The watchdog needs to know if the last reset cause was the watchdog itself.
This patch adds a function to easily read the relevant bits form the RCU
registers.
Signed-off-by: John Crispin <blogic@xxxxxxxxxxx>
Signed-off-by: Ralph Hempel <ralph.hempel@xxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
---
arch/mips/include/asm/mach-lantiq/lantiq.h | 4 ++++
arch/mips/lantiq/xway/reset.c | 12 ++++++++++++
2 files changed, 16 insertions(+), 0 deletions(-)
diff --git a/arch/mips/include/asm/mach-lantiq/lantiq.h b/arch/mips/include/asm/mach-lantiq/lantiq.h
index 1a705b4..ce2f029 100644
--- a/arch/mips/include/asm/mach-lantiq/lantiq.h
+++ b/arch/mips/include/asm/mach-lantiq/lantiq.h
@@ -49,6 +49,10 @@ extern void ltq_disable_irq(struct irq_data *data);
extern void ltq_mask_and_ack_irq(struct irq_data *data);
extern void ltq_enable_irq(struct irq_data *data);
+/* find out what caused the last cpu reset */
+extern int ltq_reset_cause(void);
+#define LTQ_RST_CAUSE_WDTRST 0x20
+
#define IOPORT_RESOURCE_START 0x10000000
#define IOPORT_RESOURCE_END 0xffffffff
#define IOMEM_RESOURCE_START 0x10000000
diff --git a/arch/mips/lantiq/xway/reset.c b/arch/mips/lantiq/xway/reset.c
index e3ec635..a1be36d 100644
--- a/arch/mips/lantiq/xway/reset.c
+++ b/arch/mips/lantiq/xway/reset.c
@@ -10,6 +10,7 @@
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/pm.h>
+#include <linux/module.h>
#include <asm/reboot.h>
#include <lantiq_soc.h>
@@ -21,6 +22,9 @@
#define LTQ_RCU_RST 0x0010
#define LTQ_RCU_RST_ALL 0x40000000
+#define LTQ_RCU_RST_STAT 0x0014
+#define LTQ_RCU_STAT_SHIFT 26
+
static struct resource ltq_rcu_resource = {
.name = "rcu",
.start = LTQ_RCU_BASE_ADDR,
@@ -31,6 +35,14 @@ static struct resource ltq_rcu_resource = {
/* remapped base addr of the reset control unit */
static void __iomem *ltq_rcu_membase;
+/* This function is used by the watchdog driver */
+int ltq_reset_cause(void)
+{
+ u32 val = ltq_rcu_r32(LTQ_RCU_RST_STAT);
+ return val >> LTQ_RCU_STAT_SHIFT;
+}
+EXPORT_SYMBOL_GPL(ltq_reset_cause);
+
static void ltq_machine_restart(char *command)
{
pr_notice("System restart\n");
--
1.7.2.3
