timer.c

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/* SPDX-License-Identifier: BSD-3-Clause */
 
#include <device/mmio.h>
#include <delay.h>
#include <soc/iomap.h>
#include <soc/ipq_timer.h>
#include <timer.h>
 
#define GCNT_FREQ_MHZ           48
 
#define TIMER_TICKS(us)         (GCNT_FREQ_MHZ * (us))
#define TIMER_USECS(ticks)      ((ticks) / GCNT_FREQ_MHZ)
 
/**
 * init_timer - initialize timer
 */
void init_timer(void)
{
        /* disable timer */
        write32(GCNT_CNTCR, 0);
 
        /* Reset the counters to zero */
        write32(GCNT_GLB_CNTCV_LO, 0);
        write32(GCNT_GLB_CNTCV_HI, 0);
 
        /* Enable timer */
        write32(GCNT_CNTCR, 1);
}
 
static inline uint64_t read_gcnt_val(void)
{
        uint32_t hi, lo;
 
        do {
                hi = read32(GCNT_CNTCV_HI);
                lo = read32(GCNT_CNTCV_LO);
        } while (hi != read32(GCNT_CNTCV_HI));
 
        return ((((uint64_t)hi) << 32) | lo);
}
 
/**
 * udelay -  generates micro second delay.
 * @param usec: delay duration in microseconds
 */
void udelay(unsigned int usec)
{
        uint64_t expire;
 
        expire = read_gcnt_val() + TIMER_TICKS(usec);
 
        while (expire >= read_gcnt_val())
                ;
}
 
void timer_monotonic_get(struct mono_time *mt)
{
        mono_time_set_usecs(mt, TIMER_USECS(read_gcnt_val()));
}