diff options
Diffstat (limited to 'arch/arm/cpu/armv7/socfpga/timer.c')
-rw-r--r-- | arch/arm/cpu/armv7/socfpga/timer.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/arch/arm/cpu/armv7/socfpga/timer.c b/arch/arm/cpu/armv7/socfpga/timer.c new file mode 100644 index 0000000000..321e9b4181 --- /dev/null +++ b/arch/arm/cpu/armv7/socfpga/timer.c @@ -0,0 +1,104 @@ +/* + * Copyright (C) 2012 Altera Corporation <www.altera.com> + * + * 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, see <http://www.gnu.org/licenses/>. + */ + +#include <common.h> +#include <asm/io.h> +#include <asm/arch/timer.h> + +DECLARE_GLOBAL_DATA_PTR; + +static const struct socfpga_timer *timer_base = (void *)CONFIG_SYS_TIMERBASE; + +/* + * Timer initialization + */ +int timer_init(void) +{ + writel(TIMER_LOAD_VAL, &timer_base->load_val); + writel(TIMER_LOAD_VAL, &timer_base->curr_val); + writel(readl(&timer_base->ctrl) | 0x3, &timer_base->ctrl); + return 0; +} + +static u32 read_timer(void) +{ + return readl(&timer_base->curr_val); +} + +/* + * Delay x useconds + */ +void __udelay(unsigned long usec) +{ + unsigned long now, last; + /* + * get the tmo value based on timer clock speed + * tmo = delay required / period of timer clock + */ + long tmo = usec * CONFIG_TIMER_CLOCK_KHZ / 1000; + + last = read_timer(); + while (tmo > 0) { + now = read_timer(); + if (last >= now) + /* normal mode (non roll) */ + tmo -= last - now; + else + /* we have overflow of the count down timer */ + tmo -= TIMER_LOAD_VAL - last + now; + last = now; + } +} + +/* + * Get the timer value + */ +ulong get_timer(ulong base) +{ + return get_timer_masked() - base; +} + +/* + * Timer : get the time difference + * Unit of tick is based on the CONFIG_SYS_HZ + */ +ulong get_timer_masked(void) +{ + /* current tick value */ + ulong now = read_timer() / (CONFIG_TIMER_CLOCK_KHZ/CONFIG_SYS_HZ); + if (gd->lastinc >= now) { + /* normal mode (non roll) */ + /* move stamp forward with absolute diff ticks */ + gd->tbl += gd->lastinc - now; + } else { + /* we have overflow of the count down timer */ + gd->tbl += TIMER_LOAD_VAL - gd->lastinc + now; + } + gd->lastinc = now; + return gd->tbl; +} + +/* + * Reset the timer + */ +void reset_timer(void) +{ + /* capture current decrementer value time */ + gd->lastinc = read_timer() / (CONFIG_TIMER_CLOCK_KHZ/CONFIG_SYS_HZ); + /* start "advancing" time stamp from 0 */ + gd->tbl = 0; +} |