From 32f26f56b3b918444ee2b3bf8f928bec506021b8 Mon Sep 17 00:00:00 2001 From: Stefan Agner Date: Tue, 11 Apr 2017 11:12:11 +0530 Subject: [PATCH] video: fsl_dcu_fb: Enable pixel clock after initialization When enabling the DCU and pixel clock, the test mode is activated since this is the reset configuration. The test mode immediately shows a red screen on a LCD. A moment later, the DCU gets initialized properly. This patch enables the pixel clock after initialization of the DCU control register. This avoids this initial flicker on LCD screens. While at it change the polarity of pixel clock to display samples data on the rising edge. Signed-off-by: Stefan Agner Signed-off-by: Sanchayan Maity Reviewed-by: Alison Wang --- drivers/video/fsl_dcu_fb.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/video/fsl_dcu_fb.c b/drivers/video/fsl_dcu_fb.c index 7f03290b74..c6ed3c40bc 100644 --- a/drivers/video/fsl_dcu_fb.c +++ b/drivers/video/fsl_dcu_fb.c @@ -41,7 +41,7 @@ #define DCU_VSYN_PARA_BP(x) ((x) << 22) #define DCU_VSYN_PARA_PW(x) ((x) << 11) #define DCU_VSYN_PARA_FP(x) (x) -#define DCU_SYN_POL_INV_PXCK_FALL (0 << 6) +#define DCU_SYN_POL_INV_PXCK_FALL (1 << 6) #define DCU_SYN_POL_NEG_REMAIN (0 << 5) #define DCU_SYN_POL_INV_VS_LOW (1 << 1) #define DCU_SYN_POL_INV_HS_LOW (1) @@ -191,8 +191,6 @@ static void reset_total_layers(void) dcu_write32(®s->ctrldescl[i][9], 0); dcu_write32(®s->ctrldescl[i][10], 0); } - - dcu_write32(®s->update_mode, DCU_UPDATE_MODE_READREG); } static int layer_ctrldesc_init(int index, u32 pixel_format) @@ -246,8 +244,6 @@ static int layer_ctrldesc_init(int index, u32 pixel_format) dcu_write32(®s->ctrldescl[index][7], DCU_CTRLDESCLN_8_FG_FCOLOR(0)); dcu_write32(®s->ctrldescl[index][8], DCU_CTRLDESCLN_9_BG_BCOLOR(0)); - dcu_write32(®s->update_mode, DCU_UPDATE_MODE_READREG); - return 0; } @@ -273,8 +269,6 @@ int fsl_dcu_init(unsigned int xres, unsigned int yres, memset(info.screen_base, 0, info.screen_size); reset_total_layers(); - div = dcu_set_pixel_clock(info.var.pixclock); - dcu_write32(®s->div_ratio, (div - 1)); dcu_write32(®s->disp_size, DCU_DISP_SIZE_DELTA_Y(info.var.yres) | @@ -313,6 +307,11 @@ int fsl_dcu_init(unsigned int xres, unsigned int yres, layer_ctrldesc_init(0, pixel_format); + div = dcu_set_pixel_clock(info.var.pixclock); + dcu_write32(®s->div_ratio, (div - 1)); + + dcu_write32(®s->update_mode, DCU_UPDATE_MODE_READREG); + return 0; } -- 2.25.1