diff options
author | Gabe Black <gabeblack@google.com> | 2013-05-16 05:45:57 -0700 |
---|---|---|
committer | Stefan Reinauer <stefan.reinauer@coreboot.org> | 2013-07-10 20:08:53 +0200 |
commit | 607c0b6d63f88c84661582800f2ee9a49325fcdb (patch) | |
tree | 9b26c0530ee09ef661610fb1faef2a1813e3da6c /src/cpu/samsung/exynos5420/timer.c | |
parent | dc006c1db4fa3606d657c78cc87dc13d056e970d (diff) |
pit: Create an exynos5420 directory which is nearly a copy of exynos5250.
This change creates an exynos5420 directory with code that will eventually
implement support for the exynos5420 cpu from Samsung. Currently it's a copy
of the exynos5250 directory with the name changed. There are going to be some
problems where headers in src/cpu/samsung/exynos-common include headers in the
exynos5250 directory directly.
Change-Id: Ia8d7244310d32499238bbc171c0c668ec48178e1
Signed-off-by: Gabe Black <gabeblack@chromium.org>
Reviewed-on: http://review.coreboot.org/3644
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Diffstat (limited to 'src/cpu/samsung/exynos5420/timer.c')
-rw-r--r-- | src/cpu/samsung/exynos5420/timer.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/src/cpu/samsung/exynos5420/timer.c b/src/cpu/samsung/exynos5420/timer.c new file mode 100644 index 0000000000..405effac5b --- /dev/null +++ b/src/cpu/samsung/exynos5420/timer.c @@ -0,0 +1,110 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2009 Samsung Electronics + * + * 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; version 2 of the License. + * + * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <console/console.h> +#include <arch/io.h> +#include <timer.h> +#include <delay.h> +#include "timer.h" +#include "pwm.h" +#include "clk.h" +#include "cpu.h" + +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); +} + +void 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 */ + timer_reset_value = 0; + + /* Use this as the last timer value we saw */ + lastinc = timer_get_us_down(); + } +} + +/* + * 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. + */ + timer_reset_value += lastinc - now; + lastinc = now; + + /* Divide by 1000 to convert from us to ms */ + return timer_reset_value / 1000 - base; +} + +/* delay x useconds */ +void udelay(unsigned 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%08x 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); +} + |