[PATCH] video: da8xx-fb: do clock reset of revision 2 LCDC before enabling
From: Manjunathappa, Prakash <hidden>
Date: 2012-07-20 16:03:11
Subsystem:
framebuffer layer, the rest · Maintainers:
Helge Deller, Linus Torvalds
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 <redacted> --- drivers/video/da8xx-fb.c | 12 ++++++++---- 1 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/video/da8xx-fb.c b/drivers/video/da8xx-fb.c
index 3d2d0d1..4440292 100644
--- a/drivers/video/da8xx-fb.c
+++ b/drivers/video/da8xx-fb.c@@ -262,10 +262,18 @@ 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);
@@ -279,10 +287,6 @@ 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)
--
1.7.1