timer.c

Go to the documentation of this file.

/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <device/mmio.h>
#include <timer.h>
#include <delay.h>
#include <thread.h>
 
#include <soc/addressmap.h>
#include <soc/timer.h>
 
static struct mtk_gpt_regs *const mtk_gpt = (void *)GPT_BASE;
 
__weak void timer_prepare(void) { /* do nothing */ }
 
static uint64_t timer_raw_value(void)
{
        /*
         * According to "General-Purpose Timer (GPT).pdf", The read operation of
         * gpt6_cnt_l will make gpt6_cnt_h fixed until the next read operation
         * of gpt6_cnt_l. Therefore, we must read gpt6_cnt_l before gpt6_cnt_h.
         */
        uint32_t low = read32(&mtk_gpt->gpt6_cnt_l);
        uint32_t high = read32(&mtk_gpt->gpt6_cnt_h);
 
        return low | (uint64_t)high << 32;
}
 
void timer_monotonic_get(struct mono_time *mt)
{
        mono_time_set_usecs(mt, timer_raw_value() / GPT_MHZ);
}
 
void init_timer(void)
{
        timer_prepare();
 
        /* Disable timer and clear the counter */
        clrbits32(&mtk_gpt->gpt6_con, GPT6_CON_EN);
        setbits32(&mtk_gpt->gpt6_con, GPT6_CON_CLR);
 
        /* Set clock source to system clock and set clock divider to 1 */
        SET32_BITFIELDS(&GPT6_CLOCK_REG(mtk_gpt),
                        GPT6_CLK_CLK6, GPT6_CLK_CLK6_SYS,
                        GPT6_CLK_CLKDIV6, GPT6_CLK_CLKDIV_DIV1);
        /* Set operation mode to FREERUN mode and enable timer */
        SET32_BITFIELDS(&mtk_gpt->gpt6_con,
                        GPT6_CON_MODE6, GPT6_MODE_FREERUN,
                        GPT6_CON_EN6, GPT6_CON_EN);
}