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 ret;
147 	uint8_t reg_val;
148 
149 	mutex_lock(&data->lock);
150 	ret = adp5520_read(data->master, reg, &reg_val);
151 	mutex_unlock(&data->lock);
152 
153 	if (ret < 0)
154 		return ret;
155 
156 	return sprintf(buf, "%u\n", reg_val);
157 }
158 
159 static ssize_t adp5520_store(struct device *dev, const char *buf,
160 			 size_t count, int reg)
161 {
162 	struct adp5520_bl *data = dev_get_drvdata(dev);
163 	unsigned long val;
164 	int ret;
165 
166 	ret = kstrtoul(buf, 10, &val);
167 	if (ret)
168 		return ret;
169 
170 	mutex_lock(&data->lock);
171 	adp5520_write(data->master, reg, val);
172 	mutex_unlock(&data->lock);
173 
174 	return count;
175 }
176 
177 static ssize_t adp5520_bl_dark_max_show(struct device *dev,
178 			struct device_attribute *attr, char *buf)
179 {
180 	return adp5520_show(dev, buf, ADP5520_DARK_MAX);
181 }
182 
183 static ssize_t adp5520_bl_dark_max_store(struct device *dev,
184 			struct device_attribute *attr,
185 			const char *buf, size_t count)
186 {
187 	return adp5520_store(dev, buf, count, ADP5520_DARK_MAX);
188 }
189 static DEVICE_ATTR(dark_max, 0664, adp5520_bl_dark_max_show,
190 			adp5520_bl_dark_max_store);
191 
192 static ssize_t adp5520_bl_office_max_show(struct device *dev,
193 			struct device_attribute *attr, char *buf)
194 {
195 	return adp5520_show(dev, buf, ADP5520_OFFICE_MAX);
196 }
197 
198 static ssize_t adp5520_bl_office_max_store(struct device *dev,
199 			struct device_attribute *attr,
200 			const char *buf, size_t count)
201 {
202 	return adp5520_store(dev, buf, count, ADP5520_OFFICE_MAX);
203 }
204 static DEVICE_ATTR(office_max, 0664, adp5520_bl_office_max_show,
205 			adp5520_bl_office_max_store);
206 
207 static ssize_t adp5520_bl_daylight_max_show(struct device *dev,
208 			struct device_attribute *attr, char *buf)
209 {
210 	return adp5520_show(dev, buf, ADP5520_DAYLIGHT_MAX);
211 }
212 
213 static ssize_t adp5520_bl_daylight_max_store(struct device *dev,
214 			struct device_attribute *attr,
215 			const char *buf, size_t count)
216 {
217 	struct adp5520_bl *data = dev_get_drvdata(dev);
218 	int ret;
219 
220 	ret = kstrtoul(buf, 10, &data->cached_daylight_max);
221 	if (ret < 0)
222 		return ret;
223 
224 	return adp5520_store(dev, buf, count, ADP5520_DAYLIGHT_MAX);
225 }
226 static DEVICE_ATTR(daylight_max, 0664, adp5520_bl_daylight_max_show,
227 			adp5520_bl_daylight_max_store);
228 
229 static ssize_t adp5520_bl_dark_dim_show(struct device *dev,
230 			struct device_attribute *attr, char *buf)
231 {
232 	return adp5520_show(dev, buf, ADP5520_DARK_DIM);
233 }
234 
235 static ssize_t adp5520_bl_dark_dim_store(struct device *dev,
236 			struct device_attribute *attr,
237 			const char *buf, size_t count)
238 {
239 	return adp5520_store(dev, buf, count, ADP5520_DARK_DIM);
240 }
241 static DEVICE_ATTR(dark_dim, 0664, adp5520_bl_dark_dim_show,
242 			adp5520_bl_dark_dim_store);
243 
244 static ssize_t adp5520_bl_office_dim_show(struct device *dev,
245 			struct device_attribute *attr, char *buf)
246 {
247 	return adp5520_show(dev, buf, ADP5520_OFFICE_DIM);
248 }
249 
250 static ssize_t adp5520_bl_office_dim_store(struct device *dev,
251 			struct device_attribute *attr,
252 			const char *buf, size_t count)
253 {
254 	return adp5520_store(dev, buf, count, ADP5520_OFFICE_DIM);
255 }
256 static DEVICE_ATTR(office_dim, 0664, adp5520_bl_office_dim_show,
257 			adp5520_bl_office_dim_store);
258 
259 static ssize_t adp5520_bl_daylight_dim_show(struct device *dev,
260 			struct device_attribute *attr, char *buf)
261 {
262 	return adp5520_show(dev, buf, ADP5520_DAYLIGHT_DIM);
263 }
264 
265 static ssize_t adp5520_bl_daylight_dim_store(struct device *dev,
266 			struct device_attribute *attr,
267 			const char *buf, size_t count)
268 {
269 	return adp5520_store(dev, buf, count, ADP5520_DAYLIGHT_DIM);
270 }
271 static DEVICE_ATTR(daylight_dim, 0664, adp5520_bl_daylight_dim_show,
272 			adp5520_bl_daylight_dim_store);
273 
274 static struct attribute *adp5520_bl_attributes[] = {
275 	&dev_attr_dark_max.attr,
276 	&dev_attr_dark_dim.attr,
277 	&dev_attr_office_max.attr,
278 	&dev_attr_office_dim.attr,
279 	&dev_attr_daylight_max.attr,
280 	&dev_attr_daylight_dim.attr,
281 	NULL
282 };
283 
284 static const struct attribute_group adp5520_bl_attr_group = {
285 	.attrs = adp5520_bl_attributes,
286 };
287 
288 static int adp5520_bl_probe(struct platform_device *pdev)
289 {
290 	struct backlight_properties props;
291 	struct backlight_device *bl;
292 	struct adp5520_bl *data;
293 	int ret = 0;
294 
295 	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
296 	if (data == NULL)
297 		return -ENOMEM;
298 
299 	data->master = pdev->dev.parent;
300 	data->pdata = dev_get_platdata(&pdev->dev);
301 
302 	if (data->pdata  == NULL) {
303 		dev_err(&pdev->dev, "missing platform data\n");
304 		return -ENODEV;
305 	}
306 
307 	data->id = pdev->id;
308 	data->current_brightness = 0;
309 
310 	mutex_init(&data->lock);
311 
312 	memset(&props, 0, sizeof(struct backlight_properties));
313 	props.type = BACKLIGHT_RAW;
314 	props.max_brightness = ADP5020_MAX_BRIGHTNESS;
315 	bl = devm_backlight_device_register(&pdev->dev, pdev->name,
316 					data->master, data, &adp5520_bl_ops,
317 					&props);
318 	if (IS_ERR(bl)) {
319 		dev_err(&pdev->dev, "failed to register backlight\n");
320 		return PTR_ERR(bl);
321 	}
322 
323 	bl->props.brightness = ADP5020_MAX_BRIGHTNESS;
324 	if (data->pdata->en_ambl_sens)
325 		ret = sysfs_create_group(&bl->dev.kobj,
326 			&adp5520_bl_attr_group);
327 
328 	if (ret) {
329 		dev_err(&pdev->dev, "failed to register sysfs\n");
330 		return ret;
331 	}
332 
333 	platform_set_drvdata(pdev, bl);
334 	ret |= adp5520_bl_setup(bl);
335 	backlight_update_status(bl);
336 
337 	return ret;
338 }
339 
340 static int adp5520_bl_remove(struct platform_device *pdev)
341 {
342 	struct backlight_device *bl = platform_get_drvdata(pdev);
343 	struct adp5520_bl *data = bl_get_data(bl);
344 
345 	adp5520_clr_bits(data->master, ADP5520_MODE_STATUS, ADP5520_BL_EN);
346 
347 	if (data->pdata->en_ambl_sens)
348 		sysfs_remove_group(&bl->dev.kobj,
349 				&adp5520_bl_attr_group);
350 
351 	return 0;
352 }
353 
354 #ifdef CONFIG_PM_SLEEP
355 static int adp5520_bl_suspend(struct device *dev)
356 {
357 	struct backlight_device *bl = dev_get_drvdata(dev);
358 
359 	return adp5520_bl_set(bl, 0);
360 }
361 
362 static int adp5520_bl_resume(struct device *dev)
363 {
364 	struct backlight_device *bl = dev_get_drvdata(dev);
365 
366 	backlight_update_status(bl);
367 	return 0;
368 }
369 #endif
370 
371 static SIMPLE_DEV_PM_OPS(adp5520_bl_pm_ops, adp5520_bl_suspend,
372 			adp5520_bl_resume);
373 
374 static struct platform_driver adp5520_bl_driver = {
375 	.driver		= {
376 		.name	= "adp5520-backlight",
377 		.owner	= THIS_MODULE,
378 		.pm	= &adp5520_bl_pm_ops,
379 	},
380 	.probe		= adp5520_bl_probe,
381 	.remove		= adp5520_bl_remove,
382 };
383 
384 module_platform_driver(adp5520_bl_driver);
385 
386 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
387 MODULE_DESCRIPTION("ADP5520(01) Backlight Driver");
388 MODULE_LICENSE("GPL");
389 MODULE_ALIAS("platform:adp5520-backlight");
390