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