viafb: dvi.c, dvi.h, global.c and global.h

dvi.c, dvi.h: TMDS generic process and setting.
global.c, global.h: define global variabls.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Joseph Chan <josephchan@via.com.tw>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 682 insertions, 0 deletions

diff --git a/drivers/video/via/dvi.c b/drivers/video/via/dvi.c
new file mode 100644
index 00000000000..d6965447ca6
--- /dev/null
+++ b/drivers/video/via/dvi.c
@@ -0,0 +1,682 @@
+/*
+ * Copyright 1998-2008 VIA Technologies, Inc. All Rights Reserved.
+ * Copyright 2001-2008 S3 Graphics, Inc. All Rights Reserved.
+
+ * 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, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTIES OR REPRESENTATIONS; 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.
+ */
+#include "global.h"
+
+static void tmds_register_write(int index, u8 data);
+static int tmds_register_read(int index);
+static int tmds_register_read_bytes(int index, u8 *buff, int buff_len);
+static int check_reduce_blanking_mode(int mode_index,
+	int refresh_rate);
+static int dvi_get_panel_size_from_DDCv1(void);
+static int dvi_get_panel_size_from_DDCv2(void);
+static unsigned char dvi_get_panel_info(void);
+static int viafb_dvi_query_EDID(void);
+
+static int check_tmds_chip(int device_id_subaddr, int device_id)
+{
+	if (tmds_register_read(device_id_subaddr) == device_id)
+		return OK;
+	else
+		return FAIL;
+}
+
+void viafb_init_dvi_size(void)
+{
+	DEBUG_MSG(KERN_INFO "viafb_init_dvi_size()\n");
+	DEBUG_MSG(KERN_INFO
+		"viaparinfo->tmds_setting_info->get_dvi_size_method %d\n",
+		  viaparinfo->tmds_setting_info->get_dvi_size_method);
+
+	switch (viaparinfo->tmds_setting_info->get_dvi_size_method) {
+	case GET_DVI_SIZE_BY_SYSTEM_BIOS:
+		break;
+	case GET_DVI_SZIE_BY_HW_STRAPPING:
+		break;
+	case GET_DVI_SIZE_BY_VGA_BIOS:
+	default:
+		dvi_get_panel_info();
+		break;
+	}
+	return;
+}
+
+int viafb_tmds_trasmitter_identify(void)
+{
+	unsigned char sr2a = 0, sr1e = 0, sr3e = 0;
+
+	/* Turn on ouputting pad */
+	switch (viaparinfo->chip_info->gfx_chip_name) {
+	case UNICHROME_K8M890:
+	    /*=* DFP Low Pad on *=*/
+		sr2a = viafb_read_reg(VIASR, SR2A);
+		viafb_write_reg_mask(SR2A, VIASR, 0x03, BIT0 + BIT1);
+		break;
+
+	case UNICHROME_P4M900:
+	case UNICHROME_P4M890:
+		/* DFP Low Pad on */
+		sr2a = viafb_read_reg(VIASR, SR2A);
+		viafb_write_reg_mask(SR2A, VIASR, 0x03, BIT0 + BIT1);
+		/* DVP0 Pad on */
+		sr1e = viafb_read_reg(VIASR, SR1E);
+		viafb_write_reg_mask(SR1E, VIASR, 0xC0, BIT6 + BIT7);
+		break;
+
+	default:
+	    /* DVP0/DVP1 Pad on */
+		sr1e = viafb_read_reg(VIASR, SR1E);
+		viafb_write_reg_mask(SR1E, VIASR, 0xF0, BIT4 +
+			BIT5 + BIT6 + BIT7);
+	    /* SR3E[1]Multi-function selection:
+	    0 = Emulate I2C and DDC bus by GPIO2/3/4. */
+		sr3e = viafb_read_reg(VIASR, SR3E);
+		viafb_write_reg_mask(SR3E, VIASR, 0x0, BIT5);
+		break;
+	}
+
+	/* Check for VT1632: */
+	viaparinfo->chip_info->tmds_chip_info.tmds_chip_name = VT1632_TMDS;
+	viaparinfo->chip_info->
+		tmds_chip_info.tmds_chip_slave_addr = VT1632_TMDS_I2C_ADDR;
+	viaparinfo->chip_info->tmds_chip_info.i2c_port = I2CPORTINDEX;
+	if (check_tmds_chip(VT1632_DEVICE_ID_REG, VT1632_DEVICE_ID) != FAIL) {
+		/*
+		 * Currently only support 12bits,dual edge,add 24bits mode later
+		 */
+		tmds_register_write(0x08, 0x3b);
+
+		DEBUG_MSG(KERN_INFO "\n VT1632 TMDS ! \n");
+		DEBUG_MSG(KERN_INFO "\n %2d",
+			  viaparinfo->chip_info->tmds_chip_info.tmds_chip_name);
+		DEBUG_MSG(KERN_INFO "\n %2d",
+			  viaparinfo->chip_info->tmds_chip_info.i2c_port);
+		return OK;
+	} else {
+		viaparinfo->chip_info->tmds_chip_info.i2c_port = GPIOPORTINDEX;
+		if (check_tmds_chip(VT1632_DEVICE_ID_REG, VT1632_DEVICE_ID)
+		    != FAIL) {
+			tmds_register_write(0x08, 0x3b);
+			DEBUG_MSG(KERN_INFO "\n VT1632 TMDS ! \n");
+			DEBUG_MSG(KERN_INFO "\n %2d",
+				  viaparinfo->chip_info->
+				  tmds_chip_info.tmds_chip_name);
+			DEBUG_MSG(KERN_INFO "\n %2d",
+				  viaparinfo->chip_info->
+				  tmds_chip_info.i2c_port);
+			return OK;
+		}
+	}
+
+	viaparinfo->chip_info->tmds_chip_info.tmds_chip_name = INTEGRATED_TMDS;
+
+	if ((viaparinfo->chip_info->gfx_chip_name == UNICHROME_CX700) &&
+	    ((viafb_display_hardware_layout == HW_LAYOUT_DVI_ONLY) ||
+	     (viafb_display_hardware_layout == HW_LAYOUT_LCD_DVI))) {
+		DEBUG_MSG(KERN_INFO "\n Integrated TMDS ! \n");
+		return OK;
+	}
+
+	switch (viaparinfo->chip_info->gfx_chip_name) {
+	case UNICHROME_K8M890:
+		viafb_write_reg(SR2A, VIASR, sr2a);
+		break;
+
+	case UNICHROME_P4M900:
+	case UNICHROME_P4M890:
+		viafb_write_reg(SR2A, VIASR, sr2a);
+		viafb_write_reg(SR1E, VIASR, sr1e);
+		break;
+
+	default:
+		viafb_write_reg(SR1E, VIASR, sr1e);
+		viafb_write_reg(SR3E, VIASR, sr3e);
+		break;
+	}
+
+	viaparinfo->chip_info->
+		tmds_chip_info.tmds_chip_name = NON_TMDS_TRANSMITTER;
+	viaparinfo->chip_info->tmds_chip_info.
+		tmds_chip_slave_addr = VT1632_TMDS_I2C_ADDR;
+	return FAIL;
+}
+
+static void tmds_register_write(int index, u8 data)
+{
+	viaparinfo->i2c_stuff.i2c_port =
+		viaparinfo->chip_info->tmds_chip_info.i2c_port;
+
+	viafb_i2c_writebyte(viaparinfo->chip_info->tmds_chip_info.
+		tmds_chip_slave_addr, index,
+		     data);
+}
+
+static int tmds_register_read(int index)
+{
+	u8 data;
+
+	viaparinfo->i2c_stuff.i2c_port =
+		viaparinfo->chip_info->tmds_chip_info.i2c_port;
+	viafb_i2c_readbyte((u8) viaparinfo->chip_info->
+	    tmds_chip_info.tmds_chip_slave_addr,
+			(u8) index, &data);
+	return data;
+}
+
+static int tmds_register_read_bytes(int index, u8 *buff, int buff_len)
+{
+	viaparinfo->i2c_stuff.i2c_port =
+		viaparinfo->chip_info->tmds_chip_info.i2c_port;
+	viafb_i2c_readbytes((u8) viaparinfo->chip_info->tmds_chip_info.
+			 tmds_chip_slave_addr, (u8) index, buff, buff_len);
+	return 0;
+}
+
+static int check_reduce_blanking_mode(int mode_index,
+	int refresh_rate)
+{
+	if (refresh_rate != 60)
+		return false;
+
+	switch (mode_index) {
+		/* Following modes have reduce blanking mode. */
+	case VIA_RES_1360X768:
+	case VIA_RES_1400X1050:
+	case VIA_RES_1440X900:
+	case VIA_RES_1600X900:
+	case VIA_RES_1680X1050:
+	case VIA_RES_1920X1080:
+	case VIA_RES_1920X1200:
+		break;
+
+	default:
+		DEBUG_MSG(KERN_INFO
+			  "This dvi mode %d have no reduce blanking mode!\n",
+			  mode_index);
+		return false;
+	}
+
+	return true;
+}
+
+/* DVI Set Mode */
+void viafb_dvi_set_mode(int video_index, int mode_bpp, int set_iga)
+{
+	struct VideoModeTable *videoMode = NULL;
+	struct crt_mode_table *pDviTiming;
+	unsigned long desirePixelClock, maxPixelClock;
+	int status = 0;
+	videoMode = viafb_get_modetbl_pointer(video_index);
+	pDviTiming = videoMode->crtc;
+	desirePixelClock = pDviTiming->clk / 1000000;
+	maxPixelClock = (unsigned long)viaparinfo->
+		tmds_setting_info->max_pixel_clock;
+
+	DEBUG_MSG(KERN_INFO "\nDVI_set_mode!!\n");
+
+	if ((maxPixelClock != 0) && (desirePixelClock > maxPixelClock)) {
+		/*Check if reduce-blanking mode is exist */
+		status =
+		    check_reduce_blanking_mode(video_index,
+					       pDviTiming->refresh_rate);
+		if (status) {
+			video_index += 100;	/*Use reduce-blanking mode */
+			videoMode = viafb_get_modetbl_pointer(video_index);
+			pDviTiming = videoMode->crtc;
+			DEBUG_MSG(KERN_INFO
+				  "DVI use reduce blanking mode %d!!\n",
+				  video_index);
+		}
+	}
+	viafb_fill_crtc_timing(pDviTiming, video_index, mode_bpp / 8, set_iga);
+	viafb_set_output_path(DEVICE_DVI, set_iga,
+			viaparinfo->chip_info->tmds_chip_info.output_interface);
+}
+
+/* Sense DVI Connector */
+int viafb_dvi_sense(void)
+{
+	u8 RegSR1E = 0, RegSR3E = 0, RegCR6B = 0, RegCR91 = 0,
+		RegCR93 = 0, RegCR9B = 0, data;
+	int ret = false;
+
+	DEBUG_MSG(KERN_INFO "viafb_dvi_sense!!\n");
+
+	if (viaparinfo->chip_info->gfx_chip_name == UNICHROME_CLE266) {
+		/* DI1 Pad on */
+		RegSR1E = viafb_read_reg(VIASR, SR1E);
+		viafb_write_reg(SR1E, VIASR, RegSR1E | 0x30);
+
+		/* CR6B[0]VCK Input Selection: 1 = External clock. */
+		RegCR6B = viafb_read_reg(VIACR, CR6B);
+		viafb_write_reg(CR6B, VIACR, RegCR6B | 0x08);
+
+		/* CR91[4] VDD On [3] Data On [2] VEE On [1] Back Light Off
+		   [0] Software Control Power Sequence */
+		RegCR91 = viafb_read_reg(VIACR, CR91);
+		viafb_write_reg(CR91, VIACR, 0x1D);
+
+		/* CR93[7] DI1 Data Source Selection: 1 = DSP2.
+		   CR93[5] DI1 Clock Source: 1 = internal.
+		   CR93[4] DI1 Clock Polarity.
+		   CR93[3:1] DI1 Clock Adjust. CR93[0] DI1 enable */
+		RegCR93 = viafb_read_reg(VIACR, CR93);
+		viafb_write_reg(CR93, VIACR, 0x01);
+	} else {
+		/* DVP0/DVP1 Pad on */
+		RegSR1E = viafb_read_reg(VIASR, SR1E);
+		viafb_write_reg(SR1E, VIASR, RegSR1E | 0xF0);
+
+		/* SR3E[1]Multi-function selection:
+		   0 = Emulate I2C and DDC bus by GPIO2/3/4. */
+		RegSR3E = viafb_read_reg(VIASR, SR3E);
+		viafb_write_reg(SR3E, VIASR, RegSR3E & (~0x20));
+
+		/* CR91[4] VDD On [3] Data On [2] VEE On [1] Back Light Off
+		   [0] Software Control Power Sequence */
+		RegCR91 = viafb_read_reg(VIACR, CR91);
+		viafb_write_reg(CR91, VIACR, 0x1D);
+
+		/*CR9B[4] DVP1 Data Source Selection: 1 = From secondary
+		display.CR9B[2:0] DVP1 Clock Adjust */
+		RegCR9B = viafb_read_reg(VIACR, CR9B);
+		viafb_write_reg(CR9B, VIACR, 0x01);
+	}
+
+	data = (u8) tmds_register_read(0x09);
+	if (data & 0x04)
+		ret = true;
+
+	if (ret == false) {
+		if (viafb_dvi_query_EDID())
+			ret = true;
+	}
+
+	/* Restore status */
+	viafb_write_reg(SR1E, VIASR, RegSR1E);
+	viafb_write_reg(CR91, VIACR, RegCR91);
+	if (viaparinfo->chip_info->gfx_chip_name == UNICHROME_CLE266) {
+		viafb_write_reg(CR6B, VIACR, RegCR6B);
+		viafb_write_reg(CR93, VIACR, RegCR93);
+	} else {
+		viafb_write_reg(SR3E, VIASR, RegSR3E);
+		viafb_write_reg(CR9B, VIACR, RegCR9B);
+	}
+
+	return ret;
+}
+
+/* Query Flat Panel's EDID Table Version Through DVI Connector */
+static int viafb_dvi_query_EDID(void)
+{
+	u8 data0, data1;
+	int restore;
+
+	DEBUG_MSG(KERN_INFO "viafb_dvi_query_EDID!!\n");
+
+	restore = viaparinfo->chip_info->tmds_chip_info.tmds_chip_slave_addr;
+	viaparinfo->chip_info->tmds_chip_info.tmds_chip_slave_addr = 0xA0;
+
+	data0 = (u8) tmds_register_read(0x00);
+	data1 = (u8) tmds_register_read(0x01);
+	if ((data0 == 0) && (data1 == 0xFF)) {
+		viaparinfo->chip_info->
+			tmds_chip_info.tmds_chip_slave_addr = restore;
+		return EDID_VERSION_1;	/* Found EDID1 Table */
+	}
+
+	data0 = (u8) tmds_register_read(0x00);
+	viaparinfo->chip_info->tmds_chip_info.tmds_chip_slave_addr = restore;
+	if (data0 == 0x20)
+		return EDID_VERSION_2;	/* Found EDID2 Table */
+	else
+		return false;
+}
+
+/*
+ *
+ * int dvi_get_panel_size_from_DDCv1(void)
+ *
+ *     - Get Panel Size Using EDID1 Table
+ *
+ * Return Type:    int
+ *
+ */
+static int dvi_get_panel_size_from_DDCv1(void)
+{
+	int i, max_h = 0, max_v = 0, tmp, restore;
+	unsigned char rData;
+	unsigned char EDID_DATA[18];
+
+	DEBUG_MSG(KERN_INFO "\n dvi_get_panel_size_from_DDCv1 \n");
+
+	restore = viaparinfo->chip_info->tmds_chip_info.tmds_chip_slave_addr;
+	viaparinfo->chip_info->tmds_chip_info.tmds_chip_slave_addr = 0xA0;
+
+	rData = tmds_register_read(0x23);
+	if (rData & 0x3C)
+		max_h = 640;
+	if (rData & 0xC0)
+		max_h = 720;
+	if (rData & 0x03)
+		max_h = 800;
+
+	rData = tmds_register_read(0x24);
+	if (rData & 0xC0)
+		max_h = 800;
+	if (rData & 0x1E)
+		max_h = 1024;
+	if (rData & 0x01)
+		max_h = 1280;
+
+	for (i = 0x25; i < 0x6D; i++) {
+		switch (i) {
+		case 0x26:
+		case 0x28:
+		case 0x2A:
+		case 0x2C:
+		case 0x2E:
+		case 0x30:
+		case 0x32:
+		case 0x34:
+			rData = tmds_register_read(i);
+			if (rData == 1)
+				break;
+			/* data = (data + 31) * 8 */
+			tmp = (rData + 31) << 3;
+			if (tmp > max_h)
+				max_h = tmp;
+			break;
+
+		case 0x36:
+		case 0x48:
+		case 0x5A:
+		case 0x6C:
+			tmds_register_read_bytes(i, EDID_DATA, 10);
+			if (!(EDID_DATA[0] || EDID_DATA[1])) {
+				/* The first two byte must be zero. */
+				if (EDID_DATA[3] == 0xFD) {
+					/* To get max pixel clock. */
+					viaparinfo->tmds_setting_info->
+					max_pixel_clock = EDID_DATA[9] * 10;
+				}
+			}
+			break;
+
+		default:
+			break;
+		}
+	}
+
+	switch (max_h) {
+	case 640:
+		viaparinfo->tmds_setting_info->dvi_panel_size =
+			VIA_RES_640X480;
+		break;
+	case 800:
+		viaparinfo->tmds_setting_info->dvi_panel_size =
+			VIA_RES_800X600;
+		break;
+	case 1024:
+		viaparinfo->tmds_setting_info->dvi_panel_size =
+			VIA_RES_1024X768;
+		break;
+	case 1280:
+		viaparinfo->tmds_setting_info->dvi_panel_size =
+			VIA_RES_1280X1024;
+		break;
+	case 1400:
+		viaparinfo->tmds_setting_info->dvi_panel_size =
+			VIA_RES_1400X1050;
+		break;
+	case 1440:
+		viaparinfo->tmds_setting_info->dvi_panel_size =
+			VIA_RES_1440X1050;
+		break;
+	case 1600:
+		viaparinfo->tmds_setting_info->dvi_panel_size =
+			VIA_RES_1600X1200;
+		break;
+	case 1920:
+		if (max_v == 1200) {
+			viaparinfo->tmds_setting_info->dvi_panel_size =
+				VIA_RES_1920X1200;
+		} else {
+			viaparinfo->tmds_setting_info->dvi_panel_size =
+				VIA_RES_1920X1080;
+		}
+
+		break;
+	default:
+		viaparinfo->tmds_setting_info->dvi_panel_size =
+			VIA_RES_1024X768;
+		DEBUG_MSG(KERN_INFO "Unknow panel size max resolution = %d !\
+					 set default panel size.\n", max_h);
+		break;
+	}
+
+	DEBUG_MSG(KERN_INFO "DVI max pixelclock = %d\n",
+		  viaparinfo->tmds_setting_info->max_pixel_clock);
+	viaparinfo->chip_info->tmds_chip_info.tmds_chip_slave_addr = restore;
+	return viaparinfo->tmds_setting_info->dvi_panel_size;
+}
+
+/*
+ *
+ * int dvi_get_panel_size_from_DDCv2(void)
+ *
+ *     - Get Panel Size Using EDID2 Table
+ *
+ * Return Type:    int
+ *
+ */
+static int dvi_get_panel_size_from_DDCv2(void)
+{
+	int HSize = 0, restore;
+	unsigned char R_Buffer[2];
+
+	DEBUG_MSG(KERN_INFO "\n dvi_get_panel_size_from_DDCv2 \n");
+
+	restore = viaparinfo->chip_info->tmds_chip_info.tmds_chip_slave_addr;
+	viaparinfo->chip_info->tmds_chip_info.tmds_chip_slave_addr = 0xA2;
+
+	/* Horizontal: 0x76, 0x77 */
+	tmds_register_read_bytes(0x76, R_Buffer, 2);
+	HSize = R_Buffer[0];
+	HSize += R_Buffer[1] << 8;
+
+	switch (HSize) {
+	case 640:
+		viaparinfo->tmds_setting_info->dvi_panel_size =
+			VIA_RES_640X480;
+		break;
+	case 800:
+		viaparinfo->tmds_setting_info->dvi_panel_size =
+			VIA_RES_800X600;
+		break;
+	case 1024:
+		viaparinfo->tmds_setting_info->dvi_panel_size =
+			VIA_RES_1024X768;
+		break;
+	case 1280:
+		viaparinfo->tmds_setting_info->dvi_panel_size =
+			VIA_RES_1280X1024;
+		break;
+	case 1400:
+		viaparinfo->tmds_setting_info->dvi_panel_size =
+			VIA_RES_1400X1050;
+		break;
+	case 1440:
+		viaparinfo->tmds_setting_info->dvi_panel_size =
+			VIA_RES_1440X1050;
+		break;
+	case 1600:
+		viaparinfo->tmds_setting_info->dvi_panel_size =
+			VIA_RES_1600X1200;
+		break;
+	default:
+		viaparinfo->tmds_setting_info->dvi_panel_size =
+			VIA_RES_1024X768;
+		DEBUG_MSG(KERN_INFO "Unknow panel size max resolution = %d!\
+					set default panel size.\n", HSize);
+		break;
+	}
+
+	viaparinfo->chip_info->tmds_chip_info.tmds_chip_slave_addr = restore;
+	return viaparinfo->tmds_setting_info->dvi_panel_size;
+}
+
+/*
+ *
+ * unsigned char dvi_get_panel_info(void)
+ *
+ *     - Get Panel Size
+ *
+ * Return Type:    unsigned char
+ */
+static unsigned char dvi_get_panel_info(void)
+{
+	unsigned char dvipanelsize;
+	DEBUG_MSG(KERN_INFO "dvi_get_panel_info! \n");
+
+	viafb_dvi_sense();
+	switch (viafb_dvi_query_EDID()) {
+	case 1:
+		dvi_get_panel_size_from_DDCv1();
+		break;
+	case 2:
+		dvi_get_panel_size_from_DDCv2();
+		break;
+	default:
+		break;
+	}
+
+	DEBUG_MSG(KERN_INFO "dvi panel size is %2d \n",
+		  viaparinfo->tmds_setting_info->dvi_panel_size);
+	dvipanelsize = (unsigned char)(viaparinfo->
+		tmds_setting_info->dvi_panel_size);
+	return dvipanelsize;
+}
+
+/* If Disable DVI, turn off pad */
+void viafb_dvi_disable(void)
+{
+	if (viaparinfo->chip_info->
+		tmds_chip_info.output_interface == INTERFACE_DVP0)
+		viafb_write_reg(SR1E, VIASR,
+		viafb_read_reg(VIASR, SR1E) & (~0xC0));
+
+	if (viaparinfo->chip_info->
+		tmds_chip_info.output_interface == INTERFACE_DVP1)
+		viafb_write_reg(SR1E, VIASR,
+		viafb_read_reg(VIASR, SR1E) & (~0x30));
+
+	if (viaparinfo->chip_info->
+		tmds_chip_info.output_interface == INTERFACE_DFP_HIGH)
+		viafb_write_reg(SR2A, VIASR,
+		viafb_read_reg(VIASR, SR2A) & (~0x0C));
+
+	if (viaparinfo->chip_info->
+		tmds_chip_info.output_interface == INTERFACE_DFP_LOW)
+		viafb_write_reg(SR2A, VIASR,
+		viafb_read_reg(VIASR, SR2A) & (~0x03));
+
+	if (viaparinfo->chip_info->
+		tmds_chip_info.output_interface == INTERFACE_TMDS)
+		/* Turn off TMDS power. */
+		viafb_write_reg(CRD2, VIACR,
+		viafb_read_reg(VIACR, CRD2) | 0x08);
+}
+
+/* If Enable DVI, turn off pad */
+void viafb_dvi_enable(void)
+{
+	u8 data;
+
+	if (viaparinfo->chip_info->
+		tmds_chip_info.output_interface == INTERFACE_DVP0) {
+		viafb_write_reg(SR1E, VIASR,
+			viafb_read_reg(VIASR, SR1E) | 0xC0);
+		if (viaparinfo->chip_info->gfx_chip_name == UNICHROME_CLE266)
+			tmds_register_write(0x88, 0x3b);
+		else
+			/*clear CR91[5] to direct on display period
+			   in the secondary diplay path */
+			viafb_write_reg(CR91, VIACR,
+			viafb_read_reg(VIACR, CR91) & 0xDF);
+	}
+
+	if (viaparinfo->chip_info->
+		tmds_chip_info.output_interface == INTERFACE_DVP1) {
+		viafb_write_reg(SR1E, VIASR,
+			viafb_read_reg(VIASR, SR1E) | 0x30);
+
+		/*fix dvi cann't be enabled with MB VT5718C4 - Al Zhang */
+		if (viaparinfo->chip_info->gfx_chip_name == UNICHROME_CLE266) {
+			tmds_register_write(0x88, 0x3b);
+		} else {
+			/*clear CR91[5] to direct on display period
+			  in the secondary diplay path */
+			viafb_write_reg(CR91, VIACR,
+			viafb_read_reg(VIACR, CR91) & 0xDF);
+		}
+
+		/*fix DVI cannot enable on EPIA-M board */
+		if (viafb_platform_epia_dvi == 1) {
+			viafb_write_reg_mask(CR91, VIACR, 0x1f, 0x1f);
+			viafb_write_reg_mask(CR88, VIACR, 0x00, BIT6 + BIT0);
+			if (viafb_bus_width == 24) {
+				if (viafb_device_lcd_dualedge == 1)
+					data = 0x3F;
+				else
+					data = 0x37;
+				viafb_i2c_writebyte(viaparinfo->chip_info->
+					     tmds_chip_info.
+					     tmds_chip_slave_addr,
+					     0x08, data);
+			}
+		}
+	}
+
+	if (viaparinfo->chip_info->
+		tmds_chip_info.output_interface == INTERFACE_DFP_HIGH) {
+		viafb_write_reg(SR2A, VIASR,
+			viafb_read_reg(VIASR, SR2A) | 0x0C);
+		viafb_write_reg(CR91, VIACR,
+			viafb_read_reg(VIACR, CR91) & 0xDF);
+	}
+
+	if (viaparinfo->chip_info->
+		tmds_chip_info.output_interface == INTERFACE_DFP_LOW) {
+		viafb_write_reg(SR2A, VIASR,
+			viafb_read_reg(VIASR, SR2A) | 0x03);
+		viafb_write_reg(CR91, VIACR,
+			viafb_read_reg(VIACR, CR91) & 0xDF);
+	}
+	if (viaparinfo->chip_info->
+		tmds_chip_info.output_interface == INTERFACE_TMDS) {
+		/* Turn on Display period in the panel path. */
+		viafb_write_reg_mask(CR91, VIACR, 0, BIT7);
+
+		/* Turn on TMDS power. */
+		viafb_write_reg_mask(CRD2, VIACR, 0, BIT3);
+	}
+}
+