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[POWERPC] Add restart support for mpc52xx based platforms

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Add common helper routines: mpc52xx_map_wdt() and mpc52xx_restart().

Signed-off-by: Marian Balakowicz <m8@semihalf.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This commit is contained in:
Marian Balakowicz 2007-10-19 04:44:33 +10:00 committed by Grant Likely
parent d24bc314c9
commit 86b92cdda9
2 changed files with 53 additions and 0 deletions
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50
arch/powerpc/platforms/52xx/mpc52xx_common.c
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@ -18,6 +18,13 @@
#include <asm/prom.h> #include <asm/prom.h>
#include <asm/mpc52xx.h> #include <asm/mpc52xx.h>
/*
* This variable is mapped in mpc52xx_map_wdt() and used in mpc52xx_restart().
* Permanent mapping is required because mpc52xx_restart() can be called
* from interrupt context while node mapping (which calls ioremap())
* cannot be used at such point.
*/
static volatile struct mpc52xx_gpt *mpc52xx_wdt = NULL;
static void __iomem * static void __iomem *
mpc52xx_map_node(struct device_node *ofn) mpc52xx_map_node(struct device_node *ofn)
@ -126,3 +133,46 @@ mpc52xx_declare_of_platform_devices(void)
"Error while probing of_platform bus\n"); "Error while probing of_platform bus\n");
} }
void __init
mpc52xx_map_wdt(void)
{
const void *has_wdt;
struct device_node *np;
/* mpc52xx_wdt is mapped here and used in mpc52xx_restart,
* possibly from a interrupt context. wdt is only implement
* on a gpt0, so check has-wdt property before mapping.
*/
for_each_compatible_node(np, NULL, "fsl,mpc5200-gpt") {
has_wdt = of_get_property(np, "fsl,has-wdt", NULL);
if (has_wdt) {
mpc52xx_wdt = mpc52xx_map_node(np);
return;
}
}
for_each_compatible_node(np, NULL, "mpc5200-gpt") {
has_wdt = of_get_property(np, "has-wdt", NULL);
if (has_wdt) {
mpc52xx_wdt = mpc52xx_map_node(np);
return;
}
}
}
void
mpc52xx_restart(char *cmd)
{
local_irq_disable();
/* Turn on the watchdog and wait for it to expire.
* It effectively does a reset. */
if (mpc52xx_wdt) {
out_be32(&mpc52xx_wdt->mode, 0x00000000);
out_be32(&mpc52xx_wdt->count, 0x000000ff);
out_be32(&mpc52xx_wdt->mode, 0x00009004);
} else
printk("mpc52xx_restart: Can't access wdt. "
"Restart impossible, system halted.\n");
while (1);
}

3
include/asm-powerpc/mpc52xx.h
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@ -259,6 +259,9 @@ extern unsigned int mpc52xx_get_irq(void);
extern int __init mpc52xx_add_bridge(struct device_node *node); extern int __init mpc52xx_add_bridge(struct device_node *node);
extern void __init mpc52xx_map_wdt(void);
extern void mpc52xx_restart(char *cmd);
#endif /* __ASSEMBLY__ */ #endif /* __ASSEMBLY__ */
#ifdef CONFIG_PM #ifdef CONFIG_PM