cpu.c

/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2006-03-13     Bernard      first version
 */

#include <rtthread.h>
#include <sep4020.h>

extern rt_uint32_t rt_hw_interrupt_disable(void);

//TODO
#warning I DON'T KNOW IF THE MMU OPERATION WORKS ON SEP4020

/**
 * @addtogroup S3C24X0
 */
/*@{*/

#define ICACHE_MASK (rt_uint32_t)(1 << 12)
#define DCACHE_MASK (rt_uint32_t)(1 << 2)

#ifdef __GNUC__
rt_inline rt_uint32_t cp15_rd(void)
{
    rt_uint32_t i;

    asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));
    return i;
}

rt_inline void cache_enable(rt_uint32_t bit)
{
    __asm__ __volatile__(           \
        "mrc  p15,0,r0,c1,c0,0\n\t" \
        "orr  r0,r0,%0\n\t"         \
        "mcr  p15,0,r0,c1,c0,0"     \
        :                           \
        :"r" (bit)                  \
        :"memory");
}

rt_inline void cache_disable(rt_uint32_t bit)
{
    __asm__ __volatile__(           \
        "mrc  p15,0,r0,c1,c0,0\n\t" \
        "bic  r0,r0,%0\n\t"         \
        "mcr  p15,0,r0,c1,c0,0"     \
        :                           \
        :"r" (bit)                  \
        :"memory");
}
#endif

#ifdef __CC_ARM
rt_inline rt_uint32_t cp15_rd(void)
{
    rt_uint32_t i;

    __asm
    {
        mrc p15, 0, i, c1, c0, 0
    }

    return i;
}

rt_inline void cache_enable(rt_uint32_t bit)
{
    rt_uint32_t value;

    __asm
    {
        mrc p15, 0, value, c1, c0, 0
        orr value, value, bit
        mcr p15, 0, value, c1, c0, 0
    }
}

rt_inline void cache_disable(rt_uint32_t bit)
{
    rt_uint32_t value;

    __asm
    {
        mrc p15, 0, value, c1, c0, 0
        bic value, value, bit
        mcr p15, 0, value, c1, c0, 0
    }
}
#endif

/**
 * enable I-Cache
 *
 */
void rt_hw_cpu_icache_enable()
{
    cache_enable(ICACHE_MASK);
}

/**
 * disable I-Cache
 *
 */
void rt_hw_cpu_icache_disable()
{
    cache_disable(ICACHE_MASK);
}

/**
 * return the status of I-Cache
 *
 */
rt_base_t rt_hw_cpu_icache_status()
{
    return (cp15_rd() & ICACHE_MASK);
}

/**
 * enable D-Cache
 *
 */
void rt_hw_cpu_dcache_enable()
{
    cache_enable(DCACHE_MASK);
}

/**
 * disable D-Cache
 *
 */
void rt_hw_cpu_dcache_disable()
{
    cache_disable(DCACHE_MASK);
}

/**
 * return the status of D-Cache
 *
 */
rt_base_t rt_hw_cpu_dcache_status()
{
    return (cp15_rd() & DCACHE_MASK);
}

/**
 * reset cpu by dog's time-out
 *
 */
RT_WEAK void rt_hw_cpu_reset()
{

    /* enable watchdog */
    *(RP)(RTC_CTR) = 0x02;

    /*Enable watchdog reset*/
    *(RP)(RTC_INT_EN) = 0x20;

    /* Initialize watchdog timer count register */
    *(RP)(RTC_WD_CNT) = 0x0001;

    while(1);   /* loop forever and wait for reset to happen */

    /* NEVER REACHED */
}

/**
 *  shutdown CPU
 *
 */
RT_WEAK void rt_hw_cpu_shutdown()
{
    rt_uint32_t UNUSED level;
    rt_kprintf("shutdown...\n");

    level = rt_hw_interrupt_disable();

    RT_ASSERT(RT_NULL);
}

/*@}*/