Re: [PATCH 07/11] drm/fbdevdrm: Add DRM <-> fbdev pixel-format conversion

On Tue, Mar 26, 2019 at 10:17:40AM +0100, Thomas Zimmermann wrote:

Signed-off-by: Thomas Zimmermann tzimmermann@suse.de

drivers/gpu/drm/fbdevdrm/Makefile | 1 + drivers/gpu/drm/fbdevdrm/fbdevdrm_format.c | 441 +++++++++++++++++++++ drivers/gpu/drm/fbdevdrm/fbdevdrm_format.h | 26 ++ 3 files changed, 468 insertions(+) create mode 100644 drivers/gpu/drm/fbdevdrm/fbdevdrm_format.c create mode 100644 drivers/gpu/drm/fbdevdrm/fbdevdrm_format.h

diff --git a/drivers/gpu/drm/fbdevdrm/Makefile b/drivers/gpu/drm/fbdevdrm/Makefile index b8fab9d52faa..aef60d0f4888 100644 --- a/drivers/gpu/drm/fbdevdrm/Makefile +++ b/drivers/gpu/drm/fbdevdrm/Makefile @@ -2,6 +2,7 @@ ccflags-y = -Iinclude/drm fbdevdrm-y := fbdevdrm_bo.o \ fbdevdrm_device.o \ fbdevdrm_drv.o \

•      fbdevdrm_format.o \
     fbdevdrm_modeset.o \
     fbdevdrm_ttm.o
  
  

diff --git a/drivers/gpu/drm/fbdevdrm/fbdevdrm_format.c b/drivers/gpu/drm/fbdevdrm/fbdevdrm_format.c new file mode 100644 index 000000000000..208f7c60e525 --- /dev/null +++ b/drivers/gpu/drm/fbdevdrm/fbdevdrm_format.c @@ -0,0 +1,441 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later

• • One purpose of this driver is to allow for easy conversion of framebuffer
• • drivers to DRM. As a special exception to the GNU GPL, you are allowed to
• • relicense this file under the terms of a license of your choice if you're
• • porting a framebuffer driver. In order to do so, update the SPDX license
• • identifier to the new license and remove this exception.
• • If you add code to this file, please ensure that it's compatible with the
• • stated exception.
• */

+#include "fbdevdrm_format.h" +#include <asm/byteorder.h> +#include <linux/fb.h>

+#if defined __BIG_ENDIAN +#define HOST_FUNC(_func) \

• _func ## _be

+#elif defined __LITTLE_ENDIAN +#define HOST_FUNC(_func) \

• _func ## _le

+#else +#error "Unsupported endianess" +#endif

+static bool is_c8(const struct fb_info* fb_info) +{

• return fb_info->var.bits_per_pixel == 8;

+}

+static bool is_rgb565_be(const struct fb_info* fb_info) +{

• return (fb_info->var.bits_per_pixel == 16) &&

•       (fb_info->var.red.offset == 0) &&
  

•       (fb_info->var.red.length == 5) &&
  

•       (fb_info->var.green.offset == 5) &&
  

•       (fb_info->var.green.length == 6) &&
  

•       (fb_info->var.blue.offset == 11) &&
  

•       (fb_info->var.blue.length == 5);
  

+}

You can't distinguish LE vs. BE like this.

Maybe FBINFO_FOREIGN_ENDIAN is trustworthy?