1/*
2 * IIO driver for the light sensor ISL29028.
3 * ISL29028 is Concurrent Ambient Light and Proximity Sensor
4 *
5 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms and conditions of the GNU General Public License,
9 * version 2, as published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14 * more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include <linux/module.h>
21#include <linux/i2c.h>
22#include <linux/err.h>
23#include <linux/mutex.h>
24#include <linux/delay.h>
25#include <linux/slab.h>
26#include <linux/regmap.h>
27#include <linux/iio/iio.h>
28#include <linux/iio/sysfs.h>
29
30#define CONVERSION_TIME_MS		100
31
32#define ISL29028_REG_CONFIGURE		0x01
33
34#define CONFIGURE_ALS_IR_MODE_ALS	0
35#define CONFIGURE_ALS_IR_MODE_IR	BIT(0)
36#define CONFIGURE_ALS_IR_MODE_MASK	BIT(0)
37
38#define CONFIGURE_ALS_RANGE_LOW_LUX	0
39#define CONFIGURE_ALS_RANGE_HIGH_LUX	BIT(1)
40#define CONFIGURE_ALS_RANGE_MASK	BIT(1)
41
42#define CONFIGURE_ALS_DIS		0
43#define CONFIGURE_ALS_EN		BIT(2)
44#define CONFIGURE_ALS_EN_MASK		BIT(2)
45
46#define CONFIGURE_PROX_DRIVE		BIT(3)
47
48#define CONFIGURE_PROX_SLP_SH		4
49#define CONFIGURE_PROX_SLP_MASK		(7 << CONFIGURE_PROX_SLP_SH)
50
51#define CONFIGURE_PROX_EN		BIT(7)
52#define CONFIGURE_PROX_EN_MASK		BIT(7)
53
54#define ISL29028_REG_INTERRUPT		0x02
55
56#define ISL29028_REG_PROX_DATA		0x08
57#define ISL29028_REG_ALSIR_L		0x09
58#define ISL29028_REG_ALSIR_U		0x0A
59
60#define ISL29028_REG_TEST1_MODE		0x0E
61#define ISL29028_REG_TEST2_MODE		0x0F
62
63#define ISL29028_NUM_REGS		(ISL29028_REG_TEST2_MODE + 1)
64
65enum als_ir_mode {
66	MODE_NONE = 0,
67	MODE_ALS,
68	MODE_IR
69};
70
71struct isl29028_chip {
72	struct device		*dev;
73	struct mutex		lock;
74	struct regmap		*regmap;
75
76	unsigned int		prox_sampling;
77	bool			enable_prox;
78
79	int			lux_scale;
80	int			als_ir_mode;
81};
82
83static int isl29028_set_proxim_sampling(struct isl29028_chip *chip,
84			unsigned int sampling)
85{
86	static unsigned int prox_period[] = {800, 400, 200, 100, 75, 50, 12, 0};
87	int sel;
88	unsigned int period = DIV_ROUND_UP(1000, sampling);
89
90	for (sel = 0; sel < ARRAY_SIZE(prox_period); ++sel) {
91		if (period >= prox_period[sel])
92			break;
93	}
94	return regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
95			CONFIGURE_PROX_SLP_MASK, sel << CONFIGURE_PROX_SLP_SH);
96}
97
98static int isl29028_enable_proximity(struct isl29028_chip *chip, bool enable)
99{
100	int ret;
101	int val = 0;
102
103	if (enable)
104		val = CONFIGURE_PROX_EN;
105	ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
106			CONFIGURE_PROX_EN_MASK, val);
107	if (ret < 0)
108		return ret;
109
110	/* Wait for conversion to be complete for first sample */
111	mdelay(DIV_ROUND_UP(1000, chip->prox_sampling));
112	return 0;
113}
114
115static int isl29028_set_als_scale(struct isl29028_chip *chip, int lux_scale)
116{
117	int val = (lux_scale == 2000) ? CONFIGURE_ALS_RANGE_HIGH_LUX :
118					CONFIGURE_ALS_RANGE_LOW_LUX;
119
120	return regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
121		CONFIGURE_ALS_RANGE_MASK, val);
122}
123
124static int isl29028_set_als_ir_mode(struct isl29028_chip *chip,
125	enum als_ir_mode mode)
126{
127	int ret = 0;
128
129	switch (mode) {
130	case MODE_ALS:
131		ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
132			CONFIGURE_ALS_IR_MODE_MASK, CONFIGURE_ALS_IR_MODE_ALS);
133		if (ret < 0)
134			return ret;
135
136		ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
137			CONFIGURE_ALS_RANGE_MASK, CONFIGURE_ALS_RANGE_HIGH_LUX);
138		break;
139
140	case MODE_IR:
141		ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
142			CONFIGURE_ALS_IR_MODE_MASK, CONFIGURE_ALS_IR_MODE_IR);
143		break;
144
145	case MODE_NONE:
146		return regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
147			CONFIGURE_ALS_EN_MASK, CONFIGURE_ALS_DIS);
148	}
149
150	if (ret < 0)
151		return ret;
152
153	/* Enable the ALS/IR */
154	ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
155			CONFIGURE_ALS_EN_MASK, CONFIGURE_ALS_EN);
156	if (ret < 0)
157		return ret;
158
159	/* Need to wait for conversion time if ALS/IR mode enabled */
160	mdelay(CONVERSION_TIME_MS);
161	return 0;
162}
163
164static int isl29028_read_als_ir(struct isl29028_chip *chip, int *als_ir)
165{
166	unsigned int lsb;
167	unsigned int msb;
168	int ret;
169
170	ret = regmap_read(chip->regmap, ISL29028_REG_ALSIR_L, &lsb);
171	if (ret < 0) {
172		dev_err(chip->dev,
173			"Error in reading register ALSIR_L err %d\n", ret);
174		return ret;
175	}
176
177	ret = regmap_read(chip->regmap, ISL29028_REG_ALSIR_U, &msb);
178	if (ret < 0) {
179		dev_err(chip->dev,
180			"Error in reading register ALSIR_U err %d\n", ret);
181		return ret;
182	}
183
184	*als_ir = ((msb & 0xF) << 8) | (lsb & 0xFF);
185	return 0;
186}
187
188static int isl29028_read_proxim(struct isl29028_chip *chip, int *prox)
189{
190	unsigned int data;
191	int ret;
192
193	ret = regmap_read(chip->regmap, ISL29028_REG_PROX_DATA, &data);
194	if (ret < 0) {
195		dev_err(chip->dev, "Error in reading register %d, error %d\n",
196				ISL29028_REG_PROX_DATA, ret);
197		return ret;
198	}
199	*prox = data;
200	return 0;
201}
202
203static int isl29028_proxim_get(struct isl29028_chip *chip, int *prox_data)
204{
205	int ret;
206
207	if (!chip->enable_prox) {
208		ret = isl29028_enable_proximity(chip, true);
209		if (ret < 0)
210			return ret;
211		chip->enable_prox = true;
212	}
213	return isl29028_read_proxim(chip, prox_data);
214}
215
216static int isl29028_als_get(struct isl29028_chip *chip, int *als_data)
217{
218	int ret;
219	int als_ir_data;
220
221	if (chip->als_ir_mode != MODE_ALS) {
222		ret = isl29028_set_als_ir_mode(chip, MODE_ALS);
223		if (ret < 0) {
224			dev_err(chip->dev,
225				"Error in enabling ALS mode err %d\n", ret);
226			return ret;
227		}
228		chip->als_ir_mode = MODE_ALS;
229	}
230
231	ret = isl29028_read_als_ir(chip, &als_ir_data);
232	if (ret < 0)
233		return ret;
234
235	/*
236	 * convert als data count to lux.
237	 * if lux_scale = 125,  lux = count * 0.031
238	 * if lux_scale = 2000, lux = count * 0.49
239	 */
240	if (chip->lux_scale == 125)
241		als_ir_data = (als_ir_data * 31) / 1000;
242	else
243		als_ir_data = (als_ir_data * 49) / 100;
244
245	*als_data = als_ir_data;
246	return 0;
247}
248
249static int isl29028_ir_get(struct isl29028_chip *chip, int *ir_data)
250{
251	int ret;
252
253	if (chip->als_ir_mode != MODE_IR) {
254		ret = isl29028_set_als_ir_mode(chip, MODE_IR);
255		if (ret < 0) {
256			dev_err(chip->dev,
257				"Error in enabling IR mode err %d\n", ret);
258			return ret;
259		}
260		chip->als_ir_mode = MODE_IR;
261	}
262	return isl29028_read_als_ir(chip, ir_data);
263}
264
265/* Channel IO */
266static int isl29028_write_raw(struct iio_dev *indio_dev,
267	     struct iio_chan_spec const *chan, int val, int val2, long mask)
268{
269	struct isl29028_chip *chip = iio_priv(indio_dev);
270	int ret = -EINVAL;
271
272	mutex_lock(&chip->lock);
273	switch (chan->type) {
274	case IIO_PROXIMITY:
275		if (mask != IIO_CHAN_INFO_SAMP_FREQ) {
276			dev_err(chip->dev,
277				"proximity: mask value 0x%08lx not supported\n",
278				mask);
279			break;
280		}
281		if (val < 1 || val > 100) {
282			dev_err(chip->dev,
283				"Samp_freq %d is not in range[1:100]\n", val);
284			break;
285		}
286		ret = isl29028_set_proxim_sampling(chip, val);
287		if (ret < 0) {
288			dev_err(chip->dev,
289				"Setting proximity samp_freq fail, err %d\n",
290				ret);
291			break;
292		}
293		chip->prox_sampling = val;
294		break;
295
296	case IIO_LIGHT:
297		if (mask != IIO_CHAN_INFO_SCALE) {
298			dev_err(chip->dev,
299				"light: mask value 0x%08lx not supported\n",
300				mask);
301			break;
302		}
303		if ((val != 125) && (val != 2000)) {
304			dev_err(chip->dev,
305				"lux scale %d is invalid [125, 2000]\n", val);
306			break;
307		}
308		ret = isl29028_set_als_scale(chip, val);
309		if (ret < 0) {
310			dev_err(chip->dev,
311				"Setting lux scale fail with error %d\n", ret);
312			break;
313		}
314		chip->lux_scale = val;
315		break;
316
317	default:
318		dev_err(chip->dev, "Unsupported channel type\n");
319		break;
320	}
321	mutex_unlock(&chip->lock);
322	return ret;
323}
324
325static int isl29028_read_raw(struct iio_dev *indio_dev,
326	     struct iio_chan_spec const *chan, int *val, int *val2, long mask)
327{
328	struct isl29028_chip *chip = iio_priv(indio_dev);
329	int ret = -EINVAL;
330
331	mutex_lock(&chip->lock);
332	switch (mask) {
333	case IIO_CHAN_INFO_RAW:
334	case IIO_CHAN_INFO_PROCESSED:
335		switch (chan->type) {
336		case IIO_LIGHT:
337			ret = isl29028_als_get(chip, val);
338			break;
339		case IIO_INTENSITY:
340			ret = isl29028_ir_get(chip, val);
341			break;
342		case IIO_PROXIMITY:
343			ret = isl29028_proxim_get(chip, val);
344			break;
345		default:
346			break;
347		}
348		if (ret < 0)
349			break;
350		ret = IIO_VAL_INT;
351		break;
352
353	case IIO_CHAN_INFO_SAMP_FREQ:
354		if (chan->type != IIO_PROXIMITY)
355			break;
356		*val = chip->prox_sampling;
357		ret = IIO_VAL_INT;
358		break;
359
360	case IIO_CHAN_INFO_SCALE:
361		if (chan->type != IIO_LIGHT)
362			break;
363		*val = chip->lux_scale;
364		ret = IIO_VAL_INT;
365		break;
366
367	default:
368		dev_err(chip->dev, "mask value 0x%08lx not supported\n", mask);
369		break;
370	}
371	mutex_unlock(&chip->lock);
372	return ret;
373}
374
375static IIO_CONST_ATTR(in_proximity_sampling_frequency_available,
376				"1, 3, 5, 10, 13, 20, 83, 100");
377static IIO_CONST_ATTR(in_illuminance_scale_available, "125, 2000");
378
379#define ISL29028_DEV_ATTR(name) (&iio_dev_attr_##name.dev_attr.attr)
380#define ISL29028_CONST_ATTR(name) (&iio_const_attr_##name.dev_attr.attr)
381static struct attribute *isl29028_attributes[] = {
382	ISL29028_CONST_ATTR(in_proximity_sampling_frequency_available),
383	ISL29028_CONST_ATTR(in_illuminance_scale_available),
384	NULL,
385};
386
387static const struct attribute_group isl29108_group = {
388	.attrs = isl29028_attributes,
389};
390
391static const struct iio_chan_spec isl29028_channels[] = {
392	{
393		.type = IIO_LIGHT,
394		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
395		BIT(IIO_CHAN_INFO_SCALE),
396	}, {
397		.type = IIO_INTENSITY,
398		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
399	}, {
400		.type = IIO_PROXIMITY,
401		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
402		BIT(IIO_CHAN_INFO_SAMP_FREQ),
403	}
404};
405
406static const struct iio_info isl29028_info = {
407	.attrs = &isl29108_group,
408	.driver_module = THIS_MODULE,
409	.read_raw = &isl29028_read_raw,
410	.write_raw = &isl29028_write_raw,
411};
412
413static int isl29028_chip_init(struct isl29028_chip *chip)
414{
415	int ret;
416
417	chip->enable_prox  = false;
418	chip->prox_sampling = 20;
419	chip->lux_scale = 2000;
420	chip->als_ir_mode = MODE_NONE;
421
422	ret = regmap_write(chip->regmap, ISL29028_REG_TEST1_MODE, 0x0);
423	if (ret < 0) {
424		dev_err(chip->dev, "%s(): write to reg %d failed, err = %d\n",
425			__func__, ISL29028_REG_TEST1_MODE, ret);
426		return ret;
427	}
428	ret = regmap_write(chip->regmap, ISL29028_REG_TEST2_MODE, 0x0);
429	if (ret < 0) {
430		dev_err(chip->dev, "%s(): write to reg %d failed, err = %d\n",
431			__func__, ISL29028_REG_TEST2_MODE, ret);
432		return ret;
433	}
434
435	ret = regmap_write(chip->regmap, ISL29028_REG_CONFIGURE, 0x0);
436	if (ret < 0) {
437		dev_err(chip->dev, "%s(): write to reg %d failed, err = %d\n",
438			__func__, ISL29028_REG_CONFIGURE, ret);
439		return ret;
440	}
441
442	ret = isl29028_set_proxim_sampling(chip, chip->prox_sampling);
443	if (ret < 0) {
444		dev_err(chip->dev, "setting the proximity, err = %d\n",
445			ret);
446		return ret;
447	}
448
449	ret = isl29028_set_als_scale(chip, chip->lux_scale);
450	if (ret < 0)
451		dev_err(chip->dev,
452			"setting als scale failed, err = %d\n", ret);
453	return ret;
454}
455
456static bool is_volatile_reg(struct device *dev, unsigned int reg)
457{
458	switch (reg) {
459	case ISL29028_REG_INTERRUPT:
460	case ISL29028_REG_PROX_DATA:
461	case ISL29028_REG_ALSIR_L:
462	case ISL29028_REG_ALSIR_U:
463		return true;
464	default:
465		return false;
466	}
467}
468
469static const struct regmap_config isl29028_regmap_config = {
470	.reg_bits = 8,
471	.val_bits = 8,
472	.volatile_reg = is_volatile_reg,
473	.max_register = ISL29028_NUM_REGS - 1,
474	.num_reg_defaults_raw = ISL29028_NUM_REGS,
475	.cache_type = REGCACHE_RBTREE,
476};
477
478static int isl29028_probe(struct i2c_client *client,
479	const struct i2c_device_id *id)
480{
481	struct isl29028_chip *chip;
482	struct iio_dev *indio_dev;
483	int ret;
484
485	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
486	if (!indio_dev) {
487		dev_err(&client->dev, "iio allocation fails\n");
488		return -ENOMEM;
489	}
490
491	chip = iio_priv(indio_dev);
492
493	i2c_set_clientdata(client, indio_dev);
494	chip->dev = &client->dev;
495	mutex_init(&chip->lock);
496
497	chip->regmap = devm_regmap_init_i2c(client, &isl29028_regmap_config);
498	if (IS_ERR(chip->regmap)) {
499		ret = PTR_ERR(chip->regmap);
500		dev_err(chip->dev, "regmap initialization failed: %d\n", ret);
501		return ret;
502	}
503
504	ret = isl29028_chip_init(chip);
505	if (ret < 0) {
506		dev_err(chip->dev, "chip initialization failed: %d\n", ret);
507		return ret;
508	}
509
510	indio_dev->info = &isl29028_info;
511	indio_dev->channels = isl29028_channels;
512	indio_dev->num_channels = ARRAY_SIZE(isl29028_channels);
513	indio_dev->name = id->name;
514	indio_dev->dev.parent = &client->dev;
515	indio_dev->modes = INDIO_DIRECT_MODE;
516	ret = iio_device_register(indio_dev);
517	if (ret < 0) {
518		dev_err(chip->dev, "iio registration fails with error %d\n",
519			ret);
520		return ret;
521	}
522	return 0;
523}
524
525static int isl29028_remove(struct i2c_client *client)
526{
527	struct iio_dev *indio_dev = i2c_get_clientdata(client);
528
529	iio_device_unregister(indio_dev);
530	return 0;
531}
532
533static const struct i2c_device_id isl29028_id[] = {
534	{"isl29028", 0},
535	{}
536};
537MODULE_DEVICE_TABLE(i2c, isl29028_id);
538
539static const struct of_device_id isl29028_of_match[] = {
540	{ .compatible = "isl,isl29028", }, /* for backward compat., don't use */
541	{ .compatible = "isil,isl29028", },
542	{ },
543};
544MODULE_DEVICE_TABLE(of, isl29028_of_match);
545
546static struct i2c_driver isl29028_driver = {
547	.class	= I2C_CLASS_HWMON,
548	.driver  = {
549		.name = "isl29028",
550		.owner = THIS_MODULE,
551		.of_match_table = isl29028_of_match,
552	},
553	.probe	 = isl29028_probe,
554	.remove  = isl29028_remove,
555	.id_table = isl29028_id,
556};
557
558module_i2c_driver(isl29028_driver);
559
560MODULE_DESCRIPTION("ISL29028 Ambient Light and Proximity Sensor driver");
561MODULE_LICENSE("GPL v2");
562MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
563