1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * lm3533-bl.c -- LM3533 Backlight driver
4 *
5 * Copyright (C) 2011-2012 Texas Instruments
6 *
7 * Author: Johan Hovold <jhovold@gmail.com>
8 */
9
10#include <linux/module.h>
11#include <linux/init.h>
12#include <linux/platform_device.h>
13#include <linux/backlight.h>
14#include <linux/fb.h>
15#include <linux/slab.h>
16
17#include <linux/mfd/lm3533.h>
18
19
20#define LM3533_HVCTRLBANK_COUNT		2
21#define LM3533_BL_MAX_BRIGHTNESS	255
22
23#define LM3533_REG_CTRLBANK_AB_BCONF	0x1a
24
25
26struct lm3533_bl {
27	struct lm3533 *lm3533;
28	struct lm3533_ctrlbank cb;
29	struct backlight_device *bd;
30	int id;
31};
32
33
34static inline int lm3533_bl_get_ctrlbank_id(struct lm3533_bl *bl)
35{
36	return bl->id;
37}
38
39static int lm3533_bl_update_status(struct backlight_device *bd)
40{
41	struct lm3533_bl *bl = bl_get_data(bd);
42
43	return lm3533_ctrlbank_set_brightness(&bl->cb, backlight_get_brightness(bd));
44}
45
46static int lm3533_bl_get_brightness(struct backlight_device *bd)
47{
48	struct lm3533_bl *bl = bl_get_data(bd);
49	u8 val;
50	int ret;
51
52	ret = lm3533_ctrlbank_get_brightness(&bl->cb, &val);
53	if (ret)
54		return ret;
55
56	return val;
57}
58
59static const struct backlight_ops lm3533_bl_ops = {
60	.get_brightness	= lm3533_bl_get_brightness,
61	.update_status	= lm3533_bl_update_status,
62};
63
64static ssize_t show_id(struct device *dev,
65				struct device_attribute *attr, char *buf)
66{
67	struct lm3533_bl *bl = dev_get_drvdata(dev);
68
69	return scnprintf(buf, PAGE_SIZE, "%d\n", bl->id);
70}
71
72static ssize_t show_als_channel(struct device *dev,
73				struct device_attribute *attr, char *buf)
74{
75	struct lm3533_bl *bl = dev_get_drvdata(dev);
76	unsigned channel = lm3533_bl_get_ctrlbank_id(bl);
77
78	return scnprintf(buf, PAGE_SIZE, "%u\n", channel);
79}
80
81static ssize_t show_als_en(struct device *dev,
82				struct device_attribute *attr, char *buf)
83{
84	struct lm3533_bl *bl = dev_get_drvdata(dev);
85	int ctrlbank = lm3533_bl_get_ctrlbank_id(bl);
86	u8 val;
87	u8 mask;
88	bool enable;
89	int ret;
90
91	ret = lm3533_read(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, &val);
92	if (ret)
93		return ret;
94
95	mask = 1 << (2 * ctrlbank);
96	enable = val & mask;
97
98	return scnprintf(buf, PAGE_SIZE, "%d\n", enable);
99}
100
101static ssize_t store_als_en(struct device *dev,
102					struct device_attribute *attr,
103					const char *buf, size_t len)
104{
105	struct lm3533_bl *bl = dev_get_drvdata(dev);
106	int ctrlbank = lm3533_bl_get_ctrlbank_id(bl);
107	int enable;
108	u8 val;
109	u8 mask;
110	int ret;
111
112	if (kstrtoint(buf, 0, &enable))
113		return -EINVAL;
114
115	mask = 1 << (2 * ctrlbank);
116
117	if (enable)
118		val = mask;
119	else
120		val = 0;
121
122	ret = lm3533_update(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, val,
123									mask);
124	if (ret)
125		return ret;
126
127	return len;
128}
129
130static ssize_t show_linear(struct device *dev,
131				struct device_attribute *attr, char *buf)
132{
133	struct lm3533_bl *bl = dev_get_drvdata(dev);
134	u8 val;
135	u8 mask;
136	int linear;
137	int ret;
138
139	ret = lm3533_read(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, &val);
140	if (ret)
141		return ret;
142
143	mask = 1 << (2 * lm3533_bl_get_ctrlbank_id(bl) + 1);
144
145	if (val & mask)
146		linear = 1;
147	else
148		linear = 0;
149
150	return scnprintf(buf, PAGE_SIZE, "%x\n", linear);
151}
152
153static ssize_t store_linear(struct device *dev,
154					struct device_attribute *attr,
155					const char *buf, size_t len)
156{
157	struct lm3533_bl *bl = dev_get_drvdata(dev);
158	unsigned long linear;
159	u8 mask;
160	u8 val;
161	int ret;
162
163	if (kstrtoul(buf, 0, &linear))
164		return -EINVAL;
165
166	mask = 1 << (2 * lm3533_bl_get_ctrlbank_id(bl) + 1);
167
168	if (linear)
169		val = mask;
170	else
171		val = 0;
172
173	ret = lm3533_update(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, val,
174									mask);
175	if (ret)
176		return ret;
177
178	return len;
179}
180
181static ssize_t show_pwm(struct device *dev,
182					struct device_attribute *attr,
183					char *buf)
184{
185	struct lm3533_bl *bl = dev_get_drvdata(dev);
186	u8 val;
187	int ret;
188
189	ret = lm3533_ctrlbank_get_pwm(&bl->cb, &val);
190	if (ret)
191		return ret;
192
193	return scnprintf(buf, PAGE_SIZE, "%u\n", val);
194}
195
196static ssize_t store_pwm(struct device *dev,
197					struct device_attribute *attr,
198					const char *buf, size_t len)
199{
200	struct lm3533_bl *bl = dev_get_drvdata(dev);
201	u8 val;
202	int ret;
203
204	if (kstrtou8(buf, 0, &val))
205		return -EINVAL;
206
207	ret = lm3533_ctrlbank_set_pwm(&bl->cb, val);
208	if (ret)
209		return ret;
210
211	return len;
212}
213
214static LM3533_ATTR_RO(als_channel);
215static LM3533_ATTR_RW(als_en);
216static LM3533_ATTR_RO(id);
217static LM3533_ATTR_RW(linear);
218static LM3533_ATTR_RW(pwm);
219
220static struct attribute *lm3533_bl_attributes[] = {
221	&dev_attr_als_channel.attr,
222	&dev_attr_als_en.attr,
223	&dev_attr_id.attr,
224	&dev_attr_linear.attr,
225	&dev_attr_pwm.attr,
226	NULL,
227};
228
229static umode_t lm3533_bl_attr_is_visible(struct kobject *kobj,
230					     struct attribute *attr, int n)
231{
232	struct device *dev = kobj_to_dev(kobj);
233	struct lm3533_bl *bl = dev_get_drvdata(dev);
234	umode_t mode = attr->mode;
235
236	if (attr == &dev_attr_als_channel.attr ||
237					attr == &dev_attr_als_en.attr) {
238		if (!bl->lm3533->have_als)
239			mode = 0;
240	}
241
242	return mode;
243};
244
245static struct attribute_group lm3533_bl_attribute_group = {
246	.is_visible	= lm3533_bl_attr_is_visible,
247	.attrs		= lm3533_bl_attributes
248};
249
250static int lm3533_bl_setup(struct lm3533_bl *bl,
251					struct lm3533_bl_platform_data *pdata)
252{
253	int ret;
254
255	ret = lm3533_ctrlbank_set_max_current(&bl->cb, pdata->max_current);
256	if (ret)
257		return ret;
258
259	return lm3533_ctrlbank_set_pwm(&bl->cb, pdata->pwm);
260}
261
262static int lm3533_bl_probe(struct platform_device *pdev)
263{
264	struct lm3533 *lm3533;
265	struct lm3533_bl_platform_data *pdata;
266	struct lm3533_bl *bl;
267	struct backlight_device *bd;
268	struct backlight_properties props;
269	int ret;
270
271	dev_dbg(&pdev->dev, "%s\n", __func__);
272
273	lm3533 = dev_get_drvdata(pdev->dev.parent);
274	if (!lm3533)
275		return -EINVAL;
276
277	pdata = dev_get_platdata(&pdev->dev);
278	if (!pdata) {
279		dev_err(&pdev->dev, "no platform data\n");
280		return -EINVAL;
281	}
282
283	if (pdev->id < 0 || pdev->id >= LM3533_HVCTRLBANK_COUNT) {
284		dev_err(&pdev->dev, "illegal backlight id %d\n", pdev->id);
285		return -EINVAL;
286	}
287
288	bl = devm_kzalloc(&pdev->dev, sizeof(*bl), GFP_KERNEL);
289	if (!bl)
290		return -ENOMEM;
291
292	bl->lm3533 = lm3533;
293	bl->id = pdev->id;
294
295	bl->cb.lm3533 = lm3533;
296	bl->cb.id = lm3533_bl_get_ctrlbank_id(bl);
297	bl->cb.dev = NULL;			/* until registered */
298
299	memset(&props, 0, sizeof(props));
300	props.type = BACKLIGHT_RAW;
301	props.max_brightness = LM3533_BL_MAX_BRIGHTNESS;
302	props.brightness = pdata->default_brightness;
303	bd = devm_backlight_device_register(&pdev->dev, pdata->name,
304					pdev->dev.parent, bl, &lm3533_bl_ops,
305					&props);
306	if (IS_ERR(bd)) {
307		dev_err(&pdev->dev, "failed to register backlight device\n");
308		return PTR_ERR(bd);
309	}
310
311	bl->bd = bd;
312	bl->cb.dev = &bl->bd->dev;
313
314	platform_set_drvdata(pdev, bl);
315
316	ret = sysfs_create_group(&bd->dev.kobj, &lm3533_bl_attribute_group);
317	if (ret < 0) {
318		dev_err(&pdev->dev, "failed to create sysfs attributes\n");
319		return ret;
320	}
321
322	backlight_update_status(bd);
323
324	ret = lm3533_bl_setup(bl, pdata);
325	if (ret)
326		goto err_sysfs_remove;
327
328	ret = lm3533_ctrlbank_enable(&bl->cb);
329	if (ret)
330		goto err_sysfs_remove;
331
332	return 0;
333
334err_sysfs_remove:
335	sysfs_remove_group(&bd->dev.kobj, &lm3533_bl_attribute_group);
336
337	return ret;
338}
339
340static void lm3533_bl_remove(struct platform_device *pdev)
341{
342	struct lm3533_bl *bl = platform_get_drvdata(pdev);
343	struct backlight_device *bd = bl->bd;
344
345	dev_dbg(&bd->dev, "%s\n", __func__);
346
347	bd->props.power = FB_BLANK_POWERDOWN;
348	bd->props.brightness = 0;
349
350	lm3533_ctrlbank_disable(&bl->cb);
351	sysfs_remove_group(&bd->dev.kobj, &lm3533_bl_attribute_group);
352}
353
354#ifdef CONFIG_PM_SLEEP
355static int lm3533_bl_suspend(struct device *dev)
356{
357	struct lm3533_bl *bl = dev_get_drvdata(dev);
358
359	dev_dbg(dev, "%s\n", __func__);
360
361	return lm3533_ctrlbank_disable(&bl->cb);
362}
363
364static int lm3533_bl_resume(struct device *dev)
365{
366	struct lm3533_bl *bl = dev_get_drvdata(dev);
367
368	dev_dbg(dev, "%s\n", __func__);
369
370	return lm3533_ctrlbank_enable(&bl->cb);
371}
372#endif
373
374static SIMPLE_DEV_PM_OPS(lm3533_bl_pm_ops, lm3533_bl_suspend, lm3533_bl_resume);
375
376static void lm3533_bl_shutdown(struct platform_device *pdev)
377{
378	struct lm3533_bl *bl = platform_get_drvdata(pdev);
379
380	dev_dbg(&pdev->dev, "%s\n", __func__);
381
382	lm3533_ctrlbank_disable(&bl->cb);
383}
384
385static struct platform_driver lm3533_bl_driver = {
386	.driver = {
387		.name	= "lm3533-backlight",
388		.pm	= &lm3533_bl_pm_ops,
389	},
390	.probe		= lm3533_bl_probe,
391	.remove_new	= lm3533_bl_remove,
392	.shutdown	= lm3533_bl_shutdown,
393};
394module_platform_driver(lm3533_bl_driver);
395
396MODULE_AUTHOR("Johan Hovold <jhovold@gmail.com>");
397MODULE_DESCRIPTION("LM3533 Backlight driver");
398MODULE_LICENSE("GPL");
399MODULE_ALIAS("platform:lm3533-backlight");
400