xref: /linux/drivers/iio/light/rpr0521.c (revision bb9707077b4ee5f77bc9939b057ff8a0d410296f)
1 /*
2  * RPR-0521 ROHM Ambient Light and Proximity Sensor
3  *
4  * Copyright (c) 2015, Intel Corporation.
5  *
6  * This file is subject to the terms and conditions of version 2 of
7  * the GNU General Public License.  See the file COPYING in the main
8  * directory of this archive for more details.
9  *
10  * IIO driver for RPR-0521RS (7-bit I2C slave address 0x38).
11  *
12  * TODO: illuminance channel, PM support, buffer
13  */
14 
15 #include <linux/module.h>
16 #include <linux/init.h>
17 #include <linux/i2c.h>
18 #include <linux/regmap.h>
19 #include <linux/delay.h>
20 #include <linux/acpi.h>
21 
22 #include <linux/iio/iio.h>
23 #include <linux/iio/sysfs.h>
24 #include <linux/pm_runtime.h>
25 
26 #define RPR0521_REG_SYSTEM_CTRL		0x40
27 #define RPR0521_REG_MODE_CTRL		0x41
28 #define RPR0521_REG_ALS_CTRL		0x42
29 #define RPR0521_REG_PXS_CTRL		0x43
30 #define RPR0521_REG_PXS_DATA		0x44 /* 16-bit, little endian */
31 #define RPR0521_REG_ALS_DATA0		0x46 /* 16-bit, little endian */
32 #define RPR0521_REG_ALS_DATA1		0x48 /* 16-bit, little endian */
33 #define RPR0521_REG_ID			0x92
34 
35 #define RPR0521_MODE_ALS_MASK		BIT(7)
36 #define RPR0521_MODE_PXS_MASK		BIT(6)
37 #define RPR0521_MODE_MEAS_TIME_MASK	GENMASK(3, 0)
38 #define RPR0521_ALS_DATA0_GAIN_MASK	GENMASK(5, 4)
39 #define RPR0521_ALS_DATA0_GAIN_SHIFT	4
40 #define RPR0521_ALS_DATA1_GAIN_MASK	GENMASK(3, 2)
41 #define RPR0521_ALS_DATA1_GAIN_SHIFT	2
42 #define RPR0521_PXS_GAIN_MASK		GENMASK(5, 4)
43 #define RPR0521_PXS_GAIN_SHIFT		4
44 
45 #define RPR0521_MODE_ALS_ENABLE		BIT(7)
46 #define RPR0521_MODE_ALS_DISABLE	0x00
47 #define RPR0521_MODE_PXS_ENABLE		BIT(6)
48 #define RPR0521_MODE_PXS_DISABLE	0x00
49 
50 #define RPR0521_MANUFACT_ID		0xE0
51 #define RPR0521_DEFAULT_MEAS_TIME	0x06 /* ALS - 100ms, PXS - 100ms */
52 
53 #define RPR0521_DRV_NAME		"RPR0521"
54 #define RPR0521_REGMAP_NAME		"rpr0521_regmap"
55 
56 #define RPR0521_SLEEP_DELAY_MS	2000
57 
58 #define RPR0521_ALS_SCALE_AVAIL "0.007812 0.015625 0.5 1"
59 #define RPR0521_PXS_SCALE_AVAIL "0.125 0.5 1"
60 
61 struct rpr0521_gain {
62 	int scale;
63 	int uscale;
64 };
65 
66 static const struct rpr0521_gain rpr0521_als_gain[4] = {
67 	{1, 0},		/* x1 */
68 	{0, 500000},	/* x2 */
69 	{0, 15625},	/* x64 */
70 	{0, 7812},	/* x128 */
71 };
72 
73 static const struct rpr0521_gain rpr0521_pxs_gain[3] = {
74 	{1, 0},		/* x1 */
75 	{0, 500000},	/* x2 */
76 	{0, 125000},	/* x4 */
77 };
78 
79 enum rpr0521_channel {
80 	RPR0521_CHAN_ALS_DATA0,
81 	RPR0521_CHAN_ALS_DATA1,
82 	RPR0521_CHAN_PXS,
83 };
84 
85 struct rpr0521_reg_desc {
86 	u8 address;
87 	u8 device_mask;
88 };
89 
90 static const struct rpr0521_reg_desc rpr0521_data_reg[] = {
91 	[RPR0521_CHAN_ALS_DATA0] = {
92 		.address	= RPR0521_REG_ALS_DATA0,
93 		.device_mask	= RPR0521_MODE_ALS_MASK,
94 	},
95 	[RPR0521_CHAN_ALS_DATA1] = {
96 		.address	= RPR0521_REG_ALS_DATA1,
97 		.device_mask	= RPR0521_MODE_ALS_MASK,
98 	},
99 	[RPR0521_CHAN_PXS]	= {
100 		.address	= RPR0521_REG_PXS_DATA,
101 		.device_mask	= RPR0521_MODE_PXS_MASK,
102 	},
103 };
104 
105 static const struct rpr0521_gain_info {
106 	u8 reg;
107 	u8 mask;
108 	u8 shift;
109 	const struct rpr0521_gain *gain;
110 	int size;
111 } rpr0521_gain[] = {
112 	[RPR0521_CHAN_ALS_DATA0] = {
113 		.reg	= RPR0521_REG_ALS_CTRL,
114 		.mask	= RPR0521_ALS_DATA0_GAIN_MASK,
115 		.shift	= RPR0521_ALS_DATA0_GAIN_SHIFT,
116 		.gain	= rpr0521_als_gain,
117 		.size	= ARRAY_SIZE(rpr0521_als_gain),
118 	},
119 	[RPR0521_CHAN_ALS_DATA1] = {
120 		.reg	= RPR0521_REG_ALS_CTRL,
121 		.mask	= RPR0521_ALS_DATA1_GAIN_MASK,
122 		.shift	= RPR0521_ALS_DATA1_GAIN_SHIFT,
123 		.gain	= rpr0521_als_gain,
124 		.size	= ARRAY_SIZE(rpr0521_als_gain),
125 	},
126 	[RPR0521_CHAN_PXS] = {
127 		.reg	= RPR0521_REG_PXS_CTRL,
128 		.mask	= RPR0521_PXS_GAIN_MASK,
129 		.shift	= RPR0521_PXS_GAIN_SHIFT,
130 		.gain	= rpr0521_pxs_gain,
131 		.size	= ARRAY_SIZE(rpr0521_pxs_gain),
132 	},
133 };
134 
135 struct rpr0521_data {
136 	struct i2c_client *client;
137 
138 	/* protect device params updates (e.g state, gain) */
139 	struct mutex lock;
140 
141 	/* device active status */
142 	bool als_dev_en;
143 	bool pxs_dev_en;
144 
145 	/* optimize runtime pm ops - enable device only if needed */
146 	bool als_ps_need_en;
147 	bool pxs_ps_need_en;
148 
149 	struct regmap *regmap;
150 };
151 
152 static IIO_CONST_ATTR(in_intensity_scale_available, RPR0521_ALS_SCALE_AVAIL);
153 static IIO_CONST_ATTR(in_proximity_scale_available, RPR0521_PXS_SCALE_AVAIL);
154 
155 static struct attribute *rpr0521_attributes[] = {
156 	&iio_const_attr_in_intensity_scale_available.dev_attr.attr,
157 	&iio_const_attr_in_proximity_scale_available.dev_attr.attr,
158 	NULL,
159 };
160 
161 static const struct attribute_group rpr0521_attribute_group = {
162 	.attrs = rpr0521_attributes,
163 };
164 
165 static const struct iio_chan_spec rpr0521_channels[] = {
166 	{
167 		.type = IIO_INTENSITY,
168 		.modified = 1,
169 		.address = RPR0521_CHAN_ALS_DATA0,
170 		.channel2 = IIO_MOD_LIGHT_BOTH,
171 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
172 			BIT(IIO_CHAN_INFO_SCALE),
173 	},
174 	{
175 		.type = IIO_INTENSITY,
176 		.modified = 1,
177 		.address = RPR0521_CHAN_ALS_DATA1,
178 		.channel2 = IIO_MOD_LIGHT_IR,
179 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
180 			BIT(IIO_CHAN_INFO_SCALE),
181 	},
182 	{
183 		.type = IIO_PROXIMITY,
184 		.address = RPR0521_CHAN_PXS,
185 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
186 			BIT(IIO_CHAN_INFO_SCALE),
187 	}
188 };
189 
190 static int rpr0521_als_enable(struct rpr0521_data *data, u8 status)
191 {
192 	int ret;
193 
194 	ret = regmap_update_bits(data->regmap, RPR0521_REG_MODE_CTRL,
195 				 RPR0521_MODE_ALS_MASK,
196 				 status);
197 	if (ret < 0)
198 		return ret;
199 
200 	data->als_dev_en = true;
201 
202 	return 0;
203 }
204 
205 static int rpr0521_pxs_enable(struct rpr0521_data *data, u8 status)
206 {
207 	int ret;
208 
209 	ret = regmap_update_bits(data->regmap, RPR0521_REG_MODE_CTRL,
210 				 RPR0521_MODE_PXS_MASK,
211 				 status);
212 	if (ret < 0)
213 		return ret;
214 
215 	data->pxs_dev_en = true;
216 
217 	return 0;
218 }
219 
220 /**
221  * rpr0521_set_power_state - handles runtime PM state and sensors enabled status
222  *
223  * @data: rpr0521 device private data
224  * @on: state to be set for devices in @device_mask
225  * @device_mask: bitmask specifying for which device we need to update @on state
226  *
227  * We rely on rpr0521_runtime_resume to enable our @device_mask devices, but
228  * if (for example) PXS was enabled (pxs_dev_en = true) by a previous call to
229  * rpr0521_runtime_resume and we want to enable ALS we MUST set ALS enable
230  * bit of RPR0521_REG_MODE_CTRL here because rpr0521_runtime_resume will not
231  * be called twice.
232  */
233 static int rpr0521_set_power_state(struct rpr0521_data *data, bool on,
234 				   u8 device_mask)
235 {
236 #ifdef CONFIG_PM
237 	int ret;
238 	u8 update_mask = 0;
239 
240 	if (device_mask & RPR0521_MODE_ALS_MASK) {
241 		if (on && !data->als_ps_need_en && data->pxs_dev_en)
242 			update_mask |= RPR0521_MODE_ALS_MASK;
243 		else
244 			data->als_ps_need_en = on;
245 	}
246 
247 	if (device_mask & RPR0521_MODE_PXS_MASK) {
248 		if (on && !data->pxs_ps_need_en && data->als_dev_en)
249 			update_mask |= RPR0521_MODE_PXS_MASK;
250 		else
251 			data->pxs_ps_need_en = on;
252 	}
253 
254 	if (update_mask) {
255 		ret = regmap_update_bits(data->regmap, RPR0521_REG_MODE_CTRL,
256 					 update_mask, update_mask);
257 		if (ret < 0)
258 			return ret;
259 	}
260 
261 	if (on) {
262 		ret = pm_runtime_get_sync(&data->client->dev);
263 	} else {
264 		pm_runtime_mark_last_busy(&data->client->dev);
265 		ret = pm_runtime_put_autosuspend(&data->client->dev);
266 	}
267 	if (ret < 0) {
268 		dev_err(&data->client->dev,
269 			"Failed: rpr0521_set_power_state for %d, ret %d\n",
270 			on, ret);
271 		if (on)
272 			pm_runtime_put_noidle(&data->client->dev);
273 
274 		return ret;
275 	}
276 #endif
277 	return 0;
278 }
279 
280 static int rpr0521_get_gain(struct rpr0521_data *data, int chan,
281 			    int *val, int *val2)
282 {
283 	int ret, reg, idx;
284 
285 	ret = regmap_read(data->regmap, rpr0521_gain[chan].reg, &reg);
286 	if (ret < 0)
287 		return ret;
288 
289 	idx = (rpr0521_gain[chan].mask & reg) >> rpr0521_gain[chan].shift;
290 	*val = rpr0521_gain[chan].gain[idx].scale;
291 	*val2 = rpr0521_gain[chan].gain[idx].uscale;
292 
293 	return 0;
294 }
295 
296 static int rpr0521_set_gain(struct rpr0521_data *data, int chan,
297 			    int val, int val2)
298 {
299 	int i, idx = -EINVAL;
300 
301 	/* get gain index */
302 	for (i = 0; i < rpr0521_gain[chan].size; i++)
303 		if (val == rpr0521_gain[chan].gain[i].scale &&
304 		    val2 == rpr0521_gain[chan].gain[i].uscale) {
305 			idx = i;
306 			break;
307 		}
308 
309 	if (idx < 0)
310 		return idx;
311 
312 	return regmap_update_bits(data->regmap, rpr0521_gain[chan].reg,
313 				  rpr0521_gain[chan].mask,
314 				  idx << rpr0521_gain[chan].shift);
315 }
316 
317 static int rpr0521_read_raw(struct iio_dev *indio_dev,
318 			    struct iio_chan_spec const *chan, int *val,
319 			    int *val2, long mask)
320 {
321 	struct rpr0521_data *data = iio_priv(indio_dev);
322 	int ret;
323 	u8 device_mask;
324 	__le16 raw_data;
325 
326 	switch (mask) {
327 	case IIO_CHAN_INFO_RAW:
328 		if (chan->type != IIO_INTENSITY && chan->type != IIO_PROXIMITY)
329 			return -EINVAL;
330 
331 		device_mask = rpr0521_data_reg[chan->address].device_mask;
332 
333 		mutex_lock(&data->lock);
334 		ret = rpr0521_set_power_state(data, true, device_mask);
335 		if (ret < 0) {
336 			mutex_unlock(&data->lock);
337 			return ret;
338 		}
339 
340 		ret = regmap_bulk_read(data->regmap,
341 				       rpr0521_data_reg[chan->address].address,
342 				       &raw_data, 2);
343 		if (ret < 0) {
344 			rpr0521_set_power_state(data, false, device_mask);
345 			mutex_unlock(&data->lock);
346 			return ret;
347 		}
348 
349 		ret = rpr0521_set_power_state(data, false, device_mask);
350 		mutex_unlock(&data->lock);
351 		if (ret < 0)
352 			return ret;
353 
354 		*val = le16_to_cpu(raw_data);
355 
356 		return IIO_VAL_INT;
357 	case IIO_CHAN_INFO_SCALE:
358 		mutex_lock(&data->lock);
359 		ret = rpr0521_get_gain(data, chan->address, val, val2);
360 		mutex_unlock(&data->lock);
361 		if (ret < 0)
362 			return ret;
363 
364 		return IIO_VAL_INT_PLUS_MICRO;
365 	default:
366 		return -EINVAL;
367 	}
368 }
369 
370 static int rpr0521_write_raw(struct iio_dev *indio_dev,
371 			     struct iio_chan_spec const *chan, int val,
372 			     int val2, long mask)
373 {
374 	struct rpr0521_data *data = iio_priv(indio_dev);
375 	int ret;
376 
377 	switch (mask) {
378 	case IIO_CHAN_INFO_SCALE:
379 		mutex_lock(&data->lock);
380 		ret = rpr0521_set_gain(data, chan->address, val, val2);
381 		mutex_unlock(&data->lock);
382 
383 		return ret;
384 	default:
385 		return -EINVAL;
386 	}
387 }
388 
389 static const struct iio_info rpr0521_info = {
390 	.driver_module	= THIS_MODULE,
391 	.read_raw	= rpr0521_read_raw,
392 	.write_raw	= rpr0521_write_raw,
393 	.attrs		= &rpr0521_attribute_group,
394 };
395 
396 static int rpr0521_init(struct rpr0521_data *data)
397 {
398 	int ret;
399 	int id;
400 
401 	ret = regmap_read(data->regmap, RPR0521_REG_ID, &id);
402 	if (ret < 0) {
403 		dev_err(&data->client->dev, "Failed to read REG_ID register\n");
404 		return ret;
405 	}
406 
407 	if (id != RPR0521_MANUFACT_ID) {
408 		dev_err(&data->client->dev, "Wrong id, got %x, expected %x\n",
409 			id, RPR0521_MANUFACT_ID);
410 		return -ENODEV;
411 	}
412 
413 	/* set default measurement time - 100 ms for both ALS and PS */
414 	ret = regmap_update_bits(data->regmap, RPR0521_REG_MODE_CTRL,
415 				 RPR0521_MODE_MEAS_TIME_MASK,
416 				 RPR0521_DEFAULT_MEAS_TIME);
417 	if (ret) {
418 		pr_err("regmap_update_bits returned %d\n", ret);
419 		return ret;
420 	}
421 
422 	ret = rpr0521_als_enable(data, RPR0521_MODE_ALS_ENABLE);
423 	if (ret < 0)
424 		return ret;
425 	ret = rpr0521_pxs_enable(data, RPR0521_MODE_PXS_ENABLE);
426 	if (ret < 0)
427 		return ret;
428 
429 	return 0;
430 }
431 
432 static int rpr0521_poweroff(struct rpr0521_data *data)
433 {
434 	int ret;
435 
436 	ret = regmap_update_bits(data->regmap, RPR0521_REG_MODE_CTRL,
437 				 RPR0521_MODE_ALS_MASK |
438 				 RPR0521_MODE_PXS_MASK,
439 				 RPR0521_MODE_ALS_DISABLE |
440 				 RPR0521_MODE_PXS_DISABLE);
441 	if (ret < 0)
442 		return ret;
443 
444 	data->als_dev_en = false;
445 	data->pxs_dev_en = false;
446 
447 	return 0;
448 }
449 
450 static bool rpr0521_is_volatile_reg(struct device *dev, unsigned int reg)
451 {
452 	switch (reg) {
453 	case RPR0521_REG_MODE_CTRL:
454 	case RPR0521_REG_ALS_CTRL:
455 	case RPR0521_REG_PXS_CTRL:
456 		return false;
457 	default:
458 		return true;
459 	}
460 }
461 
462 static const struct regmap_config rpr0521_regmap_config = {
463 	.name		= RPR0521_REGMAP_NAME,
464 
465 	.reg_bits	= 8,
466 	.val_bits	= 8,
467 
468 	.max_register	= RPR0521_REG_ID,
469 	.cache_type	= REGCACHE_RBTREE,
470 	.volatile_reg	= rpr0521_is_volatile_reg,
471 };
472 
473 static int rpr0521_probe(struct i2c_client *client,
474 			 const struct i2c_device_id *id)
475 {
476 	struct rpr0521_data *data;
477 	struct iio_dev *indio_dev;
478 	struct regmap *regmap;
479 	int ret;
480 
481 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
482 	if (!indio_dev)
483 		return -ENOMEM;
484 
485 	regmap = devm_regmap_init_i2c(client, &rpr0521_regmap_config);
486 	if (IS_ERR(regmap)) {
487 		dev_err(&client->dev, "regmap_init failed!\n");
488 		return PTR_ERR(regmap);
489 	}
490 
491 	data = iio_priv(indio_dev);
492 	i2c_set_clientdata(client, indio_dev);
493 	data->client = client;
494 	data->regmap = regmap;
495 
496 	mutex_init(&data->lock);
497 
498 	indio_dev->dev.parent = &client->dev;
499 	indio_dev->info = &rpr0521_info;
500 	indio_dev->name = RPR0521_DRV_NAME;
501 	indio_dev->channels = rpr0521_channels;
502 	indio_dev->num_channels = ARRAY_SIZE(rpr0521_channels);
503 	indio_dev->modes = INDIO_DIRECT_MODE;
504 
505 	ret = rpr0521_init(data);
506 	if (ret < 0) {
507 		dev_err(&client->dev, "rpr0521 chip init failed\n");
508 		return ret;
509 	}
510 
511 	ret = pm_runtime_set_active(&client->dev);
512 	if (ret < 0)
513 		return ret;
514 
515 	pm_runtime_enable(&client->dev);
516 	pm_runtime_set_autosuspend_delay(&client->dev, RPR0521_SLEEP_DELAY_MS);
517 	pm_runtime_use_autosuspend(&client->dev);
518 
519 	return iio_device_register(indio_dev);
520 }
521 
522 static int rpr0521_remove(struct i2c_client *client)
523 {
524 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
525 
526 	iio_device_unregister(indio_dev);
527 
528 	pm_runtime_disable(&client->dev);
529 	pm_runtime_set_suspended(&client->dev);
530 	pm_runtime_put_noidle(&client->dev);
531 
532 	rpr0521_poweroff(iio_priv(indio_dev));
533 
534 	return 0;
535 }
536 
537 #ifdef CONFIG_PM
538 static int rpr0521_runtime_suspend(struct device *dev)
539 {
540 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
541 	struct rpr0521_data *data = iio_priv(indio_dev);
542 	int ret;
543 
544 	/* disable channels and sets {als,pxs}_dev_en to false */
545 	mutex_lock(&data->lock);
546 	ret = rpr0521_poweroff(data);
547 	mutex_unlock(&data->lock);
548 
549 	return ret;
550 }
551 
552 static int rpr0521_runtime_resume(struct device *dev)
553 {
554 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
555 	struct rpr0521_data *data = iio_priv(indio_dev);
556 	int ret;
557 
558 	if (data->als_ps_need_en) {
559 		ret = rpr0521_als_enable(data, RPR0521_MODE_ALS_ENABLE);
560 		if (ret < 0)
561 			return ret;
562 		data->als_ps_need_en = false;
563 	}
564 
565 	if (data->pxs_ps_need_en) {
566 		ret = rpr0521_pxs_enable(data, RPR0521_MODE_PXS_ENABLE);
567 		if (ret < 0)
568 			return ret;
569 		data->pxs_ps_need_en = false;
570 	}
571 
572 	return 0;
573 }
574 #endif
575 
576 static const struct dev_pm_ops rpr0521_pm_ops = {
577 	SET_RUNTIME_PM_OPS(rpr0521_runtime_suspend,
578 			   rpr0521_runtime_resume, NULL)
579 };
580 
581 static const struct acpi_device_id rpr0521_acpi_match[] = {
582 	{"RPR0521", 0},
583 	{ }
584 };
585 MODULE_DEVICE_TABLE(acpi, rpr0521_acpi_match);
586 
587 static const struct i2c_device_id rpr0521_id[] = {
588 	{"rpr0521", 0},
589 	{ }
590 };
591 
592 MODULE_DEVICE_TABLE(i2c, rpr0521_id);
593 
594 static struct i2c_driver rpr0521_driver = {
595 	.driver = {
596 		.name	= RPR0521_DRV_NAME,
597 		.pm	= &rpr0521_pm_ops,
598 		.acpi_match_table = ACPI_PTR(rpr0521_acpi_match),
599 	},
600 	.probe		= rpr0521_probe,
601 	.remove		= rpr0521_remove,
602 	.id_table	= rpr0521_id,
603 };
604 
605 module_i2c_driver(rpr0521_driver);
606 
607 MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");
608 MODULE_DESCRIPTION("RPR0521 ROHM Ambient Light and Proximity Sensor driver");
609 MODULE_LICENSE("GPL v2");
610