1 /*
2 * Backlight driver for Dialog Semiconductor DA9030/DA9034
3 *
4 * Copyright (C) 2008 Compulab, Ltd.
5 * Mike Rapoport <mike@compulab.co.il>
6 *
7 * Copyright (C) 2006-2008 Marvell International Ltd.
8 * Eric Miao <eric.miao@marvell.com>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 */
14
15 #include <linux/kernel.h>
16 #include <linux/init.h>
17 #include <linux/platform_device.h>
18 #include <linux/fb.h>
19 #include <linux/backlight.h>
20 #include <linux/mfd/da903x.h>
21 #include <linux/slab.h>
22 #include <linux/module.h>
23
24 #define DA9030_WLED_CONTROL 0x25
25 #define DA9030_WLED_CP_EN (1 << 6)
26 #define DA9030_WLED_TRIM(x) ((x) & 0x7)
27
28 #define DA9034_WLED_CONTROL1 0x3C
29 #define DA9034_WLED_CONTROL2 0x3D
30 #define DA9034_WLED_ISET(x) ((x) & 0x1f)
31
32 #define DA9034_WLED_BOOST_EN (1 << 5)
33
34 #define DA9030_MAX_BRIGHTNESS 7
35 #define DA9034_MAX_BRIGHTNESS 0x7f
36
37 struct da903x_backlight_data {
38 struct device *da903x_dev;
39 int id;
40 int current_brightness;
41 };
42
da903x_backlight_set(struct backlight_device * bl,int brightness)43 static int da903x_backlight_set(struct backlight_device *bl, int brightness)
44 {
45 struct da903x_backlight_data *data = bl_get_data(bl);
46 struct device *dev = data->da903x_dev;
47 uint8_t val;
48 int ret = 0;
49
50 switch (data->id) {
51 case DA9034_ID_WLED:
52 ret = da903x_update(dev, DA9034_WLED_CONTROL1,
53 brightness, 0x7f);
54 if (ret)
55 return ret;
56
57 if (data->current_brightness && brightness == 0)
58 ret = da903x_clr_bits(dev,
59 DA9034_WLED_CONTROL2,
60 DA9034_WLED_BOOST_EN);
61
62 if (data->current_brightness == 0 && brightness)
63 ret = da903x_set_bits(dev,
64 DA9034_WLED_CONTROL2,
65 DA9034_WLED_BOOST_EN);
66 break;
67 case DA9030_ID_WLED:
68 val = DA9030_WLED_TRIM(brightness);
69 val |= brightness ? DA9030_WLED_CP_EN : 0;
70 ret = da903x_write(dev, DA9030_WLED_CONTROL, val);
71 break;
72 }
73
74 if (ret)
75 return ret;
76
77 data->current_brightness = brightness;
78 return 0;
79 }
80
da903x_backlight_update_status(struct backlight_device * bl)81 static int da903x_backlight_update_status(struct backlight_device *bl)
82 {
83 int brightness = bl->props.brightness;
84
85 if (bl->props.power != FB_BLANK_UNBLANK)
86 brightness = 0;
87
88 if (bl->props.fb_blank != FB_BLANK_UNBLANK)
89 brightness = 0;
90
91 if (bl->props.state & BL_CORE_SUSPENDED)
92 brightness = 0;
93
94 return da903x_backlight_set(bl, brightness);
95 }
96
da903x_backlight_get_brightness(struct backlight_device * bl)97 static int da903x_backlight_get_brightness(struct backlight_device *bl)
98 {
99 struct da903x_backlight_data *data = bl_get_data(bl);
100
101 return data->current_brightness;
102 }
103
104 static const struct backlight_ops da903x_backlight_ops = {
105 .options = BL_CORE_SUSPENDRESUME,
106 .update_status = da903x_backlight_update_status,
107 .get_brightness = da903x_backlight_get_brightness,
108 };
109
da903x_backlight_probe(struct platform_device * pdev)110 static int da903x_backlight_probe(struct platform_device *pdev)
111 {
112 struct da9034_backlight_pdata *pdata = dev_get_platdata(&pdev->dev);
113 struct da903x_backlight_data *data;
114 struct backlight_device *bl;
115 struct backlight_properties props;
116 int max_brightness;
117
118 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
119 if (data == NULL)
120 return -ENOMEM;
121
122 switch (pdev->id) {
123 case DA9030_ID_WLED:
124 max_brightness = DA9030_MAX_BRIGHTNESS;
125 break;
126 case DA9034_ID_WLED:
127 max_brightness = DA9034_MAX_BRIGHTNESS;
128 break;
129 default:
130 dev_err(&pdev->dev, "invalid backlight device ID(%d)\n",
131 pdev->id);
132 return -EINVAL;
133 }
134
135 data->id = pdev->id;
136 data->da903x_dev = pdev->dev.parent;
137 data->current_brightness = 0;
138
139 /* adjust the WLED output current */
140 if (pdata)
141 da903x_write(data->da903x_dev, DA9034_WLED_CONTROL2,
142 DA9034_WLED_ISET(pdata->output_current));
143
144 memset(&props, 0, sizeof(props));
145 props.type = BACKLIGHT_RAW;
146 props.max_brightness = max_brightness;
147 bl = devm_backlight_device_register(&pdev->dev, pdev->name,
148 data->da903x_dev, data,
149 &da903x_backlight_ops, &props);
150 if (IS_ERR(bl)) {
151 dev_err(&pdev->dev, "failed to register backlight\n");
152 return PTR_ERR(bl);
153 }
154
155 bl->props.brightness = max_brightness;
156
157 platform_set_drvdata(pdev, bl);
158 backlight_update_status(bl);
159 return 0;
160 }
161
162 static struct platform_driver da903x_backlight_driver = {
163 .driver = {
164 .name = "da903x-backlight",
165 },
166 .probe = da903x_backlight_probe,
167 };
168
169 module_platform_driver(da903x_backlight_driver);
170
171 MODULE_DESCRIPTION("Backlight Driver for Dialog Semiconductor DA9030/DA9034");
172 MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
173 MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
174 MODULE_LICENSE("GPL");
175 MODULE_ALIAS("platform:da903x-backlight");
176
