u-boot-brain/arch/arm/cpu/armv7/s5p-common
Gabe Black c059f274ad Exynos: pwm: Fix two bugs in the exynos pwm configuration code
First, the "div" value was being used incorrectly to compute the frequency of
the PWM timer. The value passed in is a constant which reflects the value
that would be found in a configuration register, 0 to 4. That should
correspond to a scaling factor of 1, 2, 4, 8, or 16, 1 << div, but div + 1 was
being used instead.

Second, the reset value of the timers were being calculated to give an overall
frequency, thrown out, and set to a maximum value. This was done so that PWM 4
could be used as the system clock by counting down from a high value, but it
was applied indiscriminantly. It should at most be applied only to PWM 4.

This change also takes the opportunity to tidy up the pwm_init function.

Test with command "sf probe 1:0; time sf read 40008000 0 1000".
Try with different numbers of bytes and see that sane values are obtained
Build and boot U-boot with this patch, backlight works properly.

Signed-off-by: Gabe Black <gabeblack@google.com>
Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
2013-04-01 14:02:08 +09:00
..
cpu_info.c Exynos: fix cpuinfo and cpu detecting 2012-07-07 14:07:25 +02:00
Makefile dm: wdt: Move s5p watchdog timer to drivers/watchdog/ 2012-11-15 21:08:19 +09:00
pwm.c Exynos: pwm: Fix two bugs in the exynos pwm configuration code 2013-04-01 14:02:08 +09:00
sromc.c S5P:SROM config code moved to s5p-common directory 2011-05-26 19:30:46 +09:00
timer.c Exynos: Add timer_get_us function 2013-04-01 14:02:08 +09:00