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Lars-Peter Clausen2ddfd122010-05-12 02:44:32 +02001/*
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
27struct 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 */
45int 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
Jingoo Hanae872db2012-12-17 16:00:30 -080055 return 0;
Lars-Peter Clausen2ddfd122010-05-12 02:44:32 +020056}
57
58static 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
90static int pcf50633_bl_get_brightness(struct backlight_device *bl)
91{
92 struct pcf50633_bl *pcf_bl = bl_get_data(bl);
Jingoo Hanc915ae52014-08-27 10:13:10 +090093
Lars-Peter Clausen2ddfd122010-05-12 02:44:32 +020094 return pcf_bl->brightness;
95}
96
97static 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
Bill Pemberton1b9e4502012-11-19 13:21:46 -0500103static int pcf50633_bl_probe(struct platform_device *pdev)
Lars-Peter Clausen2ddfd122010-05-12 02:44:32 +0200104{
Lars-Peter Clausen2ddfd122010-05-12 02:44:32 +0200105 struct pcf50633_bl *pcf_bl;
106 struct device *parent = pdev->dev.parent;
Jingoo Hanc512794c2013-11-12 15:09:04 -0800107 struct pcf50633_platform_data *pcf50633_data = dev_get_platdata(parent);
Lars-Peter Clausen2ddfd122010-05-12 02:44:32 +0200108 struct pcf50633_bl_platform_data *pdata = pcf50633_data->backlight_data;
109 struct backlight_properties bl_props;
110
Julia Lawallce969222012-03-23 15:02:00 -0700111 pcf_bl = devm_kzalloc(&pdev->dev, sizeof(*pcf_bl), GFP_KERNEL);
Lars-Peter Clausen2ddfd122010-05-12 02:44:32 +0200112 if (!pcf_bl)
113 return -ENOMEM;
114
Corentin Charyf5f4fd42012-05-29 15:07:20 -0700115 memset(&bl_props, 0, sizeof(bl_props));
Matthew Garrettbb7ca742011-03-22 16:30:21 -0700116 bl_props.type = BACKLIGHT_RAW;
Lars-Peter Clausen2ddfd122010-05-12 02:44:32 +0200117 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
Jingoo Hanc423a772013-11-12 15:09:23 -0800130 pcf_bl->bl = devm_backlight_device_register(&pdev->dev, pdev->name,
131 &pdev->dev, pcf_bl,
Lars-Peter Clausen2ddfd122010-05-12 02:44:32 +0200132 &pcf50633_bl_ops, &bl_props);
133
Julia Lawallce969222012-03-23 15:02:00 -0700134 if (IS_ERR(pcf_bl->bl))
135 return PTR_ERR(pcf_bl->bl);
Lars-Peter Clausen2ddfd122010-05-12 02:44:32 +0200136
137 platform_set_drvdata(pdev, pcf_bl);
138
139 pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDDIM, pdata->ramp_time);
140
Jingoo Hanae872db2012-12-17 16:00:30 -0800141 /*
142 * Should be different from bl_props.brightness, so we do not exit
143 * update_status early the first time it's called
144 */
Lars-Peter Clausen2ddfd122010-05-12 02:44:32 +0200145 pcf_bl->brightness = pcf_bl->bl->props.brightness + 1;
146
147 backlight_update_status(pcf_bl->bl);
148
149 return 0;
Lars-Peter Clausen2ddfd122010-05-12 02:44:32 +0200150}
151
Lars-Peter Clausen2ddfd122010-05-12 02:44:32 +0200152static struct platform_driver pcf50633_bl_driver = {
153 .probe = pcf50633_bl_probe,
Lars-Peter Clausen2ddfd122010-05-12 02:44:32 +0200154 .driver = {
155 .name = "pcf50633-backlight",
156 },
157};
158
Axel Lin81178e02012-01-10 15:09:11 -0800159module_platform_driver(pcf50633_bl_driver);
Lars-Peter Clausen2ddfd122010-05-12 02:44:32 +0200160
161MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
162MODULE_DESCRIPTION("PCF50633 backlight driver");
163MODULE_LICENSE("GPL");
164MODULE_ALIAS("platform:pcf50633-backlight");