[PATCH 1/6] fb: add a stride value to struct fb_info

[Andre Heider]

Add support for framebuffers with noncontiguous horizontal lines.

Video drivers can set this value if the hardware requires it.
In case a driver does not set it, the current value of
xres * (bpp / 8) is used instead.

Signed-off-by: Andre Heider <a.heider at gmail.com>
---
 drivers/video/fb.c | 11 +++++++++--
 include/fb.h       |  1 +
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/video/fb.c b/drivers/video/fb.c
index 420e4e3..e80fab9 100644
--- a/drivers/video/fb.c
+++ b/drivers/video/fb.c
@@ -72,12 +72,16 @@ static int fb_setup_mode(struct device_d *dev, struct param_d *param,
 
 	info->xres = info->mode->xres;
 	info->yres = info->mode->yres;
+	info->stride = 0;
 
 	ret = info->fbops->fb_activate_var(info);
 
+	if (!info->stride)
+		info->stride = info->xres * (info->bits_per_pixel >> 3);
+
 	if (!ret) {
 		dev->resource[0].start = (resource_size_t)info->screen_base;
-		info->cdev.size = info->xres * info->yres * (info->bits_per_pixel >> 3);
+		info->cdev.size = info->stride * info->yres;
 		dev->resource[0].end = dev->resource[0].start + info->cdev.size - 1;
 		dev_param_set_generic(dev, param, val);
 	} else
@@ -122,9 +126,12 @@ int register_framebuffer(struct fb_info *info)
 
 	dev = &info->dev;
 
+	if (!info->stride)
+		info->stride = info->xres * (info->bits_per_pixel >> 3);
+
 	info->cdev.ops = &fb_ops;
 	info->cdev.name = asprintf("fb%d", id);
-	info->cdev.size = info->xres * info->yres * (info->bits_per_pixel >> 3);
+	info->cdev.size = info->stride * info->yres;
 	info->cdev.dev = dev;
 	info->cdev.priv = info;
 	dev->resource = xzalloc(sizeof(struct resource));
diff --git a/include/fb.h b/include/fb.h
index df4ba8e..ba46954 100644
--- a/include/fb.h
+++ b/include/fb.h
@@ -94,6 +94,7 @@ struct fb_info {
 	u32 xres;			/* visible resolution		*/
 	u32 yres;
 	u32 bits_per_pixel;		/* guess what			*/
+	u32 stride;			/* number of bytes in each line	*/
 
 	u32 grayscale;			/* != 0 Graylevels instead of colors */
 
-- 
1.8.3.2