omap3: Reboot mode support

Reboot mode is written in scratchpad memory before reboot in the form of a
single char, that is the first letter of the reboot mode string as passed to the
reboot function.

This mechanism is supported on OMAP3 both my the upstream kernel and 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>
Reviewed-by: Tom Rini <trini@konsulko.com>

diff --git a/arch/arm/cpu/armv7/omap3/boot.c b/arch/arm/cpu/armv7/omap3/boot.c
index 66576b26c5f1b6a940c17d14924396282559f011..44d7c306620bdccbef01dd1e654f5e29f957b3da 100644 (file)
--- a/arch/arm/cpu/armv7/omap3/boot.c
+++ b/arch/arm/cpu/armv7/omap3/boot.c
@@ -56,3 +56,41 @@ u32 omap_sys_boot_device(void)
 
        return boot_devices[sys_boot];
 }
+
+char omap_reboot_mode(void)
+{
+       u32 reboot_mode;
+       char c;
+
+       reboot_mode = readl((u32 *)(OMAP34XX_SCRATCHPAD + 4));
+
+       c = (reboot_mode >> 24) & 0xff;
+       if (c != 'B')
+               return -1;
+
+       c = (reboot_mode >> 16) & 0xff;
+       if (c != 'M')
+               return -1;
+
+       c = reboot_mode & 0xff;
+
+       return c;
+}
+
+int omap_reboot_mode_clear(void)
+{
+       writel(0, (u32 *)(OMAP34XX_SCRATCHPAD + 4));
+
+       return 0;
+}
+
+int omap_reboot_mode_store(char c)
+{
+       u32 reboot_mode;
+
+       reboot_mode = 'B' << 24 | 'M' << 16 | c;
+
+       writel(reboot_mode, (u32 *)(OMAP34XX_SCRATCHPAD + 4));
+
+       return 0;
+}

diff --git a/arch/arm/include/asm/arch-omap3/omap.h b/arch/arm/include/asm/arch-omap3/omap.h
index 537d13b2637a625cbe3e79fdf49d12eaeb229731..2c94a814ef7cb9b863ac21157174ebd4fa6b8681 100644 (file)
--- a/arch/arm/include/asm/arch-omap3/omap.h
+++ b/arch/arm/include/asm/arch-omap3/omap.h
@@ -51,6 +51,9 @@ struct control_prog_io {
 /* Bit definition for CONTROL_PROG_IO1 */
 #define PRG_I2C2_PULLUPRESX            0x00000001
 
+/* Scratchpad memory */
+#define OMAP34XX_SCRATCHPAD            (OMAP34XX_CTRL_BASE + 0x910)
+
 /* UART */
 #define OMAP34XX_UART1                 (OMAP34XX_L4_IO_BASE + 0x6a000)
 #define OMAP34XX_UART2                 (OMAP34XX_L4_IO_BASE + 0x6c000)
@@ -256,6 +259,10 @@ struct omap_boot_parameters {
        unsigned char ch_flags;
        unsigned int boot_device_descriptor;
 };
+
+char omap_reboot_mode(void);
+int omap_reboot_mode_clear(void);
+int omap_reboot_mode_store(char c);
 #endif
 
 #endif