mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-04 18:41:03 +00:00
34b5ee1f6a
The pwm_config function in the exynos pwm driver divides by its period period parameter. A function was calling pwm_config with a 0ns period and a 0ns duty cycle. That doesn't actually make any sense physically, and results in a divide by zero in the driver. This change changes the parameters to be a 100000ns period and duty cycle. 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>
143 lines
3.4 KiB
C
143 lines
3.4 KiB
C
/*
|
|
* Copyright (C) 2009 Samsung Electronics
|
|
* Heungjun Kim <riverful.kim@samsung.com>
|
|
* Inki Dae <inki.dae@samsung.com>
|
|
* Minkyu Kang <mk7.kang@samsung.com>
|
|
*
|
|
* See file CREDITS for list of people who contributed to this
|
|
* project.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License as
|
|
* published by the Free Software Foundation; either version 2 of
|
|
* the License, or (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
|
|
* MA 02111-1307 USA
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <asm/io.h>
|
|
#include <asm/arch/pwm.h>
|
|
#include <asm/arch/clk.h>
|
|
#include <pwm.h>
|
|
|
|
DECLARE_GLOBAL_DATA_PTR;
|
|
|
|
unsigned long get_current_tick(void);
|
|
|
|
/* macro to read the 16 bit timer */
|
|
static inline struct s5p_timer *s5p_get_base_timer(void)
|
|
{
|
|
return (struct s5p_timer *)samsung_get_base_timer();
|
|
}
|
|
|
|
/**
|
|
* Read the countdown timer.
|
|
*
|
|
* This operates at 1MHz and counts downwards. It will wrap about every
|
|
* hour (2^32 microseconds).
|
|
*
|
|
* @return current value of timer
|
|
*/
|
|
static unsigned long timer_get_us_down(void)
|
|
{
|
|
struct s5p_timer *const timer = s5p_get_base_timer();
|
|
|
|
return readl(&timer->tcnto4);
|
|
}
|
|
|
|
int timer_init(void)
|
|
{
|
|
/* PWM Timer 4 */
|
|
pwm_init(4, MUX_DIV_4, 0);
|
|
pwm_config(4, 100000, 100000);
|
|
pwm_enable(4);
|
|
|
|
/* Use this as the current monotonic time in us */
|
|
gd->arch.timer_reset_value = 0;
|
|
|
|
/* Use this as the last timer value we saw */
|
|
gd->arch.lastinc = timer_get_us_down();
|
|
reset_timer_masked();
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* timer without interrupts
|
|
*/
|
|
unsigned long get_timer(unsigned long base)
|
|
{
|
|
ulong now = timer_get_us_down();
|
|
|
|
/*
|
|
* Increment the time by the amount elapsed since the last read.
|
|
* The timer may have wrapped around, but it makes no difference to
|
|
* our arithmetic here.
|
|
*/
|
|
gd->arch.timer_reset_value += gd->arch.lastinc - now;
|
|
gd->arch.lastinc = now;
|
|
|
|
/* Divide by 1000 to convert from us to ms */
|
|
return gd->arch.timer_reset_value / 1000 - base;
|
|
}
|
|
|
|
unsigned long timer_get_us(void)
|
|
{
|
|
static unsigned long base_time_us;
|
|
|
|
struct s5p_timer *const timer =
|
|
(struct s5p_timer *)samsung_get_base_timer();
|
|
unsigned long now_downward_us = readl(&timer->tcnto4);
|
|
|
|
if (!base_time_us)
|
|
base_time_us = now_downward_us;
|
|
|
|
/* Note that this timer counts downward. */
|
|
return base_time_us - now_downward_us;
|
|
}
|
|
|
|
/* delay x useconds */
|
|
void __udelay(unsigned long usec)
|
|
{
|
|
unsigned long count_value;
|
|
|
|
count_value = timer_get_us_down();
|
|
while ((int)(count_value - timer_get_us_down()) < (int)usec)
|
|
;
|
|
}
|
|
|
|
void reset_timer_masked(void)
|
|
{
|
|
struct s5p_timer *const timer = s5p_get_base_timer();
|
|
|
|
/* reset time */
|
|
gd->arch.lastinc = readl(&timer->tcnto4);
|
|
gd->arch.tbl = 0;
|
|
}
|
|
|
|
/*
|
|
* This function is derived from PowerPC code (read timebase as long long).
|
|
* On ARM it just returns the timer value.
|
|
*/
|
|
unsigned long long get_ticks(void)
|
|
{
|
|
return get_timer(0);
|
|
}
|
|
|
|
/*
|
|
* This function is derived from PowerPC code (timebase clock frequency).
|
|
* On ARM it returns the number of timer ticks per second.
|
|
*/
|
|
unsigned long get_tbclk(void)
|
|
{
|
|
return CONFIG_SYS_HZ;
|
|
}
|