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4f811ef0 HZ |
1 | /* |
2 | * Backlight driver for Maxim MAX8925 | |
3 | * | |
4 | * Copyright (C) 2009 Marvell International Ltd. | |
5 | * Haojian Zhuang <haojian.zhuang@marvell.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | ||
12 | #include <linux/init.h> | |
13 | #include <linux/kernel.h> | |
14 | #include <linux/platform_device.h> | |
15 | #include <linux/fb.h> | |
16 | #include <linux/i2c.h> | |
17 | #include <linux/backlight.h> | |
18 | #include <linux/mfd/max8925.h> | |
5a0e3ad6 | 19 | #include <linux/slab.h> |
4f811ef0 HZ |
20 | |
21 | #define MAX_BRIGHTNESS (0xff) | |
22 | #define MIN_BRIGHTNESS (0) | |
23 | ||
24 | #define LWX_FREQ(x) (((x - 601) / 100) & 0x7) | |
25 | ||
26 | struct max8925_backlight_data { | |
27 | struct max8925_chip *chip; | |
28 | ||
29 | int current_brightness; | |
30 | }; | |
31 | ||
32 | static int max8925_backlight_set(struct backlight_device *bl, int brightness) | |
33 | { | |
34 | struct max8925_backlight_data *data = bl_get_data(bl); | |
35 | struct max8925_chip *chip = data->chip; | |
36 | unsigned char value; | |
37 | int ret; | |
38 | ||
39 | if (brightness > MAX_BRIGHTNESS) | |
40 | value = MAX_BRIGHTNESS; | |
41 | else | |
42 | value = brightness; | |
43 | ||
44 | ret = max8925_reg_write(chip->i2c, MAX8925_WLED_CNTL, value); | |
45 | if (ret < 0) | |
46 | goto out; | |
47 | ||
48 | if (!data->current_brightness && brightness) | |
49 | /* enable WLED output */ | |
50 | ret = max8925_set_bits(chip->i2c, MAX8925_WLED_MODE_CNTL, 1, 1); | |
51 | else if (!brightness) | |
52 | /* disable WLED output */ | |
53 | ret = max8925_set_bits(chip->i2c, MAX8925_WLED_MODE_CNTL, 1, 0); | |
54 | if (ret < 0) | |
55 | goto out; | |
56 | dev_dbg(chip->dev, "set brightness %d\n", value); | |
57 | data->current_brightness = value; | |
58 | return 0; | |
59 | out: | |
60 | dev_dbg(chip->dev, "set brightness %d failure with return value:%d\n", | |
61 | value, ret); | |
62 | return ret; | |
63 | } | |
64 | ||
65 | static int max8925_backlight_update_status(struct backlight_device *bl) | |
66 | { | |
67 | int brightness = bl->props.brightness; | |
68 | ||
69 | if (bl->props.power != FB_BLANK_UNBLANK) | |
70 | brightness = 0; | |
71 | ||
72 | if (bl->props.fb_blank != FB_BLANK_UNBLANK) | |
73 | brightness = 0; | |
74 | ||
75 | if (bl->props.state & BL_CORE_SUSPENDED) | |
76 | brightness = 0; | |
77 | ||
78 | return max8925_backlight_set(bl, brightness); | |
79 | } | |
80 | ||
81 | static int max8925_backlight_get_brightness(struct backlight_device *bl) | |
82 | { | |
83 | struct max8925_backlight_data *data = bl_get_data(bl); | |
84 | struct max8925_chip *chip = data->chip; | |
85 | int ret; | |
86 | ||
87 | ret = max8925_reg_read(chip->i2c, MAX8925_WLED_CNTL); | |
88 | if (ret < 0) | |
89 | return -EINVAL; | |
90 | data->current_brightness = ret; | |
91 | dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness); | |
92 | return ret; | |
93 | } | |
94 | ||
acc2472e | 95 | static const struct backlight_ops max8925_backlight_ops = { |
4f811ef0 HZ |
96 | .options = BL_CORE_SUSPENDRESUME, |
97 | .update_status = max8925_backlight_update_status, | |
98 | .get_brightness = max8925_backlight_get_brightness, | |
99 | }; | |
100 | ||
101 | static int __devinit max8925_backlight_probe(struct platform_device *pdev) | |
102 | { | |
103 | struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent); | |
104 | struct max8925_platform_data *max8925_pdata; | |
105 | struct max8925_backlight_pdata *pdata = NULL; | |
106 | struct max8925_backlight_data *data; | |
107 | struct backlight_device *bl; | |
a19a6ee6 | 108 | struct backlight_properties props; |
4f811ef0 HZ |
109 | struct resource *res; |
110 | char name[MAX8925_NAME_SIZE]; | |
111 | unsigned char value; | |
112 | int ret; | |
113 | ||
114 | res = platform_get_resource(pdev, IORESOURCE_IO, 0); | |
115 | if (res == NULL) { | |
116 | dev_err(&pdev->dev, "No I/O resource!\n"); | |
117 | return -EINVAL; | |
118 | } | |
119 | ||
120 | if (pdev->dev.parent->platform_data) { | |
121 | max8925_pdata = pdev->dev.parent->platform_data; | |
122 | pdata = max8925_pdata->backlight; | |
123 | } | |
124 | ||
125 | if (!pdata) { | |
126 | dev_err(&pdev->dev, "platform data isn't assigned to " | |
127 | "backlight\n"); | |
128 | return -EINVAL; | |
129 | } | |
130 | ||
131 | data = kzalloc(sizeof(struct max8925_backlight_data), GFP_KERNEL); | |
132 | if (data == NULL) | |
133 | return -ENOMEM; | |
134 | strncpy(name, res->name, MAX8925_NAME_SIZE); | |
135 | data->chip = chip; | |
136 | data->current_brightness = 0; | |
137 | ||
a19a6ee6 | 138 | memset(&props, 0, sizeof(struct backlight_properties)); |
bb7ca747 | 139 | props.type = BACKLIGHT_RAW; |
a19a6ee6 | 140 | props.max_brightness = MAX_BRIGHTNESS; |
4f811ef0 | 141 | bl = backlight_device_register(name, &pdev->dev, data, |
a19a6ee6 | 142 | &max8925_backlight_ops, &props); |
4f811ef0 HZ |
143 | if (IS_ERR(bl)) { |
144 | dev_err(&pdev->dev, "failed to register backlight\n"); | |
145 | kfree(data); | |
146 | return PTR_ERR(bl); | |
147 | } | |
4f811ef0 HZ |
148 | bl->props.brightness = MAX_BRIGHTNESS; |
149 | ||
150 | platform_set_drvdata(pdev, bl); | |
151 | ||
152 | value = 0; | |
153 | if (pdata->lxw_scl) | |
154 | value |= (1 << 7); | |
155 | if (pdata->lxw_freq) | |
156 | value |= (LWX_FREQ(pdata->lxw_freq) << 4); | |
157 | if (pdata->dual_string) | |
158 | value |= (1 << 1); | |
159 | ret = max8925_set_bits(chip->i2c, MAX8925_WLED_MODE_CNTL, 0xfe, value); | |
160 | if (ret < 0) | |
161 | goto out; | |
162 | ||
163 | backlight_update_status(bl); | |
164 | return 0; | |
165 | out: | |
146e10a8 | 166 | backlight_device_unregister(bl); |
4f811ef0 HZ |
167 | kfree(data); |
168 | return ret; | |
169 | } | |
170 | ||
171 | static int __devexit max8925_backlight_remove(struct platform_device *pdev) | |
172 | { | |
173 | struct backlight_device *bl = platform_get_drvdata(pdev); | |
174 | struct max8925_backlight_data *data = bl_get_data(bl); | |
175 | ||
176 | backlight_device_unregister(bl); | |
177 | kfree(data); | |
178 | return 0; | |
179 | } | |
180 | ||
181 | static struct platform_driver max8925_backlight_driver = { | |
182 | .driver = { | |
183 | .name = "max8925-backlight", | |
184 | .owner = THIS_MODULE, | |
185 | }, | |
186 | .probe = max8925_backlight_probe, | |
187 | .remove = __devexit_p(max8925_backlight_remove), | |
188 | }; | |
189 | ||
190 | static int __init max8925_backlight_init(void) | |
191 | { | |
192 | return platform_driver_register(&max8925_backlight_driver); | |
193 | } | |
194 | module_init(max8925_backlight_init); | |
195 | ||
196 | static void __exit max8925_backlight_exit(void) | |
197 | { | |
198 | platform_driver_unregister(&max8925_backlight_driver); | |
199 | }; | |
200 | module_exit(max8925_backlight_exit); | |
201 | ||
202 | MODULE_DESCRIPTION("Backlight Driver for Maxim MAX8925"); | |
203 | MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); | |
204 | MODULE_LICENSE("GPL"); | |
205 | MODULE_ALIAS("platform:max8925-backlight"); |