diff options
Diffstat (limited to 'arch/arm/cpu/armv7/sunxi/timer.c')
-rw-r--r-- | arch/arm/cpu/armv7/sunxi/timer.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/arch/arm/cpu/armv7/sunxi/timer.c b/arch/arm/cpu/armv7/sunxi/timer.c new file mode 100644 index 0000000000..36263896d8 --- /dev/null +++ b/arch/arm/cpu/armv7/sunxi/timer.c @@ -0,0 +1,113 @@ +/* + * (C) Copyright 2007-2011 + * Allwinner Technology Co., Ltd. <www.allwinnertech.com> + * Tom Cubie <tangliang@allwinnertech.com> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <asm/io.h> +#include <asm/arch/timer.h> + +DECLARE_GLOBAL_DATA_PTR; + +#define TIMER_MODE (0x0 << 7) /* continuous mode */ +#define TIMER_DIV (0x0 << 4) /* pre scale 1 */ +#define TIMER_SRC (0x1 << 2) /* osc24m */ +#define TIMER_RELOAD (0x1 << 1) /* reload internal value */ +#define TIMER_EN (0x1 << 0) /* enable timer */ + +#define TIMER_CLOCK (24 * 1000 * 1000) +#define COUNT_TO_USEC(x) ((x) / 24) +#define USEC_TO_COUNT(x) ((x) * 24) +#define TICKS_PER_HZ (TIMER_CLOCK / CONFIG_SYS_HZ) +#define TICKS_TO_HZ(x) ((x) / TICKS_PER_HZ) + +#define TIMER_LOAD_VAL 0xffffffff + +#define TIMER_NUM 0 /* we use timer 0 */ + +/* read the 32-bit timer */ +static ulong read_timer(void) +{ + struct sunxi_timer_reg *timers = + (struct sunxi_timer_reg *)SUNXI_TIMER_BASE; + struct sunxi_timer *timer = &timers->timer[TIMER_NUM]; + + /* + * The hardware timer counts down, therefore we invert to + * produce an incrementing timer. + */ + return ~readl(&timer->val); +} + +/* init timer register */ +int timer_init(void) +{ + struct sunxi_timer_reg *timers = + (struct sunxi_timer_reg *)SUNXI_TIMER_BASE; + struct sunxi_timer *timer = &timers->timer[TIMER_NUM]; + writel(TIMER_LOAD_VAL, &timer->inter); + writel(TIMER_MODE | TIMER_DIV | TIMER_SRC | TIMER_RELOAD | TIMER_EN, + &timer->ctl); + + return 0; +} + +/* timer without interrupts */ +ulong get_timer(ulong base) +{ + return get_timer_masked() - base; +} + +ulong get_timer_masked(void) +{ + /* current tick value */ + ulong now = TICKS_TO_HZ(read_timer()); + + if (now >= gd->arch.lastinc) /* normal (non rollover) */ + gd->arch.tbl += (now - gd->arch.lastinc); + else { + /* rollover */ + gd->arch.tbl += (TICKS_TO_HZ(TIMER_LOAD_VAL) + - gd->arch.lastinc) + now; + } + gd->arch.lastinc = now; + + return gd->arch.tbl; +} + +/* delay x useconds */ +void __udelay(unsigned long usec) +{ + long tmo = USEC_TO_COUNT(usec); + ulong now, last = read_timer(); + + while (tmo > 0) { + now = read_timer(); + if (now > last) /* normal (non rollover) */ + tmo -= now - last; + else /* rollover */ + tmo -= TIMER_LOAD_VAL - last + now; + last = now; + } +} + +/* + * 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) +{ + return get_timer(0); +} + +/* + * 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; +} |