ARM: pxa: magician: Optimize powerup delays for Samsung LCD
authorPetr Cvek <petr.cvek@tul.cz>
Mon, 28 Sep 2015 21:16:14 +0000 (23:16 +0200)
committerRobert Jarzmik <robert.jarzmik@free.fr>
Wed, 14 Oct 2015 21:06:55 +0000 (23:06 +0200)
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>
Acked-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
arch/arm/mach-pxa/magician.c

index f52351a389eff4c1ff334f8c9865656f850832cd..4846f5a706967582f74c84a92fd817c8624f19f1 100644 (file)
@@ -299,21 +299,19 @@ 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