OpenCloudOS-Kernel/drivers/gpu/drm/gma500/cdv_intel_dp.c

/*
 * Copyright © 2012 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 * Authors:
 *    Keith Packard <keithp@keithp.com>
 *
 */

#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <drm/drmP.h>
#include <drm/drm_crtc.h>
#include <drm/drm_crtc_helper.h>
#include "psb_drv.h"
#include "psb_intel_drv.h"
#include "psb_intel_reg.h"
#include "gma_display.h"
#include <drm/drm_dp_helper.h>

/**
 * struct i2c_algo_dp_aux_data - driver interface structure for i2c over dp
 * 				 aux algorithm
 * @running: set by the algo indicating whether an i2c is ongoing or whether
 * 	     the i2c bus is quiescent
 * @address: i2c target address for the currently ongoing transfer
 * @aux_ch: driver callback to transfer a single byte of the i2c payload
 */
struct i2c_algo_dp_aux_data {
	bool running;
	u16 address;
	int (*aux_ch) (struct i2c_adapter *adapter,
		       int mode, uint8_t write_byte,
		       uint8_t *read_byte);
};

/* Run a single AUX_CH I2C transaction, writing/reading data as necessary */
static int
i2c_algo_dp_aux_transaction(struct i2c_adapter *adapter, int mode,
			    uint8_t write_byte, uint8_t *read_byte)
{
	struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;
	int ret;

	ret = (*algo_data->aux_ch)(adapter, mode,
				   write_byte, read_byte);
	return ret;
}

/*
 * I2C over AUX CH
 */

/*
 * Send the address. If the I2C link is running, this 'restarts'
 * the connection with the new address, this is used for doing
 * a write followed by a read (as needed for DDC)
 */
static int
i2c_algo_dp_aux_address(struct i2c_adapter *adapter, u16 address, bool reading)
{
	struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;
	int mode = MODE_I2C_START;
	int ret;

	if (reading)
		mode |= MODE_I2C_READ;
	else
		mode |= MODE_I2C_WRITE;
	algo_data->address = address;
	algo_data->running = true;
	ret = i2c_algo_dp_aux_transaction(adapter, mode, 0, NULL);
	return ret;
}

/*
 * Stop the I2C transaction. This closes out the link, sending
 * a bare address packet with the MOT bit turned off
 */
static void
i2c_algo_dp_aux_stop(struct i2c_adapter *adapter, bool reading)
{
	struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;
	int mode = MODE_I2C_STOP;

	if (reading)
		mode |= MODE_I2C_READ;
	else
		mode |= MODE_I2C_WRITE;
	if (algo_data->running) {
		(void) i2c_algo_dp_aux_transaction(adapter, mode, 0, NULL);
		algo_data->running = false;
	}
}

/*
 * Write a single byte to the current I2C address, the
 * the I2C link must be running or this returns -EIO
 */
static int
i2c_algo_dp_aux_put_byte(struct i2c_adapter *adapter, u8 byte)
{
	struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;
	int ret;

	if (!algo_data->running)
		return -EIO;

	ret = i2c_algo_dp_aux_transaction(adapter, MODE_I2C_WRITE, byte, NULL);
	return ret;
}

/*
 * Read a single byte from the current I2C address, the
 * I2C link must be running or this returns -EIO
 */
static int
i2c_algo_dp_aux_get_byte(struct i2c_adapter *adapter, u8 *byte_ret)
{
	struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;
	int ret;

	if (!algo_data->running)
		return -EIO;

	ret = i2c_algo_dp_aux_transaction(adapter, MODE_I2C_READ, 0, byte_ret);
	return ret;
}

static int
i2c_algo_dp_aux_xfer(struct i2c_adapter *adapter,
		     struct i2c_msg *msgs,
		     int num)
{
	int ret = 0;
	bool reading = false;
	int m;
	int b;

	for (m = 0; m < num; m++) {
		u16 len = msgs[m].len;
		u8 *buf = msgs[m].buf;
		reading = (msgs[m].flags & I2C_M_RD) != 0;
		ret = i2c_algo_dp_aux_address(adapter, msgs[m].addr, reading);
		if (ret < 0)
			break;
		if (reading) {
			for (b = 0; b < len; b++) {
				ret = i2c_algo_dp_aux_get_byte(adapter, &buf[b]);
				if (ret < 0)
					break;
			}
		} else {
			for (b = 0; b < len; b++) {
				ret = i2c_algo_dp_aux_put_byte(adapter, buf[b]);
				if (ret < 0)
					break;
			}
		}
		if (ret < 0)
			break;
	}
	if (ret >= 0)
		ret = num;
	i2c_algo_dp_aux_stop(adapter, reading);
	DRM_DEBUG_KMS("dp_aux_xfer return %d\n", ret);
	return ret;
}

static u32
i2c_algo_dp_aux_functionality(struct i2c_adapter *adapter)
{
	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
	       I2C_FUNC_SMBUS_READ_BLOCK_DATA |
	       I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
	       I2C_FUNC_10BIT_ADDR;
}

static const struct i2c_algorithm i2c_dp_aux_algo = {
	.master_xfer	= i2c_algo_dp_aux_xfer,
	.functionality	= i2c_algo_dp_aux_functionality,
};

static void
i2c_dp_aux_reset_bus(struct i2c_adapter *adapter)
{
	(void) i2c_algo_dp_aux_address(adapter, 0, false);
	(void) i2c_algo_dp_aux_stop(adapter, false);
}

static int
i2c_dp_aux_prepare_bus(struct i2c_adapter *adapter)
{
	adapter->algo = &i2c_dp_aux_algo;
	adapter->retries = 3;
	i2c_dp_aux_reset_bus(adapter);
	return 0;
}

/*
 * FIXME: This is the old dp aux helper, gma500 is the last driver that needs to
 * be ported over to the new helper code in drm_dp_helper.c like i915 or radeon.
 */
static int
i2c_dp_aux_add_bus(struct i2c_adapter *adapter)
{
	int error;

	error = i2c_dp_aux_prepare_bus(adapter);
	if (error)
		return error;
	error = i2c_add_adapter(adapter);
	return error;
}

#define _wait_for(COND, MS, W) ({ \
        unsigned long timeout__ = jiffies + msecs_to_jiffies(MS);       \
        int ret__ = 0;                                                  \
        while (! (COND)) {                                              \
                if (time_after(jiffies, timeout__)) {                   \
                        ret__ = -ETIMEDOUT;                             \
                        break;                                          \
                }                                                       \
                if (W && !in_dbg_master()) msleep(W);                   \
        }                                                               \
        ret__;                                                          \
})      

#define wait_for(COND, MS) _wait_for(COND, MS, 1)

#define DP_LINK_CHECK_TIMEOUT	(10 * 1000)

#define DP_LINK_CONFIGURATION_SIZE	9

#define CDV_FAST_LINK_TRAIN	1

struct cdv_intel_dp {
	uint32_t output_reg;
	uint32_t DP;
	uint8_t  link_configuration[DP_LINK_CONFIGURATION_SIZE];
	bool has_audio;
	int force_audio;
	uint32_t color_range;
	uint8_t link_bw;
	uint8_t lane_count;
	uint8_t dpcd[4];
	struct gma_encoder *encoder;
	struct i2c_adapter adapter;
	struct i2c_algo_dp_aux_data algo;
	uint8_t	train_set[4];
	uint8_t link_status[DP_LINK_STATUS_SIZE];
	int panel_power_up_delay;
	int panel_power_down_delay;
	int panel_power_cycle_delay;
	int backlight_on_delay;
	int backlight_off_delay;
	struct drm_display_mode *panel_fixed_mode;  /* for eDP */
	bool panel_on;
};

struct ddi_regoff {
	uint32_t	PreEmph1;
	uint32_t	PreEmph2;
	uint32_t	VSwing1;
	uint32_t	VSwing2;
	uint32_t	VSwing3;
	uint32_t	VSwing4;
	uint32_t	VSwing5;
};

static struct ddi_regoff ddi_DP_train_table[] = {
	{.PreEmph1 = 0x812c, .PreEmph2 = 0x8124, .VSwing1 = 0x8154,
	.VSwing2 = 0x8148, .VSwing3 = 0x814C, .VSwing4 = 0x8150,
	.VSwing5 = 0x8158,},
	{.PreEmph1 = 0x822c, .PreEmph2 = 0x8224, .VSwing1 = 0x8254,
	.VSwing2 = 0x8248, .VSwing3 = 0x824C, .VSwing4 = 0x8250,
	.VSwing5 = 0x8258,},
};

static uint32_t dp_vswing_premph_table[] = {
        0x55338954,	0x4000,
        0x554d8954,	0x2000,
        0x55668954,	0,
        0x559ac0d4,	0x6000,
};
/**
 * is_edp - is the given port attached to an eDP panel (either CPU or PCH)
 * @intel_dp: DP struct
 *
 * If a CPU or PCH DP output is attached to an eDP panel, this function
 * will return true, and false otherwise.
 */
static bool is_edp(struct gma_encoder *encoder)
{
	return encoder->type == INTEL_OUTPUT_EDP;
}


static void cdv_intel_dp_start_link_train(struct gma_encoder *encoder);
static void cdv_intel_dp_complete_link_train(struct gma_encoder *encoder);
static void cdv_intel_dp_link_down(struct gma_encoder *encoder);

static int
cdv_intel_dp_max_lane_count(struct gma_encoder *encoder)
{
	struct cdv_intel_dp *intel_dp = encoder->dev_priv;
	int max_lane_count = 4;

	if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11) {
		max_lane_count = intel_dp->dpcd[DP_MAX_LANE_COUNT] & 0x1f;
		switch (max_lane_count) {
		case 1: case 2: case 4:
			break;
		default:
			max_lane_count = 4;
		}
	}
	return max_lane_count;
}

static int
cdv_intel_dp_max_link_bw(struct gma_encoder *encoder)
{
	struct cdv_intel_dp *intel_dp = encoder->dev_priv;
	int max_link_bw = intel_dp->dpcd[DP_MAX_LINK_RATE];

	switch (max_link_bw) {
	case DP_LINK_BW_1_62:
	case DP_LINK_BW_2_7:
		break;
	default:
		max_link_bw = DP_LINK_BW_1_62;
		break;
	}
	return max_link_bw;
}

static int
cdv_intel_dp_link_clock(uint8_t link_bw)
{
	if (link_bw == DP_LINK_BW_2_7)
		return 270000;
	else
		return 162000;
}

static int
cdv_intel_dp_link_required(int pixel_clock, int bpp)
{
	return (pixel_clock * bpp + 7) / 8;
}

static int
cdv_intel_dp_max_data_rate(int max_link_clock, int max_lanes)
{
	return (max_link_clock * max_lanes * 19) / 20;
}

static void cdv_intel_edp_panel_vdd_on(struct gma_encoder *intel_encoder)
{
	struct drm_device *dev = intel_encoder->base.dev;
	struct cdv_intel_dp *intel_dp = intel_encoder->dev_priv;
	u32 pp;

	if (intel_dp->panel_on) {
		DRM_DEBUG_KMS("Skip VDD on because of panel on\n");
		return;
	}	
	DRM_DEBUG_KMS("\n");

	pp = REG_READ(PP_CONTROL);

	pp |= EDP_FORCE_VDD;
	REG_WRITE(PP_CONTROL, pp);
	REG_READ(PP_CONTROL);
	msleep(intel_dp->panel_power_up_delay);
}

static void cdv_intel_edp_panel_vdd_off(struct gma_encoder *intel_encoder)
{
	struct drm_device *dev = intel_encoder->base.dev;
	u32 pp;

	DRM_DEBUG_KMS("\n");
	pp = REG_READ(PP_CONTROL);

	pp &= ~EDP_FORCE_VDD;
	REG_WRITE(PP_CONTROL, pp);
	REG_READ(PP_CONTROL);

}

/* Returns true if the panel was already on when called */
static bool cdv_intel_edp_panel_on(struct gma_encoder *intel_encoder)
{
	struct drm_device *dev = intel_encoder->base.dev;
	struct cdv_intel_dp *intel_dp = intel_encoder->dev_priv;
	u32 pp, idle_on_mask = PP_ON | PP_SEQUENCE_NONE;

	if (intel_dp->panel_on)
		return true;

	DRM_DEBUG_KMS("\n");
	pp = REG_READ(PP_CONTROL);
	pp &= ~PANEL_UNLOCK_MASK;

	pp |= (PANEL_UNLOCK_REGS | POWER_TARGET_ON);
	REG_WRITE(PP_CONTROL, pp);
	REG_READ(PP_CONTROL);

	if (wait_for(((REG_READ(PP_STATUS) & idle_on_mask) == idle_on_mask), 1000)) {
		DRM_DEBUG_KMS("Error in Powering up eDP panel, status %x\n", REG_READ(PP_STATUS));
		intel_dp->panel_on = false;
	} else
		intel_dp->panel_on = true;	
	msleep(intel_dp->panel_power_up_delay);

	return false;
}

static void cdv_intel_edp_panel_off (struct gma_encoder *intel_encoder)
{
	struct drm_device *dev = intel_encoder->base.dev;
	u32 pp, idle_off_mask = PP_ON ;
	struct cdv_intel_dp *intel_dp = intel_encoder->dev_priv;

	DRM_DEBUG_KMS("\n");

	pp = REG_READ(PP_CONTROL);

	if ((pp & POWER_TARGET_ON) == 0) 
		return;

	intel_dp->panel_on = false;
	pp &= ~PANEL_UNLOCK_MASK;
	/* ILK workaround: disable reset around power sequence */

	pp &= ~POWER_TARGET_ON;
	pp &= ~EDP_FORCE_VDD;
	pp &= ~EDP_BLC_ENABLE;
	REG_WRITE(PP_CONTROL, pp);
	REG_READ(PP_CONTROL);
	DRM_DEBUG_KMS("PP_STATUS %x\n", REG_READ(PP_STATUS));

	if (wait_for((REG_READ(PP_STATUS) & idle_off_mask) == 0, 1000)) {
		DRM_DEBUG_KMS("Error in turning off Panel\n");	
	}

	msleep(intel_dp->panel_power_cycle_delay);
	DRM_DEBUG_KMS("Over\n");
}

static void cdv_intel_edp_backlight_on (struct gma_encoder *intel_encoder)
{
	struct drm_device *dev = intel_encoder->base.dev;
	u32 pp;

	DRM_DEBUG_KMS("\n");
	/*
	 * If we enable the backlight right away following a panel power
	 * on, we may see slight flicker as the panel syncs with the eDP
	 * link.  So delay a bit to make sure the image is solid before
	 * allowing it to appear.
	 */
	msleep(300);
	pp = REG_READ(PP_CONTROL);

	pp |= EDP_BLC_ENABLE;
	REG_WRITE(PP_CONTROL, pp);
	gma_backlight_enable(dev);
}

static void cdv_intel_edp_backlight_off (struct gma_encoder *intel_encoder)
{
	struct drm_device *dev = intel_encoder->base.dev;
	struct cdv_intel_dp *intel_dp = intel_encoder->dev_priv;
	u32 pp;

	DRM_DEBUG_KMS("\n");
	gma_backlight_disable(dev);
	msleep(10);
	pp = REG_READ(PP_CONTROL);

	pp &= ~EDP_BLC_ENABLE;
	REG_WRITE(PP_CONTROL, pp);
	msleep(intel_dp->backlight_off_delay);
}

static int
cdv_intel_dp_mode_valid(struct drm_connector *connector,
		    struct drm_display_mode *mode)
{
	struct gma_encoder *encoder = gma_attached_encoder(connector);
	struct cdv_intel_dp *intel_dp = encoder->dev_priv;
	int max_link_clock = cdv_intel_dp_link_clock(cdv_intel_dp_max_link_bw(encoder));
	int max_lanes = cdv_intel_dp_max_lane_count(encoder);
	struct drm_psb_private *dev_priv = connector->dev->dev_private;

	if (is_edp(encoder) && intel_dp->panel_fixed_mode) {
		if (mode->hdisplay > intel_dp->panel_fixed_mode->hdisplay)
			return MODE_PANEL;
		if (mode->vdisplay > intel_dp->panel_fixed_mode->vdisplay)
			return MODE_PANEL;
	}

	/* only refuse the mode on non eDP since we have seen some weird eDP panels
	   which are outside spec tolerances but somehow work by magic */
	if (!is_edp(encoder) &&
	    (cdv_intel_dp_link_required(mode->clock, dev_priv->edp.bpp)
	     > cdv_intel_dp_max_data_rate(max_link_clock, max_lanes)))
		return MODE_CLOCK_HIGH;

	if (is_edp(encoder)) {
	    if (cdv_intel_dp_link_required(mode->clock, 24)
	     	> cdv_intel_dp_max_data_rate(max_link_clock, max_lanes))
		return MODE_CLOCK_HIGH;
		
	}
	if (mode->clock < 10000)
		return MODE_CLOCK_LOW;

	return MODE_OK;
}

static uint32_t
pack_aux(uint8_t *src, int src_bytes)
{
	int	i;
	uint32_t v = 0;

	if (src_bytes > 4)
		src_bytes = 4;
	for (i = 0; i < src_bytes; i++)
		v |= ((uint32_t) src[i]) << ((3-i) * 8);
	return v;
}

static void
unpack_aux(uint32_t src, uint8_t *dst, int dst_bytes)
{
	int i;
	if (dst_bytes > 4)
		dst_bytes = 4;
	for (i = 0; i < dst_bytes; i++)
		dst[i] = src >> ((3-i) * 8);
}

static int
cdv_intel_dp_aux_ch(struct gma_encoder *encoder,
		uint8_t *send, int send_bytes,
		uint8_t *recv, int recv_size)
{
	struct cdv_intel_dp *intel_dp = encoder->dev_priv;
	uint32_t output_reg = intel_dp->output_reg;
	struct drm_device *dev = encoder->base.dev;
	uint32_t ch_ctl = output_reg + 0x10;
	uint32_t ch_data = ch_ctl + 4;
	int i;
	int recv_bytes;
	uint32_t status;
	uint32_t aux_clock_divider;
	int try, precharge;

	/* The clock divider is based off the hrawclk,
	 * and would like to run at 2MHz. So, take the
	 * hrawclk value and divide by 2 and use that
	 * On CDV platform it uses 200MHz as hrawclk.
	 *
	 */
	aux_clock_divider = 200 / 2;

	precharge = 4;
	if (is_edp(encoder))
		precharge = 10;

	if (REG_READ(ch_ctl) & DP_AUX_CH_CTL_SEND_BUSY) {
		DRM_ERROR("dp_aux_ch not started status 0x%08x\n",
			  REG_READ(ch_ctl));
		return -EBUSY;
	}

	/* Must try at least 3 times according to DP spec */
	for (try = 0; try < 5; try++) {
		/* Load the send data into the aux channel data registers */
		for (i = 0; i < send_bytes; i += 4)
			REG_WRITE(ch_data + i,
				   pack_aux(send + i, send_bytes - i));
	
		/* Send the command and wait for it to complete */
		REG_WRITE(ch_ctl,
			   DP_AUX_CH_CTL_SEND_BUSY |
			   DP_AUX_CH_CTL_TIME_OUT_400us |
			   (send_bytes << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) |
			   (precharge << DP_AUX_CH_CTL_PRECHARGE_2US_SHIFT) |
			   (aux_clock_divider << DP_AUX_CH_CTL_BIT_CLOCK_2X_SHIFT) |
			   DP_AUX_CH_CTL_DONE |
			   DP_AUX_CH_CTL_TIME_OUT_ERROR |
			   DP_AUX_CH_CTL_RECEIVE_ERROR);
		for (;;) {
			status = REG_READ(ch_ctl);
			if ((status & DP_AUX_CH_CTL_SEND_BUSY) == 0)
				break;
			udelay(100);
		}
	
		/* Clear done status and any errors */
		REG_WRITE(ch_ctl,
			   status |
			   DP_AUX_CH_CTL_DONE |
			   DP_AUX_CH_CTL_TIME_OUT_ERROR |
			   DP_AUX_CH_CTL_RECEIVE_ERROR);
		if (status & DP_AUX_CH_CTL_DONE)
			break;
	}

	if ((status & DP_AUX_CH_CTL_DONE) == 0) {
		DRM_ERROR("dp_aux_ch not done status 0x%08x\n", status);
		return -EBUSY;
	}

	/* Check for timeout or receive error.
	 * Timeouts occur when the sink is not connected
	 */
	if (status & DP_AUX_CH_CTL_RECEIVE_ERROR) {
		DRM_ERROR("dp_aux_ch receive error status 0x%08x\n", status);
		return -EIO;
	}

	/* Timeouts occur when the device isn't connected, so they're
	 * "normal" -- don't fill the kernel log with these */
	if (status & DP_AUX_CH_CTL_TIME_OUT_ERROR) {
		DRM_DEBUG_KMS("dp_aux_ch timeout status 0x%08x\n", status);
		return -ETIMEDOUT;
	}

	/* Unload any bytes sent back from the other side */
	recv_bytes = ((status & DP_AUX_CH_CTL_MESSAGE_SIZE_MASK) >>
		      DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT);
	if (recv_bytes > recv_size)
		recv_bytes = recv_size;
	
	for (i = 0; i < recv_bytes; i += 4)
		unpack_aux(REG_READ(ch_data + i),
			   recv + i, recv_bytes - i);

	return recv_bytes;
}

/* Write data to the aux channel in native mode */
static int
cdv_intel_dp_aux_native_write(struct gma_encoder *encoder,
			  uint16_t address, uint8_t *send, int send_bytes)
{
	int ret;
	uint8_t	msg[20];
	int msg_bytes;
	uint8_t	ack;

	if (send_bytes > 16)
		return -1;
	msg[0] = DP_AUX_NATIVE_WRITE << 4;
	msg[1] = address >> 8;
	msg[2] = address & 0xff;
	msg[3] = send_bytes - 1;
	memcpy(&msg[4], send, send_bytes);
	msg_bytes = send_bytes + 4;
	for (;;) {
		ret = cdv_intel_dp_aux_ch(encoder, msg, msg_bytes, &ack, 1);
		if (ret < 0)
			return ret;
		ack >>= 4;
		if ((ack & DP_AUX_NATIVE_REPLY_MASK) == DP_AUX_NATIVE_REPLY_ACK)
			break;
		else if ((ack & DP_AUX_NATIVE_REPLY_MASK) == DP_AUX_NATIVE_REPLY_DEFER)
			udelay(100);
		else
			return -EIO;
	}
	return send_bytes;
}

/* Write a single byte to the aux channel in native mode */
static int
cdv_intel_dp_aux_native_write_1(struct gma_encoder *encoder,
			    uint16_t address, uint8_t byte)
{
	return cdv_intel_dp_aux_native_write(encoder, address, &byte, 1);
}

/* read bytes from a native aux channel */
static int
cdv_intel_dp_aux_native_read(struct gma_encoder *encoder,
			 uint16_t address, uint8_t *recv, int recv_bytes)
{
	uint8_t msg[4];
	int msg_bytes;
	uint8_t reply[20];
	int reply_bytes;
	uint8_t ack;
	int ret;

	msg[0] = DP_AUX_NATIVE_READ << 4;
	msg[1] = address >> 8;
	msg[2] = address & 0xff;
	msg[3] = recv_bytes - 1;

	msg_bytes = 4;
	reply_bytes = recv_bytes + 1;

	for (;;) {
		ret = cdv_intel_dp_aux_ch(encoder, msg, msg_bytes,
				      reply, reply_bytes);
		if (ret == 0)
			return -EPROTO;
		if (ret < 0)
			return ret;
		ack = reply[0] >> 4;
		if ((ack & DP_AUX_NATIVE_REPLY_MASK) == DP_AUX_NATIVE_REPLY_ACK) {
			memcpy(recv, reply + 1, ret - 1);
			return ret - 1;
		}
		else if ((ack & DP_AUX_NATIVE_REPLY_MASK) == DP_AUX_NATIVE_REPLY_DEFER)
			udelay(100);
		else
			return -EIO;
	}
}

static int
cdv_intel_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
		    uint8_t write_byte, uint8_t *read_byte)
{
	struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;
	struct cdv_intel_dp *intel_dp = container_of(adapter,
						struct cdv_intel_dp,
						adapter);
	struct gma_encoder *encoder = intel_dp->encoder;
	uint16_t address = algo_data->address;
	uint8_t msg[5];
	uint8_t reply[2];
	unsigned retry;
	int msg_bytes;
	int reply_bytes;
	int ret;

	/* Set up the command byte */
	if (mode & MODE_I2C_READ)
		msg[0] = DP_AUX_I2C_READ << 4;
	else
		msg[0] = DP_AUX_I2C_WRITE << 4;

	if (!(mode & MODE_I2C_STOP))
		msg[0] |= DP_AUX_I2C_MOT << 4;

	msg[1] = address >> 8;
	msg[2] = address;

	switch (mode) {
	case MODE_I2C_WRITE:
		msg[3] = 0;
		msg[4] = write_byte;
		msg_bytes = 5;
		reply_bytes = 1;
		break;
	case MODE_I2C_READ:
		msg[3] = 0;
		msg_bytes = 4;
		reply_bytes = 2;
		break;
	default:
		msg_bytes = 3;
		reply_bytes = 1;
		break;
	}

	for (retry = 0; retry < 5; retry++) {
		ret = cdv_intel_dp_aux_ch(encoder,
				      msg, msg_bytes,
				      reply, reply_bytes);
		if (ret < 0) {
			DRM_DEBUG_KMS("aux_ch failed %d\n", ret);
			return ret;
		}

		switch ((reply[0] >> 4) & DP_AUX_NATIVE_REPLY_MASK) {
		case DP_AUX_NATIVE_REPLY_ACK:
			/* I2C-over-AUX Reply field is only valid
			 * when paired with AUX ACK.
			 */
			break;
		case DP_AUX_NATIVE_REPLY_NACK:
			DRM_DEBUG_KMS("aux_ch native nack\n");
			return -EREMOTEIO;
		case DP_AUX_NATIVE_REPLY_DEFER:
			udelay(100);
			continue;
		default:
			DRM_ERROR("aux_ch invalid native reply 0x%02x\n",
				  reply[0]);
			return -EREMOTEIO;
		}

		switch ((reply[0] >> 4) & DP_AUX_I2C_REPLY_MASK) {
		case DP_AUX_I2C_REPLY_ACK:
			if (mode == MODE_I2C_READ) {
				*read_byte = reply[1];
			}
			return reply_bytes - 1;
		case DP_AUX_I2C_REPLY_NACK:
			DRM_DEBUG_KMS("aux_i2c nack\n");
			return -EREMOTEIO;
		case DP_AUX_I2C_REPLY_DEFER:
			DRM_DEBUG_KMS("aux_i2c defer\n");
			udelay(100);
			break;
		default:
			DRM_ERROR("aux_i2c invalid reply 0x%02x\n", reply[0]);
			return -EREMOTEIO;
		}
	}

	DRM_ERROR("too many retries, giving up\n");
	return -EREMOTEIO;
}

static int
cdv_intel_dp_i2c_init(struct gma_connector *connector,
		      struct gma_encoder *encoder, const char *name)
{
	struct cdv_intel_dp *intel_dp = encoder->dev_priv;
	int ret;

	DRM_DEBUG_KMS("i2c_init %s\n", name);

	intel_dp->algo.running = false;
	intel_dp->algo.address = 0;
	intel_dp->algo.aux_ch = cdv_intel_dp_i2c_aux_ch;

	memset(&intel_dp->adapter, '\0', sizeof (intel_dp->adapter));
	intel_dp->adapter.owner = THIS_MODULE;
	intel_dp->adapter.class = I2C_CLASS_DDC;
	strncpy (intel_dp->adapter.name, name, sizeof(intel_dp->adapter.name) - 1);
	intel_dp->adapter.name[sizeof(intel_dp->adapter.name) - 1] = '\0';
	intel_dp->adapter.algo_data = &intel_dp->algo;
	intel_dp->adapter.dev.parent = connector->base.kdev;

	if (is_edp(encoder))
		cdv_intel_edp_panel_vdd_on(encoder);
	ret = i2c_dp_aux_add_bus(&intel_dp->adapter);
	if (is_edp(encoder))
		cdv_intel_edp_panel_vdd_off(encoder);
	
	return ret;
}

static void cdv_intel_fixed_panel_mode(struct drm_display_mode *fixed_mode,
	struct drm_display_mode *adjusted_mode)
{
	adjusted_mode->hdisplay = fixed_mode->hdisplay;
	adjusted_mode->hsync_start = fixed_mode->hsync_start;
	adjusted_mode->hsync_end = fixed_mode->hsync_end;
	adjusted_mode->htotal = fixed_mode->htotal;

	adjusted_mode->vdisplay = fixed_mode->vdisplay;
	adjusted_mode->vsync_start = fixed_mode->vsync_start;
	adjusted_mode->vsync_end = fixed_mode->vsync_end;
	adjusted_mode->vtotal = fixed_mode->vtotal;

	adjusted_mode->clock = fixed_mode->clock;

	drm_mode_set_crtcinfo(adjusted_mode, CRTC_INTERLACE_HALVE_V);
}

static bool
cdv_intel_dp_mode_fixup(struct drm_encoder *encoder, const struct drm_display_mode *mode,
		    struct drm_display_mode *adjusted_mode)
{
	struct drm_psb_private *dev_priv = encoder->dev->dev_private;
	struct gma_encoder *intel_encoder = to_gma_encoder(encoder);
	struct cdv_intel_dp *intel_dp = intel_encoder->dev_priv;
	int lane_count, clock;
	int max_lane_count = cdv_intel_dp_max_lane_count(intel_encoder);
	int max_clock = cdv_intel_dp_max_link_bw(intel_encoder) == DP_LINK_BW_2_7 ? 1 : 0;
	static int bws[2] = { DP_LINK_BW_1_62, DP_LINK_BW_2_7 };
	int refclock = mode->clock;
	int bpp = 24;

	if (is_edp(intel_encoder) && intel_dp->panel_fixed_mode) {
		cdv_intel_fixed_panel_mode(intel_dp->panel_fixed_mode, adjusted_mode);
		refclock = intel_dp->panel_fixed_mode->clock;
		bpp = dev_priv->edp.bpp;
	}

	for (lane_count = 1; lane_count <= max_lane_count; lane_count <<= 1) {
		for (clock = max_clock; clock >= 0; clock--) {
			int link_avail = cdv_intel_dp_max_data_rate(cdv_intel_dp_link_clock(bws[clock]), lane_count);

			if (cdv_intel_dp_link_required(refclock, bpp) <= link_avail) {
				intel_dp->link_bw = bws[clock];
				intel_dp->lane_count = lane_count;
				adjusted_mode->clock = cdv_intel_dp_link_clock(intel_dp->link_bw);
				DRM_DEBUG_KMS("Display port link bw %02x lane "
						"count %d clock %d\n",
				       intel_dp->link_bw, intel_dp->lane_count,
				       adjusted_mode->clock);
				return true;
			}
		}
	}
	if (is_edp(intel_encoder)) {
		/* okay we failed just pick the highest */
		intel_dp->lane_count = max_lane_count;
		intel_dp->link_bw = bws[max_clock];
		adjusted_mode->clock = cdv_intel_dp_link_clock(intel_dp->link_bw);
		DRM_DEBUG_KMS("Force picking display port link bw %02x lane "
			      "count %d clock %d\n",
			      intel_dp->link_bw, intel_dp->lane_count,
			      adjusted_mode->clock);

		return true;
	}
	return false;
}

struct cdv_intel_dp_m_n {
	uint32_t	tu;
	uint32_t	gmch_m;
	uint32_t	gmch_n;
	uint32_t	link_m;
	uint32_t	link_n;
};

static void
cdv_intel_reduce_ratio(uint32_t *num, uint32_t *den)
{
	/*
	while (*num > 0xffffff || *den > 0xffffff) {
		*num >>= 1;
		*den >>= 1;
	}*/
	uint64_t value, m;
	m = *num;
	value = m * (0x800000);
	m = do_div(value, *den);
	*num = value;
	*den = 0x800000;
}

static void
cdv_intel_dp_compute_m_n(int bpp,
		     int nlanes,
		     int pixel_clock,
		     int link_clock,
		     struct cdv_intel_dp_m_n *m_n)
{
	m_n->tu = 64;
	m_n->gmch_m = (pixel_clock * bpp + 7) >> 3;
	m_n->gmch_n = link_clock * nlanes;
	cdv_intel_reduce_ratio(&m_n->gmch_m, &m_n->gmch_n);
	m_n->link_m = pixel_clock;
	m_n->link_n = link_clock;
	cdv_intel_reduce_ratio(&m_n->link_m, &m_n->link_n);
}

void
cdv_intel_dp_set_m_n(struct drm_crtc *crtc, struct drm_display_mode *mode,
		 struct drm_display_mode *adjusted_mode)
{
	struct drm_device *dev = crtc->dev;
	struct drm_psb_private *dev_priv = dev->dev_private;
	struct drm_mode_config *mode_config = &dev->mode_config;
	struct drm_encoder *encoder;
	struct gma_crtc *gma_crtc = to_gma_crtc(crtc);
	int lane_count = 4, bpp = 24;
	struct cdv_intel_dp_m_n m_n;
	int pipe = gma_crtc->pipe;

	/*
	 * Find the lane count in the intel_encoder private
	 */
	list_for_each_entry(encoder, &mode_config->encoder_list, head) {
		struct gma_encoder *intel_encoder;
		struct cdv_intel_dp *intel_dp;

		if (encoder->crtc != crtc)
			continue;

		intel_encoder = to_gma_encoder(encoder);
		intel_dp = intel_encoder->dev_priv;
		if (intel_encoder->type == INTEL_OUTPUT_DISPLAYPORT) {
			lane_count = intel_dp->lane_count;
			break;
		} else if (is_edp(intel_encoder)) {
			lane_count = intel_dp->lane_count;
			bpp = dev_priv->edp.bpp;
			break;
		}
	}

	/*
	 * Compute the GMCH and Link ratios. The '3' here is
	 * the number of bytes_per_pixel post-LUT, which we always
	 * set up for 8-bits of R/G/B, or 3 bytes total.
	 */
	cdv_intel_dp_compute_m_n(bpp, lane_count,
			     mode->clock, adjusted_mode->clock, &m_n);

	{
		REG_WRITE(PIPE_GMCH_DATA_M(pipe),
			   ((m_n.tu - 1) << PIPE_GMCH_DATA_M_TU_SIZE_SHIFT) |
			   m_n.gmch_m);
		REG_WRITE(PIPE_GMCH_DATA_N(pipe), m_n.gmch_n);
		REG_WRITE(PIPE_DP_LINK_M(pipe), m_n.link_m);
		REG_WRITE(PIPE_DP_LINK_N(pipe), m_n.link_n);
	}
}

static void
cdv_intel_dp_mode_set(struct drm_encoder *encoder, struct drm_display_mode *mode,
		  struct drm_display_mode *adjusted_mode)
{
	struct gma_encoder *intel_encoder = to_gma_encoder(encoder);
	struct drm_crtc *crtc = encoder->crtc;
	struct gma_crtc *gma_crtc = to_gma_crtc(crtc);
	struct cdv_intel_dp *intel_dp = intel_encoder->dev_priv;
	struct drm_device *dev = encoder->dev;

	intel_dp->DP = DP_VOLTAGE_0_4 | DP_PRE_EMPHASIS_0;
	intel_dp->DP |= intel_dp->color_range;

	if (adjusted_mode->flags & DRM_MODE_FLAG_PHSYNC)
		intel_dp->DP |= DP_SYNC_HS_HIGH;
	if (adjusted_mode->flags & DRM_MODE_FLAG_PVSYNC)
		intel_dp->DP |= DP_SYNC_VS_HIGH;

	intel_dp->DP |= DP_LINK_TRAIN_OFF;

	switch (intel_dp->lane_count) {
	case 1:
		intel_dp->DP |= DP_PORT_WIDTH_1;
		break;
	case 2:
		intel_dp->DP |= DP_PORT_WIDTH_2;
		break;
	case 4:
		intel_dp->DP |= DP_PORT_WIDTH_4;
		break;
	}
	if (intel_dp->has_audio)
		intel_dp->DP |= DP_AUDIO_OUTPUT_ENABLE;

	memset(intel_dp->link_configuration, 0, DP_LINK_CONFIGURATION_SIZE);
	intel_dp->link_configuration[0] = intel_dp->link_bw;
	intel_dp->link_configuration[1] = intel_dp->lane_count;

	/*
	 * Check for DPCD version > 1.1 and enhanced framing support
	 */
	if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11 &&
	    (intel_dp->dpcd[DP_MAX_LANE_COUNT] & DP_ENHANCED_FRAME_CAP)) {
		intel_dp->link_configuration[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
		intel_dp->DP |= DP_ENHANCED_FRAMING;
	}

	/* CPT DP's pipe select is decided in TRANS_DP_CTL */
	if (gma_crtc->pipe == 1)
		intel_dp->DP |= DP_PIPEB_SELECT;

	REG_WRITE(intel_dp->output_reg, (intel_dp->DP | DP_PORT_EN));
	DRM_DEBUG_KMS("DP expected reg is %x\n", intel_dp->DP);
	if (is_edp(intel_encoder)) {
		uint32_t pfit_control;
		cdv_intel_edp_panel_on(intel_encoder);

		if (mode->hdisplay != adjusted_mode->hdisplay ||
			    mode->vdisplay != adjusted_mode->vdisplay)
			pfit_control = PFIT_ENABLE;
		else
			pfit_control = 0;

		pfit_control |= gma_crtc->pipe << PFIT_PIPE_SHIFT;

		REG_WRITE(PFIT_CONTROL, pfit_control);
	}
}


/* If the sink supports it, try to set the power state appropriately */
static void cdv_intel_dp_sink_dpms(struct gma_encoder *encoder, int mode)
{
	struct cdv_intel_dp *intel_dp = encoder->dev_priv;
	int ret, i;

	/* Should have a valid DPCD by this point */
	if (intel_dp->dpcd[DP_DPCD_REV] < 0x11)
		return;

	if (mode != DRM_MODE_DPMS_ON) {
		ret = cdv_intel_dp_aux_native_write_1(encoder, DP_SET_POWER,
						  DP_SET_POWER_D3);
		if (ret != 1)
			DRM_DEBUG_DRIVER("failed to write sink power state\n");
	} else {
		/*
		 * When turning on, we need to retry for 1ms to give the sink
		 * time to wake up.
		 */
		for (i = 0; i < 3; i++) {
			ret = cdv_intel_dp_aux_native_write_1(encoder,
							  DP_SET_POWER,
							  DP_SET_POWER_D0);
			if (ret == 1)
				break;
			udelay(1000);
		}
	}
}

static void cdv_intel_dp_prepare(struct drm_encoder *encoder)
{
	struct gma_encoder *intel_encoder = to_gma_encoder(encoder);
	int edp = is_edp(intel_encoder);

	if (edp) {
		cdv_intel_edp_backlight_off(intel_encoder);
		cdv_intel_edp_panel_off(intel_encoder);
		cdv_intel_edp_panel_vdd_on(intel_encoder);
        }
	/* Wake up the sink first */
	cdv_intel_dp_sink_dpms(intel_encoder, DRM_MODE_DPMS_ON);
	cdv_intel_dp_link_down(intel_encoder);
	if (edp)
		cdv_intel_edp_panel_vdd_off(intel_encoder);
}

static void cdv_intel_dp_commit(struct drm_encoder *encoder)
{
	struct gma_encoder *intel_encoder = to_gma_encoder(encoder);
	int edp = is_edp(intel_encoder);

	if (edp)
		cdv_intel_edp_panel_on(intel_encoder);
	cdv_intel_dp_start_link_train(intel_encoder);
	cdv_intel_dp_complete_link_train(intel_encoder);
	if (edp)
		cdv_intel_edp_backlight_on(intel_encoder);
}

static void
cdv_intel_dp_dpms(struct drm_encoder *encoder, int mode)
{
	struct gma_encoder *intel_encoder = to_gma_encoder(encoder);
	struct cdv_intel_dp *intel_dp = intel_encoder->dev_priv;
	struct drm_device *dev = encoder->dev;
	uint32_t dp_reg = REG_READ(intel_dp->output_reg);
	int edp = is_edp(intel_encoder);

	if (mode != DRM_MODE_DPMS_ON) {
		if (edp) {
			cdv_intel_edp_backlight_off(intel_encoder);
			cdv_intel_edp_panel_vdd_on(intel_encoder);
		}
		cdv_intel_dp_sink_dpms(intel_encoder, mode);
		cdv_intel_dp_link_down(intel_encoder);
		if (edp) {
			cdv_intel_edp_panel_vdd_off(intel_encoder);
			cdv_intel_edp_panel_off(intel_encoder);
		}
	} else {
        	if (edp)
			cdv_intel_edp_panel_on(intel_encoder);
		cdv_intel_dp_sink_dpms(intel_encoder, mode);
		if (!(dp_reg & DP_PORT_EN)) {
			cdv_intel_dp_start_link_train(intel_encoder);
			cdv_intel_dp_complete_link_train(intel_encoder);
		}
		if (edp)
        		cdv_intel_edp_backlight_on(intel_encoder);
	}
}

/*
 * Native read with retry for link status and receiver capability reads for
 * cases where the sink may still be asleep.
 */
static bool
cdv_intel_dp_aux_native_read_retry(struct gma_encoder *encoder, uint16_t address,
			       uint8_t *recv, int recv_bytes)
{
	int ret, i;

	/*
	 * Sinks are *supposed* to come up within 1ms from an off state,
	 * but we're also supposed to retry 3 times per the spec.
	 */
	for (i = 0; i < 3; i++) {
		ret = cdv_intel_dp_aux_native_read(encoder, address, recv,
					       recv_bytes);
		if (ret == recv_bytes)
			return true;
		udelay(1000);
	}

	return false;
}

/*
 * Fetch AUX CH registers 0x202 - 0x207 which contain
 * link status information
 */
static bool
cdv_intel_dp_get_link_status(struct gma_encoder *encoder)
{
	struct cdv_intel_dp *intel_dp = encoder->dev_priv;
	return cdv_intel_dp_aux_native_read_retry(encoder,
					      DP_LANE0_1_STATUS,
					      intel_dp->link_status,
					      DP_LINK_STATUS_SIZE);
}

static uint8_t
cdv_intel_dp_link_status(uint8_t link_status[DP_LINK_STATUS_SIZE],
		     int r)
{
	return link_status[r - DP_LANE0_1_STATUS];
}

static uint8_t
cdv_intel_get_adjust_request_voltage(uint8_t link_status[DP_LINK_STATUS_SIZE],
				 int lane)
{
	int	    i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1);
	int	    s = ((lane & 1) ?
			 DP_ADJUST_VOLTAGE_SWING_LANE1_SHIFT :
			 DP_ADJUST_VOLTAGE_SWING_LANE0_SHIFT);
	uint8_t l = cdv_intel_dp_link_status(link_status, i);

	return ((l >> s) & 3) << DP_TRAIN_VOLTAGE_SWING_SHIFT;
}

static uint8_t
cdv_intel_get_adjust_request_pre_emphasis(uint8_t link_status[DP_LINK_STATUS_SIZE],
				      int lane)
{
	int	    i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1);
	int	    s = ((lane & 1) ?
			 DP_ADJUST_PRE_EMPHASIS_LANE1_SHIFT :
			 DP_ADJUST_PRE_EMPHASIS_LANE0_SHIFT);
	uint8_t l = cdv_intel_dp_link_status(link_status, i);

	return ((l >> s) & 3) << DP_TRAIN_PRE_EMPHASIS_SHIFT;
}


#if 0
static char	*voltage_names[] = {
	"0.4V", "0.6V", "0.8V", "1.2V"
};
static char	*pre_emph_names[] = {
	"0dB", "3.5dB", "6dB", "9.5dB"
};
static char	*link_train_names[] = {
	"pattern 1", "pattern 2", "idle", "off"
};
#endif

#define CDV_DP_VOLTAGE_MAX	    DP_TRAIN_VOLTAGE_SWING_LEVEL_3
/*
static uint8_t
cdv_intel_dp_pre_emphasis_max(uint8_t voltage_swing)
{
	switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
	case DP_TRAIN_VOLTAGE_SWING_400:
		return DP_TRAIN_PRE_EMPHASIS_6;
	case DP_TRAIN_VOLTAGE_SWING_600:
		return DP_TRAIN_PRE_EMPHASIS_6;
	case DP_TRAIN_VOLTAGE_SWING_800:
		return DP_TRAIN_PRE_EMPHASIS_3_5;
	case DP_TRAIN_VOLTAGE_SWING_1200:
	default:
		return DP_TRAIN_PRE_EMPHASIS_0;
	}
}
*/
static void
cdv_intel_get_adjust_train(struct gma_encoder *encoder)
{
	struct cdv_intel_dp *intel_dp = encoder->dev_priv;
	uint8_t v = 0;
	uint8_t p = 0;
	int lane;

	for (lane = 0; lane < intel_dp->lane_count; lane++) {
		uint8_t this_v = cdv_intel_get_adjust_request_voltage(intel_dp->link_status, lane);
		uint8_t this_p = cdv_intel_get_adjust_request_pre_emphasis(intel_dp->link_status, lane);

		if (this_v > v)
			v = this_v;
		if (this_p > p)
			p = this_p;
	}
	
	if (v >= CDV_DP_VOLTAGE_MAX)
		v = CDV_DP_VOLTAGE_MAX | DP_TRAIN_MAX_SWING_REACHED;

	if (p == DP_TRAIN_PRE_EMPHASIS_MASK)
		p |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
		
	for (lane = 0; lane < 4; lane++)
		intel_dp->train_set[lane] = v | p;
}


static uint8_t
cdv_intel_get_lane_status(uint8_t link_status[DP_LINK_STATUS_SIZE],
		      int lane)
{
	int i = DP_LANE0_1_STATUS + (lane >> 1);
	int s = (lane & 1) * 4;
	uint8_t l = cdv_intel_dp_link_status(link_status, i);

	return (l >> s) & 0xf;
}

/* Check for clock recovery is done on all channels */
static bool
cdv_intel_clock_recovery_ok(uint8_t link_status[DP_LINK_STATUS_SIZE], int lane_count)
{
	int lane;
	uint8_t lane_status;

	for (lane = 0; lane < lane_count; lane++) {
		lane_status = cdv_intel_get_lane_status(link_status, lane);
		if ((lane_status & DP_LANE_CR_DONE) == 0)
			return false;
	}
	return true;
}

/* Check to see if channel eq is done on all channels */
#define CHANNEL_EQ_BITS (DP_LANE_CR_DONE|\
			 DP_LANE_CHANNEL_EQ_DONE|\
			 DP_LANE_SYMBOL_LOCKED)
static bool
cdv_intel_channel_eq_ok(struct gma_encoder *encoder)
{
	struct cdv_intel_dp *intel_dp = encoder->dev_priv;
	uint8_t lane_align;
	uint8_t lane_status;
	int lane;

	lane_align = cdv_intel_dp_link_status(intel_dp->link_status,
					  DP_LANE_ALIGN_STATUS_UPDATED);
	if ((lane_align & DP_INTERLANE_ALIGN_DONE) == 0)
		return false;
	for (lane = 0; lane < intel_dp->lane_count; lane++) {
		lane_status = cdv_intel_get_lane_status(intel_dp->link_status, lane);
		if ((lane_status & CHANNEL_EQ_BITS) != CHANNEL_EQ_BITS)
			return false;
	}
	return true;
}

static bool
cdv_intel_dp_set_link_train(struct gma_encoder *encoder,
			uint32_t dp_reg_value,
			uint8_t dp_train_pat)
{
	
	struct drm_device *dev = encoder->base.dev;
	int ret;
	struct cdv_intel_dp *intel_dp = encoder->dev_priv;

	REG_WRITE(intel_dp->output_reg, dp_reg_value);
	REG_READ(intel_dp->output_reg);

	ret = cdv_intel_dp_aux_native_write_1(encoder,
				    DP_TRAINING_PATTERN_SET,
				    dp_train_pat);

	if (ret != 1) {
		DRM_DEBUG_KMS("Failure in setting link pattern %x\n",
				dp_train_pat);
		return false;
	}

	return true;
}


static bool
cdv_intel_dplink_set_level(struct gma_encoder *encoder,
			uint8_t dp_train_pat)
{
	
	int ret;
	struct cdv_intel_dp *intel_dp = encoder->dev_priv;

	ret = cdv_intel_dp_aux_native_write(encoder,
					DP_TRAINING_LANE0_SET,
					intel_dp->train_set,
					intel_dp->lane_count);

	if (ret != intel_dp->lane_count) {
		DRM_DEBUG_KMS("Failure in setting level %d, lane_cnt= %d\n",
				intel_dp->train_set[0], intel_dp->lane_count);
		return false;
	}
	return true;
}

static void
cdv_intel_dp_set_vswing_premph(struct gma_encoder *encoder, uint8_t signal_level)
{
	struct drm_device *dev = encoder->base.dev;
	struct cdv_intel_dp *intel_dp = encoder->dev_priv;
	struct ddi_regoff *ddi_reg;
	int vswing, premph, index;

	if (intel_dp->output_reg == DP_B)
		ddi_reg = &ddi_DP_train_table[0];
	else
		ddi_reg = &ddi_DP_train_table[1];

	vswing = (signal_level & DP_TRAIN_VOLTAGE_SWING_MASK);
	premph = ((signal_level & DP_TRAIN_PRE_EMPHASIS_MASK)) >>
				DP_TRAIN_PRE_EMPHASIS_SHIFT;

	if (vswing + premph > 3)
		return;
#ifdef CDV_FAST_LINK_TRAIN
	return;
#endif
	DRM_DEBUG_KMS("Test2\n");
	//return ;
	cdv_sb_reset(dev);
	/* ;Swing voltage programming
        ;gfx_dpio_set_reg(0xc058, 0x0505313A) */
	cdv_sb_write(dev, ddi_reg->VSwing5, 0x0505313A);

	/* ;gfx_dpio_set_reg(0x8154, 0x43406055) */
	cdv_sb_write(dev, ddi_reg->VSwing1, 0x43406055);

	/* ;gfx_dpio_set_reg(0x8148, 0x55338954)
	 * The VSwing_PreEmph table is also considered based on the vswing/premp
	 */
	index = (vswing + premph) * 2;
	if (premph == 1 && vswing == 1) {
		cdv_sb_write(dev, ddi_reg->VSwing2, 0x055738954);
	} else
		cdv_sb_write(dev, ddi_reg->VSwing2, dp_vswing_premph_table[index]);

	/* ;gfx_dpio_set_reg(0x814c, 0x40802040) */
	if ((vswing + premph) == DP_TRAIN_VOLTAGE_SWING_LEVEL_3)
		cdv_sb_write(dev, ddi_reg->VSwing3, 0x70802040);
	else
		cdv_sb_write(dev, ddi_reg->VSwing3, 0x40802040);

	/* ;gfx_dpio_set_reg(0x8150, 0x2b405555) */
	/* cdv_sb_write(dev, ddi_reg->VSwing4, 0x2b405555); */

	/* ;gfx_dpio_set_reg(0x8154, 0xc3406055) */
	cdv_sb_write(dev, ddi_reg->VSwing1, 0xc3406055);

	/* ;Pre emphasis programming
	 * ;gfx_dpio_set_reg(0xc02c, 0x1f030040)
	 */
	cdv_sb_write(dev, ddi_reg->PreEmph1, 0x1f030040);

	/* ;gfx_dpio_set_reg(0x8124, 0x00004000) */
	index = 2 * premph + 1;
	cdv_sb_write(dev, ddi_reg->PreEmph2, dp_vswing_premph_table[index]);
	return;	
}


/* Enable corresponding port and start training pattern 1 */
static void
cdv_intel_dp_start_link_train(struct gma_encoder *encoder)
{
	struct drm_device *dev = encoder->base.dev;
	struct cdv_intel_dp *intel_dp = encoder->dev_priv;
	int i;
	uint8_t voltage;
	bool clock_recovery = false;
	int tries;
	u32 reg;
	uint32_t DP = intel_dp->DP;

	DP |= DP_PORT_EN;
	DP &= ~DP_LINK_TRAIN_MASK;
		
	reg = DP;	
	reg |= DP_LINK_TRAIN_PAT_1;
	/* Enable output, wait for it to become active */
	REG_WRITE(intel_dp->output_reg, reg);
	REG_READ(intel_dp->output_reg);
	gma_wait_for_vblank(dev);

	DRM_DEBUG_KMS("Link config\n");
	/* Write the link configuration data */
	cdv_intel_dp_aux_native_write(encoder, DP_LINK_BW_SET,
				  intel_dp->link_configuration,
				  2);

	memset(intel_dp->train_set, 0, 4);
	voltage = 0;
	tries = 0;
	clock_recovery = false;

	DRM_DEBUG_KMS("Start train\n");
		reg = DP | DP_LINK_TRAIN_PAT_1;


	for (;;) {
		/* Use intel_dp->train_set[0] to set the voltage and pre emphasis values */
		DRM_DEBUG_KMS("DP Link Train Set %x, Link_config %x, %x\n",
				intel_dp->train_set[0],
				intel_dp->link_configuration[0],
				intel_dp->link_configuration[1]);

		if (!cdv_intel_dp_set_link_train(encoder, reg, DP_TRAINING_PATTERN_1)) {
			DRM_DEBUG_KMS("Failure in aux-transfer setting pattern 1\n");
		}
		cdv_intel_dp_set_vswing_premph(encoder, intel_dp->train_set[0]);
		/* Set training pattern 1 */

		cdv_intel_dplink_set_level(encoder, DP_TRAINING_PATTERN_1);

		udelay(200);
		if (!cdv_intel_dp_get_link_status(encoder))
			break;

		DRM_DEBUG_KMS("DP Link status %x, %x, %x, %x, %x, %x\n",
				intel_dp->link_status[0], intel_dp->link_status[1], intel_dp->link_status[2],
				intel_dp->link_status[3], intel_dp->link_status[4], intel_dp->link_status[5]);

		if (cdv_intel_clock_recovery_ok(intel_dp->link_status, intel_dp->lane_count)) {
			DRM_DEBUG_KMS("PT1 train is done\n");
			clock_recovery = true;
			break;
		}

		/* Check to see if we've tried the max voltage */
		for (i = 0; i < intel_dp->lane_count; i++)
			if ((intel_dp->train_set[i] & DP_TRAIN_MAX_SWING_REACHED) == 0)
				break;
		if (i == intel_dp->lane_count)
			break;

		/* Check to see if we've tried the same voltage 5 times */
		if ((intel_dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) == voltage) {
			++tries;
			if (tries == 5)
				break;
		} else
			tries = 0;
		voltage = intel_dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;

		/* Compute new intel_dp->train_set as requested by target */
		cdv_intel_get_adjust_train(encoder);

	}

	if (!clock_recovery) {
		DRM_DEBUG_KMS("failure in DP patter 1 training, train set %x\n", intel_dp->train_set[0]);
	}
	
	intel_dp->DP = DP;
}

static void
cdv_intel_dp_complete_link_train(struct gma_encoder *encoder)
{
	struct drm_device *dev = encoder->base.dev;
	struct cdv_intel_dp *intel_dp = encoder->dev_priv;
	bool channel_eq = false;
	int tries, cr_tries;
	u32 reg;
	uint32_t DP = intel_dp->DP;

	/* channel equalization */
	tries = 0;
	cr_tries = 0;
	channel_eq = false;

	DRM_DEBUG_KMS("\n");
		reg = DP | DP_LINK_TRAIN_PAT_2;

	for (;;) {

		DRM_DEBUG_KMS("DP Link Train Set %x, Link_config %x, %x\n",
				intel_dp->train_set[0],
				intel_dp->link_configuration[0],
				intel_dp->link_configuration[1]);
        	/* channel eq pattern */

		if (!cdv_intel_dp_set_link_train(encoder, reg,
					     DP_TRAINING_PATTERN_2)) {
			DRM_DEBUG_KMS("Failure in aux-transfer setting pattern 2\n");
		}
		/* Use intel_dp->train_set[0] to set the voltage and pre emphasis values */

		if (cr_tries > 5) {
			DRM_ERROR("failed to train DP, aborting\n");
			cdv_intel_dp_link_down(encoder);
			break;
		}

		cdv_intel_dp_set_vswing_premph(encoder, intel_dp->train_set[0]);

		cdv_intel_dplink_set_level(encoder, DP_TRAINING_PATTERN_2);

		udelay(1000);
		if (!cdv_intel_dp_get_link_status(encoder))
			break;

		DRM_DEBUG_KMS("DP Link status %x, %x, %x, %x, %x, %x\n",
				intel_dp->link_status[0], intel_dp->link_status[1], intel_dp->link_status[2],
				intel_dp->link_status[3], intel_dp->link_status[4], intel_dp->link_status[5]);

		/* Make sure clock is still ok */
		if (!cdv_intel_clock_recovery_ok(intel_dp->link_status, intel_dp->lane_count)) {
			cdv_intel_dp_start_link_train(encoder);
			cr_tries++;
			continue;
		}

		if (cdv_intel_channel_eq_ok(encoder)) {
			DRM_DEBUG_KMS("PT2 train is done\n");
			channel_eq = true;
			break;
		}

		/* Try 5 times, then try clock recovery if that fails */
		if (tries > 5) {
			cdv_intel_dp_link_down(encoder);
			cdv_intel_dp_start_link_train(encoder);
			tries = 0;
			cr_tries++;
			continue;
		}

		/* Compute new intel_dp->train_set as requested by target */
		cdv_intel_get_adjust_train(encoder);
		++tries;

	}

	reg = DP | DP_LINK_TRAIN_OFF;

	REG_WRITE(intel_dp->output_reg, reg);
	REG_READ(intel_dp->output_reg);
	cdv_intel_dp_aux_native_write_1(encoder,
				    DP_TRAINING_PATTERN_SET, DP_TRAINING_PATTERN_DISABLE);
}

static void
cdv_intel_dp_link_down(struct gma_encoder *encoder)
{
	struct drm_device *dev = encoder->base.dev;
	struct cdv_intel_dp *intel_dp = encoder->dev_priv;
	uint32_t DP = intel_dp->DP;

	if ((REG_READ(intel_dp->output_reg) & DP_PORT_EN) == 0)
		return;

	DRM_DEBUG_KMS("\n");


	{
		DP &= ~DP_LINK_TRAIN_MASK;
		REG_WRITE(intel_dp->output_reg, DP | DP_LINK_TRAIN_PAT_IDLE);
	}
	REG_READ(intel_dp->output_reg);

	msleep(17);

	REG_WRITE(intel_dp->output_reg, DP & ~DP_PORT_EN);
	REG_READ(intel_dp->output_reg);
}

static enum drm_connector_status cdv_dp_detect(struct gma_encoder *encoder)
{
	struct cdv_intel_dp *intel_dp = encoder->dev_priv;
	enum drm_connector_status status;

	status = connector_status_disconnected;
	if (cdv_intel_dp_aux_native_read(encoder, 0x000, intel_dp->dpcd,
				     sizeof (intel_dp->dpcd)) == sizeof (intel_dp->dpcd))
	{
		if (intel_dp->dpcd[DP_DPCD_REV] != 0)
			status = connector_status_connected;
	}
	if (status == connector_status_connected)
		DRM_DEBUG_KMS("DPCD: Rev=%x LN_Rate=%x LN_CNT=%x LN_DOWNSP=%x\n",
			intel_dp->dpcd[0], intel_dp->dpcd[1],
			intel_dp->dpcd[2], intel_dp->dpcd[3]);
	return status;
}

/**
 * Uses CRT_HOTPLUG_EN and CRT_HOTPLUG_STAT to detect DP connection.
 *
 * \return true if DP port is connected.
 * \return false if DP port is disconnected.
 */
static enum drm_connector_status
cdv_intel_dp_detect(struct drm_connector *connector, bool force)
{
	struct gma_encoder *encoder = gma_attached_encoder(connector);
	struct cdv_intel_dp *intel_dp = encoder->dev_priv;
	enum drm_connector_status status;
	struct edid *edid = NULL;
	int edp = is_edp(encoder);

	intel_dp->has_audio = false;

	if (edp)
		cdv_intel_edp_panel_vdd_on(encoder);
	status = cdv_dp_detect(encoder);
	if (status != connector_status_connected) {
		if (edp)
			cdv_intel_edp_panel_vdd_off(encoder);
		return status;
        }

	if (intel_dp->force_audio) {
		intel_dp->has_audio = intel_dp->force_audio > 0;
	} else {
		edid = drm_get_edid(connector, &intel_dp->adapter);
		if (edid) {
			intel_dp->has_audio = drm_detect_monitor_audio(edid);
			kfree(edid);
		}
	}
	if (edp)
		cdv_intel_edp_panel_vdd_off(encoder);

	return connector_status_connected;
}

static int cdv_intel_dp_get_modes(struct drm_connector *connector)
{
	struct gma_encoder *intel_encoder = gma_attached_encoder(connector);
	struct cdv_intel_dp *intel_dp = intel_encoder->dev_priv;
	struct edid *edid = NULL;
	int ret = 0;
	int edp = is_edp(intel_encoder);


	edid = drm_get_edid(connector, &intel_dp->adapter);
	if (edid) {
		drm_mode_connector_update_edid_property(connector, edid);
		ret = drm_add_edid_modes(connector, edid);
		kfree(edid);
	}

	if (is_edp(intel_encoder)) {
		struct drm_device *dev = connector->dev;
		struct drm_psb_private *dev_priv = dev->dev_private;
		
		cdv_intel_edp_panel_vdd_off(intel_encoder);
		if (ret) {
			if (edp && !intel_dp->panel_fixed_mode) {
				struct drm_display_mode *newmode;
				list_for_each_entry(newmode, &connector->probed_modes,
					    head) {
					if (newmode->type & DRM_MODE_TYPE_PREFERRED) {
						intel_dp->panel_fixed_mode =
							drm_mode_duplicate(dev, newmode);
						break;
					}
				}
			}

			return ret;
		}
		if (!intel_dp->panel_fixed_mode && dev_priv->lfp_lvds_vbt_mode) {
			intel_dp->panel_fixed_mode =
				drm_mode_duplicate(dev, dev_priv->lfp_lvds_vbt_mode);
			if (intel_dp->panel_fixed_mode) {
				intel_dp->panel_fixed_mode->type |=
					DRM_MODE_TYPE_PREFERRED;
			}
		}
		if (intel_dp->panel_fixed_mode != NULL) {
			struct drm_display_mode *mode;
			mode = drm_mode_duplicate(dev, intel_dp->panel_fixed_mode);
			drm_mode_probed_add(connector, mode);
			return 1;
		}
	}

	return ret;
}

static bool
cdv_intel_dp_detect_audio(struct drm_connector *connector)
{
	struct gma_encoder *encoder = gma_attached_encoder(connector);
	struct cdv_intel_dp *intel_dp = encoder->dev_priv;
	struct edid *edid;
	bool has_audio = false;
	int edp = is_edp(encoder);

	if (edp)
		cdv_intel_edp_panel_vdd_on(encoder);

	edid = drm_get_edid(connector, &intel_dp->adapter);
	if (edid) {
		has_audio = drm_detect_monitor_audio(edid);
		kfree(edid);
	}
	if (edp)
		cdv_intel_edp_panel_vdd_off(encoder);

	return has_audio;
}

static int
cdv_intel_dp_set_property(struct drm_connector *connector,
		      struct drm_property *property,
		      uint64_t val)
{
	struct drm_psb_private *dev_priv = connector->dev->dev_private;
	struct gma_encoder *encoder = gma_attached_encoder(connector);
	struct cdv_intel_dp *intel_dp = encoder->dev_priv;
	int ret;

	ret = drm_object_property_set_value(&connector->base, property, val);
	if (ret)
		return ret;

	if (property == dev_priv->force_audio_property) {
		int i = val;
		bool has_audio;

		if (i == intel_dp->force_audio)
			return 0;

		intel_dp->force_audio = i;

		if (i == 0)
			has_audio = cdv_intel_dp_detect_audio(connector);
		else
			has_audio = i > 0;

		if (has_audio == intel_dp->has_audio)
			return 0;

		intel_dp->has_audio = has_audio;
		goto done;
	}

	if (property == dev_priv->broadcast_rgb_property) {
		if (val == !!intel_dp->color_range)
			return 0;

		intel_dp->color_range = val ? DP_COLOR_RANGE_16_235 : 0;
		goto done;
	}

	return -EINVAL;

done:
	if (encoder->base.crtc) {
		struct drm_crtc *crtc = encoder->base.crtc;
		drm_crtc_helper_set_mode(crtc, &crtc->mode,
					 crtc->x, crtc->y,
					 crtc->primary->fb);
	}

	return 0;
}

static void
cdv_intel_dp_destroy(struct drm_connector *connector)
{
	struct gma_encoder *gma_encoder = gma_attached_encoder(connector);
	struct cdv_intel_dp *intel_dp = gma_encoder->dev_priv;

	if (is_edp(gma_encoder)) {
	/*	cdv_intel_panel_destroy_backlight(connector->dev); */
		if (intel_dp->panel_fixed_mode) {
			kfree(intel_dp->panel_fixed_mode);
			intel_dp->panel_fixed_mode = NULL;
		}
	}
	i2c_del_adapter(&intel_dp->adapter);
	drm_connector_unregister(connector);
	drm_connector_cleanup(connector);
	kfree(connector);
}

static void cdv_intel_dp_encoder_destroy(struct drm_encoder *encoder)
{
	drm_encoder_cleanup(encoder);
}

static const struct drm_encoder_helper_funcs cdv_intel_dp_helper_funcs = {
	.dpms = cdv_intel_dp_dpms,
	.mode_fixup = cdv_intel_dp_mode_fixup,
	.prepare = cdv_intel_dp_prepare,
	.mode_set = cdv_intel_dp_mode_set,
	.commit = cdv_intel_dp_commit,
};

static const struct drm_connector_funcs cdv_intel_dp_connector_funcs = {
	.dpms = drm_helper_connector_dpms,
	.detect = cdv_intel_dp_detect,
	.fill_modes = drm_helper_probe_single_connector_modes,
	.set_property = cdv_intel_dp_set_property,
	.destroy = cdv_intel_dp_destroy,
};

static const struct drm_connector_helper_funcs cdv_intel_dp_connector_helper_funcs = {
	.get_modes = cdv_intel_dp_get_modes,
	.mode_valid = cdv_intel_dp_mode_valid,
	.best_encoder = gma_best_encoder,
};

static const struct drm_encoder_funcs cdv_intel_dp_enc_funcs = {
	.destroy = cdv_intel_dp_encoder_destroy,
};


static void cdv_intel_dp_add_properties(struct drm_connector *connector)
{
	cdv_intel_attach_force_audio_property(connector);
	cdv_intel_attach_broadcast_rgb_property(connector);
}

/* check the VBT to see whether the eDP is on DP-D port */
static bool cdv_intel_dpc_is_edp(struct drm_device *dev)
{
	struct drm_psb_private *dev_priv = dev->dev_private;
	struct child_device_config *p_child;
	int i;

	if (!dev_priv->child_dev_num)
		return false;

	for (i = 0; i < dev_priv->child_dev_num; i++) {
		p_child = dev_priv->child_dev + i;

		if (p_child->dvo_port == PORT_IDPC &&
		    p_child->device_type == DEVICE_TYPE_eDP)
			return true;
	}
	return false;
}

/* Cedarview display clock gating

   We need this disable dot get correct behaviour while enabling
   DP/eDP. TODO - investigate if we can turn it back to normality
   after enabling */
static void cdv_disable_intel_clock_gating(struct drm_device *dev)
{
	u32 reg_value;
	reg_value = REG_READ(DSPCLK_GATE_D);

	reg_value |= (DPUNIT_PIPEB_GATE_DISABLE |
			DPUNIT_PIPEA_GATE_DISABLE |
			DPCUNIT_CLOCK_GATE_DISABLE |
			DPLSUNIT_CLOCK_GATE_DISABLE |
			DPOUNIT_CLOCK_GATE_DISABLE |
		 	DPIOUNIT_CLOCK_GATE_DISABLE);	

	REG_WRITE(DSPCLK_GATE_D, reg_value);

	udelay(500);		
}

void
cdv_intel_dp_init(struct drm_device *dev, struct psb_intel_mode_device *mode_dev, int output_reg)
{
	struct gma_encoder *gma_encoder;
	struct gma_connector *gma_connector;
	struct drm_connector *connector;
	struct drm_encoder *encoder;
	struct cdv_intel_dp *intel_dp;
	const char *name = NULL;
	int type = DRM_MODE_CONNECTOR_DisplayPort;

	gma_encoder = kzalloc(sizeof(struct gma_encoder), GFP_KERNEL);
	if (!gma_encoder)
		return;
        gma_connector = kzalloc(sizeof(struct gma_connector), GFP_KERNEL);
        if (!gma_connector)
                goto err_connector;
	intel_dp = kzalloc(sizeof(struct cdv_intel_dp), GFP_KERNEL);
	if (!intel_dp)
	        goto err_priv;

	if ((output_reg == DP_C) && cdv_intel_dpc_is_edp(dev))
		type = DRM_MODE_CONNECTOR_eDP;

	connector = &gma_connector->base;
	encoder = &gma_encoder->base;

	drm_connector_init(dev, connector, &cdv_intel_dp_connector_funcs, type);
	drm_encoder_init(dev, encoder, &cdv_intel_dp_enc_funcs,
			 DRM_MODE_ENCODER_TMDS, NULL);

	gma_connector_attach_encoder(gma_connector, gma_encoder);

	if (type == DRM_MODE_CONNECTOR_DisplayPort)
		gma_encoder->type = INTEL_OUTPUT_DISPLAYPORT;
        else
		gma_encoder->type = INTEL_OUTPUT_EDP;


	gma_encoder->dev_priv=intel_dp;
	intel_dp->encoder = gma_encoder;
	intel_dp->output_reg = output_reg;
	
	drm_encoder_helper_add(encoder, &cdv_intel_dp_helper_funcs);
	drm_connector_helper_add(connector, &cdv_intel_dp_connector_helper_funcs);

	connector->polled = DRM_CONNECTOR_POLL_HPD;
	connector->interlace_allowed = false;
	connector->doublescan_allowed = false;

	drm_connector_register(connector);

	/* Set up the DDC bus. */
	switch (output_reg) {
		case DP_B:
			name = "DPDDC-B";
			gma_encoder->ddi_select = (DP_MASK | DDI0_SELECT);
			break;
		case DP_C:
			name = "DPDDC-C";
			gma_encoder->ddi_select = (DP_MASK | DDI1_SELECT);
			break;
	}

	cdv_disable_intel_clock_gating(dev);

	cdv_intel_dp_i2c_init(gma_connector, gma_encoder, name);
        /* FIXME:fail check */
	cdv_intel_dp_add_properties(connector);

	if (is_edp(gma_encoder)) {
		int ret;
		struct edp_power_seq cur;
                u32 pp_on, pp_off, pp_div;
		u32 pwm_ctrl;

		pp_on = REG_READ(PP_CONTROL);
		pp_on &= ~PANEL_UNLOCK_MASK;
	        pp_on |= PANEL_UNLOCK_REGS;
		
		REG_WRITE(PP_CONTROL, pp_on);

		pwm_ctrl = REG_READ(BLC_PWM_CTL2);
		pwm_ctrl |= PWM_PIPE_B;
		REG_WRITE(BLC_PWM_CTL2, pwm_ctrl);

                pp_on = REG_READ(PP_ON_DELAYS);
                pp_off = REG_READ(PP_OFF_DELAYS);
                pp_div = REG_READ(PP_DIVISOR);
	
		/* Pull timing values out of registers */
                cur.t1_t3 = (pp_on & PANEL_POWER_UP_DELAY_MASK) >>
                        PANEL_POWER_UP_DELAY_SHIFT;

                cur.t8 = (pp_on & PANEL_LIGHT_ON_DELAY_MASK) >>
                        PANEL_LIGHT_ON_DELAY_SHIFT;

                cur.t9 = (pp_off & PANEL_LIGHT_OFF_DELAY_MASK) >>
                        PANEL_LIGHT_OFF_DELAY_SHIFT;

                cur.t10 = (pp_off & PANEL_POWER_DOWN_DELAY_MASK) >>
                        PANEL_POWER_DOWN_DELAY_SHIFT;

                cur.t11_t12 = ((pp_div & PANEL_POWER_CYCLE_DELAY_MASK) >>
                               PANEL_POWER_CYCLE_DELAY_SHIFT);

                DRM_DEBUG_KMS("cur t1_t3 %d t8 %d t9 %d t10 %d t11_t12 %d\n",
                              cur.t1_t3, cur.t8, cur.t9, cur.t10, cur.t11_t12);


		intel_dp->panel_power_up_delay = cur.t1_t3 / 10;
                intel_dp->backlight_on_delay = cur.t8 / 10;
                intel_dp->backlight_off_delay = cur.t9 / 10;
                intel_dp->panel_power_down_delay = cur.t10 / 10;
                intel_dp->panel_power_cycle_delay = (cur.t11_t12 - 1) * 100;

                DRM_DEBUG_KMS("panel power up delay %d, power down delay %d, power cycle delay %d\n",
                              intel_dp->panel_power_up_delay, intel_dp->panel_power_down_delay,
                              intel_dp->panel_power_cycle_delay);

                DRM_DEBUG_KMS("backlight on delay %d, off delay %d\n",
                              intel_dp->backlight_on_delay, intel_dp->backlight_off_delay);


		cdv_intel_edp_panel_vdd_on(gma_encoder);
		ret = cdv_intel_dp_aux_native_read(gma_encoder, DP_DPCD_REV,
					       intel_dp->dpcd,
					       sizeof(intel_dp->dpcd));
		cdv_intel_edp_panel_vdd_off(gma_encoder);
		if (ret == 0) {
			/* if this fails, presume the device is a ghost */
			DRM_INFO("failed to retrieve link info, disabling eDP\n");
			cdv_intel_dp_encoder_destroy(encoder);
			cdv_intel_dp_destroy(connector);
			goto err_priv;
		} else {
        		DRM_DEBUG_KMS("DPCD: Rev=%x LN_Rate=%x LN_CNT=%x LN_DOWNSP=%x\n",
				intel_dp->dpcd[0], intel_dp->dpcd[1], 
				intel_dp->dpcd[2], intel_dp->dpcd[3]);
			
		}
		/* The CDV reference driver moves pnale backlight setup into the displays that
		   have a backlight: this is a good idea and one we should probably adopt, however
		   we need to migrate all the drivers before we can do that */
                /*cdv_intel_panel_setup_backlight(dev); */
	}
	return;

err_priv:
	kfree(gma_connector);
err_connector:
	kfree(gma_encoder);
}