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) == 0)) {
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 __devinit 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 = kzalloc(sizeof(*led) * pdata->num_leds, GFP_KERNEL);
226 	if (led == NULL) {
227 		dev_err(&client->dev, "failed to alloc memory\n");
228 		return -ENOMEM;
229 	}
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 		goto err_free;
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 			goto err;
252 		}
253 
254 		if (pdata->bl_led_assign & (1 << (led_dat->id - 1))) {
255 			dev_err(&client->dev, "LED %d used by Backlight\n",
256 				led_dat->id);
257 			goto err;
258 		}
259 
260 		led_dat->cdev.name = cur_led->name;
261 		led_dat->cdev.default_trigger = cur_led->default_trigger;
262 		led_dat->cdev.brightness_set = adp8860_led_set;
263 		led_dat->cdev.brightness = LED_OFF;
264 		led_dat->flags = cur_led->flags >> FLAG_OFFT_SHIFT;
265 		led_dat->client = client;
266 		led_dat->new_brightness = LED_OFF;
267 		INIT_WORK(&led_dat->work, adp8860_led_work);
268 
269 		ret = led_classdev_register(&client->dev, &led_dat->cdev);
270 		if (ret) {
271 			dev_err(&client->dev, "failed to register LED %d\n",
272 				led_dat->id);
273 			goto err;
274 		}
275 
276 		ret = adp8860_led_setup(led_dat);
277 		if (ret) {
278 			dev_err(&client->dev, "failed to write\n");
279 			i++;
280 			goto err;
281 		}
282 	}
283 
284 	data->led = led;
285 
286 	return 0;
287 
288  err:
289 	for (i = i - 1; i >= 0; --i) {
290 		led_classdev_unregister(&led[i].cdev);
291 		cancel_work_sync(&led[i].work);
292 	}
293 
294  err_free:
295 	kfree(led);
296 
297 	return ret;
298 }
299 
300 static int __devexit adp8860_led_remove(struct i2c_client *client)
301 {
302 	struct adp8860_backlight_platform_data *pdata =
303 		client->dev.platform_data;
304 	struct adp8860_bl *data = i2c_get_clientdata(client);
305 	int i;
306 
307 	for (i = 0; i < pdata->num_leds; i++) {
308 		led_classdev_unregister(&data->led[i].cdev);
309 		cancel_work_sync(&data->led[i].work);
310 	}
311 
312 	kfree(data->led);
313 	return 0;
314 }
315 #else
316 static int __devinit adp8860_led_probe(struct i2c_client *client)
317 {
318 	return 0;
319 }
320 
321 static int __devexit adp8860_led_remove(struct i2c_client *client)
322 {
323 	return 0;
324 }
325 #endif
326 
327 static int adp8860_bl_set(struct backlight_device *bl, int brightness)
328 {
329 	struct adp8860_bl *data = bl_get_data(bl);
330 	struct i2c_client *client = data->client;
331 	int ret = 0;
332 
333 	if (data->en_ambl_sens) {
334 		if ((brightness > 0) && (brightness < ADP8860_MAX_BRIGHTNESS)) {
335 			/* Disable Ambient Light auto adjust */
336 			ret |= adp8860_clr_bits(client, ADP8860_MDCR,
337 					CMP_AUTOEN);
338 			ret |= adp8860_write(client, ADP8860_BLMX1, brightness);
339 		} else {
340 			/*
341 			 * MAX_BRIGHTNESS -> Enable Ambient Light auto adjust
342 			 * restore daylight l1 sysfs brightness
343 			 */
344 			ret |= adp8860_write(client, ADP8860_BLMX1,
345 					 data->cached_daylight_max);
346 			ret |= adp8860_set_bits(client, ADP8860_MDCR,
347 					 CMP_AUTOEN);
348 		}
349 	} else
350 		ret |= adp8860_write(client, ADP8860_BLMX1, brightness);
351 
352 	if (data->current_brightness && brightness == 0)
353 		ret |= adp8860_set_bits(client,
354 				ADP8860_MDCR, DIM_EN);
355 	else if (data->current_brightness == 0 && brightness)
356 		ret |= adp8860_clr_bits(client,
357 				ADP8860_MDCR, DIM_EN);
358 
359 	if (!ret)
360 		data->current_brightness = brightness;
361 
362 	return ret;
363 }
364 
365 static int adp8860_bl_update_status(struct backlight_device *bl)
366 {
367 	int brightness = bl->props.brightness;
368 	if (bl->props.power != FB_BLANK_UNBLANK)
369 		brightness = 0;
370 
371 	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
372 		brightness = 0;
373 
374 	return adp8860_bl_set(bl, brightness);
375 }
376 
377 static int adp8860_bl_get_brightness(struct backlight_device *bl)
378 {
379 	struct adp8860_bl *data = bl_get_data(bl);
380 
381 	return data->current_brightness;
382 }
383 
384 static const struct backlight_ops adp8860_bl_ops = {
385 	.update_status	= adp8860_bl_update_status,
386 	.get_brightness	= adp8860_bl_get_brightness,
387 };
388 
389 static int adp8860_bl_setup(struct backlight_device *bl)
390 {
391 	struct adp8860_bl *data = bl_get_data(bl);
392 	struct i2c_client *client = data->client;
393 	struct adp8860_backlight_platform_data *pdata = data->pdata;
394 	int ret = 0;
395 
396 	ret |= adp8860_write(client, ADP8860_BLSEN, ~pdata->bl_led_assign);
397 	ret |= adp8860_write(client, ADP8860_BLMX1, pdata->l1_daylight_max);
398 	ret |= adp8860_write(client, ADP8860_BLDM1, pdata->l1_daylight_dim);
399 
400 	if (data->en_ambl_sens) {
401 		data->cached_daylight_max = pdata->l1_daylight_max;
402 		ret |= adp8860_write(client, ADP8860_BLMX2,
403 						pdata->l2_office_max);
404 		ret |= adp8860_write(client, ADP8860_BLDM2,
405 						pdata->l2_office_dim);
406 		ret |= adp8860_write(client, ADP8860_BLMX3,
407 						pdata->l3_dark_max);
408 		ret |= adp8860_write(client, ADP8860_BLDM3,
409 						pdata->l3_dark_dim);
410 
411 		ret |= adp8860_write(client, ADP8860_L2_TRP, pdata->l2_trip);
412 		ret |= adp8860_write(client, ADP8860_L2_HYS, pdata->l2_hyst);
413 		ret |= adp8860_write(client, ADP8860_L3_TRP, pdata->l3_trip);
414 		ret |= adp8860_write(client, ADP8860_L3_HYS, pdata->l3_hyst);
415 		ret |= adp8860_write(client, ADP8860_CCFG, L2_EN | L3_EN |
416 						ALS_CCFG_VAL(pdata->abml_filt));
417 	}
418 
419 	ret |= adp8860_write(client, ADP8860_CFGR,
420 			BL_CFGR_VAL(pdata->bl_fade_law, 0));
421 
422 	ret |= adp8860_write(client, ADP8860_BLFR, FADE_VAL(pdata->bl_fade_in,
423 			pdata->bl_fade_out));
424 
425 	ret |= adp8860_set_bits(client, ADP8860_MDCR, BLEN | DIM_EN | NSTBY |
426 			(data->gdwn_dis ? GDWN_DIS : 0));
427 
428 	return ret;
429 }
430 
431 static ssize_t adp8860_show(struct device *dev, char *buf, int reg)
432 {
433 	struct adp8860_bl *data = dev_get_drvdata(dev);
434 	int error;
435 	uint8_t reg_val;
436 
437 	mutex_lock(&data->lock);
438 	error = adp8860_read(data->client, reg, &reg_val);
439 	mutex_unlock(&data->lock);
440 
441 	if (error < 0)
442 		return error;
443 
444 	return sprintf(buf, "%u\n", reg_val);
445 }
446 
447 static ssize_t adp8860_store(struct device *dev, const char *buf,
448 			 size_t count, int reg)
449 {
450 	struct adp8860_bl *data = dev_get_drvdata(dev);
451 	unsigned long val;
452 	int ret;
453 
454 	ret = strict_strtoul(buf, 10, &val);
455 	if (ret)
456 		return ret;
457 
458 	mutex_lock(&data->lock);
459 	adp8860_write(data->client, reg, val);
460 	mutex_unlock(&data->lock);
461 
462 	return count;
463 }
464 
465 static ssize_t adp8860_bl_l3_dark_max_show(struct device *dev,
466 				     struct device_attribute *attr, char *buf)
467 {
468 	return adp8860_show(dev, buf, ADP8860_BLMX3);
469 }
470 
471 static ssize_t adp8860_bl_l3_dark_max_store(struct device *dev,
472 		struct device_attribute *attr, const char *buf, size_t count)
473 {
474 	return adp8860_store(dev, buf, count, ADP8860_BLMX3);
475 }
476 
477 static DEVICE_ATTR(l3_dark_max, 0664, adp8860_bl_l3_dark_max_show,
478 			adp8860_bl_l3_dark_max_store);
479 
480 static ssize_t adp8860_bl_l2_office_max_show(struct device *dev,
481 		struct device_attribute *attr, char *buf)
482 {
483 	return adp8860_show(dev, buf, ADP8860_BLMX2);
484 }
485 
486 static ssize_t adp8860_bl_l2_office_max_store(struct device *dev,
487 		struct device_attribute *attr, const char *buf, size_t count)
488 {
489 	return adp8860_store(dev, buf, count, ADP8860_BLMX2);
490 }
491 static DEVICE_ATTR(l2_office_max, 0664, adp8860_bl_l2_office_max_show,
492 			adp8860_bl_l2_office_max_store);
493 
494 static ssize_t adp8860_bl_l1_daylight_max_show(struct device *dev,
495 			struct device_attribute *attr, char *buf)
496 {
497 	return adp8860_show(dev, buf, ADP8860_BLMX1);
498 }
499 
500 static ssize_t adp8860_bl_l1_daylight_max_store(struct device *dev,
501 		struct device_attribute *attr, const char *buf, size_t count)
502 {
503 	struct adp8860_bl *data = dev_get_drvdata(dev);
504 	int ret = strict_strtoul(buf, 10, &data->cached_daylight_max);
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 = strict_strtoul(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 __devinit 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 		client->dev.platform_data;
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 = kzalloc(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 		goto out2;
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 		ret = -ENODEV;
698 		goto out2;
699 	}
700 
701 	/* It's confirmed that the DEVID field is actually a REVID */
702 
703 	data->revid = ADP8860_DEVID(reg_val);
704 	data->client = client;
705 	data->pdata = pdata;
706 	data->id = id->driver_data;
707 	data->current_brightness = 0;
708 	i2c_set_clientdata(client, data);
709 
710 	memset(&props, 0, sizeof(props));
711 	props.type = BACKLIGHT_RAW;
712 	props.max_brightness = ADP8860_MAX_BRIGHTNESS;
713 
714 	mutex_init(&data->lock);
715 
716 	bl = backlight_device_register(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 		ret = PTR_ERR(bl);
721 		goto out2;
722 	}
723 
724 	bl->props.brightness = ADP8860_MAX_BRIGHTNESS;
725 
726 	data->bl = bl;
727 
728 	if (data->en_ambl_sens)
729 		ret = sysfs_create_group(&bl->dev.kobj,
730 			&adp8860_bl_attr_group);
731 
732 	if (ret) {
733 		dev_err(&client->dev, "failed to register sysfs\n");
734 		goto out1;
735 	}
736 
737 	ret = adp8860_bl_setup(bl);
738 	if (ret) {
739 		ret = -EIO;
740 		goto out;
741 	}
742 
743 	backlight_update_status(bl);
744 
745 	dev_info(&client->dev, "%s Rev.%d Backlight\n",
746 		client->name, data->revid);
747 
748 	if (pdata->num_leds)
749 		adp8860_led_probe(client);
750 
751 	return 0;
752 
753 out:
754 	if (data->en_ambl_sens)
755 		sysfs_remove_group(&data->bl->dev.kobj,
756 			&adp8860_bl_attr_group);
757 out1:
758 	backlight_device_unregister(bl);
759 out2:
760 	kfree(data);
761 
762 	return ret;
763 }
764 
765 static int __devexit adp8860_remove(struct i2c_client *client)
766 {
767 	struct adp8860_bl *data = i2c_get_clientdata(client);
768 
769 	adp8860_clr_bits(client, ADP8860_MDCR, NSTBY);
770 
771 	if (data->led)
772 		adp8860_led_remove(client);
773 
774 	if (data->en_ambl_sens)
775 		sysfs_remove_group(&data->bl->dev.kobj,
776 			&adp8860_bl_attr_group);
777 
778 	backlight_device_unregister(data->bl);
779 	kfree(data);
780 
781 	return 0;
782 }
783 
784 #ifdef CONFIG_PM
785 static int adp8860_i2c_suspend(struct i2c_client *client, pm_message_t message)
786 {
787 	adp8860_clr_bits(client, ADP8860_MDCR, NSTBY);
788 
789 	return 0;
790 }
791 
792 static int adp8860_i2c_resume(struct i2c_client *client)
793 {
794 	adp8860_set_bits(client, ADP8860_MDCR, NSTBY);
795 
796 	return 0;
797 }
798 #else
799 #define adp8860_i2c_suspend NULL
800 #define adp8860_i2c_resume NULL
801 #endif
802 
803 static const struct i2c_device_id adp8860_id[] = {
804 	{ "adp8860", adp8860 },
805 	{ "adp8861", adp8861 },
806 	{ "adp8863", adp8863 },
807 	{ }
808 };
809 MODULE_DEVICE_TABLE(i2c, adp8860_id);
810 
811 static struct i2c_driver adp8860_driver = {
812 	.driver = {
813 		.name = KBUILD_MODNAME,
814 	},
815 	.probe    = adp8860_probe,
816 	.remove   = __devexit_p(adp8860_remove),
817 	.suspend = adp8860_i2c_suspend,
818 	.resume  = adp8860_i2c_resume,
819 	.id_table = adp8860_id,
820 };
821 
822 static int __init adp8860_init(void)
823 {
824 	return i2c_add_driver(&adp8860_driver);
825 }
826 module_init(adp8860_init);
827 
828 static void __exit adp8860_exit(void)
829 {
830 	i2c_del_driver(&adp8860_driver);
831 }
832 module_exit(adp8860_exit);
833 
834 MODULE_LICENSE("GPL v2");
835 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
836 MODULE_DESCRIPTION("ADP8860 Backlight driver");
837 MODULE_ALIAS("i2c:adp8860-backlight");
838