omap4: Reboot mode support
Reboot mode is written to SAR memory before reboot in the form of a string.
This mechanism is supported on OMAP4 by various TI kernels.
It is up to each board to make use of this mechanism or not.
Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
diff --git a/arch/arm/cpu/armv7/omap4/boot.c b/arch/arm/cpu/armv7/omap4/boot.c
index 4b5aa77..bae49f4 100644
--- a/arch/arm/cpu/armv7/omap4/boot.c
+++ b/arch/arm/cpu/armv7/omap4/boot.c
@@ -58,3 +58,44 @@
return boot_devices[sys_boot];
}
+
+int omap_reboot_mode(char *mode, unsigned int length)
+{
+ unsigned int limit;
+ unsigned int i;
+
+ if (length < 2)
+ return -1;
+
+ limit = (length < OMAP_REBOOT_REASON_SIZE) ? length :
+ OMAP_REBOOT_REASON_SIZE;
+
+ for (i = 0; i < (limit - 1); i++)
+ mode[i] = readb((u8 *)(OMAP44XX_SAR_RAM_BASE +
+ OMAP_REBOOT_REASON_OFFSET + i));
+
+ mode[i] = '\0';
+
+ return 0;
+}
+
+int omap_reboot_mode_clear(void)
+{
+ writeb(0, (u8 *)(OMAP44XX_SAR_RAM_BASE + OMAP_REBOOT_REASON_OFFSET));
+
+ return 0;
+}
+
+int omap_reboot_mode_store(char *mode)
+{
+ unsigned int i;
+
+ for (i = 0; i < (OMAP_REBOOT_REASON_SIZE - 1) && mode[i] != '\0'; i++)
+ writeb(mode[i], (u8 *)(OMAP44XX_SAR_RAM_BASE +
+ OMAP_REBOOT_REASON_OFFSET + i));
+
+ writeb('\0', (u8 *)(OMAP44XX_SAR_RAM_BASE +
+ OMAP_REBOOT_REASON_OFFSET + i));
+
+ return 0;
+}
diff --git a/arch/arm/include/asm/arch-omap4/omap.h b/arch/arm/include/asm/arch-omap4/omap.h
index 4712722..5ccda6e 100644
--- a/arch/arm/include/asm/arch-omap4/omap.h
+++ b/arch/arm/include/asm/arch-omap4/omap.h
@@ -120,6 +120,10 @@
/* ABB tranxdone mask */
#define OMAP_ABB_MPU_TXDONE_MASK (0x1 << 7)
+#define OMAP44XX_SAR_RAM_BASE 0x4a326000
+#define OMAP_REBOOT_REASON_OFFSET 0xA0C
+#define OMAP_REBOOT_REASON_SIZE 0x0F
+
/* Boot parameters */
#ifndef __ASSEMBLY__
struct omap_boot_parameters {
@@ -129,6 +133,10 @@
unsigned char reset_reason;
unsigned char ch_flags;
};
+
+int omap_reboot_mode(char *mode, unsigned int length);
+int omap_reboot_mode_clear(void);
+int omap_reboot_mode_store(char *mode);
#endif
#endif