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author | fishsoupisgood <github@madingley.org> | 2019-04-29 01:17:54 +0100 |
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committer | fishsoupisgood <github@madingley.org> | 2019-05-27 03:43:43 +0100 |
commit | 3f2546b2ef55b661fd8dd69682b38992225e86f6 (patch) | |
tree | 65ca85f13617aee1dce474596800950f266a456c /roms/u-boot/arch/arm/cpu/arm920t/s3c24x0/timer.c | |
download | qemu-master.tar.gz qemu-master.tar.bz2 qemu-master.zip |
Diffstat (limited to 'roms/u-boot/arch/arm/cpu/arm920t/s3c24x0/timer.c')
-rw-r--r-- | roms/u-boot/arch/arm/cpu/arm920t/s3c24x0/timer.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/roms/u-boot/arch/arm/cpu/arm920t/s3c24x0/timer.c b/roms/u-boot/arch/arm/cpu/arm920t/s3c24x0/timer.c new file mode 100644 index 00000000..ba1e616b --- /dev/null +++ b/roms/u-boot/arch/arm/cpu/arm920t/s3c24x0/timer.c @@ -0,0 +1,160 @@ +/* + * (C) Copyright 2002 + * Sysgo Real-Time Solutions, GmbH <www.elinos.com> + * Marius Groeger <mgroeger@sysgo.de> + * + * (C) Copyright 2002 + * Sysgo Real-Time Solutions, GmbH <www.elinos.com> + * Alex Zuepke <azu@sysgo.de> + * + * (C) Copyright 2002 + * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#ifdef CONFIG_S3C24X0 + +#include <asm/io.h> +#include <asm/arch/s3c24x0_cpu.h> + +DECLARE_GLOBAL_DATA_PTR; + +int timer_init(void) +{ + struct s3c24x0_timers *timers = s3c24x0_get_base_timers(); + ulong tmr; + + /* use PWM Timer 4 because it has no output */ + /* prescaler for Timer 4 is 16 */ + writel(0x0f00, &timers->tcfg0); + if (gd->arch.tbu == 0) { + /* + * for 10 ms clock period @ PCLK with 4 bit divider = 1/2 + * (default) and prescaler = 16. Should be 10390 + * @33.25MHz and 15625 @ 50 MHz + */ + gd->arch.tbu = get_PCLK() / (2 * 16 * 100); + gd->arch.timer_rate_hz = get_PCLK() / (2 * 16); + } + /* load value for 10 ms timeout */ + writel(gd->arch.tbu, &timers->tcntb4); + /* auto load, manual update of timer 4 */ + tmr = (readl(&timers->tcon) & ~0x0700000) | 0x0600000; + writel(tmr, &timers->tcon); + /* auto load, start timer 4 */ + tmr = (tmr & ~0x0700000) | 0x0500000; + writel(tmr, &timers->tcon); + gd->arch.lastinc = 0; + gd->arch.tbl = 0; + + return 0; +} + +/* + * timer without interrupts + */ +ulong get_timer(ulong base) +{ + return get_timer_masked() - base; +} + +void __udelay (unsigned long usec) +{ + ulong tmo; + ulong start = get_ticks(); + + tmo = usec / 1000; + tmo *= (gd->arch.tbu * 100); + tmo /= 1000; + + while ((ulong) (get_ticks() - start) < tmo) + /*NOP*/; +} + +ulong get_timer_masked(void) +{ + ulong tmr = get_ticks(); + + return tmr / (gd->arch.timer_rate_hz / CONFIG_SYS_HZ); +} + +void udelay_masked(unsigned long usec) +{ + ulong tmo; + ulong endtime; + signed long diff; + + if (usec >= 1000) { + tmo = usec / 1000; + tmo *= (gd->arch.tbu * 100); + tmo /= 1000; + } else { + tmo = usec * (gd->arch.tbu * 100); + tmo /= (1000 * 1000); + } + + endtime = get_ticks() + tmo; + + do { + ulong now = get_ticks(); + diff = endtime - now; + } while (diff >= 0); +} + +/* + * 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) +{ + struct s3c24x0_timers *timers = s3c24x0_get_base_timers(); + ulong now = readl(&timers->tcnto4) & 0xffff; + + if (gd->arch.lastinc >= now) { + /* normal mode */ + gd->arch.tbl += gd->arch.lastinc - now; + } else { + /* we have an overflow ... */ + gd->arch.tbl += gd->arch.lastinc + gd->arch.tbu - now; + } + gd->arch.lastinc = now; + + return gd->arch.tbl; +} + +/* + * This function is derived from PowerPC code (timebase clock frequency). + * On ARM it returns the number of timer ticks per second. + */ +ulong get_tbclk(void) +{ + return CONFIG_SYS_HZ; +} + +/* + * reset the cpu by setting up the watchdog timer and let him time out + */ +void reset_cpu(ulong ignored) +{ + struct s3c24x0_watchdog *watchdog; + + watchdog = s3c24x0_get_base_watchdog(); + + /* Disable watchdog */ + writel(0x0000, &watchdog->wtcon); + + /* Initialize watchdog timer count register */ + writel(0x0001, &watchdog->wtcnt); + + /* Enable watchdog timer; assert reset at timer timeout */ + writel(0x0021, &watchdog->wtcon); + + while (1) + /* loop forever and wait for reset to happen */; + + /*NOTREACHED*/ +} + +#endif /* CONFIG_S3C24X0 */ |