1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
|
/*
*
* Backlight driver for HP Jornada 700 series (710/720/728)
* Copyright (C) 2006-2009 Kristoffer Ericson <kristoffer.ericson@gmail.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 or any later version as published by the Free Software Foundation.
*
*/
#include <linux/backlight.h>
#include <linux/device.h>
#include <linux/fb.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <mach/jornada720.h>
#include <mach/hardware.h>
#include <video/s1d13xxxfb.h>
#define BL_MAX_BRIGHT 255
#define BL_DEF_BRIGHT 25
static int jornada_bl_get_brightness(struct backlight_device *bd)
{
int ret;
/* check if backlight is on */
if (!(PPSR & PPC_LDD1))
return 0;
jornada_ssp_start();
/* cmd should return txdummy */
ret = jornada_ssp_byte(GETBRIGHTNESS);
if (jornada_ssp_byte(GETBRIGHTNESS) != TXDUMMY) {
dev_err(&bd->dev, "get brightness timeout\n");
jornada_ssp_end();
return -ETIMEDOUT;
} else {
/* exchange txdummy for value */
ret = jornada_ssp_byte(TXDUMMY);
}
jornada_ssp_end();
return BL_MAX_BRIGHT - ret;
}
static int jornada_bl_update_status(struct backlight_device *bd)
{
int ret = 0;
jornada_ssp_start();
/* If backlight is off then really turn it off */
if ((bd->props.power != FB_BLANK_UNBLANK) || (bd->props.fb_blank != FB_BLANK_UNBLANK)) {
ret = jornada_ssp_byte(BRIGHTNESSOFF);
if (ret != TXDUMMY) {
dev_info(&bd->dev, "brightness off timeout\n");
/* turn off backlight */
PPSR &= ~PPC_LDD1;
PPDR |= PPC_LDD1;
ret = -ETIMEDOUT;
}
} else /* turn on backlight */
PPSR |= PPC_LDD1;
/* send command to our mcu */
if (jornada_ssp_byte(SETBRIGHTNESS) != TXDUMMY) {
dev_info(&bd->dev, "failed to set brightness\n");
ret = -ETIMEDOUT;
goto out;
}
/*
* at this point we expect that the mcu has accepted
* our command and is waiting for our new value
* please note that maximum brightness is 255,
* but due to physical layout it is equal to 0, so we simply
* invert the value (MAX VALUE - NEW VALUE).
*/
if (jornada_ssp_byte(BL_MAX_BRIGHT - bd->props.brightness)
!= TXDUMMY) {
dev_err(&bd->dev, "set brightness failed\n");
ret = -ETIMEDOUT;
}
/*
* If infact we get an TXDUMMY as output we are happy and dont
* make any further comments about it
*/
out:
jornada_ssp_end();
return ret;
}
static const struct backlight_ops jornada_bl_ops = {
.get_brightness = jornada_bl_get_brightness,
.update_status = jornada_bl_update_status,
.options = BL_CORE_SUSPENDRESUME,
};
static int jornada_bl_probe(struct platform_device *pdev)
{
struct backlight_properties props;
int ret;
struct backlight_device *bd;
memset(&props, 0, sizeof(struct backlight_properties));
props.type = BACKLIGHT_RAW;
props.max_brightness = BL_MAX_BRIGHT;
bd = backlight_device_register(S1D_DEVICENAME, &pdev->dev, NULL,
&jornada_bl_ops, &props);
if (IS_ERR(bd)) {
ret = PTR_ERR(bd);
dev_err(&pdev->dev, "failed to register device, err=%x\n", ret);
return ret;
}
bd->props.power = FB_BLANK_UNBLANK;
bd->props.brightness = BL_DEF_BRIGHT;
/*
* note. make sure max brightness is set otherwise
* you will get seemingly non-related errors when
* trying to change brightness
*/
jornada_bl_update_status(bd);
platform_set_drvdata(pdev, bd);
dev_info(&pdev->dev, "HP Jornada 700 series backlight driver\n");
return 0;
}
static int jornada_bl_remove(struct platform_device *pdev)
{
struct backlight_device *bd = platform_get_drvdata(pdev);
backlight_device_unregister(bd);
return 0;
}
static struct platform_driver jornada_bl_driver = {
.probe = jornada_bl_probe,
.remove = jornada_bl_remove,
.driver = {
.name = "jornada_bl",
},
};
module_platform_driver(jornada_bl_driver);
MODULE_AUTHOR("Kristoffer Ericson <kristoffer.ericson>");
MODULE_DESCRIPTION("HP Jornada 710/720/728 Backlight driver");
MODULE_LICENSE("GPL");
|
