[U-Boot] [PATCH 1/1] ppc4xx: Reset and relock memory DLL after SDRAM_CLKTR change

[Adam Graham]

After changing SDRAM_CLKTR phase value rerun the memory preload initialization sequence (INITPLR) to reset and relock the memory DLL.  Changing the SDRAM_CLKTR memory clock phase coarse timing adjustment effects the phase relationship of the internal, to the PPC chip, and external, to the PPC chip, versions of MEMCLK_OUT.

Signed-off-by: Adam Graham <agraham at amcc.com>
Signed-off-by: Victor Gallardo <vgallardo at amcc.com>
---
 cpu/ppc4xx/4xx_ibm_ddr2_autocalib.c |   21 +++++++++++++++++++++
 1 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/cpu/ppc4xx/4xx_ibm_ddr2_autocalib.c b/cpu/ppc4xx/4xx_ibm_ddr2_autocalib.c
index 83b9883..47ab39b 100644
--- a/cpu/ppc4xx/4xx_ibm_ddr2_autocalib.c
+++ b/cpu/ppc4xx/4xx_ibm_ddr2_autocalib.c
@@ -174,6 +174,23 @@ static inline void ecc_clear_status_reg(void)
 #endif
 }
 
+/*
+ * Reset and relock memory DLL after SDRAM_CLKTR change
+ */
+static inline void relock_memory_DLL(void)
+{
+	u32 reg;
+
+	mtsdram(SDRAM_MCOPT2, SDRAM_MCOPT2_IPTR_EXECUTE);
+
+	do {
+		mfsdram(SDRAM_MCSTAT, reg);
+	} while (!(reg & SDRAM_MCSTAT_MIC_COMP));
+
+	mfsdram(SDRAM_MCOPT2, reg);
+	mtsdram(SDRAM_MCOPT2, reg | SDRAM_MCOPT2_DCEN_ENABLE);
+}
+
 static int ecc_check_status_reg(void)
 {
 	u32 ecc_status;
@@ -981,6 +998,8 @@ u32 DQS_autocalibration(void)
 
 		mtsdram(SDRAM_CLKTR, clkp << 30);
 
+		relock_memory_DLL();
+
 		putc('\b');
 		putc(slash[loopi++ % 8]);
 
@@ -1170,6 +1189,8 @@ u32 DQS_autocalibration(void)
 
 		mtsdram(SDRAM_CLKTR, tcal.clocks.clktr << 30);
 
+		relock_memory_DLL();
+
 		mfsdram(SDRAM_RQDC, rqdc_reg);
 		rqdc_reg &= ~(SDRAM_RQDC_RQFD_MASK);
 		mtsdram(SDRAM_RQDC, rqdc_reg |
-- 
1.5.5