[coreboot-gerrit] Change in coreboot[master]: mb/ocp/deltalake: Override DDR frequency limit via VPD variable

[Tim Chu (Code Review)]

Tim Chu has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/48946 )

Change subject: mb/ocp/deltalake: Override DDR frequency limit via VPD variable
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mb/ocp/deltalake: Override DDR frequency limit via VPD variable

Use VPD variable "fsp_dimm_freq" to select DDR frequency limit.

Tested=On OCP Delta Lake, DDR frequency limit can be changed via VPD.

Signed-off-by: Tim Chu 
Change-Id: I1232feae5090420d8fa42596b46f2d4dcaf9d635
---
M src/mainboard/ocp/deltalake/romstage.c
M src/mainboard/ocp/deltalake/vpd.h
2 files changed, 26 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/46/48946/1

diff --git a/src/mainboard/ocp/deltalake/romstage.c b/src/mainboard/ocp/deltalake/romstage.c
index f0cdd3d..58ee968 100644
--- a/src/mainboard/ocp/deltalake/romstage.c
+++ b/src/mainboard/ocp/deltalake/romstage.c
@@ -75,6 +75,28 @@
    	printk(BIOS_DEBUG, "Setting MemRefreshWatermark %d from VPD\n", val);
    	mupd->FspmConfig.UnusedUpdSpace0[0] = val;
    }
+
+	/*
+	 * Select DDR Frequency Limit
+	 * 0x0:Auto, 0x5:DDR_1333, 0x7:DDR_1600, 0x9:DDR_1866, 0xb:DDR_2133, 0xd:DDR_2400,
+	 * 0xf:DDR_2666, 0x11:DDR_2933, 0x13:DDR_3200
+	 */
+	static const unsigned int limit[] = { 0x0, 0x5, 0x7, 0x9, 0xb, 0xd, 0xf, 0x11, 0x13};
+	if (vpd_gets(FSP_DIMM_FREQ, val_str, VPD_LEN, VPD_RW_THEN_RO)) {
+		val = (uint8_t)atol(val_str);
+		if (val > 8) {
+			printk(BIOS_DEBUG, "Invalid DdrFreqLimit value from VPD: "
+				"%d\n", val);
+			val = FSP_DIMM_FREQ_DEFAULT;
+		}
+		printk(BIOS_DEBUG, "Setting DdrFreqLimit %d from VPD\n", val);
+		mupd->FspmConfig.DdrFreqLimit = limit[val];
+	} else {
+		printk(BIOS_INFO, "Not able to get VPD %s, default set "
+			"DebugPrintLevel to %d\n", FSP_DIMM_FREQ,
+			FSP_DIMM_FREQ_DEFAULT);
+		mupd->FspmConfig.DdrFreqLimit = limit[FSP_DIMM_FREQ_DEFAULT];
+	}
 }

/* Update bifurcation settings according to different Configs */
diff --git a/src/mainboard/ocp/deltalake/vpd.h b/src/mainboard/ocp/deltalake/vpd.h
index 71a3b09..9246fb0 100644
--- a/src/mainboard/ocp/deltalake/vpd.h
+++ b/src/mainboard/ocp/deltalake/vpd.h
@@ -40,4 +40,8 @@
 #define FSPM_MEMREFRESHWATERMARK "fspm_mem_refresh_watermark"
 #define FSPM_MEMREFRESHWATERMARK_DEFAULT 1

+/* FSP dimm frequency limit, 0:Auto, 1:DDR_1333, 2:DDR_1600, 3:DDR_1866, 4:DDR_2133, 5:DDR_2400, 6:DDR_2666, 7:DDR_2933, 8:DDR_3200 */
+#define FSP_DIMM_FREQ "fsp_dimm_freq"
+#define FSP_DIMM_FREQ_DEFAULT 0
+
 #endif