rt-thread-official/bsp/imx/imx6ull-smart/drivers/drv_timer.c

/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2018-11-22     Jesven       first version
 */

#include <rthw.h>
#include <rtthread.h>
#include <stdint.h>

#include <board.h>
#include "mmu.h"

#define TICK_PERIOD (g_sys_freq / RT_TICK_PER_SECOND)
static int g_sys_freq;

#define IRQ_SECURE_PHY_TIMER   29  /* Secure physical timer event */
#define IRQ_NOSECURE_PHY_TIMER 30  /* No-Secure physical timer event */

#define IRQ_SYS_TICK  IRQ_SECURE_PHY_TIMER


/* System Counter */
struct sctr_regs {
    rt_uint32_t cntcr;
    rt_uint32_t cntsr;
    rt_uint32_t cntcv1;
    rt_uint32_t cntcv2;
    rt_uint32_t resv1[4];
    rt_uint32_t cntfid0;
    rt_uint32_t cntfid1;
    rt_uint32_t cntfid2;
    rt_uint32_t resv2[1001];
    rt_uint32_t counterid[1];
};

#define SC_CNTCR_ENABLE     (1 << 0)
#define SC_CNTCR_HDBG       (1 << 1)
#define SC_CNTCR_FREQ0      (1 << 8)
#define SC_CNTCR_FREQ1      (1 << 9)


#define isb() __asm__ __volatile__ ("" : : : "memory")
#define dsb() __asm__ __volatile__ ("" : : : "memory")
#define dmb() __asm__ __volatile__ ("" : : : "memory")


static inline void enable_cntp(void)
{
    rt_uint32_t cntv_ctl;
    cntv_ctl = 1;
    asm volatile ("mcr p15, 0, %0, c14, c2, 1" :: "r"(cntv_ctl)); // write CNTP_CTL
    isb();
}

static inline void disable_cntp(void)
{
    rt_uint32_t cntv_ctl;
    cntv_ctl = 0;
    asm volatile ("mcr p15, 0, %0, c14, c2, 1" :: "r"(cntv_ctl)); // write CNTP_CTL
    isb();
}

static inline rt_uint32_t read_cntfrq(void)
{
    rt_uint32_t val;
    asm volatile ("mrc p15, 0, %0, c14, c0, 0" : "=r"(val));
    return val;
}

static inline  void write_cntp_tval(rt_uint32_t val)
{
    asm volatile ("mcr p15, 0, %0, c14, c2, 0" :: "r"(val));
    isb();
    return;
}

static inline  void write_cntp_cval(rt_uint64_t val)
{
    asm volatile ("mcrr p15, 2, %Q0, %R0, c14" :: "r" (val));
    isb();
    return;
}

static inline rt_uint64_t read_cntp_cval(void)
{
    rt_uint64_t val;
    asm volatile ("mrrc p15, 2, %Q0, %R0, c14" : "=r" (val));
    return (val);
}

volatile unsigned int *CCM_CLPCR;

static void imx6ull_enable_clk_in_waitmode(void)
{
    CCM_CLPCR = rt_ioremap((void*)0x20C4054, 4);
    *CCM_CLPCR &= ~((1 << 5) | 0x3);
}

static void system_counter_clk_source_init(void)
{
    /* to do */
}

static void system_counter_init(void)
{
    /* enable system_counter */
#define SCTR_BASE_ADDR  0x021DC000
#define CONFIG_SC_TIMER_CLK  8000000

    /* imx6ull, enable system counter */
    struct sctr_regs *sctr = (struct sctr_regs *)rt_ioremap((void*)SCTR_BASE_ADDR, sizeof(struct sctr_regs));
    unsigned long val, freq;

    freq = CONFIG_SC_TIMER_CLK;
    asm volatile("mcr p15, 0, %0, c14, c0, 0" : : "r" (freq));

    sctr->cntfid0 = freq;

    /* Enable system counter */
    val = sctr->cntcr;
    val &= ~(SC_CNTCR_FREQ0 | SC_CNTCR_FREQ1);
    val |= SC_CNTCR_FREQ0 | SC_CNTCR_ENABLE | SC_CNTCR_HDBG;
    sctr->cntcr = val;

    imx6ull_enable_clk_in_waitmode();
}

static void arch_timer_init(void)
{
    g_sys_freq = read_cntfrq();

    /* set timeout val */
    disable_cntp();
    write_cntp_tval(TICK_PERIOD);

    /* start timer */
    enable_cntp();

    /* enable irq */
}

static void rt_hw_timer_isr(int vector, void *param)
{
    rt_tick_increase();

    /* setup for next irq */
    /* clear interrupt */
    disable_cntp();
    write_cntp_cval(read_cntp_cval() + TICK_PERIOD);
    enable_cntp();
}

int rt_hw_timer_init(void)
{
    /* Setup Timer for generating irq */
    /* enable timer */
    system_counter_clk_source_init();
    system_counter_init();
    arch_timer_init();

    /* insall irq, enable irq */
    rt_hw_interrupt_install(IRQ_SYS_TICK, rt_hw_timer_isr, RT_NULL, "tick");
    rt_hw_interrupt_umask(IRQ_SYS_TICK);

    return 0;
}
INIT_BOARD_EXPORT(rt_hw_timer_init);