diff --git a/board/nvidia/cardhu/cardhu.c b/board/nvidia/cardhu/cardhu.c
index 08e9b7b..3544b41 100644
--- a/board/nvidia/cardhu/cardhu.c
+++ b/board/nvidia/cardhu/cardhu.c
@@ -25,6 +25,10 @@
 #include <asm/arch/pinmux.h>
 #include <asm/arch/gp_padctrl.h>
 #include "pinmux-config-cardhu.h"
+#include <i2c.h>
+
+#define PMU_I2C_ADDRESS		0x2D
+#define MAX_I2C_RETRY		3
 
 /*
  * Routine: pinmux_init
@@ -41,3 +45,50 @@
 	/* Initialize any non-default pad configs (APB_MISC_GP regs) */
 	padgrp_config_table(cardhu_padctrl, ARRAY_SIZE(cardhu_padctrl));
 }
+
+#if defined(CONFIG_TEGRA_MMC)
+/*
+ * Do I2C/PMU writes to bring up SD card bus power
+ *
+ */
+void board_sdmmc_voltage_init(void)
+{
+	uchar reg, data_buffer[1];
+	int i;
+
+	i2c_set_bus_num(0);	/* PMU is on bus 0 */
+
+	/* TPS659110: LDO5_REG = 3.3v, ACTIVE to SDMMC1 */
+	data_buffer[0] = 0x65;
+	reg = 0x32;
+
+	for (i = 0; i < MAX_I2C_RETRY; ++i) {
+		if (i2c_write(PMU_I2C_ADDRESS, reg, 1, data_buffer, 1))
+			udelay(100);
+	}
+
+	/* TPS659110: GPIO7_REG = PDEN, output a 1 to EN_3V3_SYS */
+	data_buffer[0] = 0x09;
+	reg = 0x67;
+
+	for (i = 0; i < MAX_I2C_RETRY; ++i) {
+		if (i2c_write(PMU_I2C_ADDRESS, reg, 1, data_buffer, 1))
+			udelay(100);
+	}
+}
+
+/*
+ * Routine: pin_mux_mmc
+ * Description: setup the MMC muxes, power rails, etc.
+ */
+void pin_mux_mmc(void)
+{
+	/*
+	 * NOTE: We don't do mmc-specific pin muxes here.
+	 * They were done globally in pinmux_init().
+	 */
+
+	/* Bring up the SDIO1 power rail */
+	board_sdmmc_voltage_init();
+}
+#endif	/* MMC */