OMAP: Store reboot mode in scratchpad on OMAP34xx

The reboot mode can be communicated to a bootloader (or the
kernel itself) with a scratchpad register. This functionality
is especially useful, if userspace is allowed to change
the reboot mode.

Signed-off-by: Juha Yrjola <juha.yrjola@solidboot.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/arch/arm/mach-omap2/prcm.c b/arch/arm/mach-omap2/prcm.c
index f945156d55859cbf97e0f70f9f917c7d2630107f..2f828cb86361f0c404da15ffab9a6a3b2b018ea8 100644 (file)
--- a/arch/arm/mach-omap2/prcm.c
+++ b/arch/arm/mach-omap2/prcm.c
@@ -43,9 +43,18 @@ void omap_prcm_arch_reset(char mode)
 
        if (cpu_is_omap24xx())
                prcm_offs = WKUP_MOD;
-       else if (cpu_is_omap34xx())
+       else if (cpu_is_omap34xx()) {
+               u32 l;
+
                prcm_offs = OMAP3430_GR_MOD;
-       else
+               l = ('B' << 24) | ('M' << 16) | mode;
+               /* Reserve the first word in scratchpad for communicating
+                * with the boot ROM. A pointer to a data structure
+                * describing the boot process can be stored there,
+                * cf. OMAP34xx TRM, Initialization / Software Booting
+                * Configuration. */
+               omap_writel(l, OMAP343X_SCRATCHPAD + 4);
+       } else
                WARN_ON(1);
 
        prm_set_mod_reg_bits(OMAP_RST_DPLL3, prcm_offs, RM_RSTCTRL);