diff options
Diffstat (limited to 'src/cpu/samsung/exynos5250/timer.c')
| -rw-r--r-- | src/cpu/samsung/exynos5250/timer.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/src/cpu/samsung/exynos5250/timer.c b/src/cpu/samsung/exynos5250/timer.c new file mode 100644 index 0000000000..e7cadc3b9d --- /dev/null +++ b/src/cpu/samsung/exynos5250/timer.c @@ -0,0 +1,164 @@ +/* + * 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 <arch/io.h> +#include <timer.h> +#include <console/console.h> +#include <cpu/samsung/exynos5250/pwm.h> +#include <cpu/samsung/exynos5250/clk.h> +#include <cpu/samsung/exynos5250/cpu.h> +#include <cpu/samsung/exynos5250/exynos5-common.h> + +//#include <pwm.h> + +//DECLARE_GLOBAL_DATA_PTR; +static unsigned long long timer_reset_value; +static unsigned long lastinc; + +/* macro to read the 16 bit timer */ +static inline struct s5p_timer *s5p_get_base_timer(void) +{ + return 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 init_timer(void) +{ + /* Timer may have been enabled in SPL */ + if (!pwm_check_enabled(4)) { + /* 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->timer_reset_value = 0; + timer_reset_value = 0; + + /* Use this as the last timer value we saw */ + //gd->lastinc = timer_get_us_down(); + lastinc = timer_get_us_down(); + } + + return 0; +} + +/* + * timer without interrupts + */ +unsigned long get_timer(unsigned long base) +{ + unsigned long 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. + */ +#if 0 + gd->timer_reset_value += gd->lastinc - now; + gd->lastinc = now; + + /* Divide by 1000 to convert from us to ms */ + return gd->timer_reset_value / 1000 - base; +#endif + timer_reset_value += lastinc - now; + lastinc = now; + + /* Divide by 1000 to convert from us to ms */ + return timer_reset_value / 1000 - base; +} + +unsigned long timer_get_us(void) +{ + struct s5p_timer *const timer = s5p_get_base_timer(); + unsigned long now_downward_us = readl(&timer->tcnto4); + + /* + * Note that this timer counts downward. The pre-SPL process (BL1) + * takes about 100ms, so add this in here. + */ + return CONFIG_SPL_TIME_US - now_downward_us; +} + +/* delay x useconds */ +void udelay(unsigned long usec) +{ + struct mono_time current, end; + + timer_monotonic_get(¤t); + end = current; + mono_time_add_usecs(&end, usec); + + if (mono_time_after(¤t, &end)) { + printk(BIOS_EMERG, "udelay: 0x%08lx is impossibly large\n", + usec); + /* There's not much we can do if usec is too big. Use a long, + * paranoid delay value and hope for the best... */ + end = current; + mono_time_add_usecs(&end, USECS_PER_SEC); + } + + while (mono_time_before(¤t, &end)) + timer_monotonic_get(¤t); +} + +/* + * 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; +} + +unsigned long timer_get_boot_us(void) +{ + return timer_get_us(); +} |