81 lines
		
	
	
	
		
			2.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			81 lines
		
	
	
	
		
			2.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
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								/*
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								 * Copyright (C) 1999 ARM Limited
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								 * Copyright (C) 2000 Deep Blue Solutions Ltd
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								 * Copyright 2006-2007,2010 Freescale Semiconductor, Inc. All Rights Reserved.
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								 * Copyright 2008 Juergen Beisert, kernel@pengutronix.de
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								 * Copyright 2009 Ilya Yanok, Emcraft Systems Ltd, yanok@emcraft.com
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								 * Copyright (C) 2011 Wolfram Sang, Pengutronix e.K.
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								 *
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								 * This program is free software; you can redistribute it and/or modify
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								 * it under the terms of the GNU General Public License as published by
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								 * the Free Software Foundation; either version 2 of the License, or
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								 * (at your option) any later version.
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								 */
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								#include <linux/io.h>
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								#include <linux/errno.h>
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								#include <linux/delay.h>
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								#include <linux/module.h>
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								#include <linux/stmp_device.h>
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								#define STMP_MODULE_CLKGATE	(1 << 30)
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								#define STMP_MODULE_SFTRST	(1 << 31)
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								/*
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								 * Clear the bit and poll it cleared.  This is usually called with
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								 * a reset address and mask being either SFTRST(bit 31) or CLKGATE
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								 * (bit 30).
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								 */
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								static int stmp_clear_poll_bit(void __iomem *addr, u32 mask)
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								{
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									int timeout = 0x400;
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									writel(mask, addr + STMP_OFFSET_REG_CLR);
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									udelay(1);
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									while ((readl(addr) & mask) && --timeout)
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										/* nothing */;
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									return !timeout;
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								}
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								int stmp_reset_block(void __iomem *reset_addr)
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								{
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									int ret;
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									int timeout = 0x400;
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									/* clear and poll SFTRST */
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									ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_SFTRST);
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									if (unlikely(ret))
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										goto error;
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									/* clear CLKGATE */
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									writel(STMP_MODULE_CLKGATE, reset_addr + STMP_OFFSET_REG_CLR);
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									/* set SFTRST to reset the block */
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									writel(STMP_MODULE_SFTRST, reset_addr + STMP_OFFSET_REG_SET);
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									udelay(1);
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									/* poll CLKGATE becoming set */
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									while ((!(readl(reset_addr) & STMP_MODULE_CLKGATE)) && --timeout)
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										/* nothing */;
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									if (unlikely(!timeout))
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										goto error;
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									/* clear and poll SFTRST */
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									ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_SFTRST);
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									if (unlikely(ret))
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										goto error;
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									/* clear and poll CLKGATE */
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									ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_CLKGATE);
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									if (unlikely(ret))
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										goto error;
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									return 0;
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								error:
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									pr_err("%s(%p): module reset timeout\n", __func__, reset_addr);
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									return -ETIMEDOUT;
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								}
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								EXPORT_SYMBOL(stmp_reset_block);
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