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 #include <linux/module.h>
22 #include <linux/kernel.h>
23 #include <linux/init.h>
24 #include <linux/platform_device.h>
25 #include <linux/fb.h>
26 #include <linux/backlight.h>
27
28 #include <mach/hardware.h>
29 #include <mach/board.h>
30 #include <mach/mux.h>
31
32 #define OMAPBL_MAX_INTENSITY 0xff
33
34 struct omap_backlight {
35 int powermode;
36 int current_intensity;
37
38 struct device *dev;
39 struct omap_backlight_config *pdata;
40 };
41
omapbl_send_intensity(int intensity)42 static void inline omapbl_send_intensity(int intensity)
43 {
44 omap_writeb(intensity, OMAP_PWL_ENABLE);
45 }
46
omapbl_send_enable(int enable)47 static void inline omapbl_send_enable(int enable)
48 {
49 omap_writeb(enable, OMAP_PWL_CLK_ENABLE);
50 }
51
omapbl_blank(struct omap_backlight * bl,int mode)52 static void omapbl_blank(struct omap_backlight *bl, int mode)
53 {
54 if (bl->pdata->set_power)
55 bl->pdata->set_power(bl->dev, mode);
56
57 switch (mode) {
58 case FB_BLANK_NORMAL:
59 case FB_BLANK_VSYNC_SUSPEND:
60 case FB_BLANK_HSYNC_SUSPEND:
61 case FB_BLANK_POWERDOWN:
62 omapbl_send_intensity(0);
63 omapbl_send_enable(0);
64 break;
65
66 case FB_BLANK_UNBLANK:
67 omapbl_send_intensity(bl->current_intensity);
68 omapbl_send_enable(1);
69 break;
70 }
71 }
72
73 #ifdef CONFIG_PM
omapbl_suspend(struct platform_device * pdev,pm_message_t state)74 static int omapbl_suspend(struct platform_device *pdev, pm_message_t state)
75 {
76 struct backlight_device *dev = platform_get_drvdata(pdev);
77 struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
78
79 omapbl_blank(bl, FB_BLANK_POWERDOWN);
80 return 0;
81 }
82
omapbl_resume(struct platform_device * pdev)83 static int omapbl_resume(struct platform_device *pdev)
84 {
85 struct backlight_device *dev = platform_get_drvdata(pdev);
86 struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
87
88 omapbl_blank(bl, bl->powermode);
89 return 0;
90 }
91 #else
92 #define omapbl_suspend NULL
93 #define omapbl_resume NULL
94 #endif
95
omapbl_set_power(struct backlight_device * dev,int state)96 static int omapbl_set_power(struct backlight_device *dev, int state)
97 {
98 struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
99
100 omapbl_blank(bl, state);
101 bl->powermode = state;
102
103 return 0;
104 }
105
omapbl_update_status(struct backlight_device * dev)106 static int omapbl_update_status(struct backlight_device *dev)
107 {
108 struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
109
110 if (bl->current_intensity != dev->props.brightness) {
111 if (bl->powermode == FB_BLANK_UNBLANK)
112 omapbl_send_intensity(dev->props.brightness);
113 bl->current_intensity = dev->props.brightness;
114 }
115
116 if (dev->props.fb_blank != bl->powermode)
117 omapbl_set_power(dev, dev->props.fb_blank);
118
119 return 0;
120 }
121
omapbl_get_intensity(struct backlight_device * dev)122 static int omapbl_get_intensity(struct backlight_device *dev)
123 {
124 struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
125 return bl->current_intensity;
126 }
127
128 static struct backlight_ops omapbl_ops = {
129 .get_brightness = omapbl_get_intensity,
130 .update_status = omapbl_update_status,
131 };
132
omapbl_probe(struct platform_device * pdev)133 static int omapbl_probe(struct platform_device *pdev)
134 {
135 struct backlight_device *dev;
136 struct omap_backlight *bl;
137 struct omap_backlight_config *pdata = pdev->dev.platform_data;
138
139 if (!pdata)
140 return -ENXIO;
141
142 omapbl_ops.check_fb = pdata->check_fb;
143
144 bl = kzalloc(sizeof(struct omap_backlight), GFP_KERNEL);
145 if (unlikely(!bl))
146 return -ENOMEM;
147
148 dev = backlight_device_register("omap-bl", &pdev->dev, bl, &omapbl_ops);
149 if (IS_ERR(dev)) {
150 kfree(bl);
151 return PTR_ERR(dev);
152 }
153
154 bl->powermode = FB_BLANK_POWERDOWN;
155 bl->current_intensity = 0;
156
157 bl->pdata = pdata;
158 bl->dev = &pdev->dev;
159
160 platform_set_drvdata(pdev, dev);
161
162 omap_cfg_reg(PWL); /* Conflicts with UART3 */
163
164 dev->props.fb_blank = FB_BLANK_UNBLANK;
165 dev->props.max_brightness = OMAPBL_MAX_INTENSITY;
166 dev->props.brightness = pdata->default_intensity;
167 omapbl_update_status(dev);
168
169 printk(KERN_INFO "OMAP LCD backlight initialised\n");
170
171 return 0;
172 }
173
omapbl_remove(struct platform_device * pdev)174 static int omapbl_remove(struct platform_device *pdev)
175 {
176 struct backlight_device *dev = platform_get_drvdata(pdev);
177 struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
178
179 backlight_device_unregister(dev);
180 kfree(bl);
181
182 return 0;
183 }
184
185 static struct platform_driver omapbl_driver = {
186 .probe = omapbl_probe,
187 .remove = omapbl_remove,
188 .suspend = omapbl_suspend,
189 .resume = omapbl_resume,
190 .driver = {
191 .name = "omap-bl",
192 },
193 };
194
omapbl_init(void)195 static int __init omapbl_init(void)
196 {
197 return platform_driver_register(&omapbl_driver);
198 }
199
omapbl_exit(void)200 static void __exit omapbl_exit(void)
201 {
202 platform_driver_unregister(&omapbl_driver);
203 }
204
205 module_init(omapbl_init);
206 module_exit(omapbl_exit);
207
208 MODULE_AUTHOR("Andrzej Zaborowski <balrog@zabor.org>");
209 MODULE_DESCRIPTION("OMAP LCD Backlight driver");
210 MODULE_LICENSE("GPL");
211