From 92b4e4506550fe25c65799eebb215d47a244e635 Mon Sep 17 00:00:00 2001 From: "Manjunathappa, Prakash" Date: Fri, 20 Jul 2012 21:21:11 +0530 Subject: [PATCH] video: da8xx-fb: do clock reset of revision 2 LCDC before enabling As in specification software reset should be applied for several cycles before bringing it out of reset. Without this patch particularly during suspend and resume clock reset is not guaranteed to happen. Signed-off-by: Manjunathappa, Prakash Signed-off-by: Florian Tobias Schandinat --- drivers/video/da8xx-fb.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/video/da8xx-fb.c b/drivers/video/da8xx-fb.c index 6f0fb2d..e81a458 100644 --- a/drivers/video/da8xx-fb.c +++ b/drivers/video/da8xx-fb.c @@ -269,10 +269,18 @@ static inline void lcd_enable_raster(void) { u32 reg; + /* Put LCDC in reset for several cycles */ + if (lcd_revision == LCD_VERSION_2) + /* Write 1 to reset LCDC */ + lcdc_write(LCD_CLK_MAIN_RESET, LCD_CLK_RESET_REG); + mdelay(1); + /* Bring LCDC out of reset */ if (lcd_revision == LCD_VERSION_2) lcdc_write(0, LCD_CLK_RESET_REG); + mdelay(1); + /* Above reset sequence doesnot reset register context */ reg = lcdc_read(LCD_RASTER_CTRL_REG); if (!(reg & LCD_RASTER_ENABLE)) lcdc_write(reg | LCD_RASTER_ENABLE, LCD_RASTER_CTRL_REG); @@ -286,10 +294,6 @@ 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) -- 2.7.4