diff mbox

[v3,09/26] ARM: pxa: magician: Optimize powerup delays for Samsung LCD

Message ID 55FA483F.1040202@tul.cz (mailing list archive)
State New, archived
Headers show

Commit Message

Petr Cvek Sept. 17, 2015, 4:57 a.m. UTC 
Delays for the Samsung LCD are greater than needed. These values were
extracted from a datasheet.

Signed-off-by: Petr Cvek <petr.cvek@tul.cz>
---
 arch/arm/mach-pxa/magician.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

Comments

Robert Jarzmik Sept. 26, 2015, 2:37 p.m. UTC | #1 
Petr Cvek <petr.cvek@tul.cz> writes:

> Delays for the Samsung LCD are greater than needed. These values were
> extracted from a datasheet.
>
> Signed-off-by: Petr Cvek <petr.cvek@tul.cz>
Waiting for a week for Philipp's ack and queuing it after. An ack on this one
would be warmly welcome Philipp, as I have no way to judge if these timings fit
the board you're using as well.

Cheers.

--
Robert
diff mbox

Patch

diff --git a/arch/arm/mach-pxa/magician.c b/arch/arm/mach-pxa/magician.c
index d78fc3a..14d1f55 100644
--- a/arch/arm/mach-pxa/magician.c
+++ b/arch/arm/mach-pxa/magician.c
@@ -366,21 +366,19 @@  static void samsung_lcd_power(int on, struct fb_var_screeninfo *si)
 			gpio_set_value(GPIO75_MAGICIAN_SAMSUNG_POWER, 1);
 		else
 			gpio_set_value(EGPIO_MAGICIAN_LCD_POWER, 1);
-		mdelay(10);
+		mdelay(6);
 		gpio_set_value(GPIO106_MAGICIAN_LCD_DCDC_NRESET, 1);
-		mdelay(10);
+		mdelay(6);	/* Avdd -> Voff >5ms */
 		gpio_set_value(GPIO104_MAGICIAN_LCD_VOFF_EN, 1);
-		mdelay(30);
+		mdelay(16);	/* Voff -> Von >(5+10)ms */
 		gpio_set_value(GPIO105_MAGICIAN_LCD_VON_EN, 1);
-		mdelay(10);
 	} else {
-		mdelay(10);
 		gpio_set_value(GPIO105_MAGICIAN_LCD_VON_EN, 0);
-		mdelay(30);
+		mdelay(16);
 		gpio_set_value(GPIO104_MAGICIAN_LCD_VOFF_EN, 0);
-		mdelay(10);
+		mdelay(6);
 		gpio_set_value(GPIO106_MAGICIAN_LCD_DCDC_NRESET, 0);
-		mdelay(10);
+		mdelay(6);
 		if (system_rev < 3)
 			gpio_set_value(GPIO75_MAGICIAN_SAMSUNG_POWER, 0);
 		else