board/ml50x/ml50x.c

/*
 * Copyright Codito Technologies (www.codito.com)
 *
 *  board/aa3/aa3.c
 *
 *  Copyright (C)
 *
 * 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.
 *
 * Authors : Sandeep Patil (sandeep.patil@codito.com)
 *           Pradeep Sawlani (pradeep.sawlani@codito.com)
 */

#include <asm/arcregs.h>

#include <linux/types.h>
#include <config.h>
#include <asm/global_data.h>	/* For global data structre */
#include <asm/sys_ctrl.h>

#define TIMER_WRAP 0xffffffff         /* Maximum limit for timer      */

#if ARC_BOARD_TIMER==0
#define BOARD_REG_TIMER_LIMIT ARC_REG_TIMER0_LIMIT
#define BOARD_REG_TIMER_CTRL  ARC_REG_TIMER0_CTRL
#define BOARD_REG_TIMER_CNT   ARC_REG_TIMER0_CNT
#else
#define BOARD_REG_TIMER_LIMIT ARC_REG_TIMER1_LIMIT
#define BOARD_REG_TIMER_CTRL  ARC_REG_TIMER1_CTRL
#define BOARD_REG_TIMER_CNT   ARC_REG_TIMER1_CNT
#endif

static ulong timestamp;

#ifdef CONFIG_ARC_SYS_CTRL_DEV
static sys_ctrl_reg_t *sys_ctrl_dev = SYS_CTRL_DEVICE_ADDRESS;
#endif

/* Function to start timer from 'count' */
void set_timer (ulong count)
{
        /* Set up the LIMIT , COUNT and CONTROL registers for timer without interrupt	*/
        write_new_aux_reg(BOARD_REG_TIMER_CTRL, 0);
        write_new_aux_reg(BOARD_REG_TIMER_LIMIT, TIMER_WRAP);
        write_new_aux_reg(BOARD_REG_TIMER_CTRL, 2);
        write_new_aux_reg(BOARD_REG_TIMER_CNT, count);
}

/* Function to get the current count value */
ulong get_timer (ulong base)
{
        /* Read the count value from COUNT0     */
        timestamp = read_new_aux_reg(BOARD_REG_TIMER_CNT);
        return timestamp - base;
}

void reset_timer(void)
{
        set_timer(0);
}

void uninit_timer(void)
{
        write_new_aux_reg(BOARD_REG_TIMER_LIMIT, TIMER_WRAP);
        write_new_aux_reg(BOARD_REG_TIMER_CNT, 0);
        write_new_aux_reg(BOARD_REG_TIMER_CTRL, 0);
}

/* Delay function */
void udelay (unsigned long usec)
{
        DECLARE_GLOBAL_DATA_PTR;
        ulong uTicks;
        set_timer(0);
        uTicks = (gd->cpu_clk/1000000) * usec;
        /* Continue looping till the timer count is more thean the required delay	*/
        while(get_timer(0) < uTicks);
}

int board_init(void)
{
        DECLARE_GLOBAL_DATA_PTR;

        gd->cpu_clk = CONFIG_ARC_CLK;
        /* Intialise the timer */
        reset_timer();

        /* address of kernel parameters */
        gd->bd->bi_boot_params = TEXT_BASE - CONFIG_SYS_MALLOC_LEN + CONFIG_SYS_ENV_SIZE;

        return 0;
}