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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 int brightness = bl->props.brightness;
81
82 if (bl->props.power != FB_BLANK_UNBLANK)
83 brightness = 0;
84
85 if (bl->props.fb_blank != FB_BLANK_UNBLANK)
86 brightness = 0;
87
88 if (bl->props.state & BL_CORE_SUSPENDED)
89 brightness = 0;
90
91 return da903x_backlight_set(bl, brightness);
92}
93
94static int da903x_backlight_get_brightness(struct backlight_device *bl)
95{
96 struct da903x_backlight_data *data = bl_get_data(bl);
97
98 return data->current_brightness;
99}
100
101static const struct backlight_ops da903x_backlight_ops = {
102 .options = BL_CORE_SUSPENDRESUME,
103 .update_status = da903x_backlight_update_status,
104 .get_brightness = da903x_backlight_get_brightness,
105};
106
107static int da903x_backlight_probe(struct platform_device *pdev)
108{
109 struct da9034_backlight_pdata *pdata = dev_get_platdata(&pdev->dev);
110 struct da903x_backlight_data *data;
111 struct backlight_device *bl;
112 struct backlight_properties props;
113 int max_brightness;
114
115 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
116 if (data == NULL)
117 return -ENOMEM;
118
119 switch (pdev->id) {
120 case DA9030_ID_WLED:
121 max_brightness = DA9030_MAX_BRIGHTNESS;
122 break;
123 case DA9034_ID_WLED:
124 max_brightness = DA9034_MAX_BRIGHTNESS;
125 break;
126 default:
127 dev_err(&pdev->dev, "invalid backlight device ID(%d)\n",
128 pdev->id);
129 return -EINVAL;
130 }
131
132 data->id = pdev->id;
133 data->da903x_dev = pdev->dev.parent;
134 data->current_brightness = 0;
135
136
137 if (pdata)
138 da903x_write(data->da903x_dev, DA9034_WLED_CONTROL2,
139 DA9034_WLED_ISET(pdata->output_current));
140
141 memset(&props, 0, sizeof(props));
142 props.type = BACKLIGHT_RAW;
143 props.max_brightness = max_brightness;
144 bl = devm_backlight_device_register(&pdev->dev, pdev->name,
145 data->da903x_dev, data,
146 &da903x_backlight_ops, &props);
147 if (IS_ERR(bl)) {
148 dev_err(&pdev->dev, "failed to register backlight\n");
149 return PTR_ERR(bl);
150 }
151
152 bl->props.brightness = max_brightness;
153
154 platform_set_drvdata(pdev, bl);
155 backlight_update_status(bl);
156 return 0;
157}
158
159static struct platform_driver da903x_backlight_driver = {
160 .driver = {
161 .name = "da903x-backlight",
162 },
163 .probe = da903x_backlight_probe,
164};
165
166module_platform_driver(da903x_backlight_driver);
167
168MODULE_DESCRIPTION("Backlight Driver for Dialog Semiconductor DA9030/DA9034");
169MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
170MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
171MODULE_LICENSE("GPL");
172MODULE_ALIAS("platform:da903x-backlight");
173
