Following patch will setup KT890 HT automatically. It will find the

max width of the link and also it will take the frequency of K8 HT
already done coreboot (and checks if t can run on it).

Signed-off-by: Rudolf Marek <r.marek@assembler.cz>

Acked-by: Uwe Hermann <uwe@hermann-uwe.de>



git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3169 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

1 files changed, 55 insertions, 19 deletions

diff --git a/src/southbridge/via/k8t890/k8t890_early_car.c b/src/southbridge/via/k8t890/k8t890_early_car.c
index 6faeabbd0b..a14e2a2715 100644
--- a/src/southbridge/via/k8t890/k8t890_early_car.c
+++ b/src/southbridge/via/k8t890/k8t890_early_car.c
@@ -22,35 +22,71 @@
  * generate PCI reset or LDTSTOP to apply.
  */
 
-u8 k8t890_early_setup_car(u8 width, u8 speed)
-{
-	u8 awidth, aspeed;
+#include <stdlib.h>
 
-	print_debug("LDT width and speed for K8T890 was");
-	awidth = pci_read_config8(PCI_DEV(0, 0x0, 0), 0x67);
-	print_debug_hex8(awidth);
+/* AMD K8 LDT0, LDT1, LDT2 Link Control Registers */
+static ldtreg[3] = {0x86, 0xa6, 0xc6};
 
-	aspeed = pci_read_config8(PCI_DEV(0, 0x0, 0), 0x6d);
-	print_debug_hex8(aspeed);
+/* This functions sets KT890 link frequency and width to same values as
+ * it has been setup on K8 side, by AMD NB init.
+ */ 
 
-	if ((aspeed == speed) && (((width == 16) && (awidth == 0x11)) ||
-				  ((width == 8) && (awidth == 0x00))))
-		return 0;
+u8 k8t890_early_setup_ht(void)
+{
+	u8 awidth, afreq, cldtfreq; 
+	u8 cldtwidth_in, cldtwidth_out, vldtwidth_in, vldtwidth_out, ldtnr, width;
+	u16 vldtcaps;
+
+	/* check if connected non coherent, initcomplete (find the SB on K8 side) */
+	if (0x7 == pci_read_config8(PCI_DEV(0, 0x18, 0), 0x98)) {
+		ldtnr = 0;
+	} else if (0x7 == pci_read_config8(PCI_DEV(0, 0x18, 0), 0xb8)) {
+		ldtnr = 1;
+	} else if (0x7 == pci_read_config8(PCI_DEV(0, 0x18, 0), 0xd8)) {
+		ldtnr = 2;
+	}
+
+	print_debug("K8T890 found at LDT ");
+	print_debug_hex8(ldtnr);
 
-	/* Update the desired HT LNK capabilities in NB too. */
-	pci_write_config8(PCI_DEV(0, 0x0, 0), 0x67,
-			  (width == 16) ? 0x11 : 0x00);
-	pci_write_config8(PCI_DEV(0, 0x0, 0), 0x6d, speed);
+	/* get the maximum widths for both sides */
+	cldtwidth_in = pci_read_config8(PCI_DEV(0, 0x18, 0), ldtreg[ldtnr]) & 0x7;
+	cldtwidth_out = (pci_read_config8(PCI_DEV(0, 0x18, 0), ldtreg[ldtnr]) >> 4) & 0x7;
+	vldtwidth_in = pci_read_config8(PCI_DEV(0, 0x0, 0), 0x66) & 0x7;
+	vldtwidth_out = (pci_read_config8(PCI_DEV(0, 0x0, 0), 0x66) >> 4) & 0x7;
 
-	print_debug(" and will after HT reset: ");
+	width = MIN(MIN(MIN(cldtwidth_out, cldtwidth_in), vldtwidth_out), vldtwidth_in);
+	print_debug(" Agreed on width: ");
+	print_debug_hex8(width);
 
 	awidth = pci_read_config8(PCI_DEV(0, 0x0, 0), 0x67);
-	print_debug_hex8(awidth);
 
-	aspeed = pci_read_config8(PCI_DEV(0, 0x0, 0), 0x6d);
-	print_debug_hex8(aspeed);
+	/* Update the desired HT LNK to match AMD NB max from VIA NB is 0x1 */
+	width = (width == 0x01) ? 0x11 : 0x00;
 
+	pci_write_config8(PCI_DEV(0, 0x0, 0), 0x67, width);
+
+	/* Get programmed HT freq at base 0x89 */
+	cldtfreq = pci_read_config8(PCI_DEV(0, 0x18, 0), ldtreg[ldtnr] + 3) & 0xf;
+	print_debug(" CPU programmed to HT freq: ");
+	print_debug_hex8(cldtfreq);
+
+	print_debug(" VIA HT caps: ");
+	vldtcaps = pci_read_config16(PCI_DEV(0, 0, 0), 0x6e);
+	print_debug_hex16(vldtcaps);
+
+	if (!(vldtcaps & (1 << cldtfreq ))) {
+		die("Chipset does not support desired HT frequency\n");
+	}
+
+	afreq = pci_read_config8(PCI_DEV(0, 0x0, 0), 0x6d);
+	pci_write_config8(PCI_DEV(0, 0x0, 0), 0x6d, cldtfreq);
 	print_debug("\n");
 
+	/* no reset needed */
+	if ((width == awidth) && (afreq == cldtfreq)) {
+		return 0;
+	}
+
 	return 1;
 }