xiuos/Ubiquitous/XiZi_AIoT/services/drivers/imx6q-sabrelite/clock/timer.c

/*
 * Copyright (c) 2011-2012, Freescale Semiconductor, Inc.
 * All rights reserved.
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 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
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 *   of conditions and the following disclaimer.
 *
 * o Redistributions in binary form must reproduce the above copyright notice, this
 *   list of conditions and the following disclaimer in the documentation and/or
 *   other materials provided with the distribution.
 *
 * o Neither the name of Freescale Semiconductor, Inc. nor the names of its
 *   contributors may be used to endorse or promote products derived from this
 *   software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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/*!
 * @file timer.c
 * @brief Basic timer functions
 *
 * @ingroup diag_timer
 */

#include "timer.h"
#include "ccm_pll.h"
#include "epit.h"
#include "regsarmglobaltimer.h"
#include "regsepit.h"
#include "soc_memory_map.h"

#include "libserial.h"
#include "usyscall.h"

#include "sabrelite_timer.h"

////////////////////////////////////////////////////////////////////////////////
// Prototypes
////////////////////////////////////////////////////////////////////////////////

static void time_init_global_timer();

////////////////////////////////////////////////////////////////////////////////
// Variables
////////////////////////////////////////////////////////////////////////////////

uint32_t g_microsecondTimerMultiple;

////////////////////////////////////////////////////////////////////////////////
// Code
////////////////////////////////////////////////////////////////////////////////

//! Init the ARM global timer to a microsecond-frequency clock.
void time_init_global_timer()
{
    // The ARM private peripheral clock is half the CPU clock.
    uint32_t periphClock = get_main_clock(CPU_CLK) / 2;
    uint32_t prescaler = (periphClock / 1000000) - 1;

    // Divide down the prescaler until it fits into 8 bits. We add up the number of ticks
    // it takes to equal a microsecond interval.
    g_microsecondTimerMultiple = 1;
    while (prescaler > 0xff) {
        prescaler /= 2;
        ++g_microsecondTimerMultiple;
    }

    // Make sure the timer is off.
    HW_ARMGLOBALTIMER_CONTROL.B.TIMER_ENABLE = 0;

    // Clear counter.
    HW_ARMGLOBALTIMER_COUNTERn_WR(0, 0);
    HW_ARMGLOBALTIMER_COUNTERn_WR(1, 0);

    // Set prescaler and clear other flags.
    HW_ARMGLOBALTIMER_CONTROL_WR(BF_ARMGLOBALTIMER_CONTROL_PRESCALER(prescaler));

    // Now turn on the timer.
    HW_ARMGLOBALTIMER_CONTROL.B.TIMER_ENABLE = 1;
}

void system_time_init(void)
{
    uint32_t freq;
    // Init microsecond tick counter.
    time_init_global_timer();

    /* EPIT1 is used for the delay function */
    /* Initialize the EPIT timer used for system time functions */
    /* typical IPG_CLK is in MHz, so divide it to get a reference
       clock of 1MHz => 1us per count */
    freq = get_main_clock(IPG_CLK);
    epit_init(g_system_timer_port, CLKSRC_IPG_CLK, freq / 1000000,
        SET_AND_FORGET, 1000, WAIT_MODE_EN | STOP_MODE_EN);
}

int IPC_DO_SERVE_FUNC(Ipc_delay_us)(uint32_t* usecs)
{
    uint32_t instance = g_system_timer_port;
    if (*usecs == 0) {
        return 0;
    }

    /* enable the counter first */
    epit_counter_enable(instance, *usecs, POLLING_MODE);

    /* wait for the compare event */
    while (!epit_get_compare_event(instance)) {
        yield(SYS_TASK_YIELD_NO_REASON);
    }

    /* disable the counter to save power */
    epit_counter_disable(instance);
    return 0;
}

int IPC_DO_SERVE_FUNC(Ipc_get_microseconds)(uint64_t* microseconds)
{
    // First read upper.
    uint32_t upper = HW_ARMGLOBALTIMER_COUNTERn_RD(1);
    uint32_t lower;

    *microseconds = 0;
    while (true) {
        // Read lower.
        lower = HW_ARMGLOBALTIMER_COUNTERn_RD(0);

        // Read upper again.
        uint32_t newUpper = HW_ARMGLOBALTIMER_COUNTERn_RD(1);

        // If the first and second read of the upper bits are the same, then return.
        if (newUpper == upper) {
            *microseconds = (((uint64_t)upper << 32) | (uint64_t)lower) / g_microsecondTimerMultiple;
            break;
        }

        // Otherwise, start over again.
        upper = newUpper;
    }

    return 0;
}

IPC_SERVER_INTERFACE(Ipc_delay_us, 1);
IPC_SERVER_INTERFACE(Ipc_get_microseconds, 1);
IPC_SERVER_REGISTER_INTERFACES(IpcSabreliteTimer, 2, Ipc_delay_us, Ipc_get_microseconds);

int main(int argc, char** argv)
{
    printf("TIMER: Mapping %08x(size: %x) to %08x\n", AIPS1_ARB_PHY_BASE_ADDR, AIPS1_ARB_END_ADDR - AIPS1_ARB_BASE_ADDR, AIPS1_ARB_BASE_ADDR);
    if (!mmap(AIPS1_ARB_BASE_ADDR, AIPS1_ARB_PHY_BASE_ADDR, AIPS1_ARB_END_ADDR - AIPS1_ARB_BASE_ADDR, true)) {
        printf("TIMER : mmap AIPS1 ARB(%-08x) failed\n", AIPS1_ARB_PHY_BASE_ADDR);
    }

    printf("TIMER: Mapping %08x(size: %x) to %08x\n", AIPS2_ARB_PHY_BASE_ADDR, AIPS2_ARB_END_ADDR - AIPS2_ARB_BASE_ADDR, AIPS2_ARB_BASE_ADDR);
    if (!mmap(AIPS2_ARB_BASE_ADDR, AIPS2_ARB_PHY_BASE_ADDR, AIPS2_ARB_END_ADDR - AIPS2_ARB_BASE_ADDR, true)) {
        printf("TIMER : mmap AIPS1 ARB(%-08x) failed\n", AIPS2_ARB_PHY_BASE_ADDR);
    }

    printf("TIMER: Mapping %08x(size: %x) to %08x\n", REGS_ARMGLOBALTIMER_BASE, 0x1000, 0x00a00000);
    if (!mmap(REGS_ARMGLOBALTIMER_BASE, 0x00a00000, 0x1000, true)) {
        printf("TIMER : mmap GLOBAL TIMER(%-08x) failed\n", 0x00a00000);
    }

    static char server_name[] = "TimerServer";
    if (register_server(server_name) < 0) {
        printf("register server name %s failed\n", server_name);
        exit(1);
    }

    static uint32_t epit_instance = HW_EPIT2;

    epit_counter_disable(epit_instance);
    system_time_init();

    ipc_server_loop(&IpcSabreliteTimer);

    exit(0);
}

////////////////////////////////////////////////////////////////////////////////
// EOF
////////////////////////////////////////////////////////////////////////////////