X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=arch%2Farm%2Fcpu%2Farmv7%2Fs5p-common%2Ftimer.c;h=949abb1c8fe58fa980e1f3830dca615419003b6c;hb=6f0586e692c91ac9dc33fd479f68c3d957bf61b3;hp=359c21f5e0c9e2ad02c48b3e61615c2cc3e2dcf9;hpb=4769be21cca65f1e7bef27bc024d886842bc6bad;p=oweals%2Fu-boot.git diff --git a/arch/arm/cpu/armv7/s5p-common/timer.c b/arch/arm/cpu/armv7/s5p-common/timer.c index 359c21f5e0..949abb1c8f 100644 --- a/arch/arm/cpu/armv7/s5p-common/timer.c +++ b/arch/arm/cpu/armv7/s5p-common/timer.c @@ -4,26 +4,11 @@ * Inki Dae * Minkyu Kang * - * 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 +#include #include #include #include @@ -31,19 +16,43 @@ 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_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; } @@ -52,73 +61,56 @@ int timer_init(void) */ unsigned long get_timer(unsigned long base) { - return get_timer_masked() - base; + unsigned long long time_ms; + + 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; } -/* delay x useconds */ -void __udelay(unsigned long usec) +unsigned long __attribute__((no_instrument_function)) timer_get_us(void) { - 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 / 10); - tmo /= 1000; - } else { - /* else small number, don't kill it prior to HZ multiply */ - tmo = usec * CONFIG_SYS_HZ * count_value / 10; - tmo /= (1000 * 1000); - } - - /* get current timestamp */ - tmp = get_timer(0); - - /* 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_timer_masked() < tmo) - ; /* nop */ + 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; } -void reset_timer_masked(void) +/* delay x useconds */ +void __udelay(unsigned long usec) { - struct s5p_timer *const timer = s5p_get_base_timer(); + unsigned long count_value; - /* reset time */ - gd->lastinc = readl(&timer->tcnto4); - gd->tbl = 0; + count_value = timer_get_us_down(); + while ((int)(count_value - timer_get_us_down()) < (int)usec) + ; } -unsigned long get_timer_masked(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->lastinc >= now) - gd->tbl += gd->lastinc - now; - else - gd->tbl += gd->lastinc + count_value - now; - - gd->lastinc = now; - - return gd->tbl; + /* reset time */ + gd->arch.lastinc = readl(&timer->tcnto4); + gd->arch.tbl = 0; } /*