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hp680_bl.c
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1 /*
2  * Backlight Driver for HP Jornada 680
3  *
4  * Copyright (c) 2005 Andriy Skulysh
5  *
6  * Based on Sharp's Corgi Backlight Driver
7  *
8  * This file is subject to the terms and conditions of the GNU General Public
9  * License. See the file "COPYING" in the main directory of this archive
10  * for more details.
11  */
12 
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/platform_device.h>
17 #include <linux/spinlock.h>
18 #include <linux/fb.h>
19 #include <linux/backlight.h>
20 
21 #include <cpu/dac.h>
22 #include <mach/hp6xx.h>
23 #include <asm/hd64461.h>
24 
25 #define HP680_MAX_INTENSITY 255
26 #define HP680_DEFAULT_INTENSITY 10
27 
28 static int hp680bl_suspended;
29 static int current_intensity = 0;
30 static DEFINE_SPINLOCK(bl_lock);
31 
32 static void hp680bl_send_intensity(struct backlight_device *bd)
33 {
34  unsigned long flags;
35  u16 v;
36  int intensity = bd->props.brightness;
37 
38  if (bd->props.power != FB_BLANK_UNBLANK)
39  intensity = 0;
40  if (bd->props.fb_blank != FB_BLANK_UNBLANK)
41  intensity = 0;
42  if (hp680bl_suspended)
43  intensity = 0;
44 
45  spin_lock_irqsave(&bl_lock, flags);
46  if (intensity && current_intensity == 0) {
47  sh_dac_enable(DAC_LCD_BRIGHTNESS);
48  v = inw(HD64461_GPBDR);
50  outw(v, HD64461_GPBDR);
51  sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
52  } else if (intensity == 0 && current_intensity != 0) {
53  sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
54  sh_dac_disable(DAC_LCD_BRIGHTNESS);
55  v = inw(HD64461_GPBDR);
57  outw(v, HD64461_GPBDR);
58  } else if (intensity) {
59  sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
60  }
61  spin_unlock_irqrestore(&bl_lock, flags);
62 
63  current_intensity = intensity;
64 }
65 
66 
67 #ifdef CONFIG_PM
68 static int hp680bl_suspend(struct platform_device *pdev, pm_message_t state)
69 {
70  struct backlight_device *bd = platform_get_drvdata(pdev);
71 
72  hp680bl_suspended = 1;
73  hp680bl_send_intensity(bd);
74  return 0;
75 }
76 
77 static int hp680bl_resume(struct platform_device *pdev)
78 {
79  struct backlight_device *bd = platform_get_drvdata(pdev);
80 
81  hp680bl_suspended = 0;
82  hp680bl_send_intensity(bd);
83  return 0;
84 }
85 #else
86 #define hp680bl_suspend NULL
87 #define hp680bl_resume NULL
88 #endif
89 
90 static int hp680bl_set_intensity(struct backlight_device *bd)
91 {
92  hp680bl_send_intensity(bd);
93  return 0;
94 }
95 
96 static int hp680bl_get_intensity(struct backlight_device *bd)
97 {
98  return current_intensity;
99 }
100 
101 static const struct backlight_ops hp680bl_ops = {
102  .get_brightness = hp680bl_get_intensity,
103  .update_status = hp680bl_set_intensity,
104 };
105 
106 static int __devinit hp680bl_probe(struct platform_device *pdev)
107 {
108  struct backlight_properties props;
109  struct backlight_device *bd;
110 
111  memset(&props, 0, sizeof(struct backlight_properties));
112  props.type = BACKLIGHT_RAW;
113  props.max_brightness = HP680_MAX_INTENSITY;
114  bd = backlight_device_register("hp680-bl", &pdev->dev, NULL,
115  &hp680bl_ops, &props);
116  if (IS_ERR(bd))
117  return PTR_ERR(bd);
118 
119  platform_set_drvdata(pdev, bd);
120 
121  bd->props.brightness = HP680_DEFAULT_INTENSITY;
122  hp680bl_send_intensity(bd);
123 
124  return 0;
125 }
126 
127 static int hp680bl_remove(struct platform_device *pdev)
128 {
129  struct backlight_device *bd = platform_get_drvdata(pdev);
130 
131  bd->props.brightness = 0;
132  bd->props.power = 0;
133  hp680bl_send_intensity(bd);
134 
136 
137  return 0;
138 }
139 
140 static struct platform_driver hp680bl_driver = {
141  .probe = hp680bl_probe,
142  .remove = hp680bl_remove,
143  .suspend = hp680bl_suspend,
144  .resume = hp680bl_resume,
145  .driver = {
146  .name = "hp680-bl",
147  },
148 };
149 
150 static struct platform_device *hp680bl_device;
151 
152 static int __init hp680bl_init(void)
153 {
154  int ret;
155 
156  ret = platform_driver_register(&hp680bl_driver);
157  if (ret)
158  return ret;
159  hp680bl_device = platform_device_register_simple("hp680-bl", -1,
160  NULL, 0);
161  if (IS_ERR(hp680bl_device)) {
162  platform_driver_unregister(&hp680bl_driver);
163  return PTR_ERR(hp680bl_device);
164  }
165  return 0;
166 }
167 
168 static void __exit hp680bl_exit(void)
169 {
170  platform_device_unregister(hp680bl_device);
171  platform_driver_unregister(&hp680bl_driver);
172 }
173 
174 module_init(hp680bl_init);
175 module_exit(hp680bl_exit);
176 
177 MODULE_AUTHOR("Andriy Skulysh <[email protected]>");
178 MODULE_DESCRIPTION("HP Jornada 680 Backlight Driver");
179 MODULE_LICENSE("GPL");