diff --git a/board/gdsys/common/dp501.c b/board/gdsys/common/dp501.c
new file mode 100644
index 0000000..9aa4e3f
--- /dev/null
+++ b/board/gdsys/common/dp501.c
@@ -0,0 +1,107 @@
+/*
+ * (C) Copyright 2012
+ * Dirk Eibach,  Guntermann & Drunck GmbH, dirk.eibach@gdsys.cc
+ *
+ * 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
+ */
+
+/* Parade Technologies Inc. DP501 DisplayPort DVI/HDMI Transmitter */
+
+#include <common.h>
+#include <asm/io.h>
+#include <errno.h>
+#include <i2c.h>
+
+static void dp501_setbits(u8 addr, u8 reg, u8 mask)
+{
+	u8 val;
+
+	val = i2c_reg_read(addr, reg);
+	setbits_8(&val, mask);
+	i2c_reg_write(addr, reg, val);
+}
+
+static void dp501_clrbits(u8 addr, u8 reg, u8 mask)
+{
+	u8 val;
+
+	val = i2c_reg_read(addr, reg);
+	clrbits_8(&val, mask);
+	i2c_reg_write(addr, reg, val);
+}
+
+static int dp501_detect_cable_adapter(u8 addr)
+{
+	u8 val = i2c_reg_read(addr, 0x00);
+
+	return !(val & 0x04);
+}
+
+static void dp501_link_training(u8 addr)
+{
+	u8 val;
+
+	val = i2c_reg_read(addr, 0x51);
+	i2c_reg_write(addr, 0x5d, val); /* set link_bw */
+	val = i2c_reg_read(addr, 0x52);
+	i2c_reg_write(addr, 0x5e, val); /* set lane_cnt */
+	val = i2c_reg_read(addr, 0x53);
+	i2c_reg_write(addr, 0x5c, val); /* set downspread_ctl */
+
+	i2c_reg_write(addr, 0x5f, 0x0d); /* start training */
+}
+
+void dp501_powerup(u8 addr)
+{
+	dp501_clrbits(addr, 0x0a, 0x30); /* power on encoder */
+	i2c_reg_write(addr, 0x27, 0x30); /* Hardware auto detect DVO timing */
+	dp501_setbits(addr, 0x72, 0x80); /* DPCD read enable */
+	dp501_setbits(addr, 0x30, 0x20); /* RS polynomial select */
+	i2c_reg_write(addr, 0x71, 0x20); /* Enable Aux burst write */
+	dp501_setbits(addr, 0x78, 0x30); /* Disable HPD2 IRQ */
+	dp501_clrbits(addr, 0x2f, 0x40); /* Link FIFO reset selection */
+	i2c_reg_write(addr, 0x24, 0xc0); /* SDR mode 0, ext. H/VSYNC */
+	i2c_reg_write(addr + 2, 0x24, 0x02); /* clock input single ended */
+
+	if (dp501_detect_cable_adapter(addr)) {
+		printf("DVI/HDMI cable adapter detected\n");
+		i2c_reg_write(addr, 0x5e, 0x04); /* enable 4 channel */
+		dp501_clrbits(addr, 0x00, 0x08); /* DVI/HDMI HDCP operation */
+	} else {
+		printf("no DVI/HDMI cable adapter detected\n");
+		i2c_reg_write(addr + 2, 0x00, 0x18); /* driving strength */
+		i2c_reg_write(addr + 2, 0x03, 0x06); /* driving strength */
+		i2c_reg_write(addr, 0x2c, 0x00); /* configure N value */
+		i2c_reg_write(addr, 0x2d, 0x00); /* configure N value */
+		i2c_reg_write(addr, 0x2e, 0x0c); /* configure N value */
+		i2c_reg_write(addr, 0x76, 0xff); /* clear all interrupt */
+		dp501_setbits(addr, 0x78, 0x03); /* clear all interrupt */
+		i2c_reg_write(addr, 0x75, 0xf8); /* aux channel reset */
+		i2c_reg_write(addr, 0x75, 0x00); /* clear aux channel reset */
+		i2c_reg_write(addr, 0x87, 0x70); /* set retry counter as 7 */
+		dp501_setbits(addr, 0x00, 0x08); /* for DP HDCP operation */
+
+		dp501_link_training(addr);
+	}
+}
+
+void dp501_powerdown(u8 addr)
+{
+	dp501_setbits(addr, 0x0a, 0x30); /* power down encoder, standby mode */
+}