[U-Boot] [PATCH v2] sunxi: display: Use PWM to drive backlight where applicable

[Peter Korsgaard]

>>>>> "Hans" == Hans de Goede <hdegoede at redhat.com> writes:

 > When the backlight's pwm input is connected to a pwm output of the SoC,
 > actually use pwm to drive the backlight.

 > The mean reason for doing this is to fix the backlight turning off
 > for aprox. 1 second while the kernel is booting. This is caused by
 > the kernel actually using pwm to drive the backlight, so that it
 > can dim the backlight. First the pwm driver loads and switches the
 > pinmux for the pin driving the backlight's pwm input to the pwm
 > controller. Then about 1s later the actual backlight driver loads
 > and tells the pwm driver to actually update the pwm settings, which
 > have a power-on-reset value of "off".

 > An additional advantage is that this allows us to initatiate the
 > backlight at 80%, which is the kernel default, avoiding a brightness
 > change while the kernel loads.

 > +++ b/drivers/video/sunxi_display.c
 > @@ -12,6 +12,7 @@
 >  #include <asm/arch/clock.h>
 >  #include <asm/arch/display.h>
 >  #include <asm/arch/gpio.h>
 > +#include <asm/arch/pwm.h>
 >  #include <asm/global_data.h>
 >  #include <asm/gpio.h>
 >  #include <asm/io.h>
 > @@ -34,7 +35,6 @@
 >  #define PWM_ON 1
 >  #define PWM_OFF 0
 >  #endif
 > -

Unrelated white space change. Other than that:

Reviewed by: Peter Korsgaard <peter at korsgaard.com>

-- 
Bye, Peter Korsgaard