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/i2c/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 	if (ret)
148 		dev_err(&client->dev, "failed to write\n");
149 
150 	return ret;
151 }
152 
153 static int adp8870_set_bits(struct i2c_client *client, int reg, uint8_t bit_mask)
154 {
155 	struct adp8870_bl *data = i2c_get_clientdata(client);
156 	uint8_t reg_val;
157 	int ret;
158 
159 	mutex_lock(&data->lock);
160 
161 	ret = adp8870_read(client, reg, &reg_val);
162 
163 	if (!ret && ((reg_val & bit_mask) != bit_mask)) {
164 		reg_val |= bit_mask;
165 		ret = adp8870_write(client, reg, reg_val);
166 	}
167 
168 	mutex_unlock(&data->lock);
169 	return ret;
170 }
171 
172 static int adp8870_clr_bits(struct i2c_client *client, int reg, uint8_t bit_mask)
173 {
174 	struct adp8870_bl *data = i2c_get_clientdata(client);
175 	uint8_t reg_val;
176 	int ret;
177 
178 	mutex_lock(&data->lock);
179 
180 	ret = adp8870_read(client, reg, &reg_val);
181 
182 	if (!ret && (reg_val & bit_mask)) {
183 		reg_val &= ~bit_mask;
184 		ret = adp8870_write(client, reg, reg_val);
185 	}
186 
187 	mutex_unlock(&data->lock);
188 	return ret;
189 }
190 
191 /*
192  * Independent sink / LED
193  */
194 #if defined(ADP8870_USE_LEDS)
195 static void adp8870_led_work(struct work_struct *work)
196 {
197 	struct adp8870_led *led = container_of(work, struct adp8870_led, work);
198 	adp8870_write(led->client, ADP8870_ISC1 + led->id - 1,
199 			 led->new_brightness >> 1);
200 }
201 
202 static void adp8870_led_set(struct led_classdev *led_cdev,
203 			   enum led_brightness value)
204 {
205 	struct adp8870_led *led;
206 
207 	led = container_of(led_cdev, struct adp8870_led, cdev);
208 	led->new_brightness = value;
209 	/*
210 	 * Use workqueue for IO since I2C operations can sleep.
211 	 */
212 	schedule_work(&led->work);
213 }
214 
215 static int adp8870_led_setup(struct adp8870_led *led)
216 {
217 	struct i2c_client *client = led->client;
218 	int ret = 0;
219 
220 	ret = adp8870_write(client, ADP8870_ISC1 + led->id - 1, 0);
221 	if (ret)
222 		return ret;
223 
224 	ret = adp8870_set_bits(client, ADP8870_ISCC, 1 << (led->id - 1));
225 	if (ret)
226 		return ret;
227 
228 	if (led->id > 4)
229 		ret = adp8870_set_bits(client, ADP8870_ISCT1,
230 				(led->flags & 0x3) << ((led->id - 5) * 2));
231 	else
232 		ret = adp8870_set_bits(client, ADP8870_ISCT2,
233 				(led->flags & 0x3) << ((led->id - 1) * 2));
234 
235 	return ret;
236 }
237 
238 static int adp8870_led_probe(struct i2c_client *client)
239 {
240 	struct adp8870_backlight_platform_data *pdata =
241 		dev_get_platdata(&client->dev);
242 	struct adp8870_bl *data = i2c_get_clientdata(client);
243 	struct adp8870_led *led, *led_dat;
244 	struct led_info *cur_led;
245 	int ret, i;
246 
247 	led = devm_kzalloc(&client->dev, pdata->num_leds * sizeof(*led),
248 				GFP_KERNEL);
249 	if (led == NULL) {
250 		dev_err(&client->dev, "failed to alloc memory\n");
251 		return -ENOMEM;
252 	}
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 	if (bl->props.power != FB_BLANK_UNBLANK)
405 		brightness = 0;
406 
407 	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
408 		brightness = 0;
409 
410 	return adp8870_bl_set(bl, brightness);
411 }
412 
413 static int adp8870_bl_get_brightness(struct backlight_device *bl)
414 {
415 	struct adp8870_bl *data = bl_get_data(bl);
416 
417 	return data->current_brightness;
418 }
419 
420 static const struct backlight_ops adp8870_bl_ops = {
421 	.update_status	= adp8870_bl_update_status,
422 	.get_brightness	= adp8870_bl_get_brightness,
423 };
424 
425 static int adp8870_bl_setup(struct backlight_device *bl)
426 {
427 	struct adp8870_bl *data = bl_get_data(bl);
428 	struct i2c_client *client = data->client;
429 	struct adp8870_backlight_platform_data *pdata = data->pdata;
430 	int ret = 0;
431 
432 	ret = adp8870_write(client, ADP8870_BLSEL, ~pdata->bl_led_assign);
433 	if (ret)
434 		return ret;
435 
436 	ret = adp8870_write(client, ADP8870_PWMLED, pdata->pwm_assign);
437 	if (ret)
438 		return ret;
439 
440 	ret = adp8870_write(client, ADP8870_BLMX1, pdata->l1_daylight_max);
441 	if (ret)
442 		return ret;
443 
444 	ret = adp8870_write(client, ADP8870_BLDM1, pdata->l1_daylight_dim);
445 	if (ret)
446 		return ret;
447 
448 	if (pdata->en_ambl_sens) {
449 		data->cached_daylight_max = pdata->l1_daylight_max;
450 		ret = adp8870_write(client, ADP8870_BLMX2,
451 						pdata->l2_bright_max);
452 		if (ret)
453 			return ret;
454 		ret = adp8870_write(client, ADP8870_BLDM2,
455 						pdata->l2_bright_dim);
456 		if (ret)
457 			return ret;
458 
459 		ret = adp8870_write(client, ADP8870_BLMX3,
460 						pdata->l3_office_max);
461 		if (ret)
462 			return ret;
463 		ret = adp8870_write(client, ADP8870_BLDM3,
464 						pdata->l3_office_dim);
465 		if (ret)
466 			return ret;
467 
468 		ret = adp8870_write(client, ADP8870_BLMX4,
469 						pdata->l4_indoor_max);
470 		if (ret)
471 			return ret;
472 
473 		ret = adp8870_write(client, ADP8870_BLDM4,
474 						pdata->l4_indor_dim);
475 		if (ret)
476 			return ret;
477 
478 		ret = adp8870_write(client, ADP8870_BLMX5,
479 						pdata->l5_dark_max);
480 		if (ret)
481 			return ret;
482 
483 		ret = adp8870_write(client, ADP8870_BLDM5,
484 						pdata->l5_dark_dim);
485 		if (ret)
486 			return ret;
487 
488 		ret = adp8870_write(client, ADP8870_L2TRP, pdata->l2_trip);
489 		if (ret)
490 			return ret;
491 
492 		ret = adp8870_write(client, ADP8870_L2HYS, pdata->l2_hyst);
493 		if (ret)
494 			return ret;
495 
496 		ret = adp8870_write(client, ADP8870_L3TRP, pdata->l3_trip);
497 		if (ret)
498 			return ret;
499 
500 		ret = adp8870_write(client, ADP8870_L3HYS, pdata->l3_hyst);
501 		if (ret)
502 			return ret;
503 
504 		ret = adp8870_write(client, ADP8870_L4TRP, pdata->l4_trip);
505 		if (ret)
506 			return ret;
507 
508 		ret = adp8870_write(client, ADP8870_L4HYS, pdata->l4_hyst);
509 		if (ret)
510 			return ret;
511 
512 		ret = adp8870_write(client, ADP8870_L5TRP, pdata->l5_trip);
513 		if (ret)
514 			return ret;
515 
516 		ret = adp8870_write(client, ADP8870_L5HYS, pdata->l5_hyst);
517 		if (ret)
518 			return ret;
519 
520 		ret = adp8870_write(client, ADP8870_ALS1_EN, L5_EN | L4_EN |
521 						L3_EN | L2_EN);
522 		if (ret)
523 			return ret;
524 
525 		ret = adp8870_write(client, ADP8870_CMP_CTL,
526 			ALS_CMPR_CFG_VAL(pdata->abml_filt));
527 		if (ret)
528 			return ret;
529 	}
530 
531 	ret = adp8870_write(client, ADP8870_CFGR,
532 			BL_CFGR_VAL(pdata->bl_fade_law, 0));
533 	if (ret)
534 		return ret;
535 
536 	ret = adp8870_write(client, ADP8870_BLFR, FADE_VAL(pdata->bl_fade_in,
537 			pdata->bl_fade_out));
538 	if (ret)
539 		return ret;
540 	/*
541 	 * ADP8870 Rev0 requires GDWN_DIS bit set
542 	 */
543 
544 	ret = adp8870_set_bits(client, ADP8870_MDCR, BLEN | DIM_EN | NSTBY |
545 			(data->revid == 0 ? GDWN_DIS : 0));
546 
547 	return ret;
548 }
549 
550 static ssize_t adp8870_show(struct device *dev, char *buf, int reg)
551 {
552 	struct adp8870_bl *data = dev_get_drvdata(dev);
553 	int error;
554 	uint8_t reg_val;
555 
556 	mutex_lock(&data->lock);
557 	error = adp8870_read(data->client, reg, &reg_val);
558 	mutex_unlock(&data->lock);
559 
560 	if (error < 0)
561 		return error;
562 
563 	return sprintf(buf, "%u\n", reg_val);
564 }
565 
566 static ssize_t adp8870_store(struct device *dev, const char *buf,
567 			 size_t count, int reg)
568 {
569 	struct adp8870_bl *data = dev_get_drvdata(dev);
570 	unsigned long val;
571 	int ret;
572 
573 	ret = kstrtoul(buf, 10, &val);
574 	if (ret)
575 		return ret;
576 
577 	mutex_lock(&data->lock);
578 	adp8870_write(data->client, reg, val);
579 	mutex_unlock(&data->lock);
580 
581 	return count;
582 }
583 
584 static ssize_t adp8870_bl_l5_dark_max_show(struct device *dev,
585 		struct device_attribute *attr, char *buf)
586 {
587 	return adp8870_show(dev, buf, ADP8870_BLMX5);
588 }
589 
590 static ssize_t adp8870_bl_l5_dark_max_store(struct device *dev,
591 		struct device_attribute *attr, const char *buf, size_t count)
592 {
593 	return adp8870_store(dev, buf, count, ADP8870_BLMX5);
594 }
595 static DEVICE_ATTR(l5_dark_max, 0664, adp8870_bl_l5_dark_max_show,
596 			adp8870_bl_l5_dark_max_store);
597 
598 
599 static ssize_t adp8870_bl_l4_indoor_max_show(struct device *dev,
600 		struct device_attribute *attr, char *buf)
601 {
602 	return adp8870_show(dev, buf, ADP8870_BLMX4);
603 }
604 
605 static ssize_t adp8870_bl_l4_indoor_max_store(struct device *dev,
606 		struct device_attribute *attr, const char *buf, size_t count)
607 {
608 	return adp8870_store(dev, buf, count, ADP8870_BLMX4);
609 }
610 static DEVICE_ATTR(l4_indoor_max, 0664, adp8870_bl_l4_indoor_max_show,
611 			adp8870_bl_l4_indoor_max_store);
612 
613 
614 static ssize_t adp8870_bl_l3_office_max_show(struct device *dev,
615 				     struct device_attribute *attr, char *buf)
616 {
617 	return adp8870_show(dev, buf, ADP8870_BLMX3);
618 }
619 
620 static ssize_t adp8870_bl_l3_office_max_store(struct device *dev,
621 		struct device_attribute *attr, const char *buf, size_t count)
622 {
623 	return adp8870_store(dev, buf, count, ADP8870_BLMX3);
624 }
625 
626 static DEVICE_ATTR(l3_office_max, 0664, adp8870_bl_l3_office_max_show,
627 			adp8870_bl_l3_office_max_store);
628 
629 static ssize_t adp8870_bl_l2_bright_max_show(struct device *dev,
630 		struct device_attribute *attr, char *buf)
631 {
632 	return adp8870_show(dev, buf, ADP8870_BLMX2);
633 }
634 
635 static ssize_t adp8870_bl_l2_bright_max_store(struct device *dev,
636 		struct device_attribute *attr, const char *buf, size_t count)
637 {
638 	return adp8870_store(dev, buf, count, ADP8870_BLMX2);
639 }
640 static DEVICE_ATTR(l2_bright_max, 0664, adp8870_bl_l2_bright_max_show,
641 			adp8870_bl_l2_bright_max_store);
642 
643 static ssize_t adp8870_bl_l1_daylight_max_show(struct device *dev,
644 			struct device_attribute *attr, char *buf)
645 {
646 	return adp8870_show(dev, buf, ADP8870_BLMX1);
647 }
648 
649 static ssize_t adp8870_bl_l1_daylight_max_store(struct device *dev,
650 		struct device_attribute *attr, const char *buf, size_t count)
651 {
652 	struct adp8870_bl *data = dev_get_drvdata(dev);
653 	int ret = kstrtoul(buf, 10, &data->cached_daylight_max);
654 	if (ret)
655 		return ret;
656 
657 	return adp8870_store(dev, buf, count, ADP8870_BLMX1);
658 }
659 static DEVICE_ATTR(l1_daylight_max, 0664, adp8870_bl_l1_daylight_max_show,
660 			adp8870_bl_l1_daylight_max_store);
661 
662 static ssize_t adp8870_bl_l5_dark_dim_show(struct device *dev,
663 			struct device_attribute *attr, char *buf)
664 {
665 	return adp8870_show(dev, buf, ADP8870_BLDM5);
666 }
667 
668 static ssize_t adp8870_bl_l5_dark_dim_store(struct device *dev,
669 				     struct device_attribute *attr,
670 				     const char *buf, size_t count)
671 {
672 	return adp8870_store(dev, buf, count, ADP8870_BLDM5);
673 }
674 static DEVICE_ATTR(l5_dark_dim, 0664, adp8870_bl_l5_dark_dim_show,
675 			adp8870_bl_l5_dark_dim_store);
676 
677 static ssize_t adp8870_bl_l4_indoor_dim_show(struct device *dev,
678 			struct device_attribute *attr, char *buf)
679 {
680 	return adp8870_show(dev, buf, ADP8870_BLDM4);
681 }
682 
683 static ssize_t adp8870_bl_l4_indoor_dim_store(struct device *dev,
684 				     struct device_attribute *attr,
685 				     const char *buf, size_t count)
686 {
687 	return adp8870_store(dev, buf, count, ADP8870_BLDM4);
688 }
689 static DEVICE_ATTR(l4_indoor_dim, 0664, adp8870_bl_l4_indoor_dim_show,
690 			adp8870_bl_l4_indoor_dim_store);
691 
692 
693 static ssize_t adp8870_bl_l3_office_dim_show(struct device *dev,
694 			struct device_attribute *attr, char *buf)
695 {
696 	return adp8870_show(dev, buf, ADP8870_BLDM3);
697 }
698 
699 static ssize_t adp8870_bl_l3_office_dim_store(struct device *dev,
700 				     struct device_attribute *attr,
701 				     const char *buf, size_t count)
702 {
703 	return adp8870_store(dev, buf, count, ADP8870_BLDM3);
704 }
705 static DEVICE_ATTR(l3_office_dim, 0664, adp8870_bl_l3_office_dim_show,
706 			adp8870_bl_l3_office_dim_store);
707 
708 static ssize_t adp8870_bl_l2_bright_dim_show(struct device *dev,
709 			struct device_attribute *attr, char *buf)
710 {
711 	return adp8870_show(dev, buf, ADP8870_BLDM2);
712 }
713 
714 static ssize_t adp8870_bl_l2_bright_dim_store(struct device *dev,
715 				     struct device_attribute *attr,
716 				     const char *buf, size_t count)
717 {
718 	return adp8870_store(dev, buf, count, ADP8870_BLDM2);
719 }
720 static DEVICE_ATTR(l2_bright_dim, 0664, adp8870_bl_l2_bright_dim_show,
721 			adp8870_bl_l2_bright_dim_store);
722 
723 static ssize_t adp8870_bl_l1_daylight_dim_show(struct device *dev,
724 				     struct device_attribute *attr, char *buf)
725 {
726 	return adp8870_show(dev, buf, ADP8870_BLDM1);
727 }
728 
729 static ssize_t adp8870_bl_l1_daylight_dim_store(struct device *dev,
730 				     struct device_attribute *attr,
731 				     const char *buf, size_t count)
732 {
733 	return adp8870_store(dev, buf, count, ADP8870_BLDM1);
734 }
735 static DEVICE_ATTR(l1_daylight_dim, 0664, adp8870_bl_l1_daylight_dim_show,
736 			adp8870_bl_l1_daylight_dim_store);
737 
738 #ifdef ADP8870_EXT_FEATURES
739 static ssize_t adp8870_bl_ambient_light_level_show(struct device *dev,
740 				     struct device_attribute *attr, char *buf)
741 {
742 	struct adp8870_bl *data = dev_get_drvdata(dev);
743 	int error;
744 	uint8_t reg_val;
745 	uint16_t ret_val;
746 
747 	mutex_lock(&data->lock);
748 	error = adp8870_read(data->client, ADP8870_PH1LEVL, &reg_val);
749 	if (error < 0) {
750 		mutex_unlock(&data->lock);
751 		return error;
752 	}
753 	ret_val = reg_val;
754 	error = adp8870_read(data->client, ADP8870_PH1LEVH, &reg_val);
755 	mutex_unlock(&data->lock);
756 
757 	if (error < 0)
758 		return error;
759 
760 	/* Return 13-bit conversion value for the first light sensor */
761 	ret_val += (reg_val & 0x1F) << 8;
762 
763 	return sprintf(buf, "%u\n", ret_val);
764 }
765 static DEVICE_ATTR(ambient_light_level, 0444,
766 		adp8870_bl_ambient_light_level_show, NULL);
767 
768 static ssize_t adp8870_bl_ambient_light_zone_show(struct device *dev,
769 				     struct device_attribute *attr, char *buf)
770 {
771 	struct adp8870_bl *data = dev_get_drvdata(dev);
772 	int error;
773 	uint8_t reg_val;
774 
775 	mutex_lock(&data->lock);
776 	error = adp8870_read(data->client, ADP8870_CFGR, &reg_val);
777 	mutex_unlock(&data->lock);
778 
779 	if (error < 0)
780 		return error;
781 
782 	return sprintf(buf, "%u\n",
783 		((reg_val >> CFGR_BLV_SHIFT) & CFGR_BLV_MASK) + 1);
784 }
785 
786 static ssize_t adp8870_bl_ambient_light_zone_store(struct device *dev,
787 				     struct device_attribute *attr,
788 				     const char *buf, size_t count)
789 {
790 	struct adp8870_bl *data = dev_get_drvdata(dev);
791 	unsigned long val;
792 	uint8_t reg_val;
793 	int ret;
794 
795 	ret = kstrtoul(buf, 10, &val);
796 	if (ret)
797 		return ret;
798 
799 	if (val == 0) {
800 		/* Enable automatic ambient light sensing */
801 		adp8870_set_bits(data->client, ADP8870_MDCR, CMP_AUTOEN);
802 	} else if ((val > 0) && (val < 6)) {
803 		/* Disable automatic ambient light sensing */
804 		adp8870_clr_bits(data->client, ADP8870_MDCR, CMP_AUTOEN);
805 
806 		/* Set user supplied ambient light zone */
807 		mutex_lock(&data->lock);
808 		adp8870_read(data->client, ADP8870_CFGR, &reg_val);
809 		reg_val &= ~(CFGR_BLV_MASK << CFGR_BLV_SHIFT);
810 		reg_val |= (val - 1) << CFGR_BLV_SHIFT;
811 		adp8870_write(data->client, ADP8870_CFGR, reg_val);
812 		mutex_unlock(&data->lock);
813 	}
814 
815 	return count;
816 }
817 static DEVICE_ATTR(ambient_light_zone, 0664,
818 		adp8870_bl_ambient_light_zone_show,
819 		adp8870_bl_ambient_light_zone_store);
820 #endif
821 
822 static struct attribute *adp8870_bl_attributes[] = {
823 	&dev_attr_l5_dark_max.attr,
824 	&dev_attr_l5_dark_dim.attr,
825 	&dev_attr_l4_indoor_max.attr,
826 	&dev_attr_l4_indoor_dim.attr,
827 	&dev_attr_l3_office_max.attr,
828 	&dev_attr_l3_office_dim.attr,
829 	&dev_attr_l2_bright_max.attr,
830 	&dev_attr_l2_bright_dim.attr,
831 	&dev_attr_l1_daylight_max.attr,
832 	&dev_attr_l1_daylight_dim.attr,
833 #ifdef ADP8870_EXT_FEATURES
834 	&dev_attr_ambient_light_level.attr,
835 	&dev_attr_ambient_light_zone.attr,
836 #endif
837 	NULL
838 };
839 
840 static const struct attribute_group adp8870_bl_attr_group = {
841 	.attrs = adp8870_bl_attributes,
842 };
843 
844 static int adp8870_probe(struct i2c_client *client,
845 					const struct i2c_device_id *id)
846 {
847 	struct backlight_properties props;
848 	struct backlight_device *bl;
849 	struct adp8870_bl *data;
850 	struct adp8870_backlight_platform_data *pdata =
851 		dev_get_platdata(&client->dev);
852 	uint8_t reg_val;
853 	int ret;
854 
855 	if (!i2c_check_functionality(client->adapter,
856 					I2C_FUNC_SMBUS_BYTE_DATA)) {
857 		dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
858 		return -EIO;
859 	}
860 
861 	if (!pdata) {
862 		dev_err(&client->dev, "no platform data?\n");
863 		return -EINVAL;
864 	}
865 
866 	ret = adp8870_read(client, ADP8870_MFDVID, &reg_val);
867 	if (ret < 0)
868 		return -EIO;
869 
870 	if (ADP8870_MANID(reg_val) != ADP8870_MANUFID) {
871 		dev_err(&client->dev, "failed to probe\n");
872 		return -ENODEV;
873 	}
874 
875 	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
876 	if (data == NULL)
877 		return -ENOMEM;
878 
879 	data->revid = ADP8870_DEVID(reg_val);
880 	data->client = client;
881 	data->pdata = pdata;
882 	data->id = id->driver_data;
883 	data->current_brightness = 0;
884 	i2c_set_clientdata(client, data);
885 
886 	mutex_init(&data->lock);
887 
888 	memset(&props, 0, sizeof(props));
889 	props.type = BACKLIGHT_RAW;
890 	props.max_brightness = props.brightness = ADP8870_MAX_BRIGHTNESS;
891 	bl = devm_backlight_device_register(&client->dev,
892 				dev_driver_string(&client->dev),
893 				&client->dev, data, &adp8870_bl_ops, &props);
894 	if (IS_ERR(bl)) {
895 		dev_err(&client->dev, "failed to register backlight\n");
896 		return PTR_ERR(bl);
897 	}
898 
899 	data->bl = bl;
900 
901 	if (pdata->en_ambl_sens) {
902 		ret = sysfs_create_group(&bl->dev.kobj,
903 			&adp8870_bl_attr_group);
904 		if (ret) {
905 			dev_err(&client->dev, "failed to register sysfs\n");
906 			return ret;
907 		}
908 	}
909 
910 	ret = adp8870_bl_setup(bl);
911 	if (ret) {
912 		ret = -EIO;
913 		goto out;
914 	}
915 
916 	backlight_update_status(bl);
917 
918 	dev_info(&client->dev, "Rev.%d Backlight\n", data->revid);
919 
920 	if (pdata->num_leds)
921 		adp8870_led_probe(client);
922 
923 	return 0;
924 
925 out:
926 	if (data->pdata->en_ambl_sens)
927 		sysfs_remove_group(&data->bl->dev.kobj,
928 			&adp8870_bl_attr_group);
929 
930 	return ret;
931 }
932 
933 static int adp8870_remove(struct i2c_client *client)
934 {
935 	struct adp8870_bl *data = i2c_get_clientdata(client);
936 
937 	adp8870_clr_bits(client, ADP8870_MDCR, NSTBY);
938 
939 	if (data->led)
940 		adp8870_led_remove(client);
941 
942 	if (data->pdata->en_ambl_sens)
943 		sysfs_remove_group(&data->bl->dev.kobj,
944 			&adp8870_bl_attr_group);
945 
946 	return 0;
947 }
948 
949 #ifdef CONFIG_PM_SLEEP
950 static int adp8870_i2c_suspend(struct device *dev)
951 {
952 	struct i2c_client *client = to_i2c_client(dev);
953 
954 	adp8870_clr_bits(client, ADP8870_MDCR, NSTBY);
955 
956 	return 0;
957 }
958 
959 static int adp8870_i2c_resume(struct device *dev)
960 {
961 	struct i2c_client *client = to_i2c_client(dev);
962 
963 	adp8870_set_bits(client, ADP8870_MDCR, NSTBY | BLEN);
964 
965 	return 0;
966 }
967 #endif
968 
969 static SIMPLE_DEV_PM_OPS(adp8870_i2c_pm_ops, adp8870_i2c_suspend,
970 			adp8870_i2c_resume);
971 
972 static const struct i2c_device_id adp8870_id[] = {
973 	{ "adp8870", 0 },
974 	{ }
975 };
976 MODULE_DEVICE_TABLE(i2c, adp8870_id);
977 
978 static struct i2c_driver adp8870_driver = {
979 	.driver = {
980 		.name	= KBUILD_MODNAME,
981 		.pm	= &adp8870_i2c_pm_ops,
982 	},
983 	.probe    = adp8870_probe,
984 	.remove   = adp8870_remove,
985 	.id_table = adp8870_id,
986 };
987 
988 module_i2c_driver(adp8870_driver);
989 
990 MODULE_LICENSE("GPL v2");
991 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
992 MODULE_DESCRIPTION("ADP8870 Backlight driver");
993 MODULE_ALIAS("i2c:adp8870-backlight");
994