[SerialICE] New patch to review for serialice: 7079bf3 southbridge/amd-sbxxx.c: Init clock to 48 MHz on AMD SB800

[Paul Menzel (paulepanter@users.sourceforge.net)]

Paul Menzel (paulepanter at users.sourceforge.net) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/5213

-gerrit

commit 7079bf382ee6e63a1adee9f8d038be21bfbcd904
Author: Paul Menzel <paulepanter at users.sourceforge.net>
Date:   Mon Jul 15 13:31:51 2013 +0200

    southbridge/amd-sbxxx.c: Init clock to 48 MHz on AMD SB800
    
    Copy the init from coreboot’s `src/southbridge/amd/cimx/sb800/bootblock.c`.
    
    Daniel Gröber showed my error in forgetting to actually enable the
    clock of 48 MHz so it did not work for me with 14 MHz.
    
    The Super I/O SMSC SCH311x needs 14 MHz so the Kconfig option is
    ported over.
    
    Change-Id: I9146d2c0620c2bb338130f55ead0704fa82075c7
    Signed-off-by: Daniel Gröber <dxld at darkboxed.org>
    Signed-off-by: Paul Menzel <paulepanter at users.sourceforge.net>
---
 SerialICE/southbridge/amd-sbxxx.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/SerialICE/southbridge/amd-sbxxx.c b/SerialICE/southbridge/amd-sbxxx.c
index 37dca92..99a7240 100644
--- a/SerialICE/southbridge/amd-sbxxx.c
+++ b/SerialICE/southbridge/amd-sbxxx.c
@@ -30,24 +30,28 @@
 #define SB_MMIO 0xFED80000
 #define SB_MMIO_MISC32(x) *(volatile u32 *)(SB_MMIO + 0xE00 + (x))
 
+
 static void sbxxx_enable_48mhzout(void)
 {
-	/* most likely programming to 48MHz out signal */
 	u32 reg32;
-	reg32 = SB_MMIO_MISC32(0x28);
-	reg32 &= 0xffc7ffff;
-	reg32 |= 0x00100000;
-	SB_MMIO_MISC32(0x28) = reg32;
 
+	// Program SB800 MiscClkCntrl register to configure clock output on the
+	// 14M_25M_48M_OSC ball usually used for the Super-I/O.
+	// Almost all SIOs need 48 MHz, only the SMSC SCH311x wants 14 MHz,
+	// which is the SB800's power up default.  We could switch back to 14
+	// in the mainboard's romstage.c, but then the clock frequency would
+	// change twice.
 	reg32 = SB_MMIO_MISC32(0x40);
-	reg32 &= ~0x80u;
+	reg32 &= ~((1 << 2) | (3 << 0)); // enable, 14 MHz (power up default)
+#if !CONFIG_SUPERIO_WANTS_14MHZ_CLOCK
+	reg32 |= 2 << 0; // Device_CLK1_sel = 48 MHz
+#endif
 	SB_MMIO_MISC32(0x40) = reg32;
 }
 
 static void southbridge_init(void)
 {
 	u8 reg8;
-	u32 reg32;
 
 	/* route FED00000 - FEDFFFFF as non-posted to SB */
 	pci_write_config32(PCI_ADDR(0, 0x18, 1, 0x84),
@@ -60,6 +64,13 @@ static void southbridge_init(void)
 	pci_write_config32(PCI_ADDR(0, 0x18, 1, 0xc4),  0x0000f000);
 	pci_write_config32(PCI_ADDR(0, 0x18, 1, 0xc0),  0x00000003);
 
+	// Program AcpiMmioEn to enable MMIO access to MiscCntrl register
+	outb(0x24, 0xcd6);
+	reg8 = inb(0xcd7);
+	reg8 |= 1;
+	reg8 &= ~(1 << 1);
+	outb(reg8, 0xcd7);
+
 	/* SB  MMIO range decode enable */
 	outb(0x24, 0xcd6);
 	outb(0x1, 0xcd7);