1/*
2 * lm3533-bl.c -- LM3533 Backlight driver
3 *
4 * Copyright (C) 2011-2012 Texas Instruments
5 *
6 * Author: Johan Hovold <jhovold@gmail.com>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under  the terms of the GNU General  Public License as published by the
10 * Free Software Foundation;  either version 2 of the License, or (at your
11 * option) any later version.
12 */
13
14#include <linux/module.h>
15#include <linux/init.h>
16#include <linux/platform_device.h>
17#include <linux/backlight.h>
18#include <linux/fb.h>
19#include <linux/slab.h>
20
21#include <linux/mfd/lm3533.h>
22
23
24#define LM3533_HVCTRLBANK_COUNT		2
25#define LM3533_BL_MAX_BRIGHTNESS	255
26
27#define LM3533_REG_CTRLBANK_AB_BCONF	0x1a
28
29
30struct lm3533_bl {
31	struct lm3533 *lm3533;
32	struct lm3533_ctrlbank cb;
33	struct backlight_device *bd;
34	int id;
35};
36
37
38static inline int lm3533_bl_get_ctrlbank_id(struct lm3533_bl *bl)
39{
40	return bl->id;
41}
42
43static int lm3533_bl_update_status(struct backlight_device *bd)
44{
45	struct lm3533_bl *bl = bl_get_data(bd);
46	int brightness = bd->props.brightness;
47
48	if (bd->props.power != FB_BLANK_UNBLANK)
49		brightness = 0;
50	if (bd->props.fb_blank != FB_BLANK_UNBLANK)
51		brightness = 0;
52
53	return lm3533_ctrlbank_set_brightness(&bl->cb, (u8)brightness);
54}
55
56static int lm3533_bl_get_brightness(struct backlight_device *bd)
57{
58	struct lm3533_bl *bl = bl_get_data(bd);
59	u8 val;
60	int ret;
61
62	ret = lm3533_ctrlbank_get_brightness(&bl->cb, &val);
63	if (ret)
64		return ret;
65
66	return val;
67}
68
69static const struct backlight_ops lm3533_bl_ops = {
70	.get_brightness	= lm3533_bl_get_brightness,
71	.update_status	= lm3533_bl_update_status,
72};
73
74static ssize_t show_id(struct device *dev,
75				struct device_attribute *attr, char *buf)
76{
77	struct lm3533_bl *bl = dev_get_drvdata(dev);
78
79	return scnprintf(buf, PAGE_SIZE, "%d\n", bl->id);
80}
81
82static ssize_t show_als_channel(struct device *dev,
83				struct device_attribute *attr, char *buf)
84{
85	struct lm3533_bl *bl = dev_get_drvdata(dev);
86	unsigned channel = lm3533_bl_get_ctrlbank_id(bl);
87
88	return scnprintf(buf, PAGE_SIZE, "%u\n", channel);
89}
90
91static ssize_t show_als_en(struct device *dev,
92				struct device_attribute *attr, char *buf)
93{
94	struct lm3533_bl *bl = dev_get_drvdata(dev);
95	int ctrlbank = lm3533_bl_get_ctrlbank_id(bl);
96	u8 val;
97	u8 mask;
98	bool enable;
99	int ret;
100
101	ret = lm3533_read(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, &val);
102	if (ret)
103		return ret;
104
105	mask = 1 << (2 * ctrlbank);
106	enable = val & mask;
107
108	return scnprintf(buf, PAGE_SIZE, "%d\n", enable);
109}
110
111static ssize_t store_als_en(struct device *dev,
112					struct device_attribute *attr,
113					const char *buf, size_t len)
114{
115	struct lm3533_bl *bl = dev_get_drvdata(dev);
116	int ctrlbank = lm3533_bl_get_ctrlbank_id(bl);
117	int enable;
118	u8 val;
119	u8 mask;
120	int ret;
121
122	if (kstrtoint(buf, 0, &enable))
123		return -EINVAL;
124
125	mask = 1 << (2 * ctrlbank);
126
127	if (enable)
128		val = mask;
129	else
130		val = 0;
131
132	ret = lm3533_update(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, val,
133									mask);
134	if (ret)
135		return ret;
136
137	return len;
138}
139
140static ssize_t show_linear(struct device *dev,
141				struct device_attribute *attr, char *buf)
142{
143	struct lm3533_bl *bl = dev_get_drvdata(dev);
144	u8 val;
145	u8 mask;
146	int linear;
147	int ret;
148
149	ret = lm3533_read(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, &val);
150	if (ret)
151		return ret;
152
153	mask = 1 << (2 * lm3533_bl_get_ctrlbank_id(bl) + 1);
154
155	if (val & mask)
156		linear = 1;
157	else
158		linear = 0;
159
160	return scnprintf(buf, PAGE_SIZE, "%x\n", linear);
161}
162
163static ssize_t store_linear(struct device *dev,
164					struct device_attribute *attr,
165					const char *buf, size_t len)
166{
167	struct lm3533_bl *bl = dev_get_drvdata(dev);
168	unsigned long linear;
169	u8 mask;
170	u8 val;
171	int ret;
172
173	if (kstrtoul(buf, 0, &linear))
174		return -EINVAL;
175
176	mask = 1 << (2 * lm3533_bl_get_ctrlbank_id(bl) + 1);
177
178	if (linear)
179		val = mask;
180	else
181		val = 0;
182
183	ret = lm3533_update(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, val,
184									mask);
185	if (ret)
186		return ret;
187
188	return len;
189}
190
191static ssize_t show_pwm(struct device *dev,
192					struct device_attribute *attr,
193					char *buf)
194{
195	struct lm3533_bl *bl = dev_get_drvdata(dev);
196	u8 val;
197	int ret;
198
199	ret = lm3533_ctrlbank_get_pwm(&bl->cb, &val);
200	if (ret)
201		return ret;
202
203	return scnprintf(buf, PAGE_SIZE, "%u\n", val);
204}
205
206static ssize_t store_pwm(struct device *dev,
207					struct device_attribute *attr,
208					const char *buf, size_t len)
209{
210	struct lm3533_bl *bl = dev_get_drvdata(dev);
211	u8 val;
212	int ret;
213
214	if (kstrtou8(buf, 0, &val))
215		return -EINVAL;
216
217	ret = lm3533_ctrlbank_set_pwm(&bl->cb, val);
218	if (ret)
219		return ret;
220
221	return len;
222}
223
224static LM3533_ATTR_RO(als_channel);
225static LM3533_ATTR_RW(als_en);
226static LM3533_ATTR_RO(id);
227static LM3533_ATTR_RW(linear);
228static LM3533_ATTR_RW(pwm);
229
230static struct attribute *lm3533_bl_attributes[] = {
231	&dev_attr_als_channel.attr,
232	&dev_attr_als_en.attr,
233	&dev_attr_id.attr,
234	&dev_attr_linear.attr,
235	&dev_attr_pwm.attr,
236	NULL,
237};
238
239static umode_t lm3533_bl_attr_is_visible(struct kobject *kobj,
240					     struct attribute *attr, int n)
241{
242	struct device *dev = container_of(kobj, struct device, kobj);
243	struct lm3533_bl *bl = dev_get_drvdata(dev);
244	umode_t mode = attr->mode;
245
246	if (attr == &dev_attr_als_channel.attr ||
247					attr == &dev_attr_als_en.attr) {
248		if (!bl->lm3533->have_als)
249			mode = 0;
250	}
251
252	return mode;
253};
254
255static struct attribute_group lm3533_bl_attribute_group = {
256	.is_visible	= lm3533_bl_attr_is_visible,
257	.attrs		= lm3533_bl_attributes
258};
259
260static int lm3533_bl_setup(struct lm3533_bl *bl,
261					struct lm3533_bl_platform_data *pdata)
262{
263	int ret;
264
265	ret = lm3533_ctrlbank_set_max_current(&bl->cb, pdata->max_current);
266	if (ret)
267		return ret;
268
269	return lm3533_ctrlbank_set_pwm(&bl->cb, pdata->pwm);
270}
271
272static int lm3533_bl_probe(struct platform_device *pdev)
273{
274	struct lm3533 *lm3533;
275	struct lm3533_bl_platform_data *pdata;
276	struct lm3533_bl *bl;
277	struct backlight_device *bd;
278	struct backlight_properties props;
279	int ret;
280
281	dev_dbg(&pdev->dev, "%s\n", __func__);
282
283	lm3533 = dev_get_drvdata(pdev->dev.parent);
284	if (!lm3533)
285		return -EINVAL;
286
287	pdata = dev_get_platdata(&pdev->dev);
288	if (!pdata) {
289		dev_err(&pdev->dev, "no platform data\n");
290		return -EINVAL;
291	}
292
293	if (pdev->id < 0 || pdev->id >= LM3533_HVCTRLBANK_COUNT) {
294		dev_err(&pdev->dev, "illegal backlight id %d\n", pdev->id);
295		return -EINVAL;
296	}
297
298	bl = devm_kzalloc(&pdev->dev, sizeof(*bl), GFP_KERNEL);
299	if (!bl)
300		return -ENOMEM;
301
302	bl->lm3533 = lm3533;
303	bl->id = pdev->id;
304
305	bl->cb.lm3533 = lm3533;
306	bl->cb.id = lm3533_bl_get_ctrlbank_id(bl);
307	bl->cb.dev = NULL;			/* until registered */
308
309	memset(&props, 0, sizeof(props));
310	props.type = BACKLIGHT_RAW;
311	props.max_brightness = LM3533_BL_MAX_BRIGHTNESS;
312	props.brightness = pdata->default_brightness;
313	bd = devm_backlight_device_register(&pdev->dev, pdata->name,
314					pdev->dev.parent, bl, &lm3533_bl_ops,
315					&props);
316	if (IS_ERR(bd)) {
317		dev_err(&pdev->dev, "failed to register backlight device\n");
318		return PTR_ERR(bd);
319	}
320
321	bl->bd = bd;
322	bl->cb.dev = &bl->bd->dev;
323
324	platform_set_drvdata(pdev, bl);
325
326	ret = sysfs_create_group(&bd->dev.kobj, &lm3533_bl_attribute_group);
327	if (ret < 0) {
328		dev_err(&pdev->dev, "failed to create sysfs attributes\n");
329		return ret;
330	}
331
332	backlight_update_status(bd);
333
334	ret = lm3533_bl_setup(bl, pdata);
335	if (ret)
336		goto err_sysfs_remove;
337
338	ret = lm3533_ctrlbank_enable(&bl->cb);
339	if (ret)
340		goto err_sysfs_remove;
341
342	return 0;
343
344err_sysfs_remove:
345	sysfs_remove_group(&bd->dev.kobj, &lm3533_bl_attribute_group);
346
347	return ret;
348}
349
350static int lm3533_bl_remove(struct platform_device *pdev)
351{
352	struct lm3533_bl *bl = platform_get_drvdata(pdev);
353	struct backlight_device *bd = bl->bd;
354
355	dev_dbg(&bd->dev, "%s\n", __func__);
356
357	bd->props.power = FB_BLANK_POWERDOWN;
358	bd->props.brightness = 0;
359
360	lm3533_ctrlbank_disable(&bl->cb);
361	sysfs_remove_group(&bd->dev.kobj, &lm3533_bl_attribute_group);
362
363	return 0;
364}
365
366#ifdef CONFIG_PM_SLEEP
367static int lm3533_bl_suspend(struct device *dev)
368{
369	struct lm3533_bl *bl = dev_get_drvdata(dev);
370
371	dev_dbg(dev, "%s\n", __func__);
372
373	return lm3533_ctrlbank_disable(&bl->cb);
374}
375
376static int lm3533_bl_resume(struct device *dev)
377{
378	struct lm3533_bl *bl = dev_get_drvdata(dev);
379
380	dev_dbg(dev, "%s\n", __func__);
381
382	return lm3533_ctrlbank_enable(&bl->cb);
383}
384#endif
385
386static SIMPLE_DEV_PM_OPS(lm3533_bl_pm_ops, lm3533_bl_suspend, lm3533_bl_resume);
387
388static void lm3533_bl_shutdown(struct platform_device *pdev)
389{
390	struct lm3533_bl *bl = platform_get_drvdata(pdev);
391
392	dev_dbg(&pdev->dev, "%s\n", __func__);
393
394	lm3533_ctrlbank_disable(&bl->cb);
395}
396
397static struct platform_driver lm3533_bl_driver = {
398	.driver = {
399		.name	= "lm3533-backlight",
400		.pm	= &lm3533_bl_pm_ops,
401	},
402	.probe		= lm3533_bl_probe,
403	.remove		= lm3533_bl_remove,
404	.shutdown	= lm3533_bl_shutdown,
405};
406module_platform_driver(lm3533_bl_driver);
407
408MODULE_AUTHOR("Johan Hovold <jhovold@gmail.com>");
409MODULE_DESCRIPTION("LM3533 Backlight driver");
410MODULE_LICENSE("GPL");
411MODULE_ALIAS("platform:lm3533-backlight");
412