[PATCH 05/10] OMAP3 SDRC: initialize SDRC_POWER at boot

Paul Walmsley
2009-05-13T00:11:06Z

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>
---
arch/arm/mach-omap2/sdrc.c | 19 ++++++++++++++++++-
1 files changed, 18 insertions(+), 1 deletions(-)

diff --git a/arch/arm/mach-omap2/sdrc.c b/arch/arm/mach-omap2/sdrc.c
index 2a30060..d62e4e1 100644
--- 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);
}