From 74a0efdef1df7f576116811234ebedd8a1255ebc Mon Sep 17 00:00:00 2001 From: "Manjunathappa, Prakash" Date: Tue, 15 Nov 2011 17:32:23 +0530 Subject: video:da8xx-fb: Disable and reset sequence on version2 of LCDC 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 Signed-off-by: Florian Tobias Schandinat --- drivers/video/da8xx-fb.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'drivers/video') diff --git a/drivers/video/da8xx-fb.c b/drivers/video/da8xx-fb.c index 55f91d9ab00..29577bf1f55 100644 --- a/drivers/video/da8xx-fb.c +++ b/drivers/video/da8xx-fb.c @@ -116,6 +116,7 @@ /* 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 @@ -244,6 +245,10 @@ 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); @@ -257,6 +262,10 @@ 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) @@ -584,8 +593,12 @@ 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) -- cgit v1.2.3