Re: [PATCH] video: da8xx-fb: do clock reset of revision 2 LCDC before enabling
From: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Date: 2012-07-29 21:14:33
Subsystem:
framebuffer layer, the rest · Maintainers:
Helge Deller, Linus Torvalds
On 07/20/2012 03:51 PM, Manjunathappa, Prakash wrote:
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>
Applied. But it would be better if you made the patch dependencies
clear, as I didn't consider some of your patches mature enough for this
merge window. Now I had to figure out why my final build failed and
applied the patch below.
Best regards,
Florian Tobias Schandinat
---
commit a0239073fd75489d25575cf3aaf71ab55b416020
Author: Florian Tobias Schandinat [off-list ref]
Date: Sun Jul 29 16:47:40 2012 +0000
da8xx-fb: fix compile issue due to missing include
Signed-off-by: Florian Tobias Schandinat [off-list ref]
diff --git a/drivers/video/da8xx-fb.c b/drivers/video/da8xx-fb.c
index ca9943a..7ae9d53 100644
--- a/drivers/video/da8xx-fb.c
+++ b/drivers/video/da8xx-fb.c@@ -32,6 +32,7 @@ #include <linux/console.h> #include <linux/spinlock.h> #include <linux/slab.h> +#include <linux/delay.h> #include <linux/lcm.h> #include <video/da8xx-fb.h> #include <asm/div64.h>
quoted hunk ↗ jump to hunk
--- 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)