linux lcd驱动

时间：2010-04-21 来源：wulinnm

fbmem源代码: 1 /* 2 * linux/drivers/video/fbmem.c
3 *
4 * Copyright (C) 1994 Martin Schaller
5 *
6 *      2001 - Documented with DocBook
7 * - Brad Douglas <[email protected]>
8 *
9 * This file is subject to the terms and conditions of the GNU General Public
10 * License. See the file COPYING in the main directory of this archive
11 * for more details.
12 */
13
14 #include <linux/module.h>
15
16 #include <linux/compat.h>
17 #include <linux/types.h>
18 #include <linux/errno.h>
19 #include <linux/smp_lock.h>
20 #include <linux/kernel.h>
21 #include <linux/major.h>
22 #include <linux/slab.h>
23 #include <linux/mm.h>
24 #include <linux/mman.h>
25 #include <linux/vt.h>
26 #include <linux/init.h>
27 #include <linux/linux_logo.h>
28 #include <linux/proc_fs.h>
29 #include <linux/console.h>
30 #ifdef CONFIG_KMOD
31 #include <linux/kmod.h>
32 #endif
33 #include <linux/err.h>
34 #include <linux/device.h>
35 #include <linux/efi.h>
36 #include <linux/fb.h>
37
38 #include <asm/fb.h>
39
40
41     /*
42      * Frame buffer device initialization and setup routines
43      */
44
45 #define FBPIXMAPSIZE    (1024 * 8)
46
47 struct fb_info *registered_fb[FB_MAX] __read_mostly;
48 int num_registered_fb __read_mostly;
49
50 /*
51 * Helpers
52 */
53
54 int fb_get_color_depth(struct fb_var_screeninfo *var,
55                        struct fb_fix_screeninfo *fix)
56 {
57         int depth = 0;
58
59         if (fix->visual == FB_VISUAL_MONO01 ||
60             fix->visual == FB_VISUAL_MONO10)
61                 depth = 1;
62         else {
63                 if (var->green.length == var->blue.length &&
64                     var->green.length == var->red.length &&
65                     var->green.offset == var->blue.offset &&
66                     var->green.offset == var->red.offset)
67                         depth = var->green.length;
68                 else
69                         depth = var->green.length + var->red.length +
70                                 var->blue.length;
71         }
72
73         return depth;
74 }
75 EXPORT_SYMBOL(fb_get_color_depth);
76
77 /*
78 * Data padding functions.
79 */
80 void fb_pad_aligned_buffer(u8 *dst, u32 d_pitch, u8 *src, u32 s_pitch, u32 height)
81 {
82         __fb_pad_aligned_buffer(dst, d_pitch, src, s_pitch, height);
83 }
84 EXPORT_SYMBOL(fb_pad_aligned_buffer);
85
86 void fb_pad_unaligned_buffer(u8 *dst, u32 d_pitch, u8 *src, u32 idx, u32 height,
87                                 u32 shift_high, u32 shift_low, u32 mod)
88 {
89         u8 mask = (u8) (0xfff << shift_high), tmp;
90         int i, j;
91
92         for (i = height; i--; ) {
93                 for (j = 0; j < idx; j++) {
94                         tmp = dst[j];
95                         tmp &= mask;
96                         tmp |= *src >> shift_low;
97                         dst[j] = tmp;
98                         tmp = *src << shift_high;
99                         dst[j+1] = tmp;
100                         src++;
101                 }
102                 tmp = dst[idx];
103                 tmp &= mask;
104                 tmp |= *src >> shift_low;
105                 dst[idx] = tmp;
106                 if (shift_high < mod) {
107                         tmp = *src << shift_high;
108                         dst[idx+1] = tmp;
109                 }
110                 src++;
111                 dst += d_pitch;
112         }
113 }
114 EXPORT_SYMBOL(fb_pad_unaligned_buffer);
115
116 /*
117 * we need to lock this section since fb_cursor
118 * may use fb_imageblit()
119 */
120 char* fb_get_buffer_offset(struct fb_info *info, struct fb_pixmap *buf, u32 size)
121 {
122         u32 align = buf->buf_align - 1, offset;
123         char *addr = buf->addr;
124
125         /* If IO mapped, we need to sync before access, no sharing of
126          * the pixmap is done
127          */
128         if (buf->flags & FB_PIXMAP_IO) {
129                 if (info->fbops->fb_sync && (buf->flags & FB_PIXMAP_SYNC))
130                         info->fbops->fb_sync(info);
131                 return addr;
132         }
133
134         /* See if we fit in the remaining pixmap space */
135         offset = buf->offset + align;
136         offset &= ~align;
137         if (offset + size > buf->size) {
138                 /* We do not fit. In order to be able to re-use the buffer,
139                  * we must ensure no asynchronous DMA'ing or whatever operation
140                  * is in progress, we sync for that.
141                  */
142                 if (info->fbops->fb_sync && (buf->flags & FB_PIXMAP_SYNC))
143                         info->fbops->fb_sync(info);
144                 offset = 0;
145         }
146         buf->offset = offset + size;
147         addr += offset;
148
149         return addr;
150 }
151
152 #ifdef CONFIG_LOGO
153
154 static inline unsigned safe_shift(unsigned d, int n)
155 {
156         return n < 0 ? d >> -n : d << n;
157 }
158
159 static void fb_set_logocmap(struct fb_info *info,
160                                    const struct linux_logo *logo)
161 {
162         struct