u-boot/arch/arm/mach-rockchip/rk_timer.c
huang lin cc2244b8fa rockchip: add timer driver
some rockchip soc will not include lib/timer.c in SPL stage,
so implement timer driver for some soc can use us delay function in SPL.

Signed-off-by: Lin Huang <hl@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
2015-12-01 08:07:22 -07:00

48 lines
1,006 B
C

/*
* (C) Copyright 2015 Rockchip Electronics Co., Ltd
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <asm/arch/timer.h>
#include <asm/io.h>
#include <common.h>
#include <linux/types.h>
struct rk_timer * const timer_ptr = (void *)CONFIG_SYS_TIMER_BASE;
static uint64_t rockchip_get_ticks(void)
{
uint64_t timebase_h, timebase_l;
timebase_l = readl(&timer_ptr->timer_curr_value0);
timebase_h = readl(&timer_ptr->timer_curr_value1);
return timebase_h << 32 | timebase_l;
}
static uint64_t usec_to_tick(unsigned int usec)
{
uint64_t tick = usec;
tick *= CONFIG_SYS_TIMER_RATE / (1000 * 1000);
return tick;
}
void rockchip_udelay(unsigned int usec)
{
uint64_t tmp;
/* get timestamp */
tmp = rockchip_get_ticks() + usec_to_tick(usec);
/* loop till event */
while (rockchip_get_ticks() < tmp+1)
;
}
void rockchip_timer_init(void)
{
writel(0xffffffff, &timer_ptr->timer_load_count0);
writel(0xffffffff, &timer_ptr->timer_load_count1);
writel(1, &timer_ptr->timer_ctrl_reg);
}