uncompress.h

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/* arch/arm/plat-samsung/include/plat/uncompress.h
 *
 * Copyright 2003, 2007 Simtec Electronics
 *  http://armlinux.simtec.co.uk/
 *  Ben Dooks <[email protected]>
 *
 * S3C - uncompress code
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
*/

#ifndef __ASM_PLAT_UNCOMPRESS_H
#define __ASM_PLAT_UNCOMPRESS_H

typedef unsigned int upf_t; /* cannot include linux/serial_core.h */

/* uart setup */

unsigned int fifo_mask;
unsigned int fifo_max;

/* forward declerations */

static void arch_detect_cpu(void);

/* defines for UART registers */

#include <plat/regs-serial.h>
#include <plat/regs-watchdog.h>

/* working in physical space... */
#undef S3C2410_WDOGREG
#define S3C2410_WDOGREG(x) ((S3C24XX_PA_WATCHDOG + (x)))

/* how many bytes we allow into the FIFO at a time in FIFO mode */
#define FIFO_MAX     (14)

#ifdef S3C_PA_UART
#define uart_base S3C_PA_UART + (S3C_UART_OFFSET * CONFIG_S3C_LOWLEVEL_UART_PORT)
#endif

static __inline__ void
uart_wr(unsigned int reg, unsigned int val)
{
    volatile unsigned int *ptr;

    ptr = (volatile unsigned int *)(reg + uart_base);
    *ptr = val;
}

static __inline__ unsigned int
uart_rd(unsigned int reg)
{
    volatile unsigned int *ptr;

    ptr = (volatile unsigned int *)(reg + uart_base);
    return *ptr;
}

/* we can deal with the case the UARTs are being run
 * in FIFO mode, so that we don't hold up our execution
 * waiting for tx to happen...
*/

static void putc(int ch)
{
    if (uart_rd(S3C2410_UFCON) & S3C2410_UFCON_FIFOMODE) {
        int level;

        while (1) {
            level = uart_rd(S3C2410_UFSTAT);
            level &= fifo_mask;

            if (level < fifo_max)
                break;
        }

    } else {
        /* not using fifos */

        while ((uart_rd(S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXE) != S3C2410_UTRSTAT_TXE)
            barrier();
    }

    /* write byte to transmission register */
    uart_wr(S3C2410_UTXH, ch);
}

static inline void flush(void)
{
}

#define __raw_writel(d, ad)         \
    do {                            \
        *((volatile unsigned int __force *)(ad)) = (d); \
    } while (0)

/* CONFIG_S3C_BOOT_WATCHDOG
 *
 * Simple boot-time watchdog setup, to reboot the system if there is
 * any problem with the boot process
*/

#ifdef CONFIG_S3C_BOOT_WATCHDOG

#define WDOG_COUNT (0xff00)

static inline void arch_decomp_wdog(void)
{
    __raw_writel(WDOG_COUNT, S3C2410_WTCNT);
}

static void arch_decomp_wdog_start(void)
{
    __raw_writel(WDOG_COUNT, S3C2410_WTDAT);
    __raw_writel(WDOG_COUNT, S3C2410_WTCNT);
    __raw_writel(S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV128 | S3C2410_WTCON_RSTEN | S3C2410_WTCON_PRESCALE(0x80), S3C2410_WTCON);
}

#else
#define arch_decomp_wdog_start()
#define arch_decomp_wdog()
#endif

#ifdef CONFIG_S3C_BOOT_ERROR_RESET

static void arch_decomp_error(const char *x)
{
    putstr("\n\n");
    putstr(x);
    putstr("\n\n -- System resetting\n");

    __raw_writel(0x4000, S3C2410_WTDAT);
    __raw_writel(0x4000, S3C2410_WTCNT);
    __raw_writel(S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV128 | S3C2410_WTCON_RSTEN | S3C2410_WTCON_PRESCALE(0x40), S3C2410_WTCON);

    while(1);
}

#define arch_error arch_decomp_error
#endif

#ifdef CONFIG_S3C_BOOT_UART_FORCE_FIFO
static inline void arch_enable_uart_fifo(void)
{
    u32 fifocon = uart_rd(S3C2410_UFCON);

    if (!(fifocon & S3C2410_UFCON_FIFOMODE)) {
        fifocon |= S3C2410_UFCON_RESETBOTH;
        uart_wr(S3C2410_UFCON, fifocon);

        /* wait for fifo reset to complete */
        while (1) {
            fifocon = uart_rd(S3C2410_UFCON);
            if (!(fifocon & S3C2410_UFCON_RESETBOTH))
                break;
        }
    }
}
#else
#define arch_enable_uart_fifo() do { } while(0)
#endif


static void
arch_decomp_setup(void)
{
    /* we may need to setup the uart(s) here if we are not running
     * on an BAST... the BAST will have left the uarts configured
     * after calling linux.
     */

    arch_detect_cpu();
    arch_decomp_wdog_start();

    /* Enable the UART FIFOs if they where not enabled and our
     * configuration says we should turn them on.
     */

    arch_enable_uart_fifo();
}


#endif /* __ASM_PLAT_UNCOMPRESS_H */