* 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
+ * SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
+#include <div64.h>
#include <asm/io.h>
#include <asm/arch/pwm.h>
#include <asm/arch/clk.h>
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_2, 0);
- pwm_config(4, 0, 0);
+ 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;
*/
unsigned long get_timer(unsigned long base)
{
- return get_timer_masked() - base;
-}
+ unsigned long long time_ms;
-/* delay x useconds */
-void __udelay(unsigned long usec)
-{
- struct s5p_timer *const timer = s5p_get_base_timer();
- unsigned long tmo, tmp, count_value;
-
- count_value = readl(&timer->tcntb4);
-
- if (usec >= 1000) {
- /*
- * if "big" number, spread normalization
- * to seconds
- * 1. start to normalize for usec to ticks per sec
- * 2. find number of "ticks" to wait to achieve target
- * 3. finish normalize.
- */
- tmo = usec / 1000;
- tmo *= (CONFIG_SYS_HZ * count_value);
- tmo /= 1000;
- } else {
- /* else small number, don't kill it prior to HZ multiply */
- tmo = usec * CONFIG_SYS_HZ * count_value;
- tmo /= (1000 * 1000);
- }
-
- /* get current timestamp */
- tmp = get_current_tick();
-
- /* if setting this fordward will roll time stamp */
- /* reset "advancing" timestamp to 0, set lastinc value */
- /* else, set advancing stamp wake up time */
- if ((tmo + tmp + 1) < tmp)
- reset_timer_masked();
- else
- tmo += tmp;
-
- /* loop till event */
- while (get_current_tick() < tmo)
- ; /* nop */
+ 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 */
+ time_ms = gd->arch.timer_reset_value;
+ do_div(time_ms, 1000);
+ return time_ms - base;
}
-void reset_timer_masked(void)
+unsigned long __attribute__((no_instrument_function)) timer_get_us(void)
{
- struct s5p_timer *const timer = s5p_get_base_timer();
+ static unsigned long base_time_us;
- /* reset time */
- gd->arch.lastinc = readl(&timer->tcnto4);
- gd->arch.tbl = 0;
+ 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;
}
-unsigned long get_timer_masked(void)
+/* delay x useconds */
+void __udelay(unsigned long usec)
{
- struct s5p_timer *const timer = s5p_get_base_timer();
- unsigned long count_value = readl(&timer->tcntb4);
+ unsigned long count_value;
- return get_current_tick() / count_value;
+ count_value = timer_get_us_down();
+ while ((int)(count_value - timer_get_us_down()) < (int)usec)
+ ;
}
-unsigned long get_current_tick(void)
+void reset_timer_masked(void)
{
struct s5p_timer *const timer = s5p_get_base_timer();
- unsigned long now = readl(&timer->tcnto4);
- unsigned long count_value = readl(&timer->tcntb4);
- if (gd->arch.lastinc >= now)
- gd->arch.tbl += gd->arch.lastinc - now;
- else
- gd->arch.tbl += gd->arch.lastinc + count_value - now;
-
- gd->arch.lastinc = now;
-
- return gd->arch.tbl;
+ /* reset time */
+ gd->arch.lastinc = readl(&timer->tcnto4);
+ gd->arch.tbl = 0;
}
/*
projects / karo-tx-uboot.git / blobdiff