[coreboot] [patch] asus m2v: Set DDR2 voltage to 1.8V
Tobias Diedrich
ranma+coreboot at tdiedrich.de
Fri Nov 12 21:42:52 CET 2010
Set DDR2 voltage to 1.8V
The power-on default is 1.95V, set the DDR2 voltage to
standards-conforming 1.8V.
I also measured with a multimeter to confirm this.
Signed-off-by: Tobias Diedrich <ranma+coreboot at tdiedrich.de>
---
Index: src/mainboard/asus/m2v/romstage.c
===================================================================
--- src/mainboard/asus/m2v/romstage.c.orig 2010-11-12 21:35:25.000000000 +0100
+++ src/mainboard/asus/m2v/romstage.c 2010-11-12 21:35:42.000000000 +0100
@@ -194,6 +194,19 @@
giv++;
}
it8712f_exit_conf();
+
+ printk(BIOS_INFO, "it8712f gpio: Setting DDR2 voltage to 1.80V\n");
+ /*
+ * upper two bits of gpio_base+4 control ddr2 voltage:
+ * 11: 1.80V
+ * 01: 1.85V
+ * 10: 1.90V
+ * 00: 1.95V
+ *
+ * The lower six bits are inputs and normally read back as 1
+ * (except bit 2, which seems rather random).
+ */
+ outb(0xff, IT8712F_GPIO_BASE+4);
}
static void m2v_bus_init(void)
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