[PATCH] video:da8xx-fb: Disable and reset sequence on version2 of LCDC

[PATCH] video:da8xx-fb: Disable and reset sequence on version2 of LCDC

[Manjunathappa, Prakash]

Patch follows the disable and software reset sequence specified
in version2 to LCDC functional specification.
Without this flicker is observed on re-enabling the LCDC.

Signed-off-by: Manjunathappa, Prakash <prakash.pm@ti.com>
---
 drivers/video/da8xx-fb.c |   15 ++++++++++++++-
 1 files changed, 14 insertions(+), 1 deletions(-)

diff --git a/drivers/video/da8xx-fb.c b/drivers/video/da8xx-fb.c
index e111971..6b27751 100644
--- a/drivers/video/da8xx-fb.c
+++ b/drivers/video/da8xx-fb.c
@@ -118,6 +118,7 @@
 /* Clock registers available only on Version 2 */
 #define  LCD_CLK_ENABLE_REG			0x6c
 #define  LCD_CLK_RESET_REG			0x70
+#define  LCD_CLK_MAIN_RESET			BIT(3)
 
 #define LCD_NUM_BUFFERS	2
 
@@ -246,6 +247,10 @@ static inline void lcd_enable_raster(void)
 {
 	u32 reg;
 
+	/* Bring LCDC out of reset */
+	if (lcd_revision = LCD_VERSION_2)
+		lcdc_write(0, LCD_CLK_RESET_REG);
+
 	reg = lcdc_read(LCD_RASTER_CTRL_REG);
 	if (!(reg & LCD_RASTER_ENABLE))
 		lcdc_write(reg | LCD_RASTER_ENABLE, LCD_RASTER_CTRL_REG);
@@ -259,6 +264,10 @@ static inline void lcd_disable_raster(void)
 	reg = lcdc_read(LCD_RASTER_CTRL_REG);
 	if (reg & LCD_RASTER_ENABLE)
 		lcdc_write(reg & ~LCD_RASTER_ENABLE, LCD_RASTER_CTRL_REG);
+
+	if (lcd_revision = LCD_VERSION_2)
+		/* Write 1 to reset LCDC */
+		lcdc_write(LCD_CLK_MAIN_RESET, LCD_CLK_RESET_REG);
 }
 
 static void lcd_blit(int load_mode, struct da8xx_fb_par *par)
@@ -618,8 +627,12 @@ static void lcd_reset(struct da8xx_fb_par *par)
 	lcdc_write(0, LCD_DMA_CTRL_REG);
 	lcdc_write(0, LCD_RASTER_CTRL_REG);
 
-	if (lcd_revision = LCD_VERSION_2)
+	if (lcd_revision = LCD_VERSION_2) {
 		lcdc_write(0, LCD_INT_ENABLE_SET_REG);
+		/* Write 1 to reset */
+		lcdc_write(LCD_CLK_MAIN_RESET, LCD_CLK_RESET_REG);
+		lcdc_write(0, LCD_CLK_RESET_REG);
+	}
 }
 
 static void lcd_calc_clk_divider(struct da8xx_fb_par *par)
-- 
1.7.1

Re: [PATCH] video:da8xx-fb: Disable and reset sequence on version2

[Florian Tobias Schandinat]

On 11/15/2011 12:02 PM, Manjunathappa, Prakash wrote:
> Patch follows the disable and software reset sequence specified
> in version2 to LCDC functional specification.
> Without this flicker is observed on re-enabling the LCDC.
> 
> Signed-off-by: Manjunathappa, Prakash <prakash.pm@ti.com>

Applied.


Thanks,

Florian Tobias Schandinat

> ---
>  drivers/video/da8xx-fb.c |   15 ++++++++++++++-
>  1 files changed, 14 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/video/da8xx-fb.c b/drivers/video/da8xx-fb.c
> index e111971..6b27751 100644
> --- a/drivers/video/da8xx-fb.c
> +++ b/drivers/video/da8xx-fb.c
> @@ -118,6 +118,7 @@
>  /* Clock registers available only on Version 2 */
>  #define  LCD_CLK_ENABLE_REG			0x6c
>  #define  LCD_CLK_RESET_REG			0x70
> +#define  LCD_CLK_MAIN_RESET			BIT(3)
>  
>  #define LCD_NUM_BUFFERS	2
>  
> @@ -246,6 +247,10 @@ static inline void lcd_enable_raster(void)
>  {
>  	u32 reg;
>  
> +	/* Bring LCDC out of reset */
> +	if (lcd_revision = LCD_VERSION_2)
> +		lcdc_write(0, LCD_CLK_RESET_REG);
> +
>  	reg = lcdc_read(LCD_RASTER_CTRL_REG);
>  	if (!(reg & LCD_RASTER_ENABLE))
>  		lcdc_write(reg | LCD_RASTER_ENABLE, LCD_RASTER_CTRL_REG);
> @@ -259,6 +264,10 @@ static inline void lcd_disable_raster(void)
>  	reg = lcdc_read(LCD_RASTER_CTRL_REG);
>  	if (reg & LCD_RASTER_ENABLE)
>  		lcdc_write(reg & ~LCD_RASTER_ENABLE, LCD_RASTER_CTRL_REG);
> +
> +	if (lcd_revision = LCD_VERSION_2)
> +		/* Write 1 to reset LCDC */
> +		lcdc_write(LCD_CLK_MAIN_RESET, LCD_CLK_RESET_REG);
>  }
>  
>  static void lcd_blit(int load_mode, struct da8xx_fb_par *par)
> @@ -618,8 +627,12 @@ static void lcd_reset(struct da8xx_fb_par *par)
>  	lcdc_write(0, LCD_DMA_CTRL_REG);
>  	lcdc_write(0, LCD_RASTER_CTRL_REG);
>  
> -	if (lcd_revision = LCD_VERSION_2)
> +	if (lcd_revision = LCD_VERSION_2) {
>  		lcdc_write(0, LCD_INT_ENABLE_SET_REG);
> +		/* Write 1 to reset */
> +		lcdc_write(LCD_CLK_MAIN_RESET, LCD_CLK_RESET_REG);
> +		lcdc_write(0, LCD_CLK_RESET_REG);
> +	}
>  }
>  
>  static void lcd_calc_clk_divider(struct da8xx_fb_par *par)