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 <prakash.pm@ti.com>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
diff --git a/drivers/video/da8xx-fb.c b/drivers/video/da8xx-fb.c
index 55f91d9..29577bf 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 @@
{
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 @@
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 @@
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)