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linux-next/arch/arm/mach-omap2/wd_timer.c
Paul Walmsley 81fbc5ef9b OMAP2+: wd_timer: separate watchdog disable code from the rest of mach-omap2/devices.c
Split the wd_timer disable code out into its own file,
mach-omap2/wd_timer.c; it belongs in its own file rather than
cluttering up devices.c.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Charulatha Varadarajan <charu@ti.com>
2010-12-21 19:56:17 -07:00

69 lines
1.7 KiB
C

/*
* OMAP2+ MPU WD_TIMER-specific code
*
* 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/kernel.h>
#include <linux/io.h>
#include <linux/err.h>
#include <plat/omap_hwmod.h>
/*
* In order to avoid any assumptions from bootloader regarding WDT
* settings, WDT module is reset during init. This enables the watchdog
* timer. Hence it is required to disable the watchdog after the WDT reset
* during init. Otherwise the system would reboot as per the default
* watchdog timer registers settings.
*/
#define OMAP_WDT_WPS 0x34
#define OMAP_WDT_SPR 0x48
int omap2_wd_timer_disable(struct omap_hwmod *oh)
{
void __iomem *base;
int ret;
if (!oh) {
pr_err("%s: Could not look up wdtimer_hwmod\n", __func__);
return -EINVAL;
}
base = omap_hwmod_get_mpu_rt_va(oh);
if (!base) {
pr_err("%s: Could not get the base address for %s\n",
oh->name, __func__);
return -EINVAL;
}
/* Enable the clocks before accessing the WDT registers */
ret = omap_hwmod_enable(oh);
if (ret) {
pr_err("%s: Could not enable clocks for %s\n",
oh->name, __func__);
return ret;
}
/* sequence required to disable watchdog */
__raw_writel(0xAAAA, base + OMAP_WDT_SPR);
while (__raw_readl(base + OMAP_WDT_WPS) & 0x10)
cpu_relax();
__raw_writel(0x5555, base + OMAP_WDT_SPR);
while (__raw_readl(base + OMAP_WDT_WPS) & 0x10)
cpu_relax();
ret = omap_hwmod_idle(oh);
if (ret)
pr_err("%s: Could not disable clocks for %s\n",
oh->name, __func__);
return ret;
}