1 /*
2  * Backlight driver for Analog Devices ADP8870 Backlight Devices
3  *
4  * Copyright 2009-2011 Analog Devices Inc.
5  *
6  * Licensed under the GPL-2 or later.
7  */
8 
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/errno.h>
12 #include <linux/pm.h>
13 #include <linux/platform_device.h>
14 #include <linux/i2c.h>
15 #include <linux/fb.h>
16 #include <linux/backlight.h>
17 #include <linux/leds.h>
18 #include <linux/workqueue.h>
19 #include <linux/slab.h>
20 
21 #include <linux/platform_data/adp8870.h>
22 #define ADP8870_EXT_FEATURES
23 #define ADP8870_USE_LEDS
24 
25 
26 #define ADP8870_MFDVID	0x00  /* Manufacturer and device ID */
27 #define ADP8870_MDCR	0x01  /* Device mode and status */
28 #define ADP8870_INT_STAT 0x02  /* Interrupts status */
29 #define ADP8870_INT_EN	0x03  /* Interrupts enable */
30 #define ADP8870_CFGR	0x04  /* Configuration register */
31 #define ADP8870_BLSEL	0x05  /* Sink enable backlight or independent */
32 #define ADP8870_PWMLED	0x06  /* PWM Enable Selection Register */
33 #define ADP8870_BLOFF	0x07  /* Backlight off timeout */
34 #define ADP8870_BLDIM	0x08  /* Backlight dim timeout */
35 #define ADP8870_BLFR	0x09  /* Backlight fade in and out rates */
36 #define ADP8870_BLMX1	0x0A  /* Backlight (Brightness Level 1-daylight) maximum current */
37 #define ADP8870_BLDM1	0x0B  /* Backlight (Brightness Level 1-daylight) dim current */
38 #define ADP8870_BLMX2	0x0C  /* Backlight (Brightness Level 2-bright) maximum current */
39 #define ADP8870_BLDM2	0x0D  /* Backlight (Brightness Level 2-bright) dim current */
40 #define ADP8870_BLMX3	0x0E  /* Backlight (Brightness Level 3-office) maximum current */
41 #define ADP8870_BLDM3	0x0F  /* Backlight (Brightness Level 3-office) dim current */
42 #define ADP8870_BLMX4	0x10  /* Backlight (Brightness Level 4-indoor) maximum current */
43 #define ADP8870_BLDM4	0x11  /* Backlight (Brightness Level 4-indoor) dim current */
44 #define ADP8870_BLMX5	0x12  /* Backlight (Brightness Level 5-dark) maximum current */
45 #define ADP8870_BLDM5	0x13  /* Backlight (Brightness Level 5-dark) dim current */
46 #define ADP8870_ISCLAW	0x1A  /* Independent sink current fade law register */
47 #define ADP8870_ISCC	0x1B  /* Independent sink current control register */
48 #define ADP8870_ISCT1	0x1C  /* Independent Sink Current Timer Register LED[7:5] */
49 #define ADP8870_ISCT2	0x1D  /* Independent Sink Current Timer Register LED[4:1] */
50 #define ADP8870_ISCF	0x1E  /* Independent sink current fade register */
51 #define ADP8870_ISC1	0x1F  /* Independent Sink Current LED1 */
52 #define ADP8870_ISC2	0x20  /* Independent Sink Current LED2 */
53 #define ADP8870_ISC3	0x21  /* Independent Sink Current LED3 */
54 #define ADP8870_ISC4	0x22  /* Independent Sink Current LED4 */
55 #define ADP8870_ISC5	0x23  /* Independent Sink Current LED5 */
56 #define ADP8870_ISC6	0x24  /* Independent Sink Current LED6 */
57 #define ADP8870_ISC7	0x25  /* Independent Sink Current LED7 (Brightness Level 1-daylight) */
58 #define ADP8870_ISC7_L2	0x26  /* Independent Sink Current LED7 (Brightness Level 2-bright) */
59 #define ADP8870_ISC7_L3	0x27  /* Independent Sink Current LED7 (Brightness Level 3-office) */
60 #define ADP8870_ISC7_L4	0x28  /* Independent Sink Current LED7 (Brightness Level 4-indoor) */
61 #define ADP8870_ISC7_L5	0x29  /* Independent Sink Current LED7 (Brightness Level 5-dark) */
62 #define ADP8870_CMP_CTL	0x2D  /* ALS Comparator Control Register */
63 #define ADP8870_ALS1_EN	0x2E  /* Main ALS comparator level enable */
64 #define ADP8870_ALS2_EN	0x2F  /* Second ALS comparator level enable */
65 #define ADP8870_ALS1_STAT 0x30  /* Main ALS Comparator Status Register */
66 #define ADP8870_ALS2_STAT 0x31  /* Second ALS Comparator Status Register */
67 #define ADP8870_L2TRP	0x32  /* L2 comparator reference */
68 #define ADP8870_L2HYS	0x33  /* L2 hysteresis */
69 #define ADP8870_L3TRP	0x34  /* L3 comparator reference */
70 #define ADP8870_L3HYS	0x35  /* L3 hysteresis */
71 #define ADP8870_L4TRP	0x36  /* L4 comparator reference */
72 #define ADP8870_L4HYS	0x37  /* L4 hysteresis */
73 #define ADP8870_L5TRP	0x38  /* L5 comparator reference */
74 #define ADP8870_L5HYS	0x39  /* L5 hysteresis */
75 #define ADP8870_PH1LEVL	0x40  /* First phototransistor ambient light level-low byte register */
76 #define ADP8870_PH1LEVH	0x41  /* First phototransistor ambient light level-high byte register */
77 #define ADP8870_PH2LEVL	0x42  /* Second phototransistor ambient light level-low byte register */
78 #define ADP8870_PH2LEVH	0x43  /* Second phototransistor ambient light level-high byte register */
79 
80 #define ADP8870_MANUFID		0x3  /* Analog Devices AD8870 Manufacturer and device ID */
81 #define ADP8870_DEVID(x)	((x) & 0xF)
82 #define ADP8870_MANID(x)	((x) >> 4)
83 
84 /* MDCR Device mode and status */
85 #define D7ALSEN			(1 << 7)
86 #define INT_CFG			(1 << 6)
87 #define NSTBY			(1 << 5)
88 #define DIM_EN			(1 << 4)
89 #define GDWN_DIS		(1 << 3)
90 #define SIS_EN			(1 << 2)
91 #define CMP_AUTOEN		(1 << 1)
92 #define BLEN			(1 << 0)
93 
94 /* ADP8870_ALS1_EN Main ALS comparator level enable */
95 #define L5_EN			(1 << 3)
96 #define L4_EN			(1 << 2)
97 #define L3_EN			(1 << 1)
98 #define L2_EN			(1 << 0)
99 
100 #define CFGR_BLV_SHIFT		3
101 #define CFGR_BLV_MASK		0x7
102 #define ADP8870_FLAG_LED_MASK	0xFF
103 
104 #define FADE_VAL(in, out)	((0xF & (in)) | ((0xF & (out)) << 4))
105 #define BL_CFGR_VAL(law, blv)	((((blv) & CFGR_BLV_MASK) << CFGR_BLV_SHIFT) | ((0x3 & (law)) << 1))
106 #define ALS_CMPR_CFG_VAL(filt)	((0x7 & (filt)) << 1)
107 
108 struct adp8870_bl {
109 	struct i2c_client *client;
110 	struct backlight_device *bl;
111 	struct adp8870_led *led;
112 	struct adp8870_backlight_platform_data *pdata;
113 	struct mutex lock;
114 	unsigned long cached_daylight_max;
115 	int id;
116 	int revid;
117 	int current_brightness;
118 };
119 
120 struct adp8870_led {
121 	struct led_classdev	cdev;
122 	struct work_struct	work;
123 	struct i2c_client	*client;
124 	enum led_brightness	new_brightness;
125 	int			id;
126 	int			flags;
127 };
128 
129 static int adp8870_read(struct i2c_client *client, int reg, uint8_t *val)
130 {
131 	int ret;
132 
133 	ret = i2c_smbus_read_byte_data(client, reg);
134 	if (ret < 0) {
135 		dev_err(&client->dev, "failed reading at 0x%02x\n", reg);
136 		return ret;
137 	}
138 
139 	*val = ret;
140 	return 0;
141 }
142 
143 
144 static int adp8870_write(struct i2c_client *client, u8 reg, u8 val)
145 {
146 	int ret = i2c_smbus_write_byte_data(client, reg, val);
147 
148 	if (ret)
149 		dev_err(&client->dev, "failed to write\n");
150 
151 	return ret;
152 }
153 
154 static int adp8870_set_bits(struct i2c_client *client, int reg, uint8_t bit_mask)
155 {
156 	struct adp8870_bl *data = i2c_get_clientdata(client);
157 	uint8_t reg_val;
158 	int ret;
159 
160 	mutex_lock(&data->lock);
161 
162 	ret = adp8870_read(client, reg, &reg_val);
163 
164 	if (!ret && ((reg_val & bit_mask) != bit_mask)) {
165 		reg_val |= bit_mask;
166 		ret = adp8870_write(client, reg, reg_val);
167 	}
168 
169 	mutex_unlock(&data->lock);
170 	return ret;
171 }
172 
173 static int adp8870_clr_bits(struct i2c_client *client, int reg, uint8_t bit_mask)
174 {
175 	struct adp8870_bl *data = i2c_get_clientdata(client);
176 	uint8_t reg_val;
177 	int ret;
178 
179 	mutex_lock(&data->lock);
180 
181 	ret = adp8870_read(client, reg, &reg_val);
182 
183 	if (!ret && (reg_val & bit_mask)) {
184 		reg_val &= ~bit_mask;
185 		ret = adp8870_write(client, reg, reg_val);
186 	}
187 
188 	mutex_unlock(&data->lock);
189 	return ret;
190 }
191 
192 /*
193  * Independent sink / LED
194  */
195 #if defined(ADP8870_USE_LEDS)
196 static void adp8870_led_work(struct work_struct *work)
197 {
198 	struct adp8870_led *led = container_of(work, struct adp8870_led, work);
199 
200 	adp8870_write(led->client, ADP8870_ISC1 + led->id - 1,
201 			 led->new_brightness >> 1);
202 }
203 
204 static void adp8870_led_set(struct led_classdev *led_cdev,
205 			   enum led_brightness value)
206 {
207 	struct adp8870_led *led;
208 
209 	led = container_of(led_cdev, struct adp8870_led, cdev);
210 	led->new_brightness = value;
211 	/*
212 	 * Use workqueue for IO since I2C operations can sleep.
213 	 */
214 	schedule_work(&led->work);
215 }
216 
217 static int adp8870_led_setup(struct adp8870_led *led)
218 {
219 	struct i2c_client *client = led->client;
220 	int ret = 0;
221 
222 	ret = adp8870_write(client, ADP8870_ISC1 + led->id - 1, 0);
223 	if (ret)
224 		return ret;
225 
226 	ret = adp8870_set_bits(client, ADP8870_ISCC, 1 << (led->id - 1));
227 	if (ret)
228 		return ret;
229 
230 	if (led->id > 4)
231 		ret = adp8870_set_bits(client, ADP8870_ISCT1,
232 				(led->flags & 0x3) << ((led->id - 5) * 2));
233 	else
234 		ret = adp8870_set_bits(client, ADP8870_ISCT2,
235 				(led->flags & 0x3) << ((led->id - 1) * 2));
236 
237 	return ret;
238 }
239 
240 static int adp8870_led_probe(struct i2c_client *client)
241 {
242 	struct adp8870_backlight_platform_data *pdata =
243 		dev_get_platdata(&client->dev);
244 	struct adp8870_bl *data = i2c_get_clientdata(client);
245 	struct adp8870_led *led, *led_dat;
246 	struct led_info *cur_led;
247 	int ret, i;
248 
249 	led = devm_kcalloc(&client->dev, pdata->num_leds, sizeof(*led),
250 				GFP_KERNEL);
251 	if (led == NULL)
252 		return -ENOMEM;
253 
254 	ret = adp8870_write(client, ADP8870_ISCLAW, pdata->led_fade_law);
255 	if (ret)
256 		return ret;
257 
258 	ret = adp8870_write(client, ADP8870_ISCT1,
259 			(pdata->led_on_time & 0x3) << 6);
260 	if (ret)
261 		return ret;
262 
263 	ret = adp8870_write(client, ADP8870_ISCF,
264 			FADE_VAL(pdata->led_fade_in, pdata->led_fade_out));
265 	if (ret)
266 		return ret;
267 
268 	for (i = 0; i < pdata->num_leds; ++i) {
269 		cur_led = &pdata->leds[i];
270 		led_dat = &led[i];
271 
272 		led_dat->id = cur_led->flags & ADP8870_FLAG_LED_MASK;
273 
274 		if (led_dat->id > 7 || led_dat->id < 1) {
275 			dev_err(&client->dev, "Invalid LED ID %d\n",
276 				led_dat->id);
277 			ret = -EINVAL;
278 			goto err;
279 		}
280 
281 		if (pdata->bl_led_assign & (1 << (led_dat->id - 1))) {
282 			dev_err(&client->dev, "LED %d used by Backlight\n",
283 				led_dat->id);
284 			ret = -EBUSY;
285 			goto err;
286 		}
287 
288 		led_dat->cdev.name = cur_led->name;
289 		led_dat->cdev.default_trigger = cur_led->default_trigger;
290 		led_dat->cdev.brightness_set = adp8870_led_set;
291 		led_dat->cdev.brightness = LED_OFF;
292 		led_dat->flags = cur_led->flags >> FLAG_OFFT_SHIFT;
293 		led_dat->client = client;
294 		led_dat->new_brightness = LED_OFF;
295 		INIT_WORK(&led_dat->work, adp8870_led_work);
296 
297 		ret = led_classdev_register(&client->dev, &led_dat->cdev);
298 		if (ret) {
299 			dev_err(&client->dev, "failed to register LED %d\n",
300 				led_dat->id);
301 			goto err;
302 		}
303 
304 		ret = adp8870_led_setup(led_dat);
305 		if (ret) {
306 			dev_err(&client->dev, "failed to write\n");
307 			i++;
308 			goto err;
309 		}
310 	}
311 
312 	data->led = led;
313 
314 	return 0;
315 
316  err:
317 	for (i = i - 1; i >= 0; --i) {
318 		led_classdev_unregister(&led[i].cdev);
319 		cancel_work_sync(&led[i].work);
320 	}
321 
322 	return ret;
323 }
324 
325 static int adp8870_led_remove(struct i2c_client *client)
326 {
327 	struct adp8870_backlight_platform_data *pdata =
328 		dev_get_platdata(&client->dev);
329 	struct adp8870_bl *data = i2c_get_clientdata(client);
330 	int i;
331 
332 	for (i = 0; i < pdata->num_leds; i++) {
333 		led_classdev_unregister(&data->led[i].cdev);
334 		cancel_work_sync(&data->led[i].work);
335 	}
336 
337 	return 0;
338 }
339 #else
340 static int adp8870_led_probe(struct i2c_client *client)
341 {
342 	return 0;
343 }
344 
345 static int adp8870_led_remove(struct i2c_client *client)
346 {
347 	return 0;
348 }
349 #endif
350 
351 static int adp8870_bl_set(struct backlight_device *bl, int brightness)
352 {
353 	struct adp8870_bl *data = bl_get_data(bl);
354 	struct i2c_client *client = data->client;
355 	int ret = 0;
356 
357 	if (data->pdata->en_ambl_sens) {
358 		if ((brightness > 0) && (brightness < ADP8870_MAX_BRIGHTNESS)) {
359 			/* Disable Ambient Light auto adjust */
360 			ret = adp8870_clr_bits(client, ADP8870_MDCR,
361 					CMP_AUTOEN);
362 			if (ret)
363 				return ret;
364 			ret = adp8870_write(client, ADP8870_BLMX1, brightness);
365 			if (ret)
366 				return ret;
367 		} else {
368 			/*
369 			 * MAX_BRIGHTNESS -> Enable Ambient Light auto adjust
370 			 * restore daylight l1 sysfs brightness
371 			 */
372 			ret = adp8870_write(client, ADP8870_BLMX1,
373 					 data->cached_daylight_max);
374 			if (ret)
375 				return ret;
376 
377 			ret = adp8870_set_bits(client, ADP8870_MDCR,
378 					 CMP_AUTOEN);
379 			if (ret)
380 				return ret;
381 		}
382 	} else {
383 		ret = adp8870_write(client, ADP8870_BLMX1, brightness);
384 		if (ret)
385 			return ret;
386 	}
387 
388 	if (data->current_brightness && brightness == 0)
389 		ret = adp8870_set_bits(client,
390 				ADP8870_MDCR, DIM_EN);
391 	else if (data->current_brightness == 0 && brightness)
392 		ret = adp8870_clr_bits(client,
393 				ADP8870_MDCR, DIM_EN);
394 
395 	if (!ret)
396 		data->current_brightness = brightness;
397 
398 	return ret;
399 }
400 
401 static int adp8870_bl_update_status(struct backlight_device *bl)
402 {
403 	int brightness = bl->props.brightness;
404 
405 	if (bl->props.power != FB_BLANK_UNBLANK)
406 		brightness = 0;
407 
408 	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
409 		brightness = 0;
410 
411 	return adp8870_bl_set(bl, brightness);
412 }
413 
414 static int adp8870_bl_get_brightness(struct backlight_device *bl)
415 {
416 	struct adp8870_bl *data = bl_get_data(bl);
417 
418 	return data->current_brightness;
419 }
420 
421 static const struct backlight_ops adp8870_bl_ops = {
422 	.update_status	= adp8870_bl_update_status,
423 	.get_brightness	= adp8870_bl_get_brightness,
424 };
425 
426 static int adp8870_bl_setup(struct backlight_device *bl)
427 {
428 	struct adp8870_bl *data = bl_get_data(bl);
429 	struct i2c_client *client = data->client;
430 	struct adp8870_backlight_platform_data *pdata = data->pdata;
431 	int ret = 0;
432 
433 	ret = adp8870_write(client, ADP8870_BLSEL, ~pdata->bl_led_assign);
434 	if (ret)
435 		return ret;
436 
437 	ret = adp8870_write(client, ADP8870_PWMLED, pdata->pwm_assign);
438 	if (ret)
439 		return ret;
440 
441 	ret = adp8870_write(client, ADP8870_BLMX1, pdata->l1_daylight_max);
442 	if (ret)
443 		return ret;
444 
445 	ret = adp8870_write(client, ADP8870_BLDM1, pdata->l1_daylight_dim);
446 	if (ret)
447 		return ret;
448 
449 	if (pdata->en_ambl_sens) {
450 		data->cached_daylight_max = pdata->l1_daylight_max;
451 		ret = adp8870_write(client, ADP8870_BLMX2,
452 						pdata->l2_bright_max);
453 		if (ret)
454 			return ret;
455 		ret = adp8870_write(client, ADP8870_BLDM2,
456 						pdata->l2_bright_dim);
457 		if (ret)
458 			return ret;
459 
460 		ret = adp8870_write(client, ADP8870_BLMX3,
461 						pdata->l3_office_max);
462 		if (ret)
463 			return ret;
464 		ret = adp8870_write(client, ADP8870_BLDM3,
465 						pdata->l3_office_dim);
466 		if (ret)
467 			return ret;
468 
469 		ret = adp8870_write(client, ADP8870_BLMX4,
470 						pdata->l4_indoor_max);
471 		if (ret)
472 			return ret;
473 
474 		ret = adp8870_write(client, ADP8870_BLDM4,
475 						pdata->l4_indor_dim);
476 		if (ret)
477 			return ret;
478 
479 		ret = adp8870_write(client, ADP8870_BLMX5,
480 						pdata->l5_dark_max);
481 		if (ret)
482 			return ret;
483 
484 		ret = adp8870_write(client, ADP8870_BLDM5,
485 						pdata->l5_dark_dim);
486 		if (ret)
487 			return ret;
488 
489 		ret = adp8870_write(client, ADP8870_L2TRP, pdata->l2_trip);
490 		if (ret)
491 			return ret;
492 
493 		ret = adp8870_write(client, ADP8870_L2HYS, pdata->l2_hyst);
494 		if (ret)
495 			return ret;
496 
497 		ret = adp8870_write(client, ADP8870_L3TRP, pdata->l3_trip);
498 		if (ret)
499 			return ret;
500 
501 		ret = adp8870_write(client, ADP8870_L3HYS, pdata->l3_hyst);
502 		if (ret)
503 			return ret;
504 
505 		ret = adp8870_write(client, ADP8870_L4TRP, pdata->l4_trip);
506 		if (ret)
507 			return ret;
508 
509 		ret = adp8870_write(client, ADP8870_L4HYS, pdata->l4_hyst);
510 		if (ret)
511 			return ret;
512 
513 		ret = adp8870_write(client, ADP8870_L5TRP, pdata->l5_trip);
514 		if (ret)
515 			return ret;
516 
517 		ret = adp8870_write(client, ADP8870_L5HYS, pdata->l5_hyst);
518 		if (ret)
519 			return ret;
520 
521 		ret = adp8870_write(client, ADP8870_ALS1_EN, L5_EN | L4_EN |
522 						L3_EN | L2_EN);
523 		if (ret)
524 			return ret;
525 
526 		ret = adp8870_write(client, ADP8870_CMP_CTL,
527 			ALS_CMPR_CFG_VAL(pdata->abml_filt));
528 		if (ret)
529 			return ret;
530 	}
531 
532 	ret = adp8870_write(client, ADP8870_CFGR,
533 			BL_CFGR_VAL(pdata->bl_fade_law, 0));
534 	if (ret)
535 		return ret;
536 
537 	ret = adp8870_write(client, ADP8870_BLFR, FADE_VAL(pdata->bl_fade_in,
538 			pdata->bl_fade_out));
539 	if (ret)
540 		return ret;
541 	/*
542 	 * ADP8870 Rev0 requires GDWN_DIS bit set
543 	 */
544 
545 	ret = adp8870_set_bits(client, ADP8870_MDCR, BLEN | DIM_EN | NSTBY |
546 			(data->revid == 0 ? GDWN_DIS : 0));
547 
548 	return ret;
549 }
550 
551 static ssize_t adp8870_show(struct device *dev, char *buf, int reg)
552 {
553 	struct adp8870_bl *data = dev_get_drvdata(dev);
554 	int error;
555 	uint8_t reg_val;
556 
557 	mutex_lock(&data->lock);
558 	error = adp8870_read(data->client, reg, &reg_val);
559 	mutex_unlock(&data->lock);
560 
561 	if (error < 0)
562 		return error;
563 
564 	return sprintf(buf, "%u\n", reg_val);
565 }
566 
567 static ssize_t adp8870_store(struct device *dev, const char *buf,
568 			 size_t count, int reg)
569 {
570 	struct adp8870_bl *data = dev_get_drvdata(dev);
571 	unsigned long val;
572 	int ret;
573 
574 	ret = kstrtoul(buf, 10, &val);
575 	if (ret)
576 		return ret;
577 
578 	mutex_lock(&data->lock);
579 	adp8870_write(data->client, reg, val);
580 	mutex_unlock(&data->lock);
581 
582 	return count;
583 }
584 
585 static ssize_t adp8870_bl_l5_dark_max_show(struct device *dev,
586 		struct device_attribute *attr, char *buf)
587 {
588 	return adp8870_show(dev, buf, ADP8870_BLMX5);
589 }
590 
591 static ssize_t adp8870_bl_l5_dark_max_store(struct device *dev,
592 		struct device_attribute *attr, const char *buf, size_t count)
593 {
594 	return adp8870_store(dev, buf, count, ADP8870_BLMX5);
595 }
596 static DEVICE_ATTR(l5_dark_max, 0664, adp8870_bl_l5_dark_max_show,
597 			adp8870_bl_l5_dark_max_store);
598 
599 
600 static ssize_t adp8870_bl_l4_indoor_max_show(struct device *dev,
601 		struct device_attribute *attr, char *buf)
602 {
603 	return adp8870_show(dev, buf, ADP8870_BLMX4);
604 }
605 
606 static ssize_t adp8870_bl_l4_indoor_max_store(struct device *dev,
607 		struct device_attribute *attr, const char *buf, size_t count)
608 {
609 	return adp8870_store(dev, buf, count, ADP8870_BLMX4);
610 }
611 static DEVICE_ATTR(l4_indoor_max, 0664, adp8870_bl_l4_indoor_max_show,
612 			adp8870_bl_l4_indoor_max_store);
613 
614 
615 static ssize_t adp8870_bl_l3_office_max_show(struct device *dev,
616 				     struct device_attribute *attr, char *buf)
617 {
618 	return adp8870_show(dev, buf, ADP8870_BLMX3);
619 }
620 
621 static ssize_t adp8870_bl_l3_office_max_store(struct device *dev,
622 		struct device_attribute *attr, const char *buf, size_t count)
623 {
624 	return adp8870_store(dev, buf, count, ADP8870_BLMX3);
625 }
626 
627 static DEVICE_ATTR(l3_office_max, 0664, adp8870_bl_l3_office_max_show,
628 			adp8870_bl_l3_office_max_store);
629 
630 static ssize_t adp8870_bl_l2_bright_max_show(struct device *dev,
631 		struct device_attribute *attr, char *buf)
632 {
633 	return adp8870_show(dev, buf, ADP8870_BLMX2);
634 }
635 
636 static ssize_t adp8870_bl_l2_bright_max_store(struct device *dev,
637 		struct device_attribute *attr, const char *buf, size_t count)
638 {
639 	return adp8870_store(dev, buf, count, ADP8870_BLMX2);
640 }
641 static DEVICE_ATTR(l2_bright_max, 0664, adp8870_bl_l2_bright_max_show,
642 			adp8870_bl_l2_bright_max_store);
643 
644 static ssize_t adp8870_bl_l1_daylight_max_show(struct device *dev,
645 			struct device_attribute *attr, char *buf)
646 {
647 	return adp8870_show(dev, buf, ADP8870_BLMX1);
648 }
649 
650 static ssize_t adp8870_bl_l1_daylight_max_store(struct device *dev,
651 		struct device_attribute *attr, const char *buf, size_t count)
652 {
653 	struct adp8870_bl *data = dev_get_drvdata(dev);
654 	int ret = kstrtoul(buf, 10, &data->cached_daylight_max);
655 
656 	if (ret)
657 		return ret;
658 
659 	return adp8870_store(dev, buf, count, ADP8870_BLMX1);
660 }
661 static DEVICE_ATTR(l1_daylight_max, 0664, adp8870_bl_l1_daylight_max_show,
662 			adp8870_bl_l1_daylight_max_store);
663 
664 static ssize_t adp8870_bl_l5_dark_dim_show(struct device *dev,
665 			struct device_attribute *attr, char *buf)
666 {
667 	return adp8870_show(dev, buf, ADP8870_BLDM5);
668 }
669 
670 static ssize_t adp8870_bl_l5_dark_dim_store(struct device *dev,
671 				     struct device_attribute *attr,
672 				     const char *buf, size_t count)
673 {
674 	return adp8870_store(dev, buf, count, ADP8870_BLDM5);
675 }
676 static DEVICE_ATTR(l5_dark_dim, 0664, adp8870_bl_l5_dark_dim_show,
677 			adp8870_bl_l5_dark_dim_store);
678 
679 static ssize_t adp8870_bl_l4_indoor_dim_show(struct device *dev,
680 			struct device_attribute *attr, char *buf)
681 {
682 	return adp8870_show(dev, buf, ADP8870_BLDM4);
683 }
684 
685 static ssize_t adp8870_bl_l4_indoor_dim_store(struct device *dev,
686 				     struct device_attribute *attr,
687 				     const char *buf, size_t count)
688 {
689 	return adp8870_store(dev, buf, count, ADP8870_BLDM4);
690 }
691 static DEVICE_ATTR(l4_indoor_dim, 0664, adp8870_bl_l4_indoor_dim_show,
692 			adp8870_bl_l4_indoor_dim_store);
693 
694 
695 static ssize_t adp8870_bl_l3_office_dim_show(struct device *dev,
696 			struct device_attribute *attr, char *buf)
697 {
698 	return adp8870_show(dev, buf, ADP8870_BLDM3);
699 }
700 
701 static ssize_t adp8870_bl_l3_office_dim_store(struct device *dev,
702 				     struct device_attribute *attr,
703 				     const char *buf, size_t count)
704 {
705 	return adp8870_store(dev, buf, count, ADP8870_BLDM3);
706 }
707 static DEVICE_ATTR(l3_office_dim, 0664, adp8870_bl_l3_office_dim_show,
708 			adp8870_bl_l3_office_dim_store);
709 
710 static ssize_t adp8870_bl_l2_bright_dim_show(struct device *dev,
711 			struct device_attribute *attr, char *buf)
712 {
713 	return adp8870_show(dev, buf, ADP8870_BLDM2);
714 }
715 
716 static ssize_t adp8870_bl_l2_bright_dim_store(struct device *dev,
717 				     struct device_attribute *attr,
718 				     const char *buf, size_t count)
719 {
720 	return adp8870_store(dev, buf, count, ADP8870_BLDM2);
721 }
722 static DEVICE_ATTR(l2_bright_dim, 0664, adp8870_bl_l2_bright_dim_show,
723 			adp8870_bl_l2_bright_dim_store);
724 
725 static ssize_t adp8870_bl_l1_daylight_dim_show(struct device *dev,
726 				     struct device_attribute *attr, char *buf)
727 {
728 	return adp8870_show(dev, buf, ADP8870_BLDM1);
729 }
730 
731 static ssize_t adp8870_bl_l1_daylight_dim_store(struct device *dev,
732 				     struct device_attribute *attr,
733 				     const char *buf, size_t count)
734 {
735 	return adp8870_store(dev, buf, count, ADP8870_BLDM1);
736 }
737 static DEVICE_ATTR(l1_daylight_dim, 0664, adp8870_bl_l1_daylight_dim_show,
738 			adp8870_bl_l1_daylight_dim_store);
739 
740 #ifdef ADP8870_EXT_FEATURES
741 static ssize_t adp8870_bl_ambient_light_level_show(struct device *dev,
742 				     struct device_attribute *attr, char *buf)
743 {
744 	struct adp8870_bl *data = dev_get_drvdata(dev);
745 	int error;
746 	uint8_t reg_val;
747 	uint16_t ret_val;
748 
749 	mutex_lock(&data->lock);
750 	error = adp8870_read(data->client, ADP8870_PH1LEVL, &reg_val);
751 	if (error < 0) {
752 		mutex_unlock(&data->lock);
753 		return error;
754 	}
755 	ret_val = reg_val;
756 	error = adp8870_read(data->client, ADP8870_PH1LEVH, &reg_val);
757 	mutex_unlock(&data->lock);
758 
759 	if (error < 0)
760 		return error;
761 
762 	/* Return 13-bit conversion value for the first light sensor */
763 	ret_val += (reg_val & 0x1F) << 8;
764 
765 	return sprintf(buf, "%u\n", ret_val);
766 }
767 static DEVICE_ATTR(ambient_light_level, 0444,
768 		adp8870_bl_ambient_light_level_show, NULL);
769 
770 static ssize_t adp8870_bl_ambient_light_zone_show(struct device *dev,
771 				     struct device_attribute *attr, char *buf)
772 {
773 	struct adp8870_bl *data = dev_get_drvdata(dev);
774 	int error;
775 	uint8_t reg_val;
776 
777 	mutex_lock(&data->lock);
778 	error = adp8870_read(data->client, ADP8870_CFGR, &reg_val);
779 	mutex_unlock(&data->lock);
780 
781 	if (error < 0)
782 		return error;
783 
784 	return sprintf(buf, "%u\n",
785 		((reg_val >> CFGR_BLV_SHIFT) & CFGR_BLV_MASK) + 1);
786 }
787 
788 static ssize_t adp8870_bl_ambient_light_zone_store(struct device *dev,
789 				     struct device_attribute *attr,
790 				     const char *buf, size_t count)
791 {
792 	struct adp8870_bl *data = dev_get_drvdata(dev);
793 	unsigned long val;
794 	uint8_t reg_val;
795 	int ret;
796 
797 	ret = kstrtoul(buf, 10, &val);
798 	if (ret)
799 		return ret;
800 
801 	if (val == 0) {
802 		/* Enable automatic ambient light sensing */
803 		adp8870_set_bits(data->client, ADP8870_MDCR, CMP_AUTOEN);
804 	} else if ((val > 0) && (val < 6)) {
805 		/* Disable automatic ambient light sensing */
806 		adp8870_clr_bits(data->client, ADP8870_MDCR, CMP_AUTOEN);
807 
808 		/* Set user supplied ambient light zone */
809 		mutex_lock(&data->lock);
810 		ret = adp8870_read(data->client, ADP8870_CFGR, &reg_val);
811 		if (!ret) {
812 			reg_val &= ~(CFGR_BLV_MASK << CFGR_BLV_SHIFT);
813 			reg_val |= (val - 1) << CFGR_BLV_SHIFT;
814 			adp8870_write(data->client, ADP8870_CFGR, reg_val);
815 		}
816 		mutex_unlock(&data->lock);
817 	}
818 
819 	return count;
820 }
821 static DEVICE_ATTR(ambient_light_zone, 0664,
822 		adp8870_bl_ambient_light_zone_show,
823 		adp8870_bl_ambient_light_zone_store);
824 #endif
825 
826 static struct attribute *adp8870_bl_attributes[] = {
827 	&dev_attr_l5_dark_max.attr,
828 	&dev_attr_l5_dark_dim.attr,
829 	&dev_attr_l4_indoor_max.attr,
830 	&dev_attr_l4_indoor_dim.attr,
831 	&dev_attr_l3_office_max.attr,
832 	&dev_attr_l3_office_dim.attr,
833 	&dev_attr_l2_bright_max.attr,
834 	&dev_attr_l2_bright_dim.attr,
835 	&dev_attr_l1_daylight_max.attr,
836 	&dev_attr_l1_daylight_dim.attr,
837 #ifdef ADP8870_EXT_FEATURES
838 	&dev_attr_ambient_light_level.attr,
839 	&dev_attr_ambient_light_zone.attr,
840 #endif
841 	NULL
842 };
843 
844 static const struct attribute_group adp8870_bl_attr_group = {
845 	.attrs = adp8870_bl_attributes,
846 };
847 
848 static int adp8870_probe(struct i2c_client *client,
849 					const struct i2c_device_id *id)
850 {
851 	struct backlight_properties props;
852 	struct backlight_device *bl;
853 	struct adp8870_bl *data;
854 	struct adp8870_backlight_platform_data *pdata =
855 		dev_get_platdata(&client->dev);
856 	uint8_t reg_val;
857 	int ret;
858 
859 	if (!i2c_check_functionality(client->adapter,
860 					I2C_FUNC_SMBUS_BYTE_DATA)) {
861 		dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
862 		return -EIO;
863 	}
864 
865 	if (!pdata) {
866 		dev_err(&client->dev, "no platform data?\n");
867 		return -EINVAL;
868 	}
869 
870 	ret = adp8870_read(client, ADP8870_MFDVID, &reg_val);
871 	if (ret < 0)
872 		return -EIO;
873 
874 	if (ADP8870_MANID(reg_val) != ADP8870_MANUFID) {
875 		dev_err(&client->dev, "failed to probe\n");
876 		return -ENODEV;
877 	}
878 
879 	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
880 	if (data == NULL)
881 		return -ENOMEM;
882 
883 	data->revid = ADP8870_DEVID(reg_val);
884 	data->client = client;
885 	data->pdata = pdata;
886 	data->id = id->driver_data;
887 	data->current_brightness = 0;
888 	i2c_set_clientdata(client, data);
889 
890 	mutex_init(&data->lock);
891 
892 	memset(&props, 0, sizeof(props));
893 	props.type = BACKLIGHT_RAW;
894 	props.max_brightness = props.brightness = ADP8870_MAX_BRIGHTNESS;
895 	bl = devm_backlight_device_register(&client->dev,
896 				dev_driver_string(&client->dev),
897 				&client->dev, data, &adp8870_bl_ops, &props);
898 	if (IS_ERR(bl)) {
899 		dev_err(&client->dev, "failed to register backlight\n");
900 		return PTR_ERR(bl);
901 	}
902 
903 	data->bl = bl;
904 
905 	if (pdata->en_ambl_sens) {
906 		ret = sysfs_create_group(&bl->dev.kobj,
907 			&adp8870_bl_attr_group);
908 		if (ret) {
909 			dev_err(&client->dev, "failed to register sysfs\n");
910 			return ret;
911 		}
912 	}
913 
914 	ret = adp8870_bl_setup(bl);
915 	if (ret) {
916 		ret = -EIO;
917 		goto out;
918 	}
919 
920 	backlight_update_status(bl);
921 
922 	dev_info(&client->dev, "Rev.%d Backlight\n", data->revid);
923 
924 	if (pdata->num_leds)
925 		adp8870_led_probe(client);
926 
927 	return 0;
928 
929 out:
930 	if (data->pdata->en_ambl_sens)
931 		sysfs_remove_group(&data->bl->dev.kobj,
932 			&adp8870_bl_attr_group);
933 
934 	return ret;
935 }
936 
937 static int adp8870_remove(struct i2c_client *client)
938 {
939 	struct adp8870_bl *data = i2c_get_clientdata(client);
940 
941 	adp8870_clr_bits(client, ADP8870_MDCR, NSTBY);
942 
943 	if (data->led)
944 		adp8870_led_remove(client);
945 
946 	if (data->pdata->en_ambl_sens)
947 		sysfs_remove_group(&data->bl->dev.kobj,
948 			&adp8870_bl_attr_group);
949 
950 	return 0;
951 }
952 
953 #ifdef CONFIG_PM_SLEEP
954 static int adp8870_i2c_suspend(struct device *dev)
955 {
956 	struct i2c_client *client = to_i2c_client(dev);
957 
958 	adp8870_clr_bits(client, ADP8870_MDCR, NSTBY);
959 
960 	return 0;
961 }
962 
963 static int adp8870_i2c_resume(struct device *dev)
964 {
965 	struct i2c_client *client = to_i2c_client(dev);
966 
967 	adp8870_set_bits(client, ADP8870_MDCR, NSTBY | BLEN);
968 
969 	return 0;
970 }
971 #endif
972 
973 static SIMPLE_DEV_PM_OPS(adp8870_i2c_pm_ops, adp8870_i2c_suspend,
974 			adp8870_i2c_resume);
975 
976 static const struct i2c_device_id adp8870_id[] = {
977 	{ "adp8870", 0 },
978 	{ }
979 };
980 MODULE_DEVICE_TABLE(i2c, adp8870_id);
981 
982 static struct i2c_driver adp8870_driver = {
983 	.driver = {
984 		.name	= KBUILD_MODNAME,
985 		.pm	= &adp8870_i2c_pm_ops,
986 	},
987 	.probe    = adp8870_probe,
988 	.remove   = adp8870_remove,
989 	.id_table = adp8870_id,
990 };
991 
992 module_i2c_driver(adp8870_driver);
993 
994 MODULE_LICENSE("GPL v2");
995 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
996 MODULE_DESCRIPTION("ADP8870 Backlight driver");
997