bits
73  */
74 #define AD7291_T_LOW                    BIT(0)
75 #define AD7291_T_HIGH                   BIT(1)
76 #define AD7291_T_AVG_LOW                BIT(2)
77 #define AD7291_T_AVG_HIGH               BIT(3)
78 #define AD7291_V_LOW(x)                 BIT((x) * 2)
79 #define AD7291_V_HIGH(x)                BIT((x) * 2 + 1)
80
81
82 struct ad7291_chip_info {
83         struct i2c_client       *client;
84         struct regulator        *reg;
85         u16                     command;
86         u16                     c_mask; /* Active voltage channels for events */
87         struct mutex            state_lock;
88 };
89
90 static int ad7291_i2c_read(struct ad7291_chip_info *chip, u8 reg, u16 *data)
91 {
92         struct i2c_client *client = chip->client;
93         int ret = 0;
94
95         ret = i2c_smbus_read_word_swapped(client, reg);
96         if (ret < 0) {
97                 dev_err(&client->dev, "I2C read error\n");
98                 return ret;
99         }
100
101         *data = ret;
102
103         return 0;
104 }
105
106 static int ad7291_i2c_write(struct ad7291_chip_info *chip, u8 reg, u16 data)
107 {
108         return i2c_smbus_write_word_swapped(chip->client, reg, data);
109 }
110
111 static irqreturn_t ad7291_event_handler(int irq, void *private)
112 {
113         struct iio_dev *indio_dev = private;
114         struct ad7291_chip_info *chip = iio_priv(private);
115         u16 t_status, v_status;
116         u16 command;
117         int i;
118         s64 timestamp = iio_get_time_ns();
119
120         if (ad7291_i2c_read(chip, AD7291_T_ALERT_STATUS, &t_status))
121                 return IRQ_HANDLED;
122
123         if (ad7291_i2c_read(chip, AD7291_VOLTAGE_ALERT_STATUS, &v_status))
124                 return IRQ_HANDLED;
125
126         if (!(t_status || v_status))
127                 return IRQ_HANDLED;
128
129         command = chip->command | AD7291_ALERT_CLEAR;
130         ad7291_i2c_write(chip, AD7291_COMMAND, command);
131
132         command = chip->command & ~AD7291_ALERT_CLEAR;
133         ad7291_i2c_write(chip, AD7291_COMMAND, command);
134
135         /* For now treat t_sense and t_sense_average the same */
136         if ((t_status & AD7291_T_LOW) || (t_status & AD7291_T_AVG_LOW))
137                 iio_push_event(indio_dev,
138                                IIO_UNMOD_EVENT_CODE(IIO_TEMP,
139                                                     0,
140                                                     IIO_EV_TYPE_THRESH,
141                                                     IIO_EV_DIR_FALLING),
142                                timestamp);
143         if ((t_status & AD7291_T_HIGH) || (t_status & AD7291_T_AVG_HIGH))
144                 iio_push_event(indio_dev,
145                                IIO_UNMOD_EVENT_CODE(IIO_TEMP,
146                                                     0,
147                                                     IIO_EV_TYPE_THRESH,
148                                                     IIO_EV_DIR_RISING),
149                                timestamp);
150
151         for (i = 0; i < AD7291_VOLTAGE_LIMIT_COUNT; i++) {
152                 if (v_status & AD7291_V_LOW(i))
153                         iio_push_event(indio_dev,
154                                        IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE,
155                                                             i,
156                                                             IIO_EV_TYPE_THRESH,
157                                                             IIO_EV_DIR_FALLING),
158                                        timestamp);
159                 if (v_status & AD7291_V_HIGH(i))
160                         iio_push_event(indio_dev,
161                                        IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE,
162                                                             i,
163                                                             IIO_EV_TYPE_THRESH,
164                                                             IIO_EV_DIR_RISING),
165                                        timestamp);
166         }
167
168         return IRQ_HANDLED;
169 }
170
171 static unsigned int ad7291_threshold_reg(const struct iio_chan_spec *chan,
172                                          enum iio_event_direction dir,
173                                          enum iio_event_info info)
174 {
175         unsigned int offset;
176
177         switch (chan->type) {
178         case IIO_VOLTAGE:
179                 offset = chan->channel;
180                 break;
181         case IIO_TEMP:
182                 offset = AD7291_VOLTAGE_OFFSET;
183                 break;
184         default:
185             return 0;
186         }
187
188         switch (info) {
189         case IIO_EV_INFO_VALUE:
190                 if (dir == IIO_EV_DIR_FALLING)
191                         return AD7291_DATA_HIGH(offset);
192                 else
193                         return AD7291_DATA_LOW(offset);
194         case IIO_EV_INFO_HYSTERESIS:
195                 return AD7291_HYST(offset);
196         default:
197                 break;
198         }
199         return 0;
200 }
201
202 static int ad7291_read_event_value(struct iio_dev *indio_dev,
203                                    const struct iio_chan_spec *chan,
204                                    enum iio_event_type type,
205                                    enum iio_event_direction dir,
206                                    enum iio_event_info info,
207                                    int *val, int *val2)
208 {
209         struct ad7291_chip_info *chip = iio_priv(indio_dev);
210         int ret;
211         u16 uval;
212
213         ret = ad7291_i2c_read(chip, ad7291_threshold_reg(chan, dir, info),
214                               &uval);
215         if (ret < 0)
216                 return ret;
217
218         if (info == IIO_EV_INFO_HYSTERESIS || chan->type == IIO_VOLTAGE)
219                 *val = uval & AD7291_VALUE_MASK;
220
221         else
222                 *val = sign_extend32(uval, 11);
223
224         return IIO_VAL_INT;
225 }
226
227 static int ad7291_write_event_value(struct iio_dev *indio_dev,
228                                     const struct iio_chan_spec *chan,
229                                     enum iio_event_type type,
230                                     enum iio_event_direction dir,
231                                     enum iio_event_info info,
232                                     int val, int val2)
233 {
234         struct ad7291_chip_info *chip = iio_priv(indio_dev);
235
236         if (info == IIO_EV_INFO_HYSTERESIS || chan->type == IIO_VOLTAGE) {
237                 if (val > AD7291_VALUE_MASK || val < 0)
238                         return -EINVAL;
239         } else {
240                 if (val > 2047 || val < -2048)
241                         return -EINVAL;
242         }
243
244         return ad7291_i2c_write(chip, ad7291_threshold_reg(chan, dir, info),
245                                 val);
246 }
247
248 static int ad7291_read_event_config(struct iio_dev *indio_dev,
249                                     const struct iio_chan_spec *chan,
250                                     enum iio_event_type type,
251                                     enum iio_event_direction dir)
252 {
253         struct ad7291_chip_info *chip = iio_priv(indio_dev);
254         /*
255          * To be enabled the channel must simply be on. If any are enabled
256          * we are in continuous sampling mode
257          */
258
259         switch (chan->type) {
260         case IIO_VOLTAGE:
261                 return !!(chip->c_mask & BIT(15 - chan->channel));
262         case IIO_TEMP:
263                 /* always on */
264                 return 1;
265         default:
266                 return -EINVAL;
267         }
268
269 }
270
271 static int ad7291_write_event_config(struct iio_dev *indio_dev,
272                                      const struct iio_chan_spec *chan,
273                                      enum iio_event_type type,
274                                      enum iio_event_direction dir,
275                                      int state)
276 {
277         int ret = 0;
278         struct ad7291_chip_info *chip = iio_priv(indio_dev);
279         unsigned int mask;
280         u16 regval;
281
282         mutex_lock(&chip->state_lock);
283         regval = chip->command;
284         /*
285          * To be enabled the channel must simply be on. If any are enabled
286          * use continuous sampling mode.
287          * Possible to disable temp as well but that makes single read tricky.
288          */
289
290         mask = BIT(15 - chan->channel);
291
292         switch (chan->type) {
293         case IIO_VOLTAGE:
294                 if ((!state) && (chip->c_mask & mask))
295                         chip->c_mask &= ~mask;
296                 else if (state && (!(chip->c_mask & mask)))
297                         chip->c_mask |= mask;
298                 else
299                         break;
300
301                 regval &= ~AD7291_AUTOCYCLE;
302                 regval |= chip->c_mask;
303                 if (chip->c_mask) /* Enable autocycle? */
304                         regval |= AD7291_AUTOCYCLE;
305
306                 ret = ad7291_i2c_write(chip, AD7291_COMMAND, regval);
307                 if (ret < 0)
308                         goto error_ret;
309
310                 chip->command = regval;
311                 break;
312         default:
313                 ret = -EINVAL;
314         }
315
316 error_ret:
317         mutex_unlock(&chip->state_lock);
318         return ret;
319 }
320
321 static int ad7291_read_raw(struct iio_dev *indio_dev,
322                            struct iio_chan_spec const *chan,
323                            int *val,
324                            int *val2,
325                            long mask)
326 {
327         int ret;
328         struct ad7291_chip_info *chip = iio_priv(indio_dev);
329         u16 regval;
330
331         switch (mask) {
332         case IIO_CHAN_INFO_RAW:
333                 switch (chan->type) {
334                 case IIO_VOLTAGE:
335                         mutex_lock(&chip->state_lock);
336                         /* If in autocycle mode drop through */
337                         if (chip->command & AD7291_AUTOCYCLE) {
338                                 mutex_unlock(&chip->state_lock);
339                                 return -EBUSY;
340                         }
341                         /* Enable this channel alone */
342                         regval = chip->command & (~AD7291_VOLTAGE_MASK);
343                         regval |= BIT(15 - chan->channel);
344                         ret = ad7291_i2c_write(chip, AD7291_COMMAND, regval);
345                         if (ret < 0) {
346                                 mutex_unlock(&chip->state_lock);
347                                 return ret;
348                         }
349                         /* Read voltage */
350                         ret = i2c_smbus_read_word_swapped(chip->client,
351                                                           AD7291_VOLTAGE);
352                         if (ret < 0) {
353                                 mutex_unlock(&chip->state_lock);
354                                 return ret;
355                         }
356                         *val = ret & AD7291_VALUE_MASK;
357                         mutex_unlock(&chip->state_lock);
358                         return IIO_VAL_INT;
359                 case IIO_TEMP:
360                         /* Assumes tsense bit of command register always set */
361                         ret = i2c_smbus_read_word_swapped(chip->client,
362                                                           AD7291_T_SENSE);
363                         if (ret < 0)
364                                 return ret;
365                         *val = sign_extend32(ret, 11);
366                         return IIO_VAL_INT;
367                 default:
368                         return -EINVAL;
369                 }
370         case IIO_CHAN_INFO_AVERAGE_RAW:
371                 ret = i2c_smbus_read_word_swapped(chip->client,
372                                                   AD7291_T_AVERAGE);
373                         if (ret < 0)
374                                 return ret;
375                         *val = sign_extend32(ret, 11);
376                         return IIO_VAL_INT;
377         case IIO_CHAN_INFO_SCALE:
378                 switch (chan->type) {
379                 case IIO_VOLTAGE:
380                         if (chip->reg) {
381                                 int vref;
382
383                                 vref = regulator_get_voltage(chip->reg);
384                                 if (vref < 0)
385                                         return vref;
386                                 *val = vref / 1000;
387                         } else {
388                                 *val = 2500;
389                         }
390                         *val2 = AD7291_BITS;
391                         return IIO_VAL_FRACTIONAL_LOG2;
392                 case IIO_TEMP:
393                         /*
394                          * One LSB of the ADC corresponds to 0.25 deg C.
395                          * The temperature reading is in 12-bit twos
396                          * complement format
397                          */
398                         *val = 250;
399                         return IIO_VAL_INT;
400                 default:
401                         return -EINVAL;
402                 }
403         default:
404                 return -EINVAL;
405         }
406 }
407
408 static const struct iio_event_spec ad7291_events[] = {
409         {
410                 .type = IIO_EV_TYPE_THRESH,
411                 .dir = IIO_EV_DIR_RISING,
412                 .mask_separate = BIT(IIO_EV_INFO_VALUE) |
413                         BIT(IIO_EV_INFO_ENABLE),
414         }, {
415                 .type = IIO_EV_TYPE_THRESH,
416                 .dir = IIO_EV_DIR_FALLING,
417                 .mask_separate = BIT(IIO_EV_INFO_VALUE) |
418                         BIT(IIO_EV_INFO_ENABLE),
419         }, {
420                 .type = IIO_EV_TYPE_THRESH,
421                 .dir = IIO_EV_DIR_EITHER,
422                 .mask_separate = BIT(IIO_EV_INFO_HYSTERESIS),
423         },
424 };
425
426 #define AD7291_VOLTAGE_CHAN(_chan)                                      \
427 {                                                                       \
428         .type = IIO_VOLTAGE,                                            \
429         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),                   \
430         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),           \
431         .indexed = 1,                                                   \
432         .channel = _chan,                                               \
433         .event_spec = ad7291_events,                                    \
434         .num_event_specs = ARRAY_SIZE(ad7291_events),                   \
435 }
436
437 static const struct iio_chan_spec ad7291_channels[] = {
438         AD7291_VOLTAGE_CHAN(0),
439         AD7291_VOLTAGE_CHAN(1),
440         AD7291_VOLTAGE_CHAN(2),
441         AD7291_VOLTAGE_CHAN(3),
442         AD7291_VOLTAGE_CHAN(4),
443         AD7291_VOLTAGE_CHAN(5),
444         AD7291_VOLTAGE_CHAN(6),
445         AD7291_VOLTAGE_CHAN(7),
446         {
447                 .type = IIO_TEMP,
448                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
449                                 BIT(IIO_CHAN_INFO_AVERAGE_RAW) |
450                                 BIT(IIO_CHAN_INFO_SCALE),
451                 .indexed = 1,
452                 .channel = 0,
453                 .event_spec = ad7291_events,
454                 .num_event_specs = ARRAY_SIZE(ad7291_events),
455         }
456 };
457
458 static const struct iio_info ad7291_info = {
459         .read_raw = &ad7291_read_raw,
460         .read_event_config = &ad7291_read_event_config,
461         .write_event_config = &ad7291_write_event_config,
462         .read_event_value = &ad7291_read_event_value,
463         .write_event_value = &ad7291_write_event_value,
464         .driver_module = THIS_MODULE,
465 };
466
467 static int ad7291_probe(struct i2c_client *client,
468                         const struct i2c_device_id *id)
469 {
470         struct ad7291_platform_data *pdata = client->dev.platform_data;
471         struct ad7291_chip_info *chip;
472         struct iio_dev *indio_dev;
473         int ret;
474
475         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
476         if (!indio_dev)
477                 return -ENOMEM;
478         chip = iio_priv(indio_dev);
479
480         if (pdata && pdata->use_external_ref) {
481                 chip->reg = devm_regulator_get(&client->dev, "vref");
482                 if (IS_ERR(chip->reg))
483                         return PTR_ERR(chip->reg);
484
485                 ret = regulator_enable(chip->reg);
486                 if (ret)
487                         return ret;
488         }
489
490         mutex_init(&chip->state_lock);
491         /* this is only used for device removal purposes */
492         i2c_set_clientdata(client, indio_dev);
493
494         chip->client = client;
495
496         chip->command = AD7291_NOISE_DELAY |
497                         AD7291_T_SENSE_MASK | /* Tsense always enabled */
498                         AD7291_ALERT_POLARITY; /* set irq polarity low level */
499
500         if (pdata && pdata->use_external_ref)
501                 chip->command |= AD7291_EXT_REF;
502
503         indio_dev->name = id->name;
504         indio_dev->channels = ad7291_channels;
505         indio_dev->num_channels = ARRAY_SIZE(ad7291_channels);
506
507         indio_dev->dev.parent = &client->dev;
508         indio_dev->info = &ad7291_info;
509         indio_dev->modes = INDIO_DIRECT_MODE;
510
511         ret = ad7291_i2c_write(chip, AD7291_COMMAND, AD7291_RESET);
512         if (ret) {
513                 ret = -EIO;
514                 goto error_disable_reg;
515         }
516
517         ret = ad7291_i2c_write(chip, AD7291_COMMAND, chip->command);
518         if (ret) {
519                 ret = -EIO;
520                 goto error_disable_reg;
521         }
522
523         if (client->irq > 0) {
524                 ret = request_threaded_irq(client->irq,
525                                            NULL,
526                                            &ad7291_event_handler,
527                                            IRQF_TRIGGER_LOW | IRQF_ONESHOT,
528                                            id->name,
529                                            indio_dev);
530                 if (ret)
531                         goto error_disable_reg;
532         }
533
534         ret = iio_device_register(indio_dev);
535         if (ret)
536                 goto error_unreg_irq;
537
538         return 0;
539
540 error_unreg_irq:
541         if (client->irq)
542                 free_irq(client->irq, indio_dev);
543 error_disable_reg:
544         if (chip->reg)
545                 regulator_disable(chip->reg);
546
547         return ret;
548 }
549
550 static int ad7291_remove(struct i2c_client *client)
551 {
552         struct iio_dev *indio_dev = i2c_get_clientdata(client);
553         struct ad7291_chip_info *chip = iio_priv(indio_dev);
554
555         iio_device_unregister(indio_dev);
556
557         if (client->irq)
558                 free_irq(client->irq, indio_dev);
559
560         if (chip->reg)
561                 regulator_disable(chip->reg);
562
563         return 0;
564 }
565
566 static const struct i2c_device_id ad7291_id[] = {
567         { "ad7291", 0 },
568         {}
569 };
570
571 MODULE_DEVICE_TABLE(i2c, ad7291_id);
572
573 static struct i2c_driver ad7291_driver = {
574         .driver = {
575                 .name = KBUILD_MODNAME,
576         },
577         .probe = ad7291_probe,
578         .remove = ad7291_remove,
579         .id_table = ad7291_id,
580 };
581 module_i2c_driver(ad7291_driver);
582
583 MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
584 MODULE_DESCRIPTION("Analog Devices AD7291 ADC driver");
585 MODULE_LICENSE("GPL v2");