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2ddfd12f LPC |
1 | /* |
2 | * Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de> | |
3 | * PCF50633 backlight device driver | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms of the GNU General Public License as published by the | |
7 | * Free Software Foundation; either version 2 of the License, or (at your | |
8 | * option) any later version. | |
9 | * | |
10 | * You should have received a copy of the GNU General Public License along | |
11 | * with this program; if not, write to the Free Software Foundation, Inc., | |
12 | * 675 Mass Ave, Cambridge, MA 02139, USA. | |
13 | * | |
14 | */ | |
15 | ||
16 | #include <linux/kernel.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/platform_device.h> | |
20 | ||
21 | #include <linux/backlight.h> | |
22 | #include <linux/fb.h> | |
23 | ||
24 | #include <linux/mfd/pcf50633/core.h> | |
25 | #include <linux/mfd/pcf50633/backlight.h> | |
26 | ||
27 | struct pcf50633_bl { | |
28 | struct pcf50633 *pcf; | |
29 | struct backlight_device *bl; | |
30 | ||
31 | unsigned int brightness; | |
32 | unsigned int brightness_limit; | |
33 | }; | |
34 | ||
35 | /* | |
36 | * pcf50633_bl_set_brightness_limit | |
37 | * | |
38 | * Update the brightness limit for the pc50633 backlight. The actual brightness | |
39 | * will not go above the limit. This is useful to limit power drain for example | |
40 | * on low battery. | |
41 | * | |
42 | * @dev: Pointer to a pcf50633 device | |
43 | * @limit: The brightness limit. Valid values are 0-63 | |
44 | */ | |
45 | int pcf50633_bl_set_brightness_limit(struct pcf50633 *pcf, unsigned int limit) | |
46 | { | |
47 | struct pcf50633_bl *pcf_bl = platform_get_drvdata(pcf->bl_pdev); | |
48 | ||
49 | if (!pcf_bl) | |
50 | return -ENODEV; | |
51 | ||
52 | pcf_bl->brightness_limit = limit & 0x3f; | |
53 | backlight_update_status(pcf_bl->bl); | |
54 | ||
ae872dbb | 55 | return 0; |
2ddfd12f LPC |
56 | } |
57 | ||
58 | static int pcf50633_bl_update_status(struct backlight_device *bl) | |
59 | { | |
60 | struct pcf50633_bl *pcf_bl = bl_get_data(bl); | |
61 | unsigned int new_brightness; | |
62 | ||
63 | ||
64 | if (bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK) || | |
65 | bl->props.power != FB_BLANK_UNBLANK) | |
66 | new_brightness = 0; | |
67 | else if (bl->props.brightness < pcf_bl->brightness_limit) | |
68 | new_brightness = bl->props.brightness; | |
69 | else | |
70 | new_brightness = pcf_bl->brightness_limit; | |
71 | ||
72 | ||
73 | if (pcf_bl->brightness == new_brightness) | |
74 | return 0; | |
75 | ||
76 | if (new_brightness) { | |
77 | pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDOUT, | |
78 | new_brightness); | |
79 | if (!pcf_bl->brightness) | |
80 | pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDENA, 1); | |
81 | } else { | |
82 | pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDENA, 0); | |
83 | } | |
84 | ||
85 | pcf_bl->brightness = new_brightness; | |
86 | ||
87 | return 0; | |
88 | } | |
89 | ||
90 | static int pcf50633_bl_get_brightness(struct backlight_device *bl) | |
91 | { | |
92 | struct pcf50633_bl *pcf_bl = bl_get_data(bl); | |
c915ae50 | 93 | |
2ddfd12f LPC |
94 | return pcf_bl->brightness; |
95 | } | |
96 | ||
97 | static const struct backlight_ops pcf50633_bl_ops = { | |
98 | .get_brightness = pcf50633_bl_get_brightness, | |
99 | .update_status = pcf50633_bl_update_status, | |
100 | .options = BL_CORE_SUSPENDRESUME, | |
101 | }; | |
102 | ||
1b9e450d | 103 | static int pcf50633_bl_probe(struct platform_device *pdev) |
2ddfd12f | 104 | { |
2ddfd12f LPC |
105 | struct pcf50633_bl *pcf_bl; |
106 | struct device *parent = pdev->dev.parent; | |
c512794c | 107 | struct pcf50633_platform_data *pcf50633_data = dev_get_platdata(parent); |
2ddfd12f LPC |
108 | struct pcf50633_bl_platform_data *pdata = pcf50633_data->backlight_data; |
109 | struct backlight_properties bl_props; | |
110 | ||
ce969228 | 111 | pcf_bl = devm_kzalloc(&pdev->dev, sizeof(*pcf_bl), GFP_KERNEL); |
2ddfd12f LPC |
112 | if (!pcf_bl) |
113 | return -ENOMEM; | |
114 | ||
f5f4fd45 | 115 | memset(&bl_props, 0, sizeof(bl_props)); |
bb7ca747 | 116 | bl_props.type = BACKLIGHT_RAW; |
2ddfd12f LPC |
117 | bl_props.max_brightness = 0x3f; |
118 | bl_props.power = FB_BLANK_UNBLANK; | |
119 | ||
120 | if (pdata) { | |
121 | bl_props.brightness = pdata->default_brightness; | |
122 | pcf_bl->brightness_limit = pdata->default_brightness_limit; | |
123 | } else { | |
124 | bl_props.brightness = 0x3f; | |
125 | pcf_bl->brightness_limit = 0x3f; | |
126 | } | |
127 | ||
128 | pcf_bl->pcf = dev_to_pcf50633(pdev->dev.parent); | |
129 | ||
c423a771 JH |
130 | pcf_bl->bl = devm_backlight_device_register(&pdev->dev, pdev->name, |
131 | &pdev->dev, pcf_bl, | |
2ddfd12f LPC |
132 | &pcf50633_bl_ops, &bl_props); |
133 | ||
ce969228 JL |
134 | if (IS_ERR(pcf_bl->bl)) |
135 | return PTR_ERR(pcf_bl->bl); | |
2ddfd12f LPC |
136 | |
137 | platform_set_drvdata(pdev, pcf_bl); | |
138 | ||
139 | pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDDIM, pdata->ramp_time); | |
140 | ||
ae872dbb JH |
141 | /* |
142 | * Should be different from bl_props.brightness, so we do not exit | |
143 | * update_status early the first time it's called | |
144 | */ | |
2ddfd12f LPC |
145 | pcf_bl->brightness = pcf_bl->bl->props.brightness + 1; |
146 | ||
147 | backlight_update_status(pcf_bl->bl); | |
148 | ||
149 | return 0; | |
2ddfd12f LPC |
150 | } |
151 | ||
2ddfd12f LPC |
152 | static struct platform_driver pcf50633_bl_driver = { |
153 | .probe = pcf50633_bl_probe, | |
2ddfd12f LPC |
154 | .driver = { |
155 | .name = "pcf50633-backlight", | |
156 | }, | |
157 | }; | |
158 | ||
81178e02 | 159 | module_platform_driver(pcf50633_bl_driver); |
2ddfd12f LPC |
160 | |
161 | MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); | |
162 | MODULE_DESCRIPTION("PCF50633 backlight driver"); | |
163 | MODULE_LICENSE("GPL"); | |
164 | MODULE_ALIAS("platform:pcf50633-backlight"); |