early_kempld.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <stdint.h>
#include <arch/io.h>
#include <delay.h>
 
#include "chip.h"
#include "kempld.h"
#include "kempld_internal.h"
 
void kempld_write8(const uint8_t addr, const uint8_t data)
{
        outb(addr, KEMPLD_IDX);
        outb(data, KEMPLD_DAT);
}
 
uint8_t kempld_read8(const uint8_t addr)
{
        outb(addr, KEMPLD_IDX);
        return inb(KEMPLD_DAT);
}
 
int kempld_get_mutex(int timeout_ms)
{
        while (inb(KEMPLD_IDX) & KEMPLD_MUTEX_KEY && timeout_ms--)
                mdelay(1);
        return timeout_ms;
}
 
void kempld_release_mutex(void)
{
        outb(KEMPLD_MUTEX_KEY, KEMPLD_IDX);
}
 
void kempld_enable_uart_for_console(void)
{
        if (!CONFIG(CONSOLE_SERIAL))
                return;
 
        if (kempld_get_mutex(100) < 0)
                return;
 
        switch (CONFIG_UART_FOR_CONSOLE) {
        case 0:
                kempld_write8(KEMPLD_UART_0,
                              KEMPLD_UART_ENABLE | KEMPLD_UART_3F8 << KEMPLD_UART_IO_SHIFT);
                break;
        case 1:
                kempld_write8(KEMPLD_UART_1,
                              KEMPLD_UART_ENABLE | KEMPLD_UART_2F8 << KEMPLD_UART_IO_SHIFT);
                break;
        default:
                break;
        }
 
        kempld_release_mutex();
}