uboot-vybrid_public/arch/arm/imx-common/misc.c

/*
 * Copyright 2013 Stefan Roese <sr@denx.de>
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <common.h>
#include <asm/errno.h>
#include <asm/io.h>
#include <asm/imx-common/regs-common.h>

/* 1 second delay should be plenty of time for block reset. */
#define	RESET_MAX_TIMEOUT	1000000

#define	MXS_BLOCK_SFTRST	(1 << 31)
#define	MXS_BLOCK_CLKGATE	(1 << 30)

int mxs_wait_mask_set(struct mxs_register_32 *reg, uint32_t mask, unsigned
								int timeout)
{
	while (--timeout) {
		if ((readl(&reg->reg) & mask) == mask)
			break;
		udelay(1);
	}

	return !timeout;
}

int mxs_wait_mask_clr(struct mxs_register_32 *reg, uint32_t mask, unsigned
								int timeout)
{
	while (--timeout) {
		if ((readl(&reg->reg) & mask) == 0)
			break;
		udelay(1);
	}

	return !timeout;
}

int mxs_reset_block(struct mxs_register_32 *reg)
{
	/* Clear SFTRST */
	writel(MXS_BLOCK_SFTRST, &reg->reg_clr);

	if (mxs_wait_mask_clr(reg, MXS_BLOCK_SFTRST, RESET_MAX_TIMEOUT))
		return 1;

	/* Clear CLKGATE */
	writel(MXS_BLOCK_CLKGATE, &reg->reg_clr);

	/* Set SFTRST */
	writel(MXS_BLOCK_SFTRST, &reg->reg_set);

	/* Wait for CLKGATE being set */
	if (mxs_wait_mask_set(reg, MXS_BLOCK_CLKGATE, RESET_MAX_TIMEOUT))
		return 1;

	/* Clear SFTRST */
	writel(MXS_BLOCK_SFTRST, &reg->reg_clr);

	if (mxs_wait_mask_clr(reg, MXS_BLOCK_SFTRST, RESET_MAX_TIMEOUT))
		return 1;

	/* Clear CLKGATE */
	writel(MXS_BLOCK_CLKGATE, &reg->reg_clr);

	if (mxs_wait_mask_clr(reg, MXS_BLOCK_CLKGATE, RESET_MAX_TIMEOUT))
		return 1;

	return 0;
}