projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 09aaf268 AD |
1 | /* |
| 2 | * linux/drivers/video/fb_sys_read.c - Generic file operations where | |
| 3 | * framebuffer is in system RAM | |
| 4 | * | |
| 5 | * Copyright (C) 2007 Antonino Daplas <adaplas@pol.net> | |
| 6 | * | |
| 7 | * This file is subject to the terms and conditions of the GNU General Public | |
| 8 | * License. See the file COPYING in the main directory of this archive | |
| 9 | * for more details. | |
| 10 | * | |
| 11 | */ | |
| 12 | #include <linux/fb.h> | |
| 13 | #include <linux/module.h> | |
| 84902b7a | 14 | #include <linux/uaccess.h> |
| 09aaf268 AD |
15 | |
| 16 | ssize_t fb_sys_read(struct fb_info *info, char __user *buf, size_t count, | |
| 17 | loff_t *ppos) | |
| 18 | { | |
| 19 | unsigned long p = *ppos; | |
| 20 | void *src; | |
| 21 | int err = 0; | |
| 22 | unsigned long total_size; | |
| 23 | ||
| 24 | if (info->state != FBINFO_STATE_RUNNING) | |
| 25 | return -EPERM; | |
| 26 | ||
| 27 | total_size = info->screen_size; | |
| 28 | ||
| 29 | if (total_size == 0) | |
| 30 | total_size = info->fix.smem_len; | |
| 31 | ||
| 32 | if (p >= total_size) | |
| 33 | return 0; | |
| 34 | ||
| 35 | if (count >= total_size) | |
| 36 | count = total_size; | |
| 37 | ||
| 38 | if (count + p > total_size) | |
| 39 | count = total_size - p; | |
| 40 | ||
| 41 | src = (void __force *)(info->screen_base + p); | |
| 42 | ||
| 43 | if (info->fbops->fb_sync) | |
| 44 | info->fbops->fb_sync(info); | |
| 45 | ||
| 46 | if (copy_to_user(buf, src, count)) | |
| 47 | err = -EFAULT; | |
| 48 | ||
| 49 | if (!err) | |
| 50 | *ppos += count; | |
| 51 | ||
| 52 | return (err) ? err : count; | |
| 53 | } | |
| 54 | EXPORT_SYMBOL_GPL(fb_sys_read); | |
| 55 | ||
| 56 | ssize_t fb_sys_write(struct fb_info *info, const char __user *buf, | |
| 57 | size_t count, loff_t *ppos) | |
| 58 | { | |
| 59 | unsigned long p = *ppos; | |
| 60 | void *dst; | |
| 61 | int err = 0; | |
| 62 | unsigned long total_size; | |
| 63 | ||
| 64 | if (info->state != FBINFO_STATE_RUNNING) | |
| 65 | return -EPERM; | |
| 66 | ||
| 67 | total_size = info->screen_size; | |
| 68 | ||
| 69 | if (total_size == 0) | |
| 70 | total_size = info->fix.smem_len; | |
| 71 | ||
| 72 | if (p > total_size) | |
| 73 | return -EFBIG; | |
| 74 | ||
| 75 | if (count > total_size) { | |
| 76 | err = -EFBIG; | |
| 77 | count = total_size; | |
| 78 | } | |
| 79 | ||
| 80 | if (count + p > total_size) { | |
| 81 | if (!err) | |
| 82 | err = -ENOSPC; | |
| 83 | ||
| 84 | count = total_size - p; | |
| 85 | } | |
| 86 | ||
| 87 | dst = (void __force *) (info->screen_base + p); | |
| 88 | ||
| 89 | if (info->fbops->fb_sync) | |
| 90 | info->fbops->fb_sync(info); | |
| 91 | ||
| 92 | if (copy_from_user(dst, buf, count)) | |
| 93 | err = -EFAULT; | |
| 94 | ||
| 95 | if (!err) | |
| 96 | *ppos += count; | |
| 97 | ||
| 98 | return (err) ? err : count; | |
| 99 | } | |
| 100 | EXPORT_SYMBOL_GPL(fb_sys_write); | |
| 101 | ||
| 102 | MODULE_AUTHOR("Antonino Daplas <adaplas@pol.net>"); | |
| 103 | MODULE_DESCRIPTION("Generic file read (fb in system RAM)"); | |
| 104 | MODULE_LICENSE("GPL"); |