From 09aaf268eb1d22eee690d26a913f660e2081597f Mon Sep 17 00:00:00 2001 From: "Antonino A. Daplas" Date: Tue, 8 May 2007 00:39:03 -0700 Subject: [PATCH] fbdev: add fb_read/fb_write functions for framebuffers in system RAM The functions fb_read() and fb_write in fbmem.c assume that the framebuffer is in IO memory. However, we have 3 drivers (hecubafb, arcfb, and vfb) where the framebuffer is allocated from system RAM (via vmalloc). Using __raw_read/__raw_write (fb_readl/fb_writel) for these drivers is illegal, especially in other platforms. Create file read and write methods for these types of drivers. These are named fb_sys_read() and fb_sys_write(). Signed-off-by: Antonino Daplas Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/video/Kconfig | 5 ++ drivers/video/Makefile | 1 + drivers/video/fb_sys_fops.c | 104 ++++++++++++++++++++++++++++++++++++ include/linux/fb.h | 4 ++ 4 files changed, 114 insertions(+) create mode 100644 drivers/video/fb_sys_fops.c diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig index 6d32726e8751..85d0e8707ee3 100644 --- a/drivers/video/Kconfig +++ b/drivers/video/Kconfig @@ -122,6 +122,11 @@ config FB_SYS_IMAGEBLIT blitting. This is used by drivers that don't provide their own (accelerated) version and the framebuffer is in system RAM. +config FB_SYS_FOPS + tristate + depends on FB + default n + config FB_DEFERRED_IO bool depends on FB diff --git a/drivers/video/Makefile b/drivers/video/Makefile index fa025e786848..6c7b26e81fc2 100644 --- a/drivers/video/Makefile +++ b/drivers/video/Makefile @@ -21,6 +21,7 @@ obj-$(CONFIG_FB_CFB_IMAGEBLIT) += cfbimgblt.o obj-$(CONFIG_FB_SYS_FILLRECT) += sysfillrect.o obj-$(CONFIG_FB_SYS_COPYAREA) += syscopyarea.o obj-$(CONFIG_FB_SYS_IMAGEBLIT) += sysimgblt.o +obj-$(CONFIG_FB_SYS_FOPS) += fb_sys_fops.o obj-$(CONFIG_FB_SVGALIB) += svgalib.o obj-$(CONFIG_FB_MACMODES) += macmodes.o obj-$(CONFIG_FB_DDC) += fb_ddc.o diff --git a/drivers/video/fb_sys_fops.c b/drivers/video/fb_sys_fops.c new file mode 100644 index 000000000000..cf2538d669cd --- /dev/null +++ b/drivers/video/fb_sys_fops.c @@ -0,0 +1,104 @@ +/* + * linux/drivers/video/fb_sys_read.c - Generic file operations where + * framebuffer is in system RAM + * + * Copyright (C) 2007 Antonino Daplas + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of this archive + * for more details. + * + */ +#include +#include +#include + +ssize_t fb_sys_read(struct fb_info *info, char __user *buf, size_t count, + loff_t *ppos) +{ + unsigned long p = *ppos; + void *src; + int err = 0; + unsigned long total_size; + + if (info->state != FBINFO_STATE_RUNNING) + return -EPERM; + + total_size = info->screen_size; + + if (total_size == 0) + total_size = info->fix.smem_len; + + if (p >= total_size) + return 0; + + if (count >= total_size) + count = total_size; + + if (count + p > total_size) + count = total_size - p; + + src = (void __force *)(info->screen_base + p); + + if (info->fbops->fb_sync) + info->fbops->fb_sync(info); + + if (copy_to_user(buf, src, count)) + err = -EFAULT; + + if (!err) + *ppos += count; + + return (err) ? err : count; +} +EXPORT_SYMBOL_GPL(fb_sys_read); + +ssize_t fb_sys_write(struct fb_info *info, const char __user *buf, + size_t count, loff_t *ppos) +{ + unsigned long p = *ppos; + void *dst; + int err = 0; + unsigned long total_size; + + if (info->state != FBINFO_STATE_RUNNING) + return -EPERM; + + total_size = info->screen_size; + + if (total_size == 0) + total_size = info->fix.smem_len; + + if (p > total_size) + return -EFBIG; + + if (count > total_size) { + err = -EFBIG; + count = total_size; + } + + if (count + p > total_size) { + if (!err) + err = -ENOSPC; + + count = total_size - p; + } + + dst = (void __force *) (info->screen_base + p); + + if (info->fbops->fb_sync) + info->fbops->fb_sync(info); + + if (copy_from_user(dst, buf, count)) + err = -EFAULT; + + if (!err) + *ppos += count; + + return (err) ? err : count; +} +EXPORT_SYMBOL_GPL(fb_sys_write); + +MODULE_AUTHOR("Antonino Daplas "); +MODULE_DESCRIPTION("Generic file read (fb in system RAM)"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/fb.h b/include/linux/fb.h index acb6ddb68fa2..70d154a02c5c 100644 --- a/include/linux/fb.h +++ b/include/linux/fb.h @@ -903,6 +903,10 @@ extern void cfb_imageblit(struct fb_info *info, const struct fb_image *image); extern void sys_fillrect(struct fb_info *info, const struct fb_fillrect *rect); extern void sys_copyarea(struct fb_info *info, const struct fb_copyarea *area); extern void sys_imageblit(struct fb_info *info, const struct fb_image *image); +extern ssize_t fb_sys_read(struct fb_info *info, char __user *buf, + size_t count, loff_t *ppos); +extern ssize_t fb_sys_write(struct fb_info *info, const char __user *buf, + size_t count, loff_t *ppos); /* drivers/video/fbmem.c */ extern int register_framebuffer(struct fb_info *fb_info); -- 2.20.1