From c9fc3626fd9733df1cde19c6df6f04bdcaf62f05 Mon Sep 17 00:00:00 2001
From: Sascha Hauer <s.hauer@pengutronix.de>
Date: Thu, 22 Sep 2011 12:06:15 +0200
Subject: ppc mpc5200: add function to setup bus clocks

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 arch/ppc/mach-mpc5xxx/cpu.c                  | 38 ++++++++++++++++++++++++++++
 arch/ppc/mach-mpc5xxx/include/mach/mpc5xxx.h |  3 +++
 2 files changed, 41 insertions(+)

diff --git a/arch/ppc/mach-mpc5xxx/cpu.c b/arch/ppc/mach-mpc5xxx/cpu.c
index 649f08a87d..d695b9b545 100644
--- a/arch/ppc/mach-mpc5xxx/cpu.c
+++ b/arch/ppc/mach-mpc5xxx/cpu.c
@@ -33,6 +33,7 @@
 #include <asm/io.h>
 #include <init.h>
 #include <types.h>
+#include <errno.h>
 #include <mach/clocks.h>
 
 #if defined(CONFIG_OF_FLAT_TREE)
@@ -132,6 +133,43 @@ unsigned long mpc5200_get_sdram_size(unsigned int cs)
 	return size;
 }
 
+int mpc5200_setup_bus_clocks(unsigned int ipbdiv, unsigned long pcidiv)
+{
+	u32 cdmcfg = *(vu_long *)MPC5XXX_CDM_CFG;
+
+	cdmcfg &= ~0x103;
+
+	switch (ipbdiv) {
+	case 1:
+		break;
+	case 2:
+		cdmcfg |= 0x100;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	switch (pcidiv) {
+	case 1:
+		if (ipbdiv == 2)
+			return -EINVAL;
+		break;
+	case 2:
+		if (ipbdiv == 1)
+			cdmcfg |= 0x1; /* ipb / 2 */
+		break;
+	case 4:
+		cdmcfg |= 0x2; /* xlb / 4 */
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	*(vu_long *)MPC5XXX_CDM_CFG = cdmcfg;
+
+	return 0;
+}
+
 struct mpc5200_cs {
 	void *start;
 	void *stop;
diff --git a/arch/ppc/mach-mpc5xxx/include/mach/mpc5xxx.h b/arch/ppc/mach-mpc5xxx/include/mach/mpc5xxx.h
index 558f331160..8e95dd0c11 100644
--- a/arch/ppc/mach-mpc5xxx/include/mach/mpc5xxx.h
+++ b/arch/ppc/mach-mpc5xxx/include/mach/mpc5xxx.h
@@ -786,6 +786,9 @@ unsigned long mpc5200_get_sdram_size(unsigned int cs);
 #define MPC5200_BOOTCS 8
 void mpc5200_setup_cs(int cs, unsigned long start, unsigned long size, u32 cfg);
 
+/* configure bus speeds. Both dividers are relative to xlb clock */
+int mpc5200_setup_bus_clocks(unsigned int ipbdiv, unsigned long pcidiv);
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* __ASMPPC_MPC5XXX_H */
-- 
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