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 
71 	if (bl->props.power != FB_BLANK_UNBLANK)
72 		brightness = 0;
73 
74 	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
75 		brightness = 0;
76 
77 	return adp5520_bl_set(bl, brightness);
78 }
79 
80 static int adp5520_bl_get_brightness(struct backlight_device *bl)
81 {
82 	struct adp5520_bl *data = bl_get_data(bl);
83 	int error;
84 	uint8_t reg_val;
85 
86 	error = adp5520_read(data->master, ADP5520_BL_VALUE, &reg_val);
87 
88 	return error ? data->current_brightness : reg_val;
89 }
90 
91 static const struct backlight_ops adp5520_bl_ops = {
92 	.update_status	= adp5520_bl_update_status,
93 	.get_brightness	= adp5520_bl_get_brightness,
94 };
95 
96 static int adp5520_bl_setup(struct backlight_device *bl)
97 {
98 	struct adp5520_bl *data = bl_get_data(bl);
99 	struct device *master = data->master;
100 	struct adp5520_backlight_platform_data *pdata = data->pdata;
101 	int ret = 0;
102 
103 	ret |= adp5520_write(master, ADP5520_DAYLIGHT_MAX,
104 				pdata->l1_daylight_max);
105 	ret |= adp5520_write(master, ADP5520_DAYLIGHT_DIM,
106 				pdata->l1_daylight_dim);
107 
108 	if (pdata->en_ambl_sens) {
109 		data->cached_daylight_max = pdata->l1_daylight_max;
110 		ret |= adp5520_write(master, ADP5520_OFFICE_MAX,
111 				pdata->l2_office_max);
112 		ret |= adp5520_write(master, ADP5520_OFFICE_DIM,
113 				pdata->l2_office_dim);
114 		ret |= adp5520_write(master, ADP5520_DARK_MAX,
115 				pdata->l3_dark_max);
116 		ret |= adp5520_write(master, ADP5520_DARK_DIM,
117 				pdata->l3_dark_dim);
118 		ret |= adp5520_write(master, ADP5520_L2_TRIP,
119 				pdata->l2_trip);
120 		ret |= adp5520_write(master, ADP5520_L2_HYS,
121 				pdata->l2_hyst);
122 		ret |= adp5520_write(master, ADP5520_L3_TRIP,
123 				 pdata->l3_trip);
124 		ret |= adp5520_write(master, ADP5520_L3_HYS,
125 				pdata->l3_hyst);
126 		ret |= adp5520_write(master, ADP5520_ALS_CMPR_CFG,
127 				ALS_CMPR_CFG_VAL(pdata->abml_filt,
128 				ADP5520_L3_EN));
129 	}
130 
131 	ret |= adp5520_write(master, ADP5520_BL_CONTROL,
132 			BL_CTRL_VAL(pdata->fade_led_law,
133 					pdata->en_ambl_sens));
134 
135 	ret |= adp5520_write(master, ADP5520_BL_FADE, FADE_VAL(pdata->fade_in,
136 			pdata->fade_out));
137 
138 	ret |= adp5520_set_bits(master, ADP5520_MODE_STATUS,
139 			ADP5520_BL_EN | ADP5520_DIM_EN);
140 
141 	return ret;
142 }
143 
144 static ssize_t adp5520_show(struct device *dev, char *buf, int reg)
145 {
146 	struct adp5520_bl *data = dev_get_drvdata(dev);
147 	int ret;
148 	uint8_t reg_val;
149 
150 	mutex_lock(&data->lock);
151 	ret = adp5520_read(data->master, reg, &reg_val);
152 	mutex_unlock(&data->lock);
153 
154 	if (ret < 0)
155 		return ret;
156 
157 	return sprintf(buf, "%u\n", reg_val);
158 }
159 
160 static ssize_t adp5520_store(struct device *dev, const char *buf,
161 			 size_t count, int reg)
162 {
163 	struct adp5520_bl *data = dev_get_drvdata(dev);
164 	unsigned long val;
165 	int ret;
166 
167 	ret = kstrtoul(buf, 10, &val);
168 	if (ret)
169 		return ret;
170 
171 	mutex_lock(&data->lock);
172 	adp5520_write(data->master, reg, val);
173 	mutex_unlock(&data->lock);
174 
175 	return count;
176 }
177 
178 static ssize_t adp5520_bl_dark_max_show(struct device *dev,
179 			struct device_attribute *attr, char *buf)
180 {
181 	return adp5520_show(dev, buf, ADP5520_DARK_MAX);
182 }
183 
184 static ssize_t adp5520_bl_dark_max_store(struct device *dev,
185 			struct device_attribute *attr,
186 			const char *buf, size_t count)
187 {
188 	return adp5520_store(dev, buf, count, ADP5520_DARK_MAX);
189 }
190 static DEVICE_ATTR(dark_max, 0664, adp5520_bl_dark_max_show,
191 			adp5520_bl_dark_max_store);
192 
193 static ssize_t adp5520_bl_office_max_show(struct device *dev,
194 			struct device_attribute *attr, char *buf)
195 {
196 	return adp5520_show(dev, buf, ADP5520_OFFICE_MAX);
197 }
198 
199 static ssize_t adp5520_bl_office_max_store(struct device *dev,
200 			struct device_attribute *attr,
201 			const char *buf, size_t count)
202 {
203 	return adp5520_store(dev, buf, count, ADP5520_OFFICE_MAX);
204 }
205 static DEVICE_ATTR(office_max, 0664, adp5520_bl_office_max_show,
206 			adp5520_bl_office_max_store);
207 
208 static ssize_t adp5520_bl_daylight_max_show(struct device *dev,
209 			struct device_attribute *attr, char *buf)
210 {
211 	return adp5520_show(dev, buf, ADP5520_DAYLIGHT_MAX);
212 }
213 
214 static ssize_t adp5520_bl_daylight_max_store(struct device *dev,
215 			struct device_attribute *attr,
216 			const char *buf, size_t count)
217 {
218 	struct adp5520_bl *data = dev_get_drvdata(dev);
219 	int ret;
220 
221 	ret = kstrtoul(buf, 10, &data->cached_daylight_max);
222 	if (ret < 0)
223 		return ret;
224 
225 	return adp5520_store(dev, buf, count, ADP5520_DAYLIGHT_MAX);
226 }
227 static DEVICE_ATTR(daylight_max, 0664, adp5520_bl_daylight_max_show,
228 			adp5520_bl_daylight_max_store);
229 
230 static ssize_t adp5520_bl_dark_dim_show(struct device *dev,
231 			struct device_attribute *attr, char *buf)
232 {
233 	return adp5520_show(dev, buf, ADP5520_DARK_DIM);
234 }
235 
236 static ssize_t adp5520_bl_dark_dim_store(struct device *dev,
237 			struct device_attribute *attr,
238 			const char *buf, size_t count)
239 {
240 	return adp5520_store(dev, buf, count, ADP5520_DARK_DIM);
241 }
242 static DEVICE_ATTR(dark_dim, 0664, adp5520_bl_dark_dim_show,
243 			adp5520_bl_dark_dim_store);
244 
245 static ssize_t adp5520_bl_office_dim_show(struct device *dev,
246 			struct device_attribute *attr, char *buf)
247 {
248 	return adp5520_show(dev, buf, ADP5520_OFFICE_DIM);
249 }
250 
251 static ssize_t adp5520_bl_office_dim_store(struct device *dev,
252 			struct device_attribute *attr,
253 			const char *buf, size_t count)
254 {
255 	return adp5520_store(dev, buf, count, ADP5520_OFFICE_DIM);
256 }
257 static DEVICE_ATTR(office_dim, 0664, adp5520_bl_office_dim_show,
258 			adp5520_bl_office_dim_store);
259 
260 static ssize_t adp5520_bl_daylight_dim_show(struct device *dev,
261 			struct device_attribute *attr, char *buf)
262 {
263 	return adp5520_show(dev, buf, ADP5520_DAYLIGHT_DIM);
264 }
265 
266 static ssize_t adp5520_bl_daylight_dim_store(struct device *dev,
267 			struct device_attribute *attr,
268 			const char *buf, size_t count)
269 {
270 	return adp5520_store(dev, buf, count, ADP5520_DAYLIGHT_DIM);
271 }
272 static DEVICE_ATTR(daylight_dim, 0664, adp5520_bl_daylight_dim_show,
273 			adp5520_bl_daylight_dim_store);
274 
275 static struct attribute *adp5520_bl_attributes[] = {
276 	&dev_attr_dark_max.attr,
277 	&dev_attr_dark_dim.attr,
278 	&dev_attr_office_max.attr,
279 	&dev_attr_office_dim.attr,
280 	&dev_attr_daylight_max.attr,
281 	&dev_attr_daylight_dim.attr,
282 	NULL
283 };
284 
285 static const struct attribute_group adp5520_bl_attr_group = {
286 	.attrs = adp5520_bl_attributes,
287 };
288 
289 static int adp5520_bl_probe(struct platform_device *pdev)
290 {
291 	struct backlight_properties props;
292 	struct backlight_device *bl;
293 	struct adp5520_bl *data;
294 	int ret = 0;
295 
296 	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
297 	if (data == NULL)
298 		return -ENOMEM;
299 
300 	data->master = pdev->dev.parent;
301 	data->pdata = dev_get_platdata(&pdev->dev);
302 
303 	if (data->pdata  == NULL) {
304 		dev_err(&pdev->dev, "missing platform data\n");
305 		return -ENODEV;
306 	}
307 
308 	data->id = pdev->id;
309 	data->current_brightness = 0;
310 
311 	mutex_init(&data->lock);
312 
313 	memset(&props, 0, sizeof(struct backlight_properties));
314 	props.type = BACKLIGHT_RAW;
315 	props.max_brightness = ADP5020_MAX_BRIGHTNESS;
316 	bl = devm_backlight_device_register(&pdev->dev, pdev->name,
317 					data->master, data, &adp5520_bl_ops,
318 					&props);
319 	if (IS_ERR(bl)) {
320 		dev_err(&pdev->dev, "failed to register backlight\n");
321 		return PTR_ERR(bl);
322 	}
323 
324 	bl->props.brightness = ADP5020_MAX_BRIGHTNESS;
325 	if (data->pdata->en_ambl_sens)
326 		ret = sysfs_create_group(&bl->dev.kobj,
327 			&adp5520_bl_attr_group);
328 
329 	if (ret) {
330 		dev_err(&pdev->dev, "failed to register sysfs\n");
331 		return ret;
332 	}
333 
334 	platform_set_drvdata(pdev, bl);
335 	ret = adp5520_bl_setup(bl);
336 	if (ret) {
337 		dev_err(&pdev->dev, "failed to setup\n");
338 		if (data->pdata->en_ambl_sens)
339 			sysfs_remove_group(&bl->dev.kobj,
340 					&adp5520_bl_attr_group);
341 		return ret;
342 	}
343 
344 	backlight_update_status(bl);
345 
346 	return 0;
347 }
348 
349 static int adp5520_bl_remove(struct platform_device *pdev)
350 {
351 	struct backlight_device *bl = platform_get_drvdata(pdev);
352 	struct adp5520_bl *data = bl_get_data(bl);
353 
354 	adp5520_clr_bits(data->master, ADP5520_MODE_STATUS, ADP5520_BL_EN);
355 
356 	if (data->pdata->en_ambl_sens)
357 		sysfs_remove_group(&bl->dev.kobj,
358 				&adp5520_bl_attr_group);
359 
360 	return 0;
361 }
362 
363 #ifdef CONFIG_PM_SLEEP
364 static int adp5520_bl_suspend(struct device *dev)
365 {
366 	struct backlight_device *bl = dev_get_drvdata(dev);
367 
368 	return adp5520_bl_set(bl, 0);
369 }
370 
371 static int adp5520_bl_resume(struct device *dev)
372 {
373 	struct backlight_device *bl = dev_get_drvdata(dev);
374 
375 	backlight_update_status(bl);
376 	return 0;
377 }
378 #endif
379 
380 static SIMPLE_DEV_PM_OPS(adp5520_bl_pm_ops, adp5520_bl_suspend,
381 			adp5520_bl_resume);
382 
383 static struct platform_driver adp5520_bl_driver = {
384 	.driver		= {
385 		.name	= "adp5520-backlight",
386 		.pm	= &adp5520_bl_pm_ops,
387 	},
388 	.probe		= adp5520_bl_probe,
389 	.remove		= adp5520_bl_remove,
390 };
391 
392 module_platform_driver(adp5520_bl_driver);
393 
394 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
395 MODULE_DESCRIPTION("ADP5520(01) Backlight Driver");
396 MODULE_LICENSE("GPL");
397 MODULE_ALIAS("platform:adp5520-backlight");
398