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>

1 files changed, 41 insertions, 0 deletions

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 @@ u32 omap_sys_boot_device(void)
 
 	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;
+}