1 /*
2  * Backlight driver for Analog Devices ADP5520/ADP5501 MFD PMICs
3  *
4  * Copyright 2009 Analog Devices Inc.
5  *
6  * Licensed under the GPL-2 or later.
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/platform_device.h>
12 #include <linux/fb.h>
13 #include <linux/backlight.h>
14 #include <linux/mfd/adp5520.h>
15 #include <linux/slab.h>
16 
17 struct adp5520_bl {
18 	struct device *master;
19 	struct adp5520_backlight_platform_data *pdata;
20 	struct mutex lock;
21 	unsigned long cached_daylight_max;
22 	int id;
23 	int current_brightness;
24 };
25 
26 static int adp5520_bl_set(struct backlight_device *bl, int brightness)
27 {
28 	struct adp5520_bl *data = bl_get_data(bl);
29 	struct device *master = data->master;
30 	int ret = 0;
31 
32 	if (data->pdata->en_ambl_sens) {
33 		if ((brightness > 0) && (brightness < ADP5020_MAX_BRIGHTNESS)) {
34 			/* Disable Ambient Light auto adjust */
35 			ret |= adp5520_clr_bits(master, ADP5520_BL_CONTROL,
36 					ADP5520_BL_AUTO_ADJ);
37 			ret |= adp5520_write(master, ADP5520_DAYLIGHT_MAX,
38 					brightness);
39 		} else {
40 			/*
41 			 * MAX_BRIGHTNESS -> Enable Ambient Light auto adjust
42 			 * restore daylight l3 sysfs brightness
43 			 */
44 			ret |= adp5520_write(master, ADP5520_DAYLIGHT_MAX,
45 					 data->cached_daylight_max);
46 			ret |= adp5520_set_bits(master, ADP5520_BL_CONTROL,
47 					 ADP5520_BL_AUTO_ADJ);
48 		}
49 	} else {
50 		ret |= adp5520_write(master, ADP5520_DAYLIGHT_MAX, brightness);
51 	}
52 
53 	if (data->current_brightness && brightness == 0)
54 		ret |= adp5520_set_bits(master,
55 				ADP5520_MODE_STATUS, ADP5520_DIM_EN);
56 	else if (data->current_brightness == 0 && brightness)
57 		ret |= adp5520_clr_bits(master,
58 				ADP5520_MODE_STATUS, ADP5520_DIM_EN);
59 
60 	if (!ret)
61 		data->current_brightness = brightness;
62 
63 	return ret;
64 }
65 
66 static int adp5520_bl_update_status(struct backlight_device *bl)
67 {
68 	int brightness = bl->props.brightness;
69 	if (bl->props.power != FB_BLANK_UNBLANK)
70 		brightness = 0;
71 
72 	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
73 		brightness = 0;
74 
75 	return adp5520_bl_set(bl, brightness);
76 }
77 
78 static int adp5520_bl_get_brightness(struct backlight_device *bl)
79 {
80 	struct adp5520_bl *data = bl_get_data(bl);
81 	int error;
82 	uint8_t reg_val;
83 
84 	error = adp5520_read(data->master, ADP5520_BL_VALUE, &reg_val);
85 
86 	return error ? data->current_brightness : reg_val;
87 }
88 
89 static const struct backlight_ops adp5520_bl_ops = {
90 	.update_status	= adp5520_bl_update_status,
91 	.get_brightness	= adp5520_bl_get_brightness,
92 };
93 
94 static int adp5520_bl_setup(struct backlight_device *bl)
95 {
96 	struct adp5520_bl *data = bl_get_data(bl);
97 	struct device *master = data->master;
98 	struct adp5520_backlight_platform_data *pdata = data->pdata;
99 	int ret = 0;
100 
101 	ret |= adp5520_write(master, ADP5520_DAYLIGHT_MAX,
102 				pdata->l1_daylight_max);
103 	ret |= adp5520_write(master, ADP5520_DAYLIGHT_DIM,
104 				pdata->l1_daylight_dim);
105 
106 	if (pdata->en_ambl_sens) {
107 		data->cached_daylight_max = pdata->l1_daylight_max;
108 		ret |= adp5520_write(master, ADP5520_OFFICE_MAX,
109 				pdata->l2_office_max);
110 		ret |= adp5520_write(master, ADP5520_OFFICE_DIM,
111 				pdata->l2_office_dim);
112 		ret |= adp5520_write(master, ADP5520_DARK_MAX,
113 				pdata->l3_dark_max);
114 		ret |= adp5520_write(master, ADP5520_DARK_DIM,
115 				pdata->l3_dark_dim);
116 		ret |= adp5520_write(master, ADP5520_L2_TRIP,
117 				pdata->l2_trip);
118 		ret |= adp5520_write(master, ADP5520_L2_HYS,
119 				pdata->l2_hyst);
120 		ret |= adp5520_write(master, ADP5520_L3_TRIP,
121 				 pdata->l3_trip);
122 		ret |= adp5520_write(master, ADP5520_L3_HYS,
123 				pdata->l3_hyst);
124 		ret |= adp5520_write(master, ADP5520_ALS_CMPR_CFG,
125 				ALS_CMPR_CFG_VAL(pdata->abml_filt,
126 				ADP5520_L3_EN));
127 	}
128 
129 	ret |= adp5520_write(master, ADP5520_BL_CONTROL,
130 			BL_CTRL_VAL(pdata->fade_led_law,
131 					pdata->en_ambl_sens));
132 
133 	ret |= adp5520_write(master, ADP5520_BL_FADE, FADE_VAL(pdata->fade_in,
134 			pdata->fade_out));
135 
136 	ret |= adp5520_set_bits(master, ADP5520_MODE_STATUS,
137 			ADP5520_BL_EN | ADP5520_DIM_EN);
138 
139 	return ret;
140 }
141 
142 static ssize_t adp5520_show(struct device *dev, char *buf, int reg)
143 {
144 	struct adp5520_bl *data = dev_get_drvdata(dev);
145 	int error;
146 	uint8_t reg_val;
147 
148 	mutex_lock(&data->lock);
149 	error = adp5520_read(data->master, reg, &reg_val);
150 	mutex_unlock(&data->lock);
151 
152 	return sprintf(buf, "%u\n", reg_val);
153 }
154 
155 static ssize_t adp5520_store(struct device *dev, const char *buf,
156 			 size_t count, int reg)
157 {
158 	struct adp5520_bl *data = dev_get_drvdata(dev);
159 	unsigned long val;
160 	int ret;
161 
162 	ret = strict_strtoul(buf, 10, &val);
163 	if (ret)
164 		return ret;
165 
166 	mutex_lock(&data->lock);
167 	adp5520_write(data->master, reg, val);
168 	mutex_unlock(&data->lock);
169 
170 	return count;
171 }
172 
173 static ssize_t adp5520_bl_dark_max_show(struct device *dev,
174 			struct device_attribute *attr, char *buf)
175 {
176 	return adp5520_show(dev, buf, ADP5520_DARK_MAX);
177 }
178 
179 static ssize_t adp5520_bl_dark_max_store(struct device *dev,
180 			struct device_attribute *attr,
181 			const char *buf, size_t count)
182 {
183 	return adp5520_store(dev, buf, count, ADP5520_DARK_MAX);
184 }
185 static DEVICE_ATTR(dark_max, 0664, adp5520_bl_dark_max_show,
186 			adp5520_bl_dark_max_store);
187 
188 static ssize_t adp5520_bl_office_max_show(struct device *dev,
189 			struct device_attribute *attr, char *buf)
190 {
191 	return adp5520_show(dev, buf, ADP5520_OFFICE_MAX);
192 }
193 
194 static ssize_t adp5520_bl_office_max_store(struct device *dev,
195 			struct device_attribute *attr,
196 			const char *buf, size_t count)
197 {
198 	return adp5520_store(dev, buf, count, ADP5520_OFFICE_MAX);
199 }
200 static DEVICE_ATTR(office_max, 0664, adp5520_bl_office_max_show,
201 			adp5520_bl_office_max_store);
202 
203 static ssize_t adp5520_bl_daylight_max_show(struct device *dev,
204 			struct device_attribute *attr, char *buf)
205 {
206 	return adp5520_show(dev, buf, ADP5520_DAYLIGHT_MAX);
207 }
208 
209 static ssize_t adp5520_bl_daylight_max_store(struct device *dev,
210 			struct device_attribute *attr,
211 			const char *buf, size_t count)
212 {
213 	struct adp5520_bl *data = dev_get_drvdata(dev);
214 	int ret;
215 
216 	ret = strict_strtoul(buf, 10, &data->cached_daylight_max);
217 	if (ret < 0)
218 		return ret;
219 
220 	return adp5520_store(dev, buf, count, ADP5520_DAYLIGHT_MAX);
221 }
222 static DEVICE_ATTR(daylight_max, 0664, adp5520_bl_daylight_max_show,
223 			adp5520_bl_daylight_max_store);
224 
225 static ssize_t adp5520_bl_dark_dim_show(struct device *dev,
226 			struct device_attribute *attr, char *buf)
227 {
228 	return adp5520_show(dev, buf, ADP5520_DARK_DIM);
229 }
230 
231 static ssize_t adp5520_bl_dark_dim_store(struct device *dev,
232 			struct device_attribute *attr,
233 			const char *buf, size_t count)
234 {
235 	return adp5520_store(dev, buf, count, ADP5520_DARK_DIM);
236 }
237 static DEVICE_ATTR(dark_dim, 0664, adp5520_bl_dark_dim_show,
238 			adp5520_bl_dark_dim_store);
239 
240 static ssize_t adp5520_bl_office_dim_show(struct device *dev,
241 			struct device_attribute *attr, char *buf)
242 {
243 	return adp5520_show(dev, buf, ADP5520_OFFICE_DIM);
244 }
245 
246 static ssize_t adp5520_bl_office_dim_store(struct device *dev,
247 			struct device_attribute *attr,
248 			const char *buf, size_t count)
249 {
250 	return adp5520_store(dev, buf, count, ADP5520_OFFICE_DIM);
251 }
252 static DEVICE_ATTR(office_dim, 0664, adp5520_bl_office_dim_show,
253 			adp5520_bl_office_dim_store);
254 
255 static ssize_t adp5520_bl_daylight_dim_show(struct device *dev,
256 			struct device_attribute *attr, char *buf)
257 {
258 	return adp5520_show(dev, buf, ADP5520_DAYLIGHT_DIM);
259 }
260 
261 static ssize_t adp5520_bl_daylight_dim_store(struct device *dev,
262 			struct device_attribute *attr,
263 			const char *buf, size_t count)
264 {
265 	return adp5520_store(dev, buf, count, ADP5520_DAYLIGHT_DIM);
266 }
267 static DEVICE_ATTR(daylight_dim, 0664, adp5520_bl_daylight_dim_show,
268 			adp5520_bl_daylight_dim_store);
269 
270 static struct attribute *adp5520_bl_attributes[] = {
271 	&dev_attr_dark_max.attr,
272 	&dev_attr_dark_dim.attr,
273 	&dev_attr_office_max.attr,
274 	&dev_attr_office_dim.attr,
275 	&dev_attr_daylight_max.attr,
276 	&dev_attr_daylight_dim.attr,
277 	NULL
278 };
279 
280 static const struct attribute_group adp5520_bl_attr_group = {
281 	.attrs = adp5520_bl_attributes,
282 };
283 
284 static int __devinit adp5520_bl_probe(struct platform_device *pdev)
285 {
286 	struct backlight_properties props;
287 	struct backlight_device *bl;
288 	struct adp5520_bl *data;
289 	int ret = 0;
290 
291 	data = kzalloc(sizeof(*data), GFP_KERNEL);
292 	if (data == NULL)
293 		return -ENOMEM;
294 
295 	data->master = pdev->dev.parent;
296 	data->pdata = pdev->dev.platform_data;
297 
298 	if (data->pdata  == NULL) {
299 		dev_err(&pdev->dev, "missing platform data\n");
300 		kfree(data);
301 		return -ENODEV;
302 	}
303 
304 	data->id = pdev->id;
305 	data->current_brightness = 0;
306 
307 	mutex_init(&data->lock);
308 
309 	memset(&props, 0, sizeof(struct backlight_properties));
310 	props.type = BACKLIGHT_RAW;
311 	props.max_brightness = ADP5020_MAX_BRIGHTNESS;
312 	bl = backlight_device_register(pdev->name, data->master, data,
313 				       &adp5520_bl_ops, &props);
314 	if (IS_ERR(bl)) {
315 		dev_err(&pdev->dev, "failed to register backlight\n");
316 		kfree(data);
317 		return PTR_ERR(bl);
318 	}
319 
320 	bl->props.brightness = ADP5020_MAX_BRIGHTNESS;
321 	if (data->pdata->en_ambl_sens)
322 		ret = sysfs_create_group(&bl->dev.kobj,
323 			&adp5520_bl_attr_group);
324 
325 	if (ret) {
326 		dev_err(&pdev->dev, "failed to register sysfs\n");
327 		backlight_device_unregister(bl);
328 		kfree(data);
329 	}
330 
331 	platform_set_drvdata(pdev, bl);
332 	ret |= adp5520_bl_setup(bl);
333 	backlight_update_status(bl);
334 
335 	return ret;
336 }
337 
338 static int __devexit adp5520_bl_remove(struct platform_device *pdev)
339 {
340 	struct backlight_device *bl = platform_get_drvdata(pdev);
341 	struct adp5520_bl *data = bl_get_data(bl);
342 
343 	adp5520_clr_bits(data->master, ADP5520_MODE_STATUS, ADP5520_BL_EN);
344 
345 	if (data->pdata->en_ambl_sens)
346 		sysfs_remove_group(&bl->dev.kobj,
347 				&adp5520_bl_attr_group);
348 
349 	backlight_device_unregister(bl);
350 	kfree(data);
351 
352 	return 0;
353 }
354 
355 #ifdef CONFIG_PM
356 static int adp5520_bl_suspend(struct platform_device *pdev,
357 				 pm_message_t state)
358 {
359 	struct backlight_device *bl = platform_get_drvdata(pdev);
360 	return adp5520_bl_set(bl, 0);
361 }
362 
363 static int adp5520_bl_resume(struct platform_device *pdev)
364 {
365 	struct backlight_device *bl = platform_get_drvdata(pdev);
366 
367 	backlight_update_status(bl);
368 	return 0;
369 }
370 #else
371 #define adp5520_bl_suspend	NULL
372 #define adp5520_bl_resume	NULL
373 #endif
374 
375 static struct platform_driver adp5520_bl_driver = {
376 	.driver		= {
377 		.name	= "adp5520-backlight",
378 		.owner	= THIS_MODULE,
379 	},
380 	.probe		= adp5520_bl_probe,
381 	.remove		= __devexit_p(adp5520_bl_remove),
382 	.suspend	= adp5520_bl_suspend,
383 	.resume		= adp5520_bl_resume,
384 };
385 
386 static int __init adp5520_bl_init(void)
387 {
388 	return platform_driver_register(&adp5520_bl_driver);
389 }
390 module_init(adp5520_bl_init);
391 
392 static void __exit adp5520_bl_exit(void)
393 {
394 	platform_driver_unregister(&adp5520_bl_driver);
395 }
396 module_exit(adp5520_bl_exit);
397 
398 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
399 MODULE_DESCRIPTION("ADP5520(01) Backlight Driver");
400 MODULE_LICENSE("GPL");
401 MODULE_ALIAS("platform:adp5520-backlight");
402