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* Exynos: Tidy up the pwm_config function in the exynos pwm driverGabe Black2013-04-01-16/+6
| | | | | | | | | | | | | | | | | | | | | | | | | Some small fixes in the exynos pwm driver: 1. NS_IN_HZ is non-sensical since these are not compatible units. This constant actually describes the number of nanoseconds in a second. Renamed it to NS_IN_SEC. Also dropped the unnecessary parenthesis. 2. The variable "period" is not used to hold a period, it's used to hold a frequency. Renamed it to "frequency". 3. tcmp is an unsigned value, so (tcmp < 0) will never be true and the if which checks that condition will never execute. Also, there should be no problem if the pwm never switches, so there's no reason to subtract one from tcmp and therefore no reason to compare it against zero. Removed both ifs. If they weren't removed, tcmp should be a signed value. 4. Add a check for a 0 period. 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>
* Exynos: pwm: Fix two bugs in the exynos pwm configuration codeGabe Black2013-04-01-10/+14
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* Exynos: Change get_timer() to work correctlySimon Glass2013-04-01-0/+6
| | | | | | | | | | | | | | | | At present get_timer() does not return sane values. It should count up smoothly in milliscond intervals. We can change the PWM to count down at 1MHz, providing a resolution of 1us and a range of about an hour between required get_timer() calls. 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 Signed-off-by: Simon Glass <sjg@chromium.org> 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>
* arm/s5pxx: Fix get_timer_masked to get the time.Zhong Hongbo2012-09-01-1/+1
| | | | | | | | | | | In general, The get_timer_masked function get the system time, no the number of ticks. Such as the nand_wait_ready will use get_timer_masked to delay the operations. And change the system time to adopt to the CONFIG_SYS_HZ. Signed-off-by: Hongbo Zhong <bocui107@gmail.com> Tested-by: Jaehoon Chung<jh80.chung@samsung.com> Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
* arch/arm/cpu/armv7/s5p-common/pwm.c: fix GCC 4.6 warningAnatolij Gustschin2011-11-16-2/+0
| | | | | | | | | Fix: pwm.c: In function 'pwm_config': pwm.c:85:16: warning: variable 'timer_rate_hz' set but not used [-Wunused-but-set-variable] Signed-off-by: Anatolij Gustschin <agust@denx.de>
* ARM: S5P: pwm driver supportDonghwa Lee2011-03-27-0/+189
This is common pwm driver of S5P. Signed-off-by: Donghwa Lee <dh09.lee@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>