81 lines
		
	
	
	
		
			2.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			81 lines
		
	
	
	
		
			2.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
|   | /*
 | ||
|  |  * 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); |