[coreboot-gerrit] Patch set updated for coreboot: southbridge/amd/sb700: Fix drifting system clock

[Timothy Pearson (tpearson@raptorengineeringinc.com)]

Timothy Pearson (tpearson at raptorengineeringinc.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/12052

-gerrit

commit 81744f2d39b550a6ada555e2bfdec9c524306bea
Author: Timothy Pearson <tpearson at raptorengineeringinc.com>
Date:   Fri Aug 28 15:31:31 2015 -0500

    southbridge/amd/sb700: Fix drifting system clock
    
    Change-Id: I1698c9b9b1840d254115821f3c0e76b7211e9056
    Signed-off-by: Timothy Pearson <tpearson at raptorengineeringinc.com>
---
 src/southbridge/amd/sb700/early_setup.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/src/southbridge/amd/sb700/early_setup.c b/src/southbridge/amd/sb700/early_setup.c
index da03961..df32a42 100644
--- a/src/southbridge/amd/sb700/early_setup.c
+++ b/src/southbridge/amd/sb700/early_setup.c
@@ -431,10 +431,13 @@ static void sb700_devices_por_init(void)
 
 	/* Configure HPET Counter CLK period */
 	byte = pci_read_config8(dev, 0x43);
-	byte &= 0xF7;	/* unhide HPET regs */
+	byte &= 0xF7;						/* Unhide HPET regs */
 	pci_write_config8(dev, 0x43, byte);
-	pci_write_config32(dev, 0x34, 0x0429B17E ); /* Counter CLK period */
-	byte |= 0x08;	/* hide HPET regs */
+	if (set_sb700_revision() <= 0x12)
+		pci_write_config32(dev, 0x34, 0x0429b17e);	/* Counter CLK period */
+	else
+		pci_write_config32(dev, 0x34, 0xb0);		/* HPET_CNTRL = 0xb0 */
+	byte |= 0x08;						/* Hide HPET regs */
 	pci_write_config8(dev, 0x43, byte);
 
 	/* Features Enable */
@@ -669,6 +672,14 @@ static void sb700_pmio_por_init(void)
 	byte = pmio_read(0xbb);
 	byte |= 0xc0;
 	pmio_write(0xbb, byte);
+
+#if CONFIG_SOUTHBRIDGE_AMD_SUBTYPE_SP5100
+	/* Work around system clock drift issues */
+	byte = pmio_read(0xd4);
+	byte |= 0x1 << 6;	/* Enable alternate 14MHz clock source */
+	byte |= 0x1 << 7;	/* Disable 25MHz oscillator buffer */
+	pmio_write(0xd4, byte);
+#endif
 }
 
 /*