tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Backlight driver for OMAP based boards.
3 *
4 * Copyright (c) 2006 Andrzej Zaborowski <balrog@zabor.org>
5 *
6 * This package is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This package is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this package; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22
23#include <linux/module.h>
24#include <linux/kernel.h>
25#include <linux/init.h>
26#include <linux/platform_device.h>
27#include <linux/fb.h>
28#include <linux/backlight.h>
29#include <linux/slab.h>
30
31#include <mach/hardware.h>
32#include <plat/board.h>
33#include <plat/mux.h>
34
35#define OMAPBL_MAX_INTENSITY 0xff
36
37struct omap_backlight {
38 int powermode;
39 int current_intensity;
40
41 struct device *dev;
42 struct omap_backlight_config *pdata;
43};
44
45static void inline omapbl_send_intensity(int intensity)
46{
47 omap_writeb(intensity, OMAP_PWL_ENABLE);
48}
49
50static void inline omapbl_send_enable(int enable)
51{
52 omap_writeb(enable, OMAP_PWL_CLK_ENABLE);
53}
54
55static void omapbl_blank(struct omap_backlight *bl, int mode)
56{
57 if (bl->pdata->set_power)
58 bl->pdata->set_power(bl->dev, mode);
59
60 switch (mode) {
61 case FB_BLANK_NORMAL:
62 case FB_BLANK_VSYNC_SUSPEND:
63 case FB_BLANK_HSYNC_SUSPEND:
64 case FB_BLANK_POWERDOWN:
65 omapbl_send_intensity(0);
66 omapbl_send_enable(0);
67 break;
68
69 case FB_BLANK_UNBLANK:
70 omapbl_send_intensity(bl->current_intensity);
71 omapbl_send_enable(1);
72 break;
73 }
74}
75
76#ifdef CONFIG_PM
77static int omapbl_suspend(struct platform_device *pdev, pm_message_t state)
78{
79 struct backlight_device *dev = platform_get_drvdata(pdev);
80 struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
81
82 omapbl_blank(bl, FB_BLANK_POWERDOWN);
83 return 0;
84}
85
86static int omapbl_resume(struct platform_device *pdev)
87{
88 struct backlight_device *dev = platform_get_drvdata(pdev);
89 struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
90
91 omapbl_blank(bl, bl->powermode);
92 return 0;
93}
94#else
95#define omapbl_suspend NULL
96#define omapbl_resume NULL
97#endif
98
99static int omapbl_set_power(struct backlight_device *dev, int state)
100{
101 struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
102
103 omapbl_blank(bl, state);
104 bl->powermode = state;
105
106 return 0;
107}
108
109static int omapbl_update_status(struct backlight_device *dev)
110{
111 struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
112
113 if (bl->current_intensity != dev->props.brightness) {
114 if (bl->powermode == FB_BLANK_UNBLANK)
115 omapbl_send_intensity(dev->props.brightness);
116 bl->current_intensity = dev->props.brightness;
117 }
118
119 if (dev->props.fb_blank != bl->powermode)
120 omapbl_set_power(dev, dev->props.fb_blank);
121
122 return 0;
123}
124
125static int omapbl_get_intensity(struct backlight_device *dev)
126{
127 struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
128 return bl->current_intensity;
129}
130
131static const struct backlight_ops omapbl_ops = {
132 .get_brightness = omapbl_get_intensity,
133 .update_status = omapbl_update_status,
134};
135
136static int omapbl_probe(struct platform_device *pdev)
137{
138 struct backlight_properties props;
139 struct backlight_device *dev;
140 struct omap_backlight *bl;
141 struct omap_backlight_config *pdata = pdev->dev.platform_data;
142
143 if (!pdata)
144 return -ENXIO;
145
146 bl = devm_kzalloc(&pdev->dev, sizeof(struct omap_backlight),
147 GFP_KERNEL);
148 if (unlikely(!bl))
149 return -ENOMEM;
150
151 memset(&props, 0, sizeof(struct backlight_properties));
152 props.type = BACKLIGHT_RAW;
153 props.max_brightness = OMAPBL_MAX_INTENSITY;
154 dev = backlight_device_register("omap-bl", &pdev->dev, bl, &omapbl_ops,
155 &props);
156 if (IS_ERR(dev))
157 return PTR_ERR(dev);
158
159 bl->powermode = FB_BLANK_POWERDOWN;
160 bl->current_intensity = 0;
161
162 bl->pdata = pdata;
163 bl->dev = &pdev->dev;
164
165 platform_set_drvdata(pdev, dev);
166
167 omap_cfg_reg(PWL); /* Conflicts with UART3 */
168
169 dev->props.fb_blank = FB_BLANK_UNBLANK;
170 dev->props.brightness = pdata->default_intensity;
171 omapbl_update_status(dev);
172
173 pr_info("OMAP LCD backlight initialised\n");
174
175 return 0;
176}
177
178static int omapbl_remove(struct platform_device *pdev)
179{
180 struct backlight_device *dev = platform_get_drvdata(pdev);
181
182 backlight_device_unregister(dev);
183
184 return 0;
185}
186
187static struct platform_driver omapbl_driver = {
188 .probe = omapbl_probe,
189 .remove = omapbl_remove,
190 .suspend = omapbl_suspend,
191 .resume = omapbl_resume,
192 .driver = {
193 .name = "omap-bl",
194 },
195};
196
197module_platform_driver(omapbl_driver);
198
199MODULE_AUTHOR("Andrzej Zaborowski <balrog@zabor.org>");
200MODULE_DESCRIPTION("OMAP LCD Backlight driver");
201MODULE_LICENSE("GPL");