drivers/watchdog/wdt.c

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#include <debug.h>
#include <io.h>
#include <util.h>
#include <watchdog.h>
#include <chip/clk.h>

#define WDT_CTRL                0x00            
# define WDT_CTRL_KEY1                  (0x55 << 24)    
# define WDT_CTRL_KEY2                  (0xaa << 24)    
# define WDT_CTRL_PSEL(x)               ((x) << 8)      
# define WDT_CTRL_EN                    (1 << 0)        
#define WDT_CLR                 0x04            


#define wdt_read_reg(reg)                                       \
        mmio_read32((void *)(WDT_BASE + WDT_##reg))

#define wdt_write_reg(reg, val)                                 \
        mmio_write32((void *)(WDT_BASE + WDT_##reg), val)

void watchdog_set_timeout(unsigned long timeout_ms)
{
        unsigned long   cycles;
        unsigned int    psel;

        cycles = (PM_RCOSC_MAX_RATE * timeout_ms) / 1000;
        psel = ilog2(cycles);

        dbg_info("WDT: setting %lu ms timeout (requested %lu ms; psel=%u)\n",
                        ((1UL << (psel + 1)) * 1000) / PM_RCOSC_MAX_RATE,
                        timeout_ms, psel);

        wdt_write_reg(CTRL, WDT_CTRL_KEY1 | WDT_CTRL_PSEL(psel));
        wdt_write_reg(CTRL, WDT_CTRL_KEY2 | WDT_CTRL_PSEL(psel));
}

void watchdog_enable(void)
{
        uint32_t        ctrl;

        ctrl = wdt_read_reg(CTRL) | WDT_CTRL_EN;
        wdt_write_reg(CTRL, WDT_CTRL_KEY1 | ctrl);
        wdt_write_reg(CTRL, WDT_CTRL_KEY2 | ctrl);
}

void watchdog_disable(void)
{
        uint32_t        ctrl;

        ctrl = wdt_read_reg(CTRL) & ~WDT_CTRL_EN;
        wdt_write_reg(CTRL, WDT_CTRL_KEY1 | ctrl);
        wdt_write_reg(CTRL, WDT_CTRL_KEY2 | ctrl);
}

void watchdog_reset(void)
{
        wdt_write_reg(CLR, 0);
}

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