From: Paul Walmsley <paul@pwsan.com>
Date: Tue, 12 May 2009 23:27:09 +0000 (-0600)
Subject: OMAP3 SDRC: initialize SDRC_POWER at boot
X-Git-Tag: firefly_0821_release~13644^2~4^2~27^2~5
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=98cfe5abf24c6d2f06b70fa8a8a111681bed3ed9;p=firefly-linux-kernel-4.4.55.git

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 2a30060cb4b7..d62e4e10d4b0 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);
 }