OMAP3 SDRC: initialize SDRC_POWER at boot

Initialize SDRC_POWER to a known-good setting when the kernel boots.
Necessary since some bootloaders don't initialize SDRC_POWER properly.

Signed-off-by: Paul Walmsley <paul@pwsan.com>

diff --git a/arch/arm/mach-omap2/sdrc.c b/arch/arm/mach-omap2/sdrc.c
index 2a30060..d62e4e1 100644 (file)
--- a/arch/arm/mach-omap2/sdrc.c
+++ b/arch/arm/mach-omap2/sdrc.c
@@ -37,6 +37,10 @@ static struct omap_sdrc_params *sdrc_init_params;
 void __iomem *omap2_sdrc_base;
 void __iomem *omap2_sms_base;
 
+/* SDRC_POWER register bits */
+#define SDRC_POWER_EXTCLKDIS_SHIFT             3
+#define SDRC_POWER_PWDENA_SHIFT                        2
+#define SDRC_POWER_PAGEPOLICY_SHIFT            0
 
 /**
  * omap2_sdrc_get_params - return SDRC register values for a given clock rate
@@ -74,7 +78,14 @@ void __init omap2_set_globals_sdrc(struct omap_globals *omap2_globals)
        omap2_sms_base = omap2_globals->sms;
 }
 
-/* turn on smart idle modes for SDRAM scheduler and controller */
+/**
+ * omap2_sdrc_init - initialize SMS, SDRC devices on boot
+ * @sp: pointer to a null-terminated list of struct omap_sdrc_params
+ *
+ * Turn on smart idle modes for SDRAM scheduler and controller.
+ * Program a known-good configuration for the SDRC to deal with buggy
+ * bootloaders.
+ */
 void __init omap2_sdrc_init(struct omap_sdrc_params *sp)
 {
        u32 l;
@@ -90,4 +101,10 @@ void __init omap2_sdrc_init(struct omap_sdrc_params *sp)
        sdrc_write_reg(l, SDRC_SYSCONFIG);
 
        sdrc_init_params = sp;
+
+       /* XXX Enable SRFRONIDLEREQ here also? */
+       l = (1 << SDRC_POWER_EXTCLKDIS_SHIFT) |
+               (1 << SDRC_POWER_PWDENA_SHIFT) |
+               (1 << SDRC_POWER_PAGEPOLICY_SHIFT);
+       sdrc_write_reg(l, SDRC_POWER);
 }