From d46ecb9f79db82ce6bef4baafbcae29ac809ea67 Mon Sep 17 00:00:00 2001 From: Bernie Thompson Date: Sun, 5 Sep 2010 16:35:04 -0700 Subject: [PATCH] staging: udlfb: fbdev character read and write support Restore fbdev character read and write support Enables access to the framebuffer from simple reads and writes to /dev/fb0 (or fb1, ...). Low performance, because of extra copy and because udlfb must scan every pixel for changes. But very useful for testing and simple image display, etc. Signed-off-by: Bernie Thompson Signed-off-by: Greg Kroah-Hartman --- drivers/staging/udlfb/udlfb.c | 44 +++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) diff --git a/drivers/staging/udlfb/udlfb.c b/drivers/staging/udlfb/udlfb.c index c7e061e5e04d..a2bd5f7d2c50 100644 --- a/drivers/staging/udlfb/udlfb.c +++ b/drivers/staging/udlfb/udlfb.c @@ -602,6 +602,48 @@ int dlfb_handle_damage(struct dlfb_data *dev, int x, int y, return 0; } +static ssize_t dlfb_ops_read(struct fb_info *info, char __user *buf, + size_t count, loff_t *ppos) +{ + ssize_t result = -ENOSYS; + +#if defined CONFIG_FB_SYS_FOPS || defined CONFIG_FB_SYS_FOPS_MODULE + result = fb_sys_read(info, buf, count, ppos); +#endif + + return result; +} + +/* + * Path triggered by usermode clients who write to filesystem + * e.g. cat filename > /dev/fb1 + * Not used by X Windows or text-mode console. But useful for testing. + * Slow because of extra copy and we must assume all pixels dirty. + */ +static ssize_t dlfb_ops_write(struct fb_info *info, const char __user *buf, + size_t count, loff_t *ppos) +{ + ssize_t result = -ENOSYS; + struct dlfb_data *dev = info->par; + u32 offset = (u32) *ppos; + +#if defined CONFIG_FB_SYS_FOPS || defined CONFIG_FB_SYS_FOPS_MODULE + + result = fb_sys_write(info, buf, count, ppos); + + if (result > 0) { + int start = max((int)(offset / info->fix.line_length) - 1, 0); + int lines = min((u32)((result / info->fix.line_length) + 1), + (u32)info->var.yres); + + dlfb_handle_damage(dev, 0, start, info->var.xres, + lines, info->screen_base); + } +#endif + + return result; +} + /* hardware has native COPY command (see libdlo), but not worth it for fbcon */ static void dlfb_ops_copyarea(struct fb_info *info, const struct fb_copyarea *area) @@ -924,6 +966,8 @@ static int dlfb_ops_blank(int blank_mode, struct fb_info *info) static struct fb_ops dlfb_ops = { .owner = THIS_MODULE, + .fb_read = dlfb_ops_read, + .fb_write = dlfb_ops_write, .fb_setcolreg = dlfb_ops_setcolreg, .fb_fillrect = dlfb_ops_fillrect, .fb_copyarea = dlfb_ops_copyarea, -- 2.20.1