xref: /linux/drivers/video/backlight/adp8860_bl.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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 	adp8860_write(led->client, ADP8860_ISC1 - led->id + 1,
185 			 led->new_brightness >> 1);
186 }
187 
188 static void adp8860_led_set(struct led_classdev *led_cdev,
189 			   enum led_brightness value)
190 {
191 	struct adp8860_led *led;
192 
193 	led = container_of(led_cdev, struct adp8860_led, cdev);
194 	led->new_brightness = value;
195 	schedule_work(&led->work);
196 }
197 
198 static int adp8860_led_setup(struct adp8860_led *led)
199 {
200 	struct i2c_client *client = led->client;
201 	int ret = 0;
202 
203 	ret = adp8860_write(client, ADP8860_ISC1 - led->id + 1, 0);
204 	ret |= adp8860_set_bits(client, ADP8860_ISCC, 1 << (led->id - 1));
205 
206 	if (led->id > 4)
207 		ret |= adp8860_set_bits(client, ADP8860_ISCT1,
208 				(led->flags & 0x3) << ((led->id - 5) * 2));
209 	else
210 		ret |= adp8860_set_bits(client, ADP8860_ISCT2,
211 				(led->flags & 0x3) << ((led->id - 1) * 2));
212 
213 	return ret;
214 }
215 
216 static int adp8860_led_probe(struct i2c_client *client)
217 {
218 	struct adp8860_backlight_platform_data *pdata =
219 		client->dev.platform_data;
220 	struct adp8860_bl *data = i2c_get_clientdata(client);
221 	struct adp8860_led *led, *led_dat;
222 	struct led_info *cur_led;
223 	int ret, i;
224 
225 	led = devm_kzalloc(&client->dev, sizeof(*led) * pdata->num_leds,
226 				GFP_KERNEL);
227 	if (led == NULL) {
228 		dev_err(&client->dev, "failed to alloc memory\n");
229 		return -ENOMEM;
230 	}
231 
232 	ret = adp8860_write(client, ADP8860_ISCFR, pdata->led_fade_law);
233 	ret = adp8860_write(client, ADP8860_ISCT1,
234 			(pdata->led_on_time & 0x3) << 6);
235 	ret |= adp8860_write(client, ADP8860_ISCF,
236 			FADE_VAL(pdata->led_fade_in, pdata->led_fade_out));
237 
238 	if (ret) {
239 		dev_err(&client->dev, "failed to write\n");
240 		return ret;
241 	}
242 
243 	for (i = 0; i < pdata->num_leds; ++i) {
244 		cur_led = &pdata->leds[i];
245 		led_dat = &led[i];
246 
247 		led_dat->id = cur_led->flags & ADP8860_FLAG_LED_MASK;
248 
249 		if (led_dat->id > 7 || led_dat->id < 1) {
250 			dev_err(&client->dev, "Invalid LED ID %d\n",
251 				led_dat->id);
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 			goto err;
259 		}
260 
261 		led_dat->cdev.name = cur_led->name;
262 		led_dat->cdev.default_trigger = cur_led->default_trigger;
263 		led_dat->cdev.brightness_set = adp8860_led_set;
264 		led_dat->cdev.brightness = LED_OFF;
265 		led_dat->flags = cur_led->flags >> FLAG_OFFT_SHIFT;
266 		led_dat->client = client;
267 		led_dat->new_brightness = LED_OFF;
268 		INIT_WORK(&led_dat->work, adp8860_led_work);
269 
270 		ret = led_classdev_register(&client->dev, &led_dat->cdev);
271 		if (ret) {
272 			dev_err(&client->dev, "failed to register LED %d\n",
273 				led_dat->id);
274 			goto err;
275 		}
276 
277 		ret = adp8860_led_setup(led_dat);
278 		if (ret) {
279 			dev_err(&client->dev, "failed to write\n");
280 			i++;
281 			goto err;
282 		}
283 	}
284 
285 	data->led = led;
286 
287 	return 0;
288 
289  err:
290 	for (i = i - 1; i >= 0; --i) {
291 		led_classdev_unregister(&led[i].cdev);
292 		cancel_work_sync(&led[i].work);
293 	}
294 
295 	return ret;
296 }
297 
298 static int adp8860_led_remove(struct i2c_client *client)
299 {
300 	struct adp8860_backlight_platform_data *pdata =
301 		client->dev.platform_data;
302 	struct adp8860_bl *data = i2c_get_clientdata(client);
303 	int i;
304 
305 	for (i = 0; i < pdata->num_leds; i++) {
306 		led_classdev_unregister(&data->led[i].cdev);
307 		cancel_work_sync(&data->led[i].work);
308 	}
309 
310 	return 0;
311 }
312 #else
313 static int adp8860_led_probe(struct i2c_client *client)
314 {
315 	return 0;
316 }
317 
318 static int adp8860_led_remove(struct i2c_client *client)
319 {
320 	return 0;
321 }
322 #endif
323 
324 static int adp8860_bl_set(struct backlight_device *bl, int brightness)
325 {
326 	struct adp8860_bl *data = bl_get_data(bl);
327 	struct i2c_client *client = data->client;
328 	int ret = 0;
329 
330 	if (data->en_ambl_sens) {
331 		if ((brightness > 0) && (brightness < ADP8860_MAX_BRIGHTNESS)) {
332 			/* Disable Ambient Light auto adjust */
333 			ret |= adp8860_clr_bits(client, ADP8860_MDCR,
334 					CMP_AUTOEN);
335 			ret |= adp8860_write(client, ADP8860_BLMX1, brightness);
336 		} else {
337 			/*
338 			 * MAX_BRIGHTNESS -> Enable Ambient Light auto adjust
339 			 * restore daylight l1 sysfs brightness
340 			 */
341 			ret |= adp8860_write(client, ADP8860_BLMX1,
342 					 data->cached_daylight_max);
343 			ret |= adp8860_set_bits(client, ADP8860_MDCR,
344 					 CMP_AUTOEN);
345 		}
346 	} else
347 		ret |= adp8860_write(client, ADP8860_BLMX1, brightness);
348 
349 	if (data->current_brightness && brightness == 0)
350 		ret |= adp8860_set_bits(client,
351 				ADP8860_MDCR, DIM_EN);
352 	else if (data->current_brightness == 0 && brightness)
353 		ret |= adp8860_clr_bits(client,
354 				ADP8860_MDCR, DIM_EN);
355 
356 	if (!ret)
357 		data->current_brightness = brightness;
358 
359 	return ret;
360 }
361 
362 static int adp8860_bl_update_status(struct backlight_device *bl)
363 {
364 	int brightness = bl->props.brightness;
365 	if (bl->props.power != FB_BLANK_UNBLANK)
366 		brightness = 0;
367 
368 	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
369 		brightness = 0;
370 
371 	return adp8860_bl_set(bl, brightness);
372 }
373 
374 static int adp8860_bl_get_brightness(struct backlight_device *bl)
375 {
376 	struct adp8860_bl *data = bl_get_data(bl);
377 
378 	return data->current_brightness;
379 }
380 
381 static const struct backlight_ops adp8860_bl_ops = {
382 	.update_status	= adp8860_bl_update_status,
383 	.get_brightness	= adp8860_bl_get_brightness,
384 };
385 
386 static int adp8860_bl_setup(struct backlight_device *bl)
387 {
388 	struct adp8860_bl *data = bl_get_data(bl);
389 	struct i2c_client *client = data->client;
390 	struct adp8860_backlight_platform_data *pdata = data->pdata;
391 	int ret = 0;
392 
393 	ret |= adp8860_write(client, ADP8860_BLSEN, ~pdata->bl_led_assign);
394 	ret |= adp8860_write(client, ADP8860_BLMX1, pdata->l1_daylight_max);
395 	ret |= adp8860_write(client, ADP8860_BLDM1, pdata->l1_daylight_dim);
396 
397 	if (data->en_ambl_sens) {
398 		data->cached_daylight_max = pdata->l1_daylight_max;
399 		ret |= adp8860_write(client, ADP8860_BLMX2,
400 						pdata->l2_office_max);
401 		ret |= adp8860_write(client, ADP8860_BLDM2,
402 						pdata->l2_office_dim);
403 		ret |= adp8860_write(client, ADP8860_BLMX3,
404 						pdata->l3_dark_max);
405 		ret |= adp8860_write(client, ADP8860_BLDM3,
406 						pdata->l3_dark_dim);
407 
408 		ret |= adp8860_write(client, ADP8860_L2_TRP, pdata->l2_trip);
409 		ret |= adp8860_write(client, ADP8860_L2_HYS, pdata->l2_hyst);
410 		ret |= adp8860_write(client, ADP8860_L3_TRP, pdata->l3_trip);
411 		ret |= adp8860_write(client, ADP8860_L3_HYS, pdata->l3_hyst);
412 		ret |= adp8860_write(client, ADP8860_CCFG, L2_EN | L3_EN |
413 						ALS_CCFG_VAL(pdata->abml_filt));
414 	}
415 
416 	ret |= adp8860_write(client, ADP8860_CFGR,
417 			BL_CFGR_VAL(pdata->bl_fade_law, 0));
418 
419 	ret |= adp8860_write(client, ADP8860_BLFR, FADE_VAL(pdata->bl_fade_in,
420 			pdata->bl_fade_out));
421 
422 	ret |= adp8860_set_bits(client, ADP8860_MDCR, BLEN | DIM_EN | NSTBY |
423 			(data->gdwn_dis ? GDWN_DIS : 0));
424 
425 	return ret;
426 }
427 
428 static ssize_t adp8860_show(struct device *dev, char *buf, int reg)
429 {
430 	struct adp8860_bl *data = dev_get_drvdata(dev);
431 	int error;
432 	uint8_t reg_val;
433 
434 	mutex_lock(&data->lock);
435 	error = adp8860_read(data->client, reg, &reg_val);
436 	mutex_unlock(&data->lock);
437 
438 	if (error < 0)
439 		return error;
440 
441 	return sprintf(buf, "%u\n", reg_val);
442 }
443 
444 static ssize_t adp8860_store(struct device *dev, const char *buf,
445 			 size_t count, int reg)
446 {
447 	struct adp8860_bl *data = dev_get_drvdata(dev);
448 	unsigned long val;
449 	int ret;
450 
451 	ret = kstrtoul(buf, 10, &val);
452 	if (ret)
453 		return ret;
454 
455 	mutex_lock(&data->lock);
456 	adp8860_write(data->client, reg, val);
457 	mutex_unlock(&data->lock);
458 
459 	return count;
460 }
461 
462 static ssize_t adp8860_bl_l3_dark_max_show(struct device *dev,
463 				     struct device_attribute *attr, char *buf)
464 {
465 	return adp8860_show(dev, buf, ADP8860_BLMX3);
466 }
467 
468 static ssize_t adp8860_bl_l3_dark_max_store(struct device *dev,
469 		struct device_attribute *attr, const char *buf, size_t count)
470 {
471 	return adp8860_store(dev, buf, count, ADP8860_BLMX3);
472 }
473 
474 static DEVICE_ATTR(l3_dark_max, 0664, adp8860_bl_l3_dark_max_show,
475 			adp8860_bl_l3_dark_max_store);
476 
477 static ssize_t adp8860_bl_l2_office_max_show(struct device *dev,
478 		struct device_attribute *attr, char *buf)
479 {
480 	return adp8860_show(dev, buf, ADP8860_BLMX2);
481 }
482 
483 static ssize_t adp8860_bl_l2_office_max_store(struct device *dev,
484 		struct device_attribute *attr, const char *buf, size_t count)
485 {
486 	return adp8860_store(dev, buf, count, ADP8860_BLMX2);
487 }
488 static DEVICE_ATTR(l2_office_max, 0664, adp8860_bl_l2_office_max_show,
489 			adp8860_bl_l2_office_max_store);
490 
491 static ssize_t adp8860_bl_l1_daylight_max_show(struct device *dev,
492 			struct device_attribute *attr, char *buf)
493 {
494 	return adp8860_show(dev, buf, ADP8860_BLMX1);
495 }
496 
497 static ssize_t adp8860_bl_l1_daylight_max_store(struct device *dev,
498 		struct device_attribute *attr, const char *buf, size_t count)
499 {
500 	struct adp8860_bl *data = dev_get_drvdata(dev);
501 	int ret = kstrtoul(buf, 10, &data->cached_daylight_max);
502 	if (ret)
503 		return ret;
504 
505 	return adp8860_store(dev, buf, count, ADP8860_BLMX1);
506 }
507 static DEVICE_ATTR(l1_daylight_max, 0664, adp8860_bl_l1_daylight_max_show,
508 			adp8860_bl_l1_daylight_max_store);
509 
510 static ssize_t adp8860_bl_l3_dark_dim_show(struct device *dev,
511 			struct device_attribute *attr, char *buf)
512 {
513 	return adp8860_show(dev, buf, ADP8860_BLDM3);
514 }
515 
516 static ssize_t adp8860_bl_l3_dark_dim_store(struct device *dev,
517 				     struct device_attribute *attr,
518 				     const char *buf, size_t count)
519 {
520 	return adp8860_store(dev, buf, count, ADP8860_BLDM3);
521 }
522 static DEVICE_ATTR(l3_dark_dim, 0664, adp8860_bl_l3_dark_dim_show,
523 			adp8860_bl_l3_dark_dim_store);
524 
525 static ssize_t adp8860_bl_l2_office_dim_show(struct device *dev,
526 			struct device_attribute *attr, char *buf)
527 {
528 	return adp8860_show(dev, buf, ADP8860_BLDM2);
529 }
530 
531 static ssize_t adp8860_bl_l2_office_dim_store(struct device *dev,
532 				     struct device_attribute *attr,
533 				     const char *buf, size_t count)
534 {
535 	return adp8860_store(dev, buf, count, ADP8860_BLDM2);
536 }
537 static DEVICE_ATTR(l2_office_dim, 0664, adp8860_bl_l2_office_dim_show,
538 			adp8860_bl_l2_office_dim_store);
539 
540 static ssize_t adp8860_bl_l1_daylight_dim_show(struct device *dev,
541 				     struct device_attribute *attr, char *buf)
542 {
543 	return adp8860_show(dev, buf, ADP8860_BLDM1);
544 }
545 
546 static ssize_t adp8860_bl_l1_daylight_dim_store(struct device *dev,
547 				     struct device_attribute *attr,
548 				     const char *buf, size_t count)
549 {
550 	return adp8860_store(dev, buf, count, ADP8860_BLDM1);
551 }
552 static DEVICE_ATTR(l1_daylight_dim, 0664, adp8860_bl_l1_daylight_dim_show,
553 			adp8860_bl_l1_daylight_dim_store);
554 
555 #ifdef ADP8860_EXT_FEATURES
556 static ssize_t adp8860_bl_ambient_light_level_show(struct device *dev,
557 				     struct device_attribute *attr, char *buf)
558 {
559 	struct adp8860_bl *data = dev_get_drvdata(dev);
560 	int error;
561 	uint8_t reg_val;
562 	uint16_t ret_val;
563 
564 	mutex_lock(&data->lock);
565 	error = adp8860_read(data->client, ADP8860_PH1LEVL, &reg_val);
566 	ret_val = reg_val;
567 	error |= adp8860_read(data->client, ADP8860_PH1LEVH, &reg_val);
568 	mutex_unlock(&data->lock);
569 
570 	if (error < 0)
571 		return error;
572 
573 	/* Return 13-bit conversion value for the first light sensor */
574 	ret_val += (reg_val & 0x1F) << 8;
575 
576 	return sprintf(buf, "%u\n", ret_val);
577 }
578 static DEVICE_ATTR(ambient_light_level, 0444,
579 		adp8860_bl_ambient_light_level_show, NULL);
580 
581 static ssize_t adp8860_bl_ambient_light_zone_show(struct device *dev,
582 				     struct device_attribute *attr, char *buf)
583 {
584 	struct adp8860_bl *data = dev_get_drvdata(dev);
585 	int error;
586 	uint8_t reg_val;
587 
588 	mutex_lock(&data->lock);
589 	error = adp8860_read(data->client, ADP8860_CFGR, &reg_val);
590 	mutex_unlock(&data->lock);
591 
592 	if (error < 0)
593 		return error;
594 
595 	return sprintf(buf, "%u\n",
596 		((reg_val >> CFGR_BLV_SHIFT) & CFGR_BLV_MASK) + 1);
597 }
598 
599 static ssize_t adp8860_bl_ambient_light_zone_store(struct device *dev,
600 				     struct device_attribute *attr,
601 				     const char *buf, size_t count)
602 {
603 	struct adp8860_bl *data = dev_get_drvdata(dev);
604 	unsigned long val;
605 	uint8_t reg_val;
606 	int ret;
607 
608 	ret = kstrtoul(buf, 10, &val);
609 	if (ret)
610 		return ret;
611 
612 	if (val == 0) {
613 		/* Enable automatic ambient light sensing */
614 		adp8860_set_bits(data->client, ADP8860_MDCR, CMP_AUTOEN);
615 	} else if ((val > 0) && (val <= 3)) {
616 		/* Disable automatic ambient light sensing */
617 		adp8860_clr_bits(data->client, ADP8860_MDCR, CMP_AUTOEN);
618 
619 		/* Set user supplied ambient light zone */
620 		mutex_lock(&data->lock);
621 		adp8860_read(data->client, ADP8860_CFGR, &reg_val);
622 		reg_val &= ~(CFGR_BLV_MASK << CFGR_BLV_SHIFT);
623 		reg_val |= (val - 1) << CFGR_BLV_SHIFT;
624 		adp8860_write(data->client, ADP8860_CFGR, reg_val);
625 		mutex_unlock(&data->lock);
626 	}
627 
628 	return count;
629 }
630 static DEVICE_ATTR(ambient_light_zone, 0664,
631 		adp8860_bl_ambient_light_zone_show,
632 		adp8860_bl_ambient_light_zone_store);
633 #endif
634 
635 static struct attribute *adp8860_bl_attributes[] = {
636 	&dev_attr_l3_dark_max.attr,
637 	&dev_attr_l3_dark_dim.attr,
638 	&dev_attr_l2_office_max.attr,
639 	&dev_attr_l2_office_dim.attr,
640 	&dev_attr_l1_daylight_max.attr,
641 	&dev_attr_l1_daylight_dim.attr,
642 #ifdef ADP8860_EXT_FEATURES
643 	&dev_attr_ambient_light_level.attr,
644 	&dev_attr_ambient_light_zone.attr,
645 #endif
646 	NULL
647 };
648 
649 static const struct attribute_group adp8860_bl_attr_group = {
650 	.attrs = adp8860_bl_attributes,
651 };
652 
653 static int adp8860_probe(struct i2c_client *client,
654 					const struct i2c_device_id *id)
655 {
656 	struct backlight_device *bl;
657 	struct adp8860_bl *data;
658 	struct adp8860_backlight_platform_data *pdata =
659 		client->dev.platform_data;
660 	struct backlight_properties props;
661 	uint8_t reg_val;
662 	int ret;
663 
664 	if (!i2c_check_functionality(client->adapter,
665 					I2C_FUNC_SMBUS_BYTE_DATA)) {
666 		dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
667 		return -EIO;
668 	}
669 
670 	if (!pdata) {
671 		dev_err(&client->dev, "no platform data?\n");
672 		return -EINVAL;
673 	}
674 
675 	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
676 	if (data == NULL)
677 		return -ENOMEM;
678 
679 	ret = adp8860_read(client, ADP8860_MFDVID, &reg_val);
680 	if (ret < 0)
681 		return ret;
682 
683 	switch (ADP8860_MANID(reg_val)) {
684 	case ADP8863_MANUFID:
685 		data->gdwn_dis = !!pdata->gdwn_dis;
686 	case ADP8860_MANUFID:
687 		data->en_ambl_sens = !!pdata->en_ambl_sens;
688 		break;
689 	case ADP8861_MANUFID:
690 		data->gdwn_dis = !!pdata->gdwn_dis;
691 		break;
692 	default:
693 		dev_err(&client->dev, "failed to probe\n");
694 		return -ENODEV;
695 	}
696 
697 	/* It's confirmed that the DEVID field is actually a REVID */
698 
699 	data->revid = ADP8860_DEVID(reg_val);
700 	data->client = client;
701 	data->pdata = pdata;
702 	data->id = id->driver_data;
703 	data->current_brightness = 0;
704 	i2c_set_clientdata(client, data);
705 
706 	memset(&props, 0, sizeof(props));
707 	props.type = BACKLIGHT_RAW;
708 	props.max_brightness = ADP8860_MAX_BRIGHTNESS;
709 
710 	mutex_init(&data->lock);
711 
712 	bl = backlight_device_register(dev_driver_string(&client->dev),
713 			&client->dev, data, &adp8860_bl_ops, &props);
714 	if (IS_ERR(bl)) {
715 		dev_err(&client->dev, "failed to register backlight\n");
716 		return PTR_ERR(bl);
717 	}
718 
719 	bl->props.brightness = ADP8860_MAX_BRIGHTNESS;
720 
721 	data->bl = bl;
722 
723 	if (data->en_ambl_sens)
724 		ret = sysfs_create_group(&bl->dev.kobj,
725 			&adp8860_bl_attr_group);
726 
727 	if (ret) {
728 		dev_err(&client->dev, "failed to register sysfs\n");
729 		goto out1;
730 	}
731 
732 	ret = adp8860_bl_setup(bl);
733 	if (ret) {
734 		ret = -EIO;
735 		goto out;
736 	}
737 
738 	backlight_update_status(bl);
739 
740 	dev_info(&client->dev, "%s Rev.%d Backlight\n",
741 		client->name, data->revid);
742 
743 	if (pdata->num_leds)
744 		adp8860_led_probe(client);
745 
746 	return 0;
747 
748 out:
749 	if (data->en_ambl_sens)
750 		sysfs_remove_group(&data->bl->dev.kobj,
751 			&adp8860_bl_attr_group);
752 out1:
753 	backlight_device_unregister(bl);
754 
755 	return ret;
756 }
757 
758 static int adp8860_remove(struct i2c_client *client)
759 {
760 	struct adp8860_bl *data = i2c_get_clientdata(client);
761 
762 	adp8860_clr_bits(client, ADP8860_MDCR, NSTBY);
763 
764 	if (data->led)
765 		adp8860_led_remove(client);
766 
767 	if (data->en_ambl_sens)
768 		sysfs_remove_group(&data->bl->dev.kobj,
769 			&adp8860_bl_attr_group);
770 
771 	backlight_device_unregister(data->bl);
772 
773 	return 0;
774 }
775 
776 #ifdef CONFIG_PM
777 static int adp8860_i2c_suspend(struct i2c_client *client, pm_message_t message)
778 {
779 	adp8860_clr_bits(client, ADP8860_MDCR, NSTBY);
780 
781 	return 0;
782 }
783 
784 static int adp8860_i2c_resume(struct i2c_client *client)
785 {
786 	adp8860_set_bits(client, ADP8860_MDCR, NSTBY);
787 
788 	return 0;
789 }
790 #else
791 #define adp8860_i2c_suspend NULL
792 #define adp8860_i2c_resume NULL
793 #endif
794 
795 static const struct i2c_device_id adp8860_id[] = {
796 	{ "adp8860", adp8860 },
797 	{ "adp8861", adp8861 },
798 	{ "adp8863", adp8863 },
799 	{ }
800 };
801 MODULE_DEVICE_TABLE(i2c, adp8860_id);
802 
803 static struct i2c_driver adp8860_driver = {
804 	.driver = {
805 		.name = KBUILD_MODNAME,
806 	},
807 	.probe    = adp8860_probe,
808 	.remove   = adp8860_remove,
809 	.suspend = adp8860_i2c_suspend,
810 	.resume  = adp8860_i2c_resume,
811 	.id_table = adp8860_id,
812 };
813 
814 module_i2c_driver(adp8860_driver);
815 
816 MODULE_LICENSE("GPL v2");
817 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
818 MODULE_DESCRIPTION("ADP8860 Backlight driver");
819 MODULE_ALIAS("i2c:adp8860-backlight");
820