1 /*
2  * Backlight driver for Analog Devices ADP8860 Backlight Devices
3  *
4  * Copyright 2009-2010 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/slab.h>
19 #include <linux/workqueue.h>
20 
21 #include <linux/i2c/adp8860.h>
22 #define ADP8860_EXT_FEATURES
23 #define ADP8860_USE_LEDS
24 
25 #define ADP8860_MFDVID 0x00 /* Manufacturer and device ID */
26 #define ADP8860_MDCR 0x01 /* Device mode and status */
27 #define ADP8860_MDCR2 0x02 /* Device mode and Status Register 2 */
28 #define ADP8860_INTR_EN 0x03 /* Interrupts enable */
29 #define ADP8860_CFGR 0x04 /* Configuration register */
30 #define ADP8860_BLSEN 0x05 /* Sink enable backlight or independent */
31 #define ADP8860_BLOFF 0x06 /* Backlight off timeout */
32 #define ADP8860_BLDIM 0x07 /* Backlight dim timeout */
33 #define ADP8860_BLFR 0x08 /* Backlight fade in and out rates */
34 #define ADP8860_BLMX1 0x09 /* Backlight (Brightness Level 1-daylight) maximum current */
35 #define ADP8860_BLDM1 0x0A /* Backlight (Brightness Level 1-daylight) dim current */
36 #define ADP8860_BLMX2 0x0B /* Backlight (Brightness Level 2-office) maximum current */
37 #define ADP8860_BLDM2 0x0C /* Backlight (Brightness Level 2-office) dim current */
38 #define ADP8860_BLMX3 0x0D /* Backlight (Brightness Level 3-dark) maximum current */
39 #define ADP8860_BLDM3 0x0E /* Backlight (Brightness Level 3-dark) dim current */
40 #define ADP8860_ISCFR 0x0F /* Independent sink current fade control register */
41 #define ADP8860_ISCC 0x10 /* Independent sink current control register */
42 #define ADP8860_ISCT1 0x11 /* Independent Sink Current Timer Register LED[7:5] */
43 #define ADP8860_ISCT2 0x12 /* Independent Sink Current Timer Register LED[4:1] */
44 #define ADP8860_ISCF 0x13 /* Independent sink current fade register */
45 #define ADP8860_ISC7 0x14 /* Independent Sink Current LED7 */
46 #define ADP8860_ISC6 0x15 /* Independent Sink Current LED6 */
47 #define ADP8860_ISC5 0x16 /* Independent Sink Current LED5 */
48 #define ADP8860_ISC4 0x17 /* Independent Sink Current LED4 */
49 #define ADP8860_ISC3 0x18 /* Independent Sink Current LED3 */
50 #define ADP8860_ISC2 0x19 /* Independent Sink Current LED2 */
51 #define ADP8860_ISC1 0x1A /* Independent Sink Current LED1 */
52 #define ADP8860_CCFG 0x1B /* Comparator configuration */
53 #define ADP8860_CCFG2 0x1C /* Second comparator configuration */
54 #define ADP8860_L2_TRP 0x1D /* L2 comparator reference */
55 #define ADP8860_L2_HYS 0x1E /* L2 hysteresis */
56 #define ADP8860_L3_TRP 0x1F /* L3 comparator reference */
57 #define ADP8860_L3_HYS 0x20 /* L3 hysteresis */
58 #define ADP8860_PH1LEVL 0x21 /* First phototransistor ambient light level-low byte register */
59 #define ADP8860_PH1LEVH 0x22 /* First phototransistor ambient light level-high byte register */
60 #define ADP8860_PH2LEVL 0x23 /* Second phototransistor ambient light level-low byte register */
61 #define ADP8860_PH2LEVH 0x24 /* Second phototransistor ambient light level-high byte register */
62 
63 #define ADP8860_MANUFID		0x0  /* Analog Devices ADP8860 Manufacturer ID */
64 #define ADP8861_MANUFID		0x4  /* Analog Devices ADP8861 Manufacturer ID */
65 #define ADP8863_MANUFID		0x2  /* Analog Devices ADP8863 Manufacturer ID */
66 
67 #define ADP8860_DEVID(x)	((x) & 0xF)
68 #define ADP8860_MANID(x)	((x) >> 4)
69 
70 /* MDCR Device mode and status */
71 #define INT_CFG			(1 << 6)
72 #define NSTBY			(1 << 5)
73 #define DIM_EN			(1 << 4)
74 #define GDWN_DIS		(1 << 3)
75 #define SIS_EN			(1 << 2)
76 #define CMP_AUTOEN		(1 << 1)
77 #define BLEN			(1 << 0)
78 
79 /* ADP8860_CCFG Main ALS comparator level enable */
80 #define L3_EN			(1 << 1)
81 #define L2_EN			(1 << 0)
82 
83 #define CFGR_BLV_SHIFT		3
84 #define CFGR_BLV_MASK		0x3
85 #define ADP8860_FLAG_LED_MASK	0xFF
86 
87 #define FADE_VAL(in, out)	((0xF & (in)) | ((0xF & (out)) << 4))
88 #define BL_CFGR_VAL(law, blv)	((((blv) & CFGR_BLV_MASK) << CFGR_BLV_SHIFT) | ((0x3 & (law)) << 1))
89 #define ALS_CCFG_VAL(filt)	((0x7 & filt) << 5)
90 
91 enum {
92 	adp8860,
93 	adp8861,
94 	adp8863
95 };
96 
97 struct adp8860_led {
98 	struct led_classdev	cdev;
99 	struct work_struct	work;
100 	struct i2c_client	*client;
101 	enum led_brightness	new_brightness;
102 	int			id;
103 	int			flags;
104 };
105 
106 struct adp8860_bl {
107 	struct i2c_client *client;
108 	struct backlight_device *bl;
109 	struct adp8860_led *led;
110 	struct adp8860_backlight_platform_data *pdata;
111 	struct mutex lock;
112 	unsigned long cached_daylight_max;
113 	int id;
114 	int revid;
115 	int current_brightness;
116 	unsigned en_ambl_sens:1;
117 	unsigned gdwn_dis:1;
118 };
119 
120 static int adp8860_read(struct i2c_client *client, int reg, uint8_t *val)
121 {
122 	int ret;
123 
124 	ret = i2c_smbus_read_byte_data(client, reg);
125 	if (ret < 0) {
126 		dev_err(&client->dev, "failed reading at 0x%02x\n", reg);
127 		return ret;
128 	}
129 
130 	*val = (uint8_t)ret;
131 	return 0;
132 }
133 
134 static int adp8860_write(struct i2c_client *client, u8 reg, u8 val)
135 {
136 	return i2c_smbus_write_byte_data(client, reg, val);
137 }
138 
139 static int adp8860_set_bits(struct i2c_client *client, int reg, uint8_t bit_mask)
140 {
141 	struct adp8860_bl *data = i2c_get_clientdata(client);
142 	uint8_t reg_val;
143 	int ret;
144 
145 	mutex_lock(&data->lock);
146 
147 	ret = adp8860_read(client, reg, &reg_val);
148 
149 	if (!ret && ((reg_val & bit_mask) != bit_mask)) {
150 		reg_val |= bit_mask;
151 		ret = adp8860_write(client, reg, reg_val);
152 	}
153 
154 	mutex_unlock(&data->lock);
155 	return ret;
156 }
157 
158 static int adp8860_clr_bits(struct i2c_client *client, int reg, uint8_t bit_mask)
159 {
160 	struct adp8860_bl *data = i2c_get_clientdata(client);
161 	uint8_t reg_val;
162 	int ret;
163 
164 	mutex_lock(&data->lock);
165 
166 	ret = adp8860_read(client, reg, &reg_val);
167 
168 	if (!ret && (reg_val & bit_mask)) {
169 		reg_val &= ~bit_mask;
170 		ret = adp8860_write(client, reg, reg_val);
171 	}
172 
173 	mutex_unlock(&data->lock);
174 	return ret;
175 }
176 
177 /*
178  * Independent sink / LED
179  */
180 #if defined(ADP8860_USE_LEDS)
181 static void adp8860_led_work(struct work_struct *work)
182 {
183 	struct adp8860_led *led = container_of(work, struct adp8860_led, work);
184 
185 	adp8860_write(led->client, ADP8860_ISC1 - led->id + 1,
186 			 led->new_brightness >> 1);
187 }
188 
189 static void adp8860_led_set(struct led_classdev *led_cdev,
190 			   enum led_brightness value)
191 {
192 	struct adp8860_led *led;
193 
194 	led = container_of(led_cdev, struct adp8860_led, cdev);
195 	led->new_brightness = value;
196 	schedule_work(&led->work);
197 }
198 
199 static int adp8860_led_setup(struct adp8860_led *led)
200 {
201 	struct i2c_client *client = led->client;
202 	int ret = 0;
203 
204 	ret = adp8860_write(client, ADP8860_ISC1 - led->id + 1, 0);
205 	ret |= adp8860_set_bits(client, ADP8860_ISCC, 1 << (led->id - 1));
206 
207 	if (led->id > 4)
208 		ret |= adp8860_set_bits(client, ADP8860_ISCT1,
209 				(led->flags & 0x3) << ((led->id - 5) * 2));
210 	else
211 		ret |= adp8860_set_bits(client, ADP8860_ISCT2,
212 				(led->flags & 0x3) << ((led->id - 1) * 2));
213 
214 	return ret;
215 }
216 
217 static int adp8860_led_probe(struct i2c_client *client)
218 {
219 	struct adp8860_backlight_platform_data *pdata =
220 		dev_get_platdata(&client->dev);
221 	struct adp8860_bl *data = i2c_get_clientdata(client);
222 	struct adp8860_led *led, *led_dat;
223 	struct led_info *cur_led;
224 	int ret, i;
225 
226 	led = devm_kzalloc(&client->dev, sizeof(*led) * pdata->num_leds,
227 				GFP_KERNEL);
228 	if (led == NULL)
229 		return -ENOMEM;
230 
231 	ret = adp8860_write(client, ADP8860_ISCFR, pdata->led_fade_law);
232 	ret = adp8860_write(client, ADP8860_ISCT1,
233 			(pdata->led_on_time & 0x3) << 6);
234 	ret |= adp8860_write(client, ADP8860_ISCF,
235 			FADE_VAL(pdata->led_fade_in, pdata->led_fade_out));
236 
237 	if (ret) {
238 		dev_err(&client->dev, "failed to write\n");
239 		return ret;
240 	}
241 
242 	for (i = 0; i < pdata->num_leds; ++i) {
243 		cur_led = &pdata->leds[i];
244 		led_dat = &led[i];
245 
246 		led_dat->id = cur_led->flags & ADP8860_FLAG_LED_MASK;
247 
248 		if (led_dat->id > 7 || led_dat->id < 1) {
249 			dev_err(&client->dev, "Invalid LED ID %d\n",
250 				led_dat->id);
251 			ret = -EINVAL;
252 			goto err;
253 		}
254 
255 		if (pdata->bl_led_assign & (1 << (led_dat->id - 1))) {
256 			dev_err(&client->dev, "LED %d used by Backlight\n",
257 				led_dat->id);
258 			ret = -EBUSY;
259 			goto err;
260 		}
261 
262 		led_dat->cdev.name = cur_led->name;
263 		led_dat->cdev.default_trigger = cur_led->default_trigger;
264 		led_dat->cdev.brightness_set = adp8860_led_set;
265 		led_dat->cdev.brightness = LED_OFF;
266 		led_dat->flags = cur_led->flags >> FLAG_OFFT_SHIFT;
267 		led_dat->client = client;
268 		led_dat->new_brightness = LED_OFF;
269 		INIT_WORK(&led_dat->work, adp8860_led_work);
270 
271 		ret = led_classdev_register(&client->dev, &led_dat->cdev);
272 		if (ret) {
273 			dev_err(&client->dev, "failed to register LED %d\n",
274 				led_dat->id);
275 			goto err;
276 		}
277 
278 		ret = adp8860_led_setup(led_dat);
279 		if (ret) {
280 			dev_err(&client->dev, "failed to write\n");
281 			i++;
282 			goto err;
283 		}
284 	}
285 
286 	data->led = led;
287 
288 	return 0;
289 
290  err:
291 	for (i = i - 1; i >= 0; --i) {
292 		led_classdev_unregister(&led[i].cdev);
293 		cancel_work_sync(&led[i].work);
294 	}
295 
296 	return ret;
297 }
298 
299 static int adp8860_led_remove(struct i2c_client *client)
300 {
301 	struct adp8860_backlight_platform_data *pdata =
302 		dev_get_platdata(&client->dev);
303 	struct adp8860_bl *data = i2c_get_clientdata(client);
304 	int i;
305 
306 	for (i = 0; i < pdata->num_leds; i++) {
307 		led_classdev_unregister(&data->led[i].cdev);
308 		cancel_work_sync(&data->led[i].work);
309 	}
310 
311 	return 0;
312 }
313 #else
314 static int adp8860_led_probe(struct i2c_client *client)
315 {
316 	return 0;
317 }
318 
319 static int adp8860_led_remove(struct i2c_client *client)
320 {
321 	return 0;
322 }
323 #endif
324 
325 static int adp8860_bl_set(struct backlight_device *bl, int brightness)
326 {
327 	struct adp8860_bl *data = bl_get_data(bl);
328 	struct i2c_client *client = data->client;
329 	int ret = 0;
330 
331 	if (data->en_ambl_sens) {
332 		if ((brightness > 0) && (brightness < ADP8860_MAX_BRIGHTNESS)) {
333 			/* Disable Ambient Light auto adjust */
334 			ret |= adp8860_clr_bits(client, ADP8860_MDCR,
335 					CMP_AUTOEN);
336 			ret |= adp8860_write(client, ADP8860_BLMX1, brightness);
337 		} else {
338 			/*
339 			 * MAX_BRIGHTNESS -> Enable Ambient Light auto adjust
340 			 * restore daylight l1 sysfs brightness
341 			 */
342 			ret |= adp8860_write(client, ADP8860_BLMX1,
343 					 data->cached_daylight_max);
344 			ret |= adp8860_set_bits(client, ADP8860_MDCR,
345 					 CMP_AUTOEN);
346 		}
347 	} else
348 		ret |= adp8860_write(client, ADP8860_BLMX1, brightness);
349 
350 	if (data->current_brightness && brightness == 0)
351 		ret |= adp8860_set_bits(client,
352 				ADP8860_MDCR, DIM_EN);
353 	else if (data->current_brightness == 0 && brightness)
354 		ret |= adp8860_clr_bits(client,
355 				ADP8860_MDCR, DIM_EN);
356 
357 	if (!ret)
358 		data->current_brightness = brightness;
359 
360 	return ret;
361 }
362 
363 static int adp8860_bl_update_status(struct backlight_device *bl)
364 {
365 	int brightness = bl->props.brightness;
366 
367 	if (bl->props.power != FB_BLANK_UNBLANK)
368 		brightness = 0;
369 
370 	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
371 		brightness = 0;
372 
373 	return adp8860_bl_set(bl, brightness);
374 }
375 
376 static int adp8860_bl_get_brightness(struct backlight_device *bl)
377 {
378 	struct adp8860_bl *data = bl_get_data(bl);
379 
380 	return data->current_brightness;
381 }
382 
383 static const struct backlight_ops adp8860_bl_ops = {
384 	.update_status	= adp8860_bl_update_status,
385 	.get_brightness	= adp8860_bl_get_brightness,
386 };
387 
388 static int adp8860_bl_setup(struct backlight_device *bl)
389 {
390 	struct adp8860_bl *data = bl_get_data(bl);
391 	struct i2c_client *client = data->client;
392 	struct adp8860_backlight_platform_data *pdata = data->pdata;
393 	int ret = 0;
394 
395 	ret |= adp8860_write(client, ADP8860_BLSEN, ~pdata->bl_led_assign);
396 	ret |= adp8860_write(client, ADP8860_BLMX1, pdata->l1_daylight_max);
397 	ret |= adp8860_write(client, ADP8860_BLDM1, pdata->l1_daylight_dim);
398 
399 	if (data->en_ambl_sens) {
400 		data->cached_daylight_max = pdata->l1_daylight_max;
401 		ret |= adp8860_write(client, ADP8860_BLMX2,
402 						pdata->l2_office_max);
403 		ret |= adp8860_write(client, ADP8860_BLDM2,
404 						pdata->l2_office_dim);
405 		ret |= adp8860_write(client, ADP8860_BLMX3,
406 						pdata->l3_dark_max);
407 		ret |= adp8860_write(client, ADP8860_BLDM3,
408 						pdata->l3_dark_dim);
409 
410 		ret |= adp8860_write(client, ADP8860_L2_TRP, pdata->l2_trip);
411 		ret |= adp8860_write(client, ADP8860_L2_HYS, pdata->l2_hyst);
412 		ret |= adp8860_write(client, ADP8860_L3_TRP, pdata->l3_trip);
413 		ret |= adp8860_write(client, ADP8860_L3_HYS, pdata->l3_hyst);
414 		ret |= adp8860_write(client, ADP8860_CCFG, L2_EN | L3_EN |
415 						ALS_CCFG_VAL(pdata->abml_filt));
416 	}
417 
418 	ret |= adp8860_write(client, ADP8860_CFGR,
419 			BL_CFGR_VAL(pdata->bl_fade_law, 0));
420 
421 	ret |= adp8860_write(client, ADP8860_BLFR, FADE_VAL(pdata->bl_fade_in,
422 			pdata->bl_fade_out));
423 
424 	ret |= adp8860_set_bits(client, ADP8860_MDCR, BLEN | DIM_EN | NSTBY |
425 			(data->gdwn_dis ? GDWN_DIS : 0));
426 
427 	return ret;
428 }
429 
430 static ssize_t adp8860_show(struct device *dev, char *buf, int reg)
431 {
432 	struct adp8860_bl *data = dev_get_drvdata(dev);
433 	int error;
434 	uint8_t reg_val;
435 
436 	mutex_lock(&data->lock);
437 	error = adp8860_read(data->client, reg, &reg_val);
438 	mutex_unlock(&data->lock);
439 
440 	if (error < 0)
441 		return error;
442 
443 	return sprintf(buf, "%u\n", reg_val);
444 }
445 
446 static ssize_t adp8860_store(struct device *dev, const char *buf,
447 			 size_t count, int reg)
448 {
449 	struct adp8860_bl *data = dev_get_drvdata(dev);
450 	unsigned long val;
451 	int ret;
452 
453 	ret = kstrtoul(buf, 10, &val);
454 	if (ret)
455 		return ret;
456 
457 	mutex_lock(&data->lock);
458 	adp8860_write(data->client, reg, val);
459 	mutex_unlock(&data->lock);
460 
461 	return count;
462 }
463 
464 static ssize_t adp8860_bl_l3_dark_max_show(struct device *dev,
465 				     struct device_attribute *attr, char *buf)
466 {
467 	return adp8860_show(dev, buf, ADP8860_BLMX3);
468 }
469 
470 static ssize_t adp8860_bl_l3_dark_max_store(struct device *dev,
471 		struct device_attribute *attr, const char *buf, size_t count)
472 {
473 	return adp8860_store(dev, buf, count, ADP8860_BLMX3);
474 }
475 
476 static DEVICE_ATTR(l3_dark_max, 0664, adp8860_bl_l3_dark_max_show,
477 			adp8860_bl_l3_dark_max_store);
478 
479 static ssize_t adp8860_bl_l2_office_max_show(struct device *dev,
480 		struct device_attribute *attr, char *buf)
481 {
482 	return adp8860_show(dev, buf, ADP8860_BLMX2);
483 }
484 
485 static ssize_t adp8860_bl_l2_office_max_store(struct device *dev,
486 		struct device_attribute *attr, const char *buf, size_t count)
487 {
488 	return adp8860_store(dev, buf, count, ADP8860_BLMX2);
489 }
490 static DEVICE_ATTR(l2_office_max, 0664, adp8860_bl_l2_office_max_show,
491 			adp8860_bl_l2_office_max_store);
492 
493 static ssize_t adp8860_bl_l1_daylight_max_show(struct device *dev,
494 			struct device_attribute *attr, char *buf)
495 {
496 	return adp8860_show(dev, buf, ADP8860_BLMX1);
497 }
498 
499 static ssize_t adp8860_bl_l1_daylight_max_store(struct device *dev,
500 		struct device_attribute *attr, const char *buf, size_t count)
501 {
502 	struct adp8860_bl *data = dev_get_drvdata(dev);
503 	int ret = kstrtoul(buf, 10, &data->cached_daylight_max);
504 
505 	if (ret)
506 		return ret;
507 
508 	return adp8860_store(dev, buf, count, ADP8860_BLMX1);
509 }
510 static DEVICE_ATTR(l1_daylight_max, 0664, adp8860_bl_l1_daylight_max_show,
511 			adp8860_bl_l1_daylight_max_store);
512 
513 static ssize_t adp8860_bl_l3_dark_dim_show(struct device *dev,
514 			struct device_attribute *attr, char *buf)
515 {
516 	return adp8860_show(dev, buf, ADP8860_BLDM3);
517 }
518 
519 static ssize_t adp8860_bl_l3_dark_dim_store(struct device *dev,
520 				     struct device_attribute *attr,
521 				     const char *buf, size_t count)
522 {
523 	return adp8860_store(dev, buf, count, ADP8860_BLDM3);
524 }
525 static DEVICE_ATTR(l3_dark_dim, 0664, adp8860_bl_l3_dark_dim_show,
526 			adp8860_bl_l3_dark_dim_store);
527 
528 static ssize_t adp8860_bl_l2_office_dim_show(struct device *dev,
529 			struct device_attribute *attr, char *buf)
530 {
531 	return adp8860_show(dev, buf, ADP8860_BLDM2);
532 }
533 
534 static ssize_t adp8860_bl_l2_office_dim_store(struct device *dev,
535 				     struct device_attribute *attr,
536 				     const char *buf, size_t count)
537 {
538 	return adp8860_store(dev, buf, count, ADP8860_BLDM2);
539 }
540 static DEVICE_ATTR(l2_office_dim, 0664, adp8860_bl_l2_office_dim_show,
541 			adp8860_bl_l2_office_dim_store);
542 
543 static ssize_t adp8860_bl_l1_daylight_dim_show(struct device *dev,
544 				     struct device_attribute *attr, char *buf)
545 {
546 	return adp8860_show(dev, buf, ADP8860_BLDM1);
547 }
548 
549 static ssize_t adp8860_bl_l1_daylight_dim_store(struct device *dev,
550 				     struct device_attribute *attr,
551 				     const char *buf, size_t count)
552 {
553 	return adp8860_store(dev, buf, count, ADP8860_BLDM1);
554 }
555 static DEVICE_ATTR(l1_daylight_dim, 0664, adp8860_bl_l1_daylight_dim_show,
556 			adp8860_bl_l1_daylight_dim_store);
557 
558 #ifdef ADP8860_EXT_FEATURES
559 static ssize_t adp8860_bl_ambient_light_level_show(struct device *dev,
560 				     struct device_attribute *attr, char *buf)
561 {
562 	struct adp8860_bl *data = dev_get_drvdata(dev);
563 	int error;
564 	uint8_t reg_val;
565 	uint16_t ret_val;
566 
567 	mutex_lock(&data->lock);
568 	error = adp8860_read(data->client, ADP8860_PH1LEVL, &reg_val);
569 	ret_val = reg_val;
570 	error |= adp8860_read(data->client, ADP8860_PH1LEVH, &reg_val);
571 	mutex_unlock(&data->lock);
572 
573 	if (error < 0)
574 		return error;
575 
576 	/* Return 13-bit conversion value for the first light sensor */
577 	ret_val += (reg_val & 0x1F) << 8;
578 
579 	return sprintf(buf, "%u\n", ret_val);
580 }
581 static DEVICE_ATTR(ambient_light_level, 0444,
582 		adp8860_bl_ambient_light_level_show, NULL);
583 
584 static ssize_t adp8860_bl_ambient_light_zone_show(struct device *dev,
585 				     struct device_attribute *attr, char *buf)
586 {
587 	struct adp8860_bl *data = dev_get_drvdata(dev);
588 	int error;
589 	uint8_t reg_val;
590 
591 	mutex_lock(&data->lock);
592 	error = adp8860_read(data->client, ADP8860_CFGR, &reg_val);
593 	mutex_unlock(&data->lock);
594 
595 	if (error < 0)
596 		return error;
597 
598 	return sprintf(buf, "%u\n",
599 		((reg_val >> CFGR_BLV_SHIFT) & CFGR_BLV_MASK) + 1);
600 }
601 
602 static ssize_t adp8860_bl_ambient_light_zone_store(struct device *dev,
603 				     struct device_attribute *attr,
604 				     const char *buf, size_t count)
605 {
606 	struct adp8860_bl *data = dev_get_drvdata(dev);
607 	unsigned long val;
608 	uint8_t reg_val;
609 	int ret;
610 
611 	ret = kstrtoul(buf, 10, &val);
612 	if (ret)
613 		return ret;
614 
615 	if (val == 0) {
616 		/* Enable automatic ambient light sensing */
617 		adp8860_set_bits(data->client, ADP8860_MDCR, CMP_AUTOEN);
618 	} else if ((val > 0) && (val <= 3)) {
619 		/* Disable automatic ambient light sensing */
620 		adp8860_clr_bits(data->client, ADP8860_MDCR, CMP_AUTOEN);
621 
622 		/* Set user supplied ambient light zone */
623 		mutex_lock(&data->lock);
624 		adp8860_read(data->client, ADP8860_CFGR, &reg_val);
625 		reg_val &= ~(CFGR_BLV_MASK << CFGR_BLV_SHIFT);
626 		reg_val |= (val - 1) << CFGR_BLV_SHIFT;
627 		adp8860_write(data->client, ADP8860_CFGR, reg_val);
628 		mutex_unlock(&data->lock);
629 	}
630 
631 	return count;
632 }
633 static DEVICE_ATTR(ambient_light_zone, 0664,
634 		adp8860_bl_ambient_light_zone_show,
635 		adp8860_bl_ambient_light_zone_store);
636 #endif
637 
638 static struct attribute *adp8860_bl_attributes[] = {
639 	&dev_attr_l3_dark_max.attr,
640 	&dev_attr_l3_dark_dim.attr,
641 	&dev_attr_l2_office_max.attr,
642 	&dev_attr_l2_office_dim.attr,
643 	&dev_attr_l1_daylight_max.attr,
644 	&dev_attr_l1_daylight_dim.attr,
645 #ifdef ADP8860_EXT_FEATURES
646 	&dev_attr_ambient_light_level.attr,
647 	&dev_attr_ambient_light_zone.attr,
648 #endif
649 	NULL
650 };
651 
652 static const struct attribute_group adp8860_bl_attr_group = {
653 	.attrs = adp8860_bl_attributes,
654 };
655 
656 static int adp8860_probe(struct i2c_client *client,
657 					const struct i2c_device_id *id)
658 {
659 	struct backlight_device *bl;
660 	struct adp8860_bl *data;
661 	struct adp8860_backlight_platform_data *pdata =
662 		dev_get_platdata(&client->dev);
663 	struct backlight_properties props;
664 	uint8_t reg_val;
665 	int ret;
666 
667 	if (!i2c_check_functionality(client->adapter,
668 					I2C_FUNC_SMBUS_BYTE_DATA)) {
669 		dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
670 		return -EIO;
671 	}
672 
673 	if (!pdata) {
674 		dev_err(&client->dev, "no platform data?\n");
675 		return -EINVAL;
676 	}
677 
678 	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
679 	if (data == NULL)
680 		return -ENOMEM;
681 
682 	ret = adp8860_read(client, ADP8860_MFDVID, &reg_val);
683 	if (ret < 0)
684 		return ret;
685 
686 	switch (ADP8860_MANID(reg_val)) {
687 	case ADP8863_MANUFID:
688 		data->gdwn_dis = !!pdata->gdwn_dis;
689 	case ADP8860_MANUFID:
690 		data->en_ambl_sens = !!pdata->en_ambl_sens;
691 		break;
692 	case ADP8861_MANUFID:
693 		data->gdwn_dis = !!pdata->gdwn_dis;
694 		break;
695 	default:
696 		dev_err(&client->dev, "failed to probe\n");
697 		return -ENODEV;
698 	}
699 
700 	/* It's confirmed that the DEVID field is actually a REVID */
701 
702 	data->revid = ADP8860_DEVID(reg_val);
703 	data->client = client;
704 	data->pdata = pdata;
705 	data->id = id->driver_data;
706 	data->current_brightness = 0;
707 	i2c_set_clientdata(client, data);
708 
709 	memset(&props, 0, sizeof(props));
710 	props.type = BACKLIGHT_RAW;
711 	props.max_brightness = ADP8860_MAX_BRIGHTNESS;
712 
713 	mutex_init(&data->lock);
714 
715 	bl = devm_backlight_device_register(&client->dev,
716 				dev_driver_string(&client->dev),
717 				&client->dev, data, &adp8860_bl_ops, &props);
718 	if (IS_ERR(bl)) {
719 		dev_err(&client->dev, "failed to register backlight\n");
720 		return PTR_ERR(bl);
721 	}
722 
723 	bl->props.brightness = ADP8860_MAX_BRIGHTNESS;
724 
725 	data->bl = bl;
726 
727 	if (data->en_ambl_sens)
728 		ret = sysfs_create_group(&bl->dev.kobj,
729 			&adp8860_bl_attr_group);
730 
731 	if (ret) {
732 		dev_err(&client->dev, "failed to register sysfs\n");
733 		return ret;
734 	}
735 
736 	ret = adp8860_bl_setup(bl);
737 	if (ret) {
738 		ret = -EIO;
739 		goto out;
740 	}
741 
742 	backlight_update_status(bl);
743 
744 	dev_info(&client->dev, "%s Rev.%d Backlight\n",
745 		client->name, data->revid);
746 
747 	if (pdata->num_leds)
748 		adp8860_led_probe(client);
749 
750 	return 0;
751 
752 out:
753 	if (data->en_ambl_sens)
754 		sysfs_remove_group(&data->bl->dev.kobj,
755 			&adp8860_bl_attr_group);
756 
757 	return ret;
758 }
759 
760 static int adp8860_remove(struct i2c_client *client)
761 {
762 	struct adp8860_bl *data = i2c_get_clientdata(client);
763 
764 	adp8860_clr_bits(client, ADP8860_MDCR, NSTBY);
765 
766 	if (data->led)
767 		adp8860_led_remove(client);
768 
769 	if (data->en_ambl_sens)
770 		sysfs_remove_group(&data->bl->dev.kobj,
771 			&adp8860_bl_attr_group);
772 
773 	return 0;
774 }
775 
776 #ifdef CONFIG_PM_SLEEP
777 static int adp8860_i2c_suspend(struct device *dev)
778 {
779 	struct i2c_client *client = to_i2c_client(dev);
780 
781 	adp8860_clr_bits(client, ADP8860_MDCR, NSTBY);
782 
783 	return 0;
784 }
785 
786 static int adp8860_i2c_resume(struct device *dev)
787 {
788 	struct i2c_client *client = to_i2c_client(dev);
789 
790 	adp8860_set_bits(client, ADP8860_MDCR, NSTBY | BLEN);
791 
792 	return 0;
793 }
794 #endif
795 
796 static SIMPLE_DEV_PM_OPS(adp8860_i2c_pm_ops, adp8860_i2c_suspend,
797 			adp8860_i2c_resume);
798 
799 static const struct i2c_device_id adp8860_id[] = {
800 	{ "adp8860", adp8860 },
801 	{ "adp8861", adp8861 },
802 	{ "adp8863", adp8863 },
803 	{ }
804 };
805 MODULE_DEVICE_TABLE(i2c, adp8860_id);
806 
807 static struct i2c_driver adp8860_driver = {
808 	.driver = {
809 		.name	= KBUILD_MODNAME,
810 		.pm	= &adp8860_i2c_pm_ops,
811 	},
812 	.probe    = adp8860_probe,
813 	.remove   = adp8860_remove,
814 	.id_table = adp8860_id,
815 };
816 
817 module_i2c_driver(adp8860_driver);
818 
819 MODULE_LICENSE("GPL v2");
820 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
821 MODULE_DESCRIPTION("ADP8860 Backlight driver");
822