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/version.h>
11 #include <linux/init.h>
12 #include <linux/errno.h>
13 #include <linux/pm.h>
14 #include <linux/platform_device.h>
15 #include <linux/i2c.h>
16 #include <linux/fb.h>
17 #include <linux/backlight.h>
18 #include <linux/leds.h>
19 #include <linux/slab.h>
20 #include <linux/workqueue.h>
21 
22 #include <linux/i2c/adp8860.h>
23 #define ADP8860_EXT_FEATURES
24 #define ADP8860_USE_LEDS
25 
26 #define ADP8860_MFDVID 0x00 /* Manufacturer and device ID */
27 #define ADP8860_MDCR 0x01 /* Device mode and status */
28 #define ADP8860_MDCR2 0x02 /* Device mode and Status Register 2 */
29 #define ADP8860_INTR_EN 0x03 /* Interrupts enable */
30 #define ADP8860_CFGR 0x04 /* Configuration register */
31 #define ADP8860_BLSEN 0x05 /* Sink enable backlight or independent */
32 #define ADP8860_BLOFF 0x06 /* Backlight off timeout */
33 #define ADP8860_BLDIM 0x07 /* Backlight dim timeout */
34 #define ADP8860_BLFR 0x08 /* Backlight fade in and out rates */
35 #define ADP8860_BLMX1 0x09 /* Backlight (Brightness Level 1-daylight) maximum current */
36 #define ADP8860_BLDM1 0x0A /* Backlight (Brightness Level 1-daylight) dim current */
37 #define ADP8860_BLMX2 0x0B /* Backlight (Brightness Level 2-office) maximum current */
38 #define ADP8860_BLDM2 0x0C /* Backlight (Brightness Level 2-office) dim current */
39 #define ADP8860_BLMX3 0x0D /* Backlight (Brightness Level 3-dark) maximum current */
40 #define ADP8860_BLDM3 0x0E /* Backlight (Brightness Level 3-dark) dim current */
41 #define ADP8860_ISCFR 0x0F /* Independent sink current fade control register */
42 #define ADP8860_ISCC 0x10 /* Independent sink current control register */
43 #define ADP8860_ISCT1 0x11 /* Independent Sink Current Timer Register LED[7:5] */
44 #define ADP8860_ISCT2 0x12 /* Independent Sink Current Timer Register LED[4:1] */
45 #define ADP8860_ISCF 0x13 /* Independent sink current fade register */
46 #define ADP8860_ISC7 0x14 /* Independent Sink Current LED7 */
47 #define ADP8860_ISC6 0x15 /* Independent Sink Current LED6 */
48 #define ADP8860_ISC5 0x16 /* Independent Sink Current LED5 */
49 #define ADP8860_ISC4 0x17 /* Independent Sink Current LED4 */
50 #define ADP8860_ISC3 0x18 /* Independent Sink Current LED3 */
51 #define ADP8860_ISC2 0x19 /* Independent Sink Current LED2 */
52 #define ADP8860_ISC1 0x1A /* Independent Sink Current LED1 */
53 #define ADP8860_CCFG 0x1B /* Comparator configuration */
54 #define ADP8860_CCFG2 0x1C /* Second comparator configuration */
55 #define ADP8860_L2_TRP 0x1D /* L2 comparator reference */
56 #define ADP8860_L2_HYS 0x1E /* L2 hysteresis */
57 #define ADP8860_L3_TRP 0x1F /* L3 comparator reference */
58 #define ADP8860_L3_HYS 0x20 /* L3 hysteresis */
59 #define ADP8860_PH1LEVL 0x21 /* First phototransistor ambient light level-low byte register */
60 #define ADP8860_PH1LEVH 0x22 /* First phototransistor ambient light level-high byte register */
61 #define ADP8860_PH2LEVL 0x23 /* Second phototransistor ambient light level-low byte register */
62 #define ADP8860_PH2LEVH 0x24 /* Second phototransistor ambient light level-high byte register */
63 
64 #define ADP8860_MANUFID		0x0  /* Analog Devices ADP8860 Manufacturer ID */
65 #define ADP8861_MANUFID		0x4  /* Analog Devices ADP8861 Manufacturer ID */
66 #define ADP8863_MANUFID		0x2  /* Analog Devices ADP8863 Manufacturer ID */
67 
68 #define ADP8860_DEVID(x)	((x) & 0xF)
69 #define ADP8860_MANID(x)	((x) >> 4)
70 
71 /* MDCR Device mode and status */
72 #define INT_CFG			(1 << 6)
73 #define NSTBY			(1 << 5)
74 #define DIM_EN			(1 << 4)
75 #define GDWN_DIS		(1 << 3)
76 #define SIS_EN			(1 << 2)
77 #define CMP_AUTOEN		(1 << 1)
78 #define BLEN			(1 << 0)
79 
80 /* ADP8860_CCFG Main ALS comparator level enable */
81 #define L3_EN			(1 << 1)
82 #define L2_EN			(1 << 0)
83 
84 #define CFGR_BLV_SHIFT		3
85 #define CFGR_BLV_MASK		0x3
86 #define ADP8860_FLAG_LED_MASK	0xFF
87 
88 #define FADE_VAL(in, out)	((0xF & (in)) | ((0xF & (out)) << 4))
89 #define BL_CFGR_VAL(law, blv)	((((blv) & CFGR_BLV_MASK) << CFGR_BLV_SHIFT) | ((0x3 & (law)) << 1))
90 #define ALS_CCFG_VAL(filt)	((0x7 & filt) << 5)
91 
92 enum {
93 	adp8860,
94 	adp8861,
95 	adp8863
96 };
97 
98 struct adp8860_led {
99 	struct led_classdev	cdev;
100 	struct work_struct	work;
101 	struct i2c_client	*client;
102 	enum led_brightness	new_brightness;
103 	int			id;
104 	int			flags;
105 };
106 
107 struct adp8860_bl {
108 	struct i2c_client *client;
109 	struct backlight_device *bl;
110 	struct adp8860_led *led;
111 	struct adp8860_backlight_platform_data *pdata;
112 	struct mutex lock;
113 	unsigned long cached_daylight_max;
114 	int id;
115 	int revid;
116 	int current_brightness;
117 	unsigned en_ambl_sens:1;
118 	unsigned gdwn_dis:1;
119 };
120 
121 static int adp8860_read(struct i2c_client *client, int reg, uint8_t *val)
122 {
123 	int ret;
124 
125 	ret = i2c_smbus_read_byte_data(client, reg);
126 	if (ret < 0) {
127 		dev_err(&client->dev, "failed reading at 0x%02x\n", reg);
128 		return ret;
129 	}
130 
131 	*val = (uint8_t)ret;
132 	return 0;
133 }
134 
135 static int adp8860_write(struct i2c_client *client, u8 reg, u8 val)
136 {
137 	return i2c_smbus_write_byte_data(client, reg, val);
138 }
139 
140 static int adp8860_set_bits(struct i2c_client *client, int reg, uint8_t bit_mask)
141 {
142 	struct adp8860_bl *data = i2c_get_clientdata(client);
143 	uint8_t reg_val;
144 	int ret;
145 
146 	mutex_lock(&data->lock);
147 
148 	ret = adp8860_read(client, reg, &reg_val);
149 
150 	if (!ret && ((reg_val & bit_mask) == 0)) {
151 		reg_val |= bit_mask;
152 		ret = adp8860_write(client, reg, reg_val);
153 	}
154 
155 	mutex_unlock(&data->lock);
156 	return ret;
157 }
158 
159 static int adp8860_clr_bits(struct i2c_client *client, int reg, uint8_t bit_mask)
160 {
161 	struct adp8860_bl *data = i2c_get_clientdata(client);
162 	uint8_t reg_val;
163 	int ret;
164 
165 	mutex_lock(&data->lock);
166 
167 	ret = adp8860_read(client, reg, &reg_val);
168 
169 	if (!ret && (reg_val & bit_mask)) {
170 		reg_val &= ~bit_mask;
171 		ret = adp8860_write(client, reg, reg_val);
172 	}
173 
174 	mutex_unlock(&data->lock);
175 	return ret;
176 }
177 
178 /*
179  * Independent sink / LED
180  */
181 #if defined(ADP8860_USE_LEDS)
182 static void adp8860_led_work(struct work_struct *work)
183 {
184 	struct adp8860_led *led = container_of(work, struct adp8860_led, work);
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 __devinit adp8860_led_probe(struct i2c_client *client)
218 {
219 	struct adp8860_backlight_platform_data *pdata =
220 		client->dev.platform_data;
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 = kzalloc(sizeof(*led) * pdata->num_leds, 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 		goto err_free;
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  err_free:
296 	kfree(led);
297 
298 	return ret;
299 }
300 
301 static int __devexit adp8860_led_remove(struct i2c_client *client)
302 {
303 	struct adp8860_backlight_platform_data *pdata =
304 		client->dev.platform_data;
305 	struct adp8860_bl *data = i2c_get_clientdata(client);
306 	int i;
307 
308 	for (i = 0; i < pdata->num_leds; i++) {
309 		led_classdev_unregister(&data->led[i].cdev);
310 		cancel_work_sync(&data->led[i].work);
311 	}
312 
313 	kfree(data->led);
314 	return 0;
315 }
316 #else
317 static int __devinit adp8860_led_probe(struct i2c_client *client)
318 {
319 	return 0;
320 }
321 
322 static int __devexit adp8860_led_remove(struct i2c_client *client)
323 {
324 	return 0;
325 }
326 #endif
327 
328 static int adp8860_bl_set(struct backlight_device *bl, int brightness)
329 {
330 	struct adp8860_bl *data = bl_get_data(bl);
331 	struct i2c_client *client = data->client;
332 	int ret = 0;
333 
334 	if (data->en_ambl_sens) {
335 		if ((brightness > 0) && (brightness < ADP8860_MAX_BRIGHTNESS)) {
336 			/* Disable Ambient Light auto adjust */
337 			ret |= adp8860_clr_bits(client, ADP8860_MDCR,
338 					CMP_AUTOEN);
339 			ret |= adp8860_write(client, ADP8860_BLMX1, brightness);
340 		} else {
341 			/*
342 			 * MAX_BRIGHTNESS -> Enable Ambient Light auto adjust
343 			 * restore daylight l1 sysfs brightness
344 			 */
345 			ret |= adp8860_write(client, ADP8860_BLMX1,
346 					 data->cached_daylight_max);
347 			ret |= adp8860_set_bits(client, ADP8860_MDCR,
348 					 CMP_AUTOEN);
349 		}
350 	} else
351 		ret |= adp8860_write(client, ADP8860_BLMX1, brightness);
352 
353 	if (data->current_brightness && brightness == 0)
354 		ret |= adp8860_set_bits(client,
355 				ADP8860_MDCR, DIM_EN);
356 	else if (data->current_brightness == 0 && brightness)
357 		ret |= adp8860_clr_bits(client,
358 				ADP8860_MDCR, DIM_EN);
359 
360 	if (!ret)
361 		data->current_brightness = brightness;
362 
363 	return ret;
364 }
365 
366 static int adp8860_bl_update_status(struct backlight_device *bl)
367 {
368 	int brightness = bl->props.brightness;
369 	if (bl->props.power != FB_BLANK_UNBLANK)
370 		brightness = 0;
371 
372 	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
373 		brightness = 0;
374 
375 	return adp8860_bl_set(bl, brightness);
376 }
377 
378 static int adp8860_bl_get_brightness(struct backlight_device *bl)
379 {
380 	struct adp8860_bl *data = bl_get_data(bl);
381 
382 	return data->current_brightness;
383 }
384 
385 static const struct backlight_ops adp8860_bl_ops = {
386 	.update_status	= adp8860_bl_update_status,
387 	.get_brightness	= adp8860_bl_get_brightness,
388 };
389 
390 static int adp8860_bl_setup(struct backlight_device *bl)
391 {
392 	struct adp8860_bl *data = bl_get_data(bl);
393 	struct i2c_client *client = data->client;
394 	struct adp8860_backlight_platform_data *pdata = data->pdata;
395 	int ret = 0;
396 
397 	ret |= adp8860_write(client, ADP8860_BLSEN, ~pdata->bl_led_assign);
398 	ret |= adp8860_write(client, ADP8860_BLMX1, pdata->l1_daylight_max);
399 	ret |= adp8860_write(client, ADP8860_BLDM1, pdata->l1_daylight_dim);
400 
401 	if (data->en_ambl_sens) {
402 		data->cached_daylight_max = pdata->l1_daylight_max;
403 		ret |= adp8860_write(client, ADP8860_BLMX2,
404 						pdata->l2_office_max);
405 		ret |= adp8860_write(client, ADP8860_BLDM2,
406 						pdata->l2_office_dim);
407 		ret |= adp8860_write(client, ADP8860_BLMX3,
408 						pdata->l3_dark_max);
409 		ret |= adp8860_write(client, ADP8860_BLDM3,
410 						pdata->l3_dark_dim);
411 
412 		ret |= adp8860_write(client, ADP8860_L2_TRP, pdata->l2_trip);
413 		ret |= adp8860_write(client, ADP8860_L2_HYS, pdata->l2_hyst);
414 		ret |= adp8860_write(client, ADP8860_L3_TRP, pdata->l3_trip);
415 		ret |= adp8860_write(client, ADP8860_L3_HYS, pdata->l3_hyst);
416 		ret |= adp8860_write(client, ADP8860_CCFG, L2_EN | L3_EN |
417 						ALS_CCFG_VAL(pdata->abml_filt));
418 	}
419 
420 	ret |= adp8860_write(client, ADP8860_CFGR,
421 			BL_CFGR_VAL(pdata->bl_fade_law, 0));
422 
423 	ret |= adp8860_write(client, ADP8860_BLFR, FADE_VAL(pdata->bl_fade_in,
424 			pdata->bl_fade_out));
425 
426 	ret |= adp8860_set_bits(client, ADP8860_MDCR, BLEN | DIM_EN | NSTBY |
427 			(data->gdwn_dis ? GDWN_DIS : 0));
428 
429 	return ret;
430 }
431 
432 static ssize_t adp8860_show(struct device *dev, char *buf, int reg)
433 {
434 	struct adp8860_bl *data = dev_get_drvdata(dev);
435 	int error;
436 	uint8_t reg_val;
437 
438 	mutex_lock(&data->lock);
439 	error = adp8860_read(data->client, reg, &reg_val);
440 	mutex_unlock(&data->lock);
441 
442 	if (error < 0)
443 		return error;
444 
445 	return sprintf(buf, "%u\n", reg_val);
446 }
447 
448 static ssize_t adp8860_store(struct device *dev, const char *buf,
449 			 size_t count, int reg)
450 {
451 	struct adp8860_bl *data = dev_get_drvdata(dev);
452 	unsigned long val;
453 	int ret;
454 
455 	ret = strict_strtoul(buf, 10, &val);
456 	if (ret)
457 		return ret;
458 
459 	mutex_lock(&data->lock);
460 	adp8860_write(data->client, reg, val);
461 	mutex_unlock(&data->lock);
462 
463 	return count;
464 }
465 
466 static ssize_t adp8860_bl_l3_dark_max_show(struct device *dev,
467 				     struct device_attribute *attr, char *buf)
468 {
469 	return adp8860_show(dev, buf, ADP8860_BLMX3);
470 }
471 
472 static ssize_t adp8860_bl_l3_dark_max_store(struct device *dev,
473 		struct device_attribute *attr, const char *buf, size_t count)
474 {
475 	return adp8860_store(dev, buf, count, ADP8860_BLMX3);
476 }
477 
478 static DEVICE_ATTR(l3_dark_max, 0664, adp8860_bl_l3_dark_max_show,
479 			adp8860_bl_l3_dark_max_store);
480 
481 static ssize_t adp8860_bl_l2_office_max_show(struct device *dev,
482 		struct device_attribute *attr, char *buf)
483 {
484 	return adp8860_show(dev, buf, ADP8860_BLMX2);
485 }
486 
487 static ssize_t adp8860_bl_l2_office_max_store(struct device *dev,
488 		struct device_attribute *attr, const char *buf, size_t count)
489 {
490 	return adp8860_store(dev, buf, count, ADP8860_BLMX2);
491 }
492 static DEVICE_ATTR(l2_office_max, 0664, adp8860_bl_l2_office_max_show,
493 			adp8860_bl_l2_office_max_store);
494 
495 static ssize_t adp8860_bl_l1_daylight_max_show(struct device *dev,
496 			struct device_attribute *attr, char *buf)
497 {
498 	return adp8860_show(dev, buf, ADP8860_BLMX1);
499 }
500 
501 static ssize_t adp8860_bl_l1_daylight_max_store(struct device *dev,
502 		struct device_attribute *attr, const char *buf, size_t count)
503 {
504 	struct adp8860_bl *data = dev_get_drvdata(dev);
505 	int ret = strict_strtoul(buf, 10, &data->cached_daylight_max);
506 	if (ret)
507 		return ret;
508 
509 	return adp8860_store(dev, buf, count, ADP8860_BLMX1);
510 }
511 static DEVICE_ATTR(l1_daylight_max, 0664, adp8860_bl_l1_daylight_max_show,
512 			adp8860_bl_l1_daylight_max_store);
513 
514 static ssize_t adp8860_bl_l3_dark_dim_show(struct device *dev,
515 			struct device_attribute *attr, char *buf)
516 {
517 	return adp8860_show(dev, buf, ADP8860_BLDM3);
518 }
519 
520 static ssize_t adp8860_bl_l3_dark_dim_store(struct device *dev,
521 				     struct device_attribute *attr,
522 				     const char *buf, size_t count)
523 {
524 	return adp8860_store(dev, buf, count, ADP8860_BLDM3);
525 }
526 static DEVICE_ATTR(l3_dark_dim, 0664, adp8860_bl_l3_dark_dim_show,
527 			adp8860_bl_l3_dark_dim_store);
528 
529 static ssize_t adp8860_bl_l2_office_dim_show(struct device *dev,
530 			struct device_attribute *attr, char *buf)
531 {
532 	return adp8860_show(dev, buf, ADP8860_BLDM2);
533 }
534 
535 static ssize_t adp8860_bl_l2_office_dim_store(struct device *dev,
536 				     struct device_attribute *attr,
537 				     const char *buf, size_t count)
538 {
539 	return adp8860_store(dev, buf, count, ADP8860_BLDM2);
540 }
541 static DEVICE_ATTR(l2_office_dim, 0664, adp8860_bl_l2_office_dim_show,
542 			adp8860_bl_l2_office_dim_store);
543 
544 static ssize_t adp8860_bl_l1_daylight_dim_show(struct device *dev,
545 				     struct device_attribute *attr, char *buf)
546 {
547 	return adp8860_show(dev, buf, ADP8860_BLDM1);
548 }
549 
550 static ssize_t adp8860_bl_l1_daylight_dim_store(struct device *dev,
551 				     struct device_attribute *attr,
552 				     const char *buf, size_t count)
553 {
554 	return adp8860_store(dev, buf, count, ADP8860_BLDM1);
555 }
556 static DEVICE_ATTR(l1_daylight_dim, 0664, adp8860_bl_l1_daylight_dim_show,
557 			adp8860_bl_l1_daylight_dim_store);
558 
559 #ifdef ADP8860_EXT_FEATURES
560 static ssize_t adp8860_bl_ambient_light_level_show(struct device *dev,
561 				     struct device_attribute *attr, char *buf)
562 {
563 	struct adp8860_bl *data = dev_get_drvdata(dev);
564 	int error;
565 	uint8_t reg_val;
566 	uint16_t ret_val;
567 
568 	mutex_lock(&data->lock);
569 	error = adp8860_read(data->client, ADP8860_PH1LEVL, &reg_val);
570 	ret_val = reg_val;
571 	error |= adp8860_read(data->client, ADP8860_PH1LEVH, &reg_val);
572 	mutex_unlock(&data->lock);
573 
574 	if (error < 0)
575 		return error;
576 
577 	/* Return 13-bit conversion value for the first light sensor */
578 	ret_val += (reg_val & 0x1F) << 8;
579 
580 	return sprintf(buf, "%u\n", ret_val);
581 }
582 static DEVICE_ATTR(ambient_light_level, 0444,
583 		adp8860_bl_ambient_light_level_show, NULL);
584 
585 static ssize_t adp8860_bl_ambient_light_zone_show(struct device *dev,
586 				     struct device_attribute *attr, char *buf)
587 {
588 	struct adp8860_bl *data = dev_get_drvdata(dev);
589 	int error;
590 	uint8_t reg_val;
591 
592 	mutex_lock(&data->lock);
593 	error = adp8860_read(data->client, ADP8860_CFGR, &reg_val);
594 	mutex_unlock(&data->lock);
595 
596 	if (error < 0)
597 		return error;
598 
599 	return sprintf(buf, "%u\n",
600 		((reg_val >> CFGR_BLV_SHIFT) & CFGR_BLV_MASK) + 1);
601 }
602 
603 static ssize_t adp8860_bl_ambient_light_zone_store(struct device *dev,
604 				     struct device_attribute *attr,
605 				     const char *buf, size_t count)
606 {
607 	struct adp8860_bl *data = dev_get_drvdata(dev);
608 	unsigned long val;
609 	uint8_t reg_val;
610 	int ret;
611 
612 	ret = strict_strtoul(buf, 10, &val);
613 	if (ret)
614 		return ret;
615 
616 	if (val == 0) {
617 		/* Enable automatic ambient light sensing */
618 		adp8860_set_bits(data->client, ADP8860_MDCR, CMP_AUTOEN);
619 	} else if ((val > 0) && (val <= 3)) {
620 		/* Disable automatic ambient light sensing */
621 		adp8860_clr_bits(data->client, ADP8860_MDCR, CMP_AUTOEN);
622 
623 		/* Set user supplied ambient light zone */
624 		mutex_lock(&data->lock);
625 		adp8860_read(data->client, ADP8860_CFGR, &reg_val);
626 		reg_val &= ~(CFGR_BLV_MASK << CFGR_BLV_SHIFT);
627 		reg_val |= (val - 1) << CFGR_BLV_SHIFT;
628 		adp8860_write(data->client, ADP8860_CFGR, reg_val);
629 		mutex_unlock(&data->lock);
630 	}
631 
632 	return count;
633 }
634 static DEVICE_ATTR(ambient_light_zone, 0664,
635 		adp8860_bl_ambient_light_zone_show,
636 		adp8860_bl_ambient_light_zone_store);
637 #endif
638 
639 static struct attribute *adp8860_bl_attributes[] = {
640 	&dev_attr_l3_dark_max.attr,
641 	&dev_attr_l3_dark_dim.attr,
642 	&dev_attr_l2_office_max.attr,
643 	&dev_attr_l2_office_dim.attr,
644 	&dev_attr_l1_daylight_max.attr,
645 	&dev_attr_l1_daylight_dim.attr,
646 #ifdef ADP8860_EXT_FEATURES
647 	&dev_attr_ambient_light_level.attr,
648 	&dev_attr_ambient_light_zone.attr,
649 #endif
650 	NULL
651 };
652 
653 static const struct attribute_group adp8860_bl_attr_group = {
654 	.attrs = adp8860_bl_attributes,
655 };
656 
657 static int __devinit adp8860_probe(struct i2c_client *client,
658 					const struct i2c_device_id *id)
659 {
660 	struct backlight_device *bl;
661 	struct adp8860_bl *data;
662 	struct adp8860_backlight_platform_data *pdata =
663 		client->dev.platform_data;
664 	struct backlight_properties props;
665 	uint8_t reg_val;
666 	int ret;
667 
668 	if (!i2c_check_functionality(client->adapter,
669 					I2C_FUNC_SMBUS_BYTE_DATA)) {
670 		dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
671 		return -EIO;
672 	}
673 
674 	if (!pdata) {
675 		dev_err(&client->dev, "no platform data?\n");
676 		return -EINVAL;
677 	}
678 
679 	data = kzalloc(sizeof(*data), GFP_KERNEL);
680 	if (data == NULL)
681 		return -ENOMEM;
682 
683 	ret = adp8860_read(client, ADP8860_MFDVID, &reg_val);
684 	if (ret < 0)
685 		goto out2;
686 
687 	switch (ADP8860_MANID(reg_val)) {
688 	case ADP8863_MANUFID:
689 		data->gdwn_dis = !!pdata->gdwn_dis;
690 	case ADP8860_MANUFID:
691 		data->en_ambl_sens = !!pdata->en_ambl_sens;
692 		break;
693 	case ADP8861_MANUFID:
694 		data->gdwn_dis = !!pdata->gdwn_dis;
695 		break;
696 	default:
697 		dev_err(&client->dev, "failed to probe\n");
698 		ret = -ENODEV;
699 		goto out2;
700 	}
701 
702 	/* It's confirmed that the DEVID field is actually a REVID */
703 
704 	data->revid = ADP8860_DEVID(reg_val);
705 	data->client = client;
706 	data->pdata = pdata;
707 	data->id = id->driver_data;
708 	data->current_brightness = 0;
709 	i2c_set_clientdata(client, data);
710 
711 	memset(&props, 0, sizeof(props));
712 	props.type = BACKLIGHT_RAW;
713 	props.max_brightness = ADP8860_MAX_BRIGHTNESS;
714 
715 	mutex_init(&data->lock);
716 
717 	bl = backlight_device_register(dev_driver_string(&client->dev),
718 			&client->dev, data, &adp8860_bl_ops, &props);
719 	if (IS_ERR(bl)) {
720 		dev_err(&client->dev, "failed to register backlight\n");
721 		ret = PTR_ERR(bl);
722 		goto out2;
723 	}
724 
725 	bl->props.max_brightness =
726 		bl->props.brightness = ADP8860_MAX_BRIGHTNESS;
727 
728 	data->bl = bl;
729 
730 	if (data->en_ambl_sens)
731 		ret = sysfs_create_group(&bl->dev.kobj,
732 			&adp8860_bl_attr_group);
733 
734 	if (ret) {
735 		dev_err(&client->dev, "failed to register sysfs\n");
736 		goto out1;
737 	}
738 
739 	ret = adp8860_bl_setup(bl);
740 	if (ret) {
741 		ret = -EIO;
742 		goto out;
743 	}
744 
745 	backlight_update_status(bl);
746 
747 	dev_info(&client->dev, "%s Rev.%d Backlight\n",
748 		client->name, data->revid);
749 
750 	if (pdata->num_leds)
751 		adp8860_led_probe(client);
752 
753 	return 0;
754 
755 out:
756 	if (data->en_ambl_sens)
757 		sysfs_remove_group(&data->bl->dev.kobj,
758 			&adp8860_bl_attr_group);
759 out1:
760 	backlight_device_unregister(bl);
761 out2:
762 	kfree(data);
763 
764 	return ret;
765 }
766 
767 static int __devexit adp8860_remove(struct i2c_client *client)
768 {
769 	struct adp8860_bl *data = i2c_get_clientdata(client);
770 
771 	adp8860_clr_bits(client, ADP8860_MDCR, NSTBY);
772 
773 	if (data->led)
774 		adp8860_led_remove(client);
775 
776 	if (data->en_ambl_sens)
777 		sysfs_remove_group(&data->bl->dev.kobj,
778 			&adp8860_bl_attr_group);
779 
780 	backlight_device_unregister(data->bl);
781 	kfree(data);
782 
783 	return 0;
784 }
785 
786 #ifdef CONFIG_PM
787 static int adp8860_i2c_suspend(struct i2c_client *client, pm_message_t message)
788 {
789 	adp8860_clr_bits(client, ADP8860_MDCR, NSTBY);
790 
791 	return 0;
792 }
793 
794 static int adp8860_i2c_resume(struct i2c_client *client)
795 {
796 	adp8860_set_bits(client, ADP8860_MDCR, NSTBY);
797 
798 	return 0;
799 }
800 #else
801 #define adp8860_i2c_suspend NULL
802 #define adp8860_i2c_resume NULL
803 #endif
804 
805 static const struct i2c_device_id adp8860_id[] = {
806 	{ "adp8860", adp8860 },
807 	{ "adp8861", adp8861 },
808 	{ "adp8863", adp8863 },
809 	{ }
810 };
811 MODULE_DEVICE_TABLE(i2c, adp8860_id);
812 
813 static struct i2c_driver adp8860_driver = {
814 	.driver = {
815 		.name = KBUILD_MODNAME,
816 	},
817 	.probe    = adp8860_probe,
818 	.remove   = __devexit_p(adp8860_remove),
819 	.suspend = adp8860_i2c_suspend,
820 	.resume  = adp8860_i2c_resume,
821 	.id_table = adp8860_id,
822 };
823 
824 static int __init adp8860_init(void)
825 {
826 	return i2c_add_driver(&adp8860_driver);
827 }
828 module_init(adp8860_init);
829 
830 static void __exit adp8860_exit(void)
831 {
832 	i2c_del_driver(&adp8860_driver);
833 }
834 module_exit(adp8860_exit);
835 
836 MODULE_LICENSE("GPL v2");
837 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
838 MODULE_DESCRIPTION("ADP8860 Backlight driver");
839 MODULE_ALIAS("i2c:adp8860-backlight");
840