1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Backlight driver for Dialog Semiconductor DA9030/DA9034
4 *
5 * Copyright (C) 2008 Compulab, Ltd.
6 *	Mike Rapoport <mike@compulab.co.il>
7 *
8 * Copyright (C) 2006-2008 Marvell International Ltd.
9 *	Eric Miao <eric.miao@marvell.com>
10 */
11
12#include <linux/kernel.h>
13#include <linux/init.h>
14#include <linux/platform_device.h>
15#include <linux/fb.h>
16#include <linux/backlight.h>
17#include <linux/mfd/da903x.h>
18#include <linux/slab.h>
19#include <linux/module.h>
20
21#define DA9030_WLED_CONTROL	0x25
22#define DA9030_WLED_CP_EN	(1 << 6)
23#define DA9030_WLED_TRIM(x)	((x) & 0x7)
24
25#define DA9034_WLED_CONTROL1	0x3C
26#define DA9034_WLED_CONTROL2	0x3D
27#define DA9034_WLED_ISET(x)	((x) & 0x1f)
28
29#define DA9034_WLED_BOOST_EN	(1 << 5)
30
31#define DA9030_MAX_BRIGHTNESS	7
32#define DA9034_MAX_BRIGHTNESS	0x7f
33
34struct da903x_backlight_data {
35	struct device *da903x_dev;
36	int id;
37	int current_brightness;
38};
39
40static int da903x_backlight_set(struct backlight_device *bl, int brightness)
41{
42	struct da903x_backlight_data *data = bl_get_data(bl);
43	struct device *dev = data->da903x_dev;
44	uint8_t val;
45	int ret = 0;
46
47	switch (data->id) {
48	case DA9034_ID_WLED:
49		ret = da903x_update(dev, DA9034_WLED_CONTROL1,
50				brightness, 0x7f);
51		if (ret)
52			return ret;
53
54		if (data->current_brightness && brightness == 0)
55			ret = da903x_clr_bits(dev,
56					DA9034_WLED_CONTROL2,
57					DA9034_WLED_BOOST_EN);
58
59		if (data->current_brightness == 0 && brightness)
60			ret = da903x_set_bits(dev,
61					DA9034_WLED_CONTROL2,
62					DA9034_WLED_BOOST_EN);
63		break;
64	case DA9030_ID_WLED:
65		val = DA9030_WLED_TRIM(brightness);
66		val |= brightness ? DA9030_WLED_CP_EN : 0;
67		ret = da903x_write(dev, DA9030_WLED_CONTROL, val);
68		break;
69	}
70
71	if (ret)
72		return ret;
73
74	data->current_brightness = brightness;
75	return 0;
76}
77
78static int da903x_backlight_update_status(struct backlight_device *bl)
79{
80	return da903x_backlight_set(bl, backlight_get_brightness(bl));
81}
82
83static int da903x_backlight_get_brightness(struct backlight_device *bl)
84{
85	struct da903x_backlight_data *data = bl_get_data(bl);
86
87	return data->current_brightness;
88}
89
90static const struct backlight_ops da903x_backlight_ops = {
91	.options	= BL_CORE_SUSPENDRESUME,
92	.update_status	= da903x_backlight_update_status,
93	.get_brightness	= da903x_backlight_get_brightness,
94};
95
96static int da903x_backlight_probe(struct platform_device *pdev)
97{
98	struct da9034_backlight_pdata *pdata = dev_get_platdata(&pdev->dev);
99	struct da903x_backlight_data *data;
100	struct backlight_device *bl;
101	struct backlight_properties props;
102	int max_brightness;
103
104	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
105	if (data == NULL)
106		return -ENOMEM;
107
108	switch (pdev->id) {
109	case DA9030_ID_WLED:
110		max_brightness = DA9030_MAX_BRIGHTNESS;
111		break;
112	case DA9034_ID_WLED:
113		max_brightness = DA9034_MAX_BRIGHTNESS;
114		break;
115	default:
116		dev_err(&pdev->dev, "invalid backlight device ID(%d)\n",
117				pdev->id);
118		return -EINVAL;
119	}
120
121	data->id = pdev->id;
122	data->da903x_dev = pdev->dev.parent;
123	data->current_brightness = 0;
124
125	/* adjust the WLED output current */
126	if (pdata)
127		da903x_write(data->da903x_dev, DA9034_WLED_CONTROL2,
128				DA9034_WLED_ISET(pdata->output_current));
129
130	memset(&props, 0, sizeof(props));
131	props.type = BACKLIGHT_RAW;
132	props.max_brightness = max_brightness;
133	bl = devm_backlight_device_register(&pdev->dev, pdev->name,
134					data->da903x_dev, data,
135					&da903x_backlight_ops, &props);
136	if (IS_ERR(bl)) {
137		dev_err(&pdev->dev, "failed to register backlight\n");
138		return PTR_ERR(bl);
139	}
140
141	bl->props.brightness = max_brightness;
142
143	platform_set_drvdata(pdev, bl);
144	backlight_update_status(bl);
145	return 0;
146}
147
148static struct platform_driver da903x_backlight_driver = {
149	.driver		= {
150		.name	= "da903x-backlight",
151	},
152	.probe		= da903x_backlight_probe,
153};
154
155module_platform_driver(da903x_backlight_driver);
156
157MODULE_DESCRIPTION("Backlight Driver for Dialog Semiconductor DA9030/DA9034");
158MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
159MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
160MODULE_LICENSE("GPL");
161MODULE_ALIAS("platform:da903x-backlight");
162