/* * Copyright (C) 1999 ARM Limited * Copyright (C) 2000 Deep Blue Solutions Ltd * Copyright 2006-2007,2010 Freescale Semiconductor, Inc. All Rights Reserved. * Copyright 2008 Juergen Beisert, kernel@pengutronix.de * Copyright 2009 Ilya Yanok, Emcraft Systems Ltd, yanok@emcraft.com * Copyright (C) 2011 Wolfram Sang, Pengutronix e.K. * * 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. */ #include <linux/io.h>#include <linux/errno.h>#include <linux/delay.h>#include <linux/module.h>#include <linux/stmp_device.h> #define STMP_MODULE_CLKGATE	(1 << 30)#define STMP_MODULE_SFTRST	(1 << 31) /* * Clear the bit and poll it cleared.  This is usually called with * a reset address and mask being either SFTRST(bit 31) or CLKGATE * (bit 30). */static int stmp_clear_poll_bit(void __iomem *addr, u32 mask){	int timeout = 0x400; 	writel(mask, addr + STMP_OFFSET_REG_CLR);	udelay(1);	while ((readl(addr) & mask) && --timeout)		/* nothing */; 	return !timeout;} int stmp_reset_block(void __iomem *reset_addr){	int ret;	int timeout = 0x400; 	/* clear and poll SFTRST */	ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_SFTRST);	if (unlikely(ret))		goto error; 	/* clear CLKGATE */	writel(STMP_MODULE_CLKGATE, reset_addr + STMP_OFFSET_REG_CLR); 	/* set SFTRST to reset the block */	writel(STMP_MODULE_SFTRST, reset_addr + STMP_OFFSET_REG_SET);	udelay(1); 	/* poll CLKGATE becoming set */	while ((!(readl(reset_addr) & STMP_MODULE_CLKGATE)) && --timeout)		/* nothing */;	if (unlikely(!timeout))		goto error; 	/* clear and poll SFTRST */	ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_SFTRST);	if (unlikely(ret))		goto error; 	/* clear and poll CLKGATE */	ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_CLKGATE);	if (unlikely(ret))		goto error; 	return 0; error:	pr_err("%s(%p): module reset timeout\n", __func__, reset_addr);	return -ETIMEDOUT;}EXPORT_SYMBOL(stmp_reset_block);