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video: fbdev: mxsfb: fix pixelclock polarity

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The PIXDATA flags of the display_flags enum are controller centric,
e.g. NEGEDGE means the controller shall drive the data signals on
pixelclocks negative edge. However, the drivers flag is display
centric: Sample the data on negative (falling) edge.

Therefore, change the if statement to check for the POSEDGE flag
(which is typically not set):
Drive on positive edge => sample on negative edge

Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Shawn Guo <shawnguo@kernel.org>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Liu Ying <Ying.Liu@freescale.com>
Cc: Lothar Waßmann <LW@KARO-electronics.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Max Krummenacher <max.krummenacher@toradex.com>
Cc: Mauro Salvini <mauro.salvini@smigroup.net>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
This commit is contained in:
Stefan Agner 2017-11-09 18:09:30 +01:00 committed by Bartlomiej Zolnierkiewicz
parent ab798b9087
commit 2d81482821
1 changed files with 11 additions and 2 deletions
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13
drivers/video/fbdev/mxsfb.c
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@ -150,7 +150,7 @@
#define STMLCDIF_24BIT 3 /** pixel data bus to the display is of 24 bit width */
#define MXSFB_SYNC_DATA_ENABLE_HIGH_ACT (1 << 6)
#define MXSFB_SYNC_DOTCLK_FALLING_ACT (1 << 7) /* negtive edge sampling */
#define MXSFB_SYNC_DOTCLK_FALLING_ACT (1 << 7) /* negative edge sampling */
enum mxsfb_devtype {
MXSFB_V3,
@ -788,7 +788,16 @@ static int mxsfb_init_fbinfo_dt(struct mxsfb_info *host,
if (vm.flags & DISPLAY_FLAGS_DE_HIGH)
host->sync |= MXSFB_SYNC_DATA_ENABLE_HIGH_ACT;
if (vm.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
/*
* The PIXDATA flags of the display_flags enum are controller
* centric, e.g. NEGEDGE means drive data on negative edge.
* However, the drivers flag is display centric: Sample the
* data on negative (falling) edge. Therefore, check for the
* POSEDGE flag:
* drive on positive edge => sample on negative edge
*/
if (vm.flags & DISPLAY_FLAGS_PIXDATA_POSEDGE)
host->sync |= MXSFB_SYNC_DOTCLK_FALLING_ACT;
put_display_node: