diff --git a/arch/arm/cpu/armv7/tegra2/Makefile b/arch/arm/cpu/armv7/tegra2/Makefile
index b35764c..f673f03 100644
--- a/arch/arm/cpu/armv7/tegra2/Makefile
+++ b/arch/arm/cpu/armv7/tegra2/Makefile
@@ -28,7 +28,7 @@
 LIB	=  $(obj)lib$(SOC).o
 
 SOBJS	:= lowlevel_init.o
-COBJS	:= ap20.o board.o clock.o sys_info.o timer.o
+COBJS	:= ap20.o board.o clock.o pinmux.o sys_info.o timer.o
 
 SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(COBJS) $(SOBJS))
diff --git a/arch/arm/cpu/armv7/tegra2/pinmux.c b/arch/arm/cpu/armv7/tegra2/pinmux.c
new file mode 100644
index 0000000..5594ab8
--- /dev/null
+++ b/arch/arm/cpu/armv7/tegra2/pinmux.c
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/* Tegra2 pin multiplexing functions */
+
+#include <asm/io.h>
+#include <asm/arch/tegra2.h>
+#include <asm/arch/pinmux.h>
+#include <common.h>
+
+
+void pinmux_set_tristate(enum pmux_pin pin, int enable)
+{
+	struct pmux_tri_ctlr *pmt = (struct pmux_tri_ctlr *)NV_PA_APB_MISC_BASE;
+	u32 *tri = &pmt->pmt_tri[TRISTATE_REG(pin)];
+	u32 reg;
+
+	reg = readl(tri);
+	if (enable)
+		reg |= TRISTATE_MASK(pin);
+	else
+		reg &= ~TRISTATE_MASK(pin);
+	writel(reg, tri);
+}
+
+void pinmux_tristate_enable(enum pmux_pin pin)
+{
+	pinmux_set_tristate(pin, 1);
+}
+
+void pinmux_tristate_disable(enum pmux_pin pin)
+{
+	pinmux_set_tristate(pin, 0);
+}
diff --git a/arch/arm/include/asm/arch-tegra2/pinmux.h b/arch/arm/include/asm/arch-tegra2/pinmux.h
index cce936d..b8a4753 100644
--- a/arch/arm/include/asm/arch-tegra2/pinmux.h
+++ b/arch/arm/include/asm/arch-tegra2/pinmux.h
@@ -24,6 +24,142 @@
 #ifndef _PINMUX_H_
 #define _PINMUX_H_
 
+/* Pins which we can set to tristate or normal */
+enum pmux_pin {
+	/* APB_MISC_PP_TRISTATE_REG_A_0 */
+	PIN_ATA,
+	PIN_ATB,
+	PIN_ATC,
+	PIN_ATD,
+	PIN_CDEV1,
+	PIN_CDEV2,
+	PIN_CSUS,
+	PIN_DAP1,
+
+	PIN_DAP2,
+	PIN_DAP3,
+	PIN_DAP4,
+	PIN_DTA,
+	PIN_DTB,
+	PIN_DTC,
+	PIN_DTD,
+	PIN_DTE,
+
+	PIN_GPU,
+	PIN_GPV,
+	PIN_I2CP,
+	PIN_IRTX,
+	PIN_IRRX,
+	PIN_KBCB,
+	PIN_KBCA,
+	PIN_PMC,
+
+	PIN_PTA,
+	PIN_RM,
+	PIN_KBCE,
+	PIN_KBCF,
+	PIN_GMA,
+	PIN_GMC,
+	PIN_SDMMC1,
+	PIN_OWC,
+
+	/* 32: APB_MISC_PP_TRISTATE_REG_B_0 */
+	PIN_GME,
+	PIN_SDC,
+	PIN_SDD,
+	PIN_RESERVED0,
+	PIN_SLXA,
+	PIN_SLXC,
+	PIN_SLXD,
+	PIN_SLXK,
+
+	PIN_SPDI,
+	PIN_SPDO,
+	PIN_SPIA,
+	PIN_SPIB,
+	PIN_SPIC,
+	PIN_SPID,
+	PIN_SPIE,
+	PIN_SPIF,
+
+	PIN_SPIG,
+	PIN_SPIH,
+	PIN_UAA,
+	PIN_UAB,
+	PIN_UAC,
+	PIN_UAD,
+	PIN_UCA,
+	PIN_UCB,
+
+	PIN_RESERVED1,
+	PIN_ATE,
+	PIN_KBCC,
+	PIN_RESERVED2,
+	PIN_RESERVED3,
+	PIN_GMB,
+	PIN_GMD,
+	PIN_DDC,
+
+	/* 64: APB_MISC_PP_TRISTATE_REG_C_0 */
+	PIN_LD0,
+	PIN_LD1,
+	PIN_LD2,
+	PIN_LD3,
+	PIN_LD4,
+	PIN_LD5,
+	PIN_LD6,
+	PIN_LD7,
+
+	PIN_LD8,
+	PIN_LD9,
+	PIN_LD10,
+	PIN_LD11,
+	PIN_LD12,
+	PIN_LD13,
+	PIN_LD14,
+	PIN_LD15,
+
+	PIN_LD16,
+	PIN_LD17,
+	PIN_LHP0,
+	PIN_LHP1,
+	PIN_LHP2,
+	PIN_LVP0,
+	PIN_LVP1,
+	PIN_HDINT,
+
+	PIN_LM0,
+	PIN_LM1,
+	PIN_LVS,
+	PIN_LSC0,
+	PIN_LSC1,
+	PIN_LSCK,
+	PIN_LDC,
+	PIN_LCSN,
+
+	/* 96: APB_MISC_PP_TRISTATE_REG_D_0 */
+	PIN_LSPI,
+	PIN_LSDA,
+	PIN_LSDI,
+	PIN_LPW0,
+	PIN_LPW1,
+	PIN_LPW2,
+	PIN_LDI,
+	PIN_LHS,
+
+	PIN_LPP,
+	PIN_RESERVED4,
+	PIN_KBCD,
+	PIN_GPU7,
+	PIN_DTF,
+	PIN_UDA,
+	PIN_CRTP,
+	PIN_SDB,
+};
+
+
+#define TEGRA_TRISTATE_REGS 4
+
 /* APB MISC Pin Mux and Tristate (APB_MISC_PP_) registers */
 struct pmux_tri_ctlr {
 	uint pmt_reserved0;		/* ABP_MISC_PP_ reserved offset 00 */
@@ -31,10 +167,7 @@
 	uint pmt_strap_opt_a;		/* _STRAPPING_OPT_A_0, offset 08 */
 	uint pmt_reserved2;		/* ABP_MISC_PP_ reserved offset 0C */
 	uint pmt_reserved3;		/* ABP_MISC_PP_ reserved offset 10 */
-	uint pmt_tri_a;			/* _TRI_STATE_REG_A_0, offset 14 */
-	uint pmt_tri_b;			/* _TRI_STATE_REG_B_0, offset 18 */
-	uint pmt_tri_c;			/* _TRI_STATE_REG_C_0, offset 1C */
-	uint pmt_tri_d;			/* _TRI_STATE_REG_D_0, offset 20 */
+	uint pmt_tri[TEGRA_TRISTATE_REGS]; /* _TRI_STATE_REG_A/B/C/D_0 14-20 */
 	uint pmt_cfg_ctl;		/* _CONFIG_CTL_0, offset 24 */
 
 	uint pmt_reserved[22];		/* ABP_MISC_PP_ reserved offs 28-7C */
@@ -48,14 +181,16 @@
 	uint pmt_ctl_g;			/* _PIN_MUX_CTL_G_0, offset 98 */
 };
 
+/* Converts a pin number to a tristate register: 0=A, 1=B, 2=C, 3=D */
+#define TRISTATE_REG(id) ((id) >> 5)
+
+/* Mask value for a tristate (within TRISTATE_REG(id)) */
+#define TRISTATE_MASK(id) (1 << ((id) & 0x1f))
+
+/* Set a pin to tristate */
+void pinmux_tristate_enable(enum pmux_pin pin);
+
-#define Z_GMC			(1 << 29)
-#define Z_IRRX			(1 << 20)
-#define Z_IRTX			(1 << 19)
-#define Z_GMA			(1 << 28)
-#define Z_GME			(1 << 0)
-#define Z_ATB			(1 << 1)
-#define Z_SDB			(1 << 15)
-#define Z_SDC			(1 << 1)
-#define Z_SDD			(1 << 2)
+/* Set a pin to normal (non tristate) */
+void pinmux_tristate_disable(enum pmux_pin pin);
 
 #endif	/* PINMUX_H */
diff --git a/board/nvidia/common/board.c b/board/nvidia/common/board.c
index 945141e..799dd3a 100644
--- a/board/nvidia/common/board.c
+++ b/board/nvidia/common/board.c
@@ -143,19 +143,15 @@
 	reg &= 0xFFF0FFFF;	/* IRRX_/IRTX_SEL [19:16] = 00 UARTA */
 	writel(reg, &pmt->pmt_ctl_c);
 
-	reg = readl(&pmt->pmt_tri_a);
-	reg &= ~Z_IRRX;		/* Z_IRRX = normal (0) */
-	reg &= ~Z_IRTX;		/* Z_IRTX = normal (0) */
-	writel(reg, &pmt->pmt_tri_a);
+	pinmux_tristate_disable(PIN_IRRX);
+	pinmux_tristate_disable(PIN_IRTX);
 #endif	/* CONFIG_TEGRA2_ENABLE_UARTA */
 #if defined(CONFIG_TEGRA2_ENABLE_UARTD)
 	reg = readl(&pmt->pmt_ctl_b);
 	reg &= 0xFFFFFFF3;	/* GMC_SEL [3:2] = 00, UARTD */
 	writel(reg, &pmt->pmt_ctl_b);
 
-	reg = readl(&pmt->pmt_tri_a);
-	reg &= ~Z_GMC;		/* Z_GMC = normal (0) */
-	writel(reg, &pmt->pmt_tri_a);
+	pinmux_tristate_disable(PIN_GMC);
 #endif	/* CONFIG_TEGRA2_ENABLE_UARTD */
 }
 
@@ -222,13 +218,9 @@
 	reg |= (3 << 0);	/* GME_SEL [1:0] = 11 SDIO4 */
 	writel(reg, &pmt->pmt_ctl_d);
 
-	reg = readl(&pmt->pmt_tri_a);
-	reg &= ~Z_ATB;		/* Z_ATB = normal (0) */
-	reg &= ~Z_GMA;		/* Z_GMA = normal (0) */
-	writel(reg, &pmt->pmt_tri_a);
-	reg = readl(&pmt->pmt_tri_b);
-	reg &= ~Z_GME;		/* Z_GME = normal (0) */
-	writel(reg, &pmt->pmt_tri_b);
+	pinmux_tristate_disable(PIN_ATB);
+	pinmux_tristate_disable(PIN_GMA);
+	pinmux_tristate_disable(PIN_GME);
 
 	/* SDMMC3 */
 	/* SDIO3_CLK, SDIO3_CMD, SDIO3_DAT[3:0] */
@@ -239,13 +231,9 @@
 	reg |= (2 << 14);	/* SDD_SEL [15:14] = 01 SDIO3 */
 	writel(reg, &pmt->pmt_ctl_d);
 
-	reg = readl(&pmt->pmt_tri_b);
-	reg &= ~Z_SDC;		/* Z_SDC = normal (0) */
-	reg &= ~Z_SDD;		/* Z_SDD = normal (0) */
-	writel(reg, &pmt->pmt_tri_b);
-	reg = readl(&pmt->pmt_tri_d);
-	reg &= ~Z_SDB;		/* Z_SDB = normal (0) */
-	writel(reg, &pmt->pmt_tri_d);
+	pinmux_tristate_disable(PIN_SDC);
+	pinmux_tristate_disable(PIN_SDD);
+	pinmux_tristate_disable(PIN_SDB);
 }
 
 /*