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/*
* Copyright (C) 2009-2010 Freescale Semiconductor, Inc. All Rights Reserved.
*
* 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.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/err.h>
#include <asm/proc-fns.h>
static void (*machine_arch_reset) (char mode, const char *cmd);
void arch_idle(void)
{
cpu_do_idle();
}
void arch_reset(char mode, const char *cmd)
{
if (machine_arch_reset)
machine_arch_reset(mode, cmd);
}
static int __mxs_reset_block(void __iomem *hwreg, int just_enable)
{
u32 c;
int timeout;
/* the process of software reset of IP block is done
in several steps:
- clear SFTRST and wait for block is enabled;
- clear clock gating (CLKGATE bit);
- set the SFTRST again and wait for block is in reset;
- clear SFTRST and wait for reset completion.
*/
c = __raw_readl(hwreg);
c &= ~(1 << 31); /* clear SFTRST */
__raw_writel(c, hwreg);
for (timeout = 1000000; timeout > 0; timeout--)
/* still in SFTRST state ? */
if ((__raw_readl(hwreg) & (1 << 31)) == 0)
break;
if (timeout <= 0) {
printk(KERN_ERR "%s(%p): timeout when enabling\n",
__func__, hwreg);
return -ETIME;
}
c = __raw_readl(hwreg);
c &= ~(1 << 30); /* clear CLKGATE */
__raw_writel(c, hwreg);
if (!just_enable) {
c = __raw_readl(hwreg);
c |= (1 << 31); /* now again set SFTRST */
__raw_writel(c, hwreg);
for (timeout = 1000000; timeout > 0; timeout--)
/* poll until CLKGATE set */
if (__raw_readl(hwreg) & (1 << 30))
break;
if (timeout <= 0) {
printk(KERN_ERR "%s(%p): timeout when resetting\n",
__func__, hwreg);
return -ETIME;
}
c = __raw_readl(hwreg);
c &= ~(1 << 31); /* clear SFTRST */
__raw_writel(c, hwreg);
for (timeout = 1000000; timeout > 0; timeout--)
/* still in SFTRST state ? */
if ((__raw_readl(hwreg) & (1 << 31)) == 0)
break;
if (timeout <= 0) {
printk(KERN_ERR "%s(%p): timeout when enabling "
"after reset\n", __func__, hwreg);
return -ETIME;
}
c = __raw_readl(hwreg);
c &= ~(1 << 30); /* clear CLKGATE */
__raw_writel(c, hwreg);
}
for (timeout = 1000000; timeout > 0; timeout--)
/* still in SFTRST state ? */
if ((__raw_readl(hwreg) & (1 << 30)) == 0)
break;
if (timeout <= 0) {
printk(KERN_ERR "%s(%p): timeout when unclockgating\n",
__func__, hwreg);
return -ETIME;
}
return 0;
}
int mxs_reset_block(void __iomem *hwreg, int just_enable)
{
int try = 10;
int r;
while (try--) {
r = __mxs_reset_block(hwreg, just_enable);
if (!r)
break;
pr_debug("%s: try %d failed\n", __func__, 10 - try);
}
return r;
}
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