Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
kb3886_bl.c
Go to the documentation of this file.
1 /*
2  * Backlight Driver for the KB3886 Backlight
3  *
4  * Copyright (c) 2007-2008 Claudio Nieder
5  *
6  * Based on corgi_bl.c by Richard Purdie and kb3886 driver by Robert Woerle
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  *
12  */
13 
14 #include <linux/module.h>
15 #include <linux/kernel.h>
16 #include <linux/init.h>
17 #include <linux/platform_device.h>
18 #include <linux/mutex.h>
19 #include <linux/fb.h>
20 #include <linux/backlight.h>
21 #include <linux/delay.h>
22 #include <linux/dmi.h>
23 
24 #define KB3886_PARENT 0x64
25 #define KB3886_IO 0x60
26 #define KB3886_ADC_DAC_PWM 0xC4
27 #define KB3886_PWM0_WRITE 0x81
28 #define KB3886_PWM0_READ 0x41
29 
30 static DEFINE_MUTEX(bl_mutex);
31 
32 static void kb3886_bl_set_intensity(int intensity)
33 {
34  mutex_lock(&bl_mutex);
35  intensity = intensity&0xff;
37  usleep_range(10000, 11000);
39  usleep_range(10000, 11000);
40  outb(intensity, KB3886_IO);
41  mutex_unlock(&bl_mutex);
42 }
43 
48  void (*set_bl_intensity)(int intensity);
49 };
50 
51 static struct kb3886bl_machinfo kb3886_bl_machinfo = {
52  .max_intensity = 0xff,
53  .default_intensity = 0xa0,
54  .limit_mask = 0x7f,
55  .set_bl_intensity = kb3886_bl_set_intensity,
56 };
57 
58 static struct platform_device kb3886bl_device = {
59  .name = "kb3886-bl",
60  .dev = {
61  .platform_data = &kb3886_bl_machinfo,
62  },
63  .id = -1,
64 };
65 
66 static struct platform_device *devices[] __initdata = {
67  &kb3886bl_device,
68 };
69 
70 /*
71  * Back to driver
72  */
73 
74 static int kb3886bl_intensity;
75 static struct backlight_device *kb3886_backlight_device;
76 static struct kb3886bl_machinfo *bl_machinfo;
77 
78 static unsigned long kb3886bl_flags;
79 #define KB3886BL_SUSPENDED 0x01
80 
81 static struct dmi_system_id __initdata kb3886bl_device_table[] = {
82  {
83  .ident = "Sahara Touch-iT",
84  .matches = {
85  DMI_MATCH(DMI_SYS_VENDOR, "SDV"),
86  DMI_MATCH(DMI_PRODUCT_NAME, "iTouch T201"),
87  },
88  },
89  { }
90 };
91 
92 static int kb3886bl_send_intensity(struct backlight_device *bd)
93 {
94  int intensity = bd->props.brightness;
95 
96  if (bd->props.power != FB_BLANK_UNBLANK)
97  intensity = 0;
98  if (bd->props.fb_blank != FB_BLANK_UNBLANK)
99  intensity = 0;
100  if (kb3886bl_flags & KB3886BL_SUSPENDED)
101  intensity = 0;
102 
103  bl_machinfo->set_bl_intensity(intensity);
104 
105  kb3886bl_intensity = intensity;
106  return 0;
107 }
108 
109 #ifdef CONFIG_PM
110 static int kb3886bl_suspend(struct platform_device *pdev, pm_message_t state)
111 {
112  struct backlight_device *bd = platform_get_drvdata(pdev);
113 
114  kb3886bl_flags |= KB3886BL_SUSPENDED;
115  backlight_update_status(bd);
116  return 0;
117 }
118 
119 static int kb3886bl_resume(struct platform_device *pdev)
120 {
121  struct backlight_device *bd = platform_get_drvdata(pdev);
122 
123  kb3886bl_flags &= ~KB3886BL_SUSPENDED;
124  backlight_update_status(bd);
125  return 0;
126 }
127 #else
128 #define kb3886bl_suspend NULL
129 #define kb3886bl_resume NULL
130 #endif
131 
132 static int kb3886bl_get_intensity(struct backlight_device *bd)
133 {
134  return kb3886bl_intensity;
135 }
136 
137 static const struct backlight_ops kb3886bl_ops = {
138  .get_brightness = kb3886bl_get_intensity,
139  .update_status = kb3886bl_send_intensity,
140 };
141 
142 static int kb3886bl_probe(struct platform_device *pdev)
143 {
144  struct backlight_properties props;
145  struct kb3886bl_machinfo *machinfo = pdev->dev.platform_data;
146 
147  bl_machinfo = machinfo;
148  if (!machinfo->limit_mask)
149  machinfo->limit_mask = -1;
150 
151  memset(&props, 0, sizeof(struct backlight_properties));
152  props.type = BACKLIGHT_RAW;
153  props.max_brightness = machinfo->max_intensity;
154  kb3886_backlight_device = backlight_device_register("kb3886-bl",
155  &pdev->dev, NULL,
156  &kb3886bl_ops,
157  &props);
158  if (IS_ERR(kb3886_backlight_device))
159  return PTR_ERR(kb3886_backlight_device);
160 
161  platform_set_drvdata(pdev, kb3886_backlight_device);
162 
163  kb3886_backlight_device->props.power = FB_BLANK_UNBLANK;
164  kb3886_backlight_device->props.brightness = machinfo->default_intensity;
165  backlight_update_status(kb3886_backlight_device);
166 
167  return 0;
168 }
169 
170 static int kb3886bl_remove(struct platform_device *pdev)
171 {
172  struct backlight_device *bd = platform_get_drvdata(pdev);
173 
175 
176  return 0;
177 }
178 
179 static struct platform_driver kb3886bl_driver = {
180  .probe = kb3886bl_probe,
181  .remove = kb3886bl_remove,
182  .suspend = kb3886bl_suspend,
183  .resume = kb3886bl_resume,
184  .driver = {
185  .name = "kb3886-bl",
186  },
187 };
188 
189 static int __init kb3886_init(void)
190 {
191  if (!dmi_check_system(kb3886bl_device_table))
192  return -ENODEV;
193 
194  platform_add_devices(devices, ARRAY_SIZE(devices));
195  return platform_driver_register(&kb3886bl_driver);
196 }
197 
198 static void __exit kb3886_exit(void)
199 {
200  platform_driver_unregister(&kb3886bl_driver);
201 }
202 
203 module_init(kb3886_init);
204 module_exit(kb3886_exit);
205 
206 MODULE_AUTHOR("Claudio Nieder <[email protected]>");
207 MODULE_DESCRIPTION("Tabletkiosk Sahara Touch-iT Backlight Driver");
208 MODULE_LICENSE("GPL");
209 MODULE_ALIAS("dmi:*:svnSDV:pniTouchT201:*");