/*
 * 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:
 *    Eugeni Dodonov <eugeni.dodonov@intel.com>
 *
 */

#include "i915_drv.h"
#include "intel_drv.h"

/* HDMI/DVI modes ignore everything but the last 2 items. So we share
 * them for both DP and FDI transports, allowing those ports to
 * automatically adapt to HDMI connections as well
 */
static const u32 hsw_ddi_translations_dp[] = {
	0x00FFFFFF, 0x0006000E,		/* DP parameters */
	0x00D75FFF, 0x0005000A,
	0x00C30FFF, 0x00040006,
	0x80AAAFFF, 0x000B0000,
	0x00FFFFFF, 0x0005000A,
	0x00D75FFF, 0x000C0004,
	0x80C30FFF, 0x000B0000,
	0x00FFFFFF, 0x00040006,
	0x80D75FFF, 0x000B0000,
};

static const u32 hsw_ddi_translations_fdi[] = {
	0x00FFFFFF, 0x0007000E,		/* FDI parameters */
	0x00D75FFF, 0x000F000A,
	0x00C30FFF, 0x00060006,
	0x00AAAFFF, 0x001E0000,
	0x00FFFFFF, 0x000F000A,
	0x00D75FFF, 0x00160004,
	0x00C30FFF, 0x001E0000,
	0x00FFFFFF, 0x00060006,
	0x00D75FFF, 0x001E0000,
};

static const u32 hsw_ddi_translations_hdmi[] = {
				/* Idx	NT mV diff	T mV diff	db  */
	0x00FFFFFF, 0x0006000E, /* 0:	400		400		0   */
	0x00E79FFF, 0x000E000C, /* 1:	400		500		2   */
	0x00D75FFF, 0x0005000A, /* 2:	400		600		3.5 */
	0x00FFFFFF, 0x0005000A, /* 3:	600		600		0   */
	0x00E79FFF, 0x001D0007, /* 4:	600		750		2   */
	0x00D75FFF, 0x000C0004, /* 5:	600		900		3.5 */
	0x00FFFFFF, 0x00040006, /* 6:	800		800		0   */
	0x80E79FFF, 0x00030002, /* 7:	800		1000		2   */
	0x00FFFFFF, 0x00140005, /* 8:	850		850		0   */
	0x00FFFFFF, 0x000C0004, /* 9:	900		900		0   */
	0x00FFFFFF, 0x001C0003, /* 10:	950		950		0   */
	0x80FFFFFF, 0x00030002, /* 11:	1000		1000		0   */
};

static const u32 bdw_ddi_translations_edp[] = {
	0x00FFFFFF, 0x00000012,		/* eDP parameters */
	0x00EBAFFF, 0x00020011,
	0x00C71FFF, 0x0006000F,
	0x00FFFFFF, 0x00020011,
	0x00DB6FFF, 0x0005000F,
	0x00BEEFFF, 0x000A000C,
	0x00FFFFFF, 0x0005000F,
	0x00DB6FFF, 0x000A000C,
	0x00FFFFFF, 0x000A000C,
	0x00FFFFFF, 0x00140006		/* HDMI parameters 800mV 0dB*/
};

static const u32 bdw_ddi_translations_dp[] = {
	0x00FFFFFF, 0x0007000E,		/* DP parameters */
	0x00D75FFF, 0x000E000A,
	0x00BEFFFF, 0x00140006,
	0x00FFFFFF, 0x000E000A,
	0x00D75FFF, 0x00180004,
	0x80CB2FFF, 0x001B0002,
	0x00F7DFFF, 0x00180004,
	0x80D75FFF, 0x001B0002,
	0x80FFFFFF, 0x001B0002,
	0x00FFFFFF, 0x00140006		/* HDMI parameters 800mV 0dB*/
};

static const u32 bdw_ddi_translations_fdi[] = {
	0x00FFFFFF, 0x0001000E,		/* FDI parameters */
	0x00D75FFF, 0x0004000A,
	0x00C30FFF, 0x00070006,
	0x00AAAFFF, 0x000C0000,
	0x00FFFFFF, 0x0004000A,
	0x00D75FFF, 0x00090004,
	0x00C30FFF, 0x000C0000,
	0x00FFFFFF, 0x00070006,
	0x00D75FFF, 0x000C0000,
	0x00FFFFFF, 0x00140006		/* HDMI parameters 800mV 0dB*/
};

enum port intel_ddi_get_encoder_port(struct intel_encoder *intel_encoder)
{
	struct drm_encoder *encoder = &intel_encoder->base;
	int type = intel_encoder->type;

	if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP ||
	    type == INTEL_OUTPUT_HDMI || type == INTEL_OUTPUT_UNKNOWN) {
		struct intel_digital_port *intel_dig_port =
			enc_to_dig_port(encoder);
		return intel_dig_port->port;

	} else if (type == INTEL_OUTPUT_ANALOG) {
		return PORT_E;

	} else {
		DRM_ERROR("Invalid DDI encoder type %d\n", type);
		BUG();
	}
}

/*
 * Starting with Haswell, DDI port buffers must be programmed with correct
 * values in advance. The buffer values are different for FDI and DP modes,
 * but the HDMI/DVI fields are shared among those. So we program the DDI
 * in either FDI or DP modes only, as HDMI connections will work with both
 * of those
 */
static void intel_prepare_ddi_buffers(struct drm_device *dev, enum port port)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	u32 reg;
	int i;
	int hdmi_level = dev_priv->vbt.ddi_port_info[port].hdmi_level_shift;
	const u32 *ddi_translations_fdi;
	const u32 *ddi_translations_dp;
	const u32 *ddi_translations_edp;
	const u32 *ddi_translations;

	if (IS_BROADWELL(dev)) {
		ddi_translations_fdi = bdw_ddi_translations_fdi;
		ddi_translations_dp = bdw_ddi_translations_dp;
		ddi_translations_edp = bdw_ddi_translations_edp;
	} else if (IS_HASWELL(dev)) {
		ddi_translations_fdi = hsw_ddi_translations_fdi;
		ddi_translations_dp = hsw_ddi_translations_dp;
		ddi_translations_edp = hsw_ddi_translations_dp;
	} else {
		WARN(1, "ddi translation table missing\n");
		ddi_translations_edp = bdw_ddi_translations_dp;
		ddi_translations_fdi = bdw_ddi_translations_fdi;
		ddi_translations_dp = bdw_ddi_translations_dp;
	}

	switch (port) {
	case PORT_A:
		ddi_translations = ddi_translations_edp;
		break;
	case PORT_B:
	case PORT_C:
		ddi_translations = ddi_translations_dp;
		break;
	case PORT_D:
		if (intel_dp_is_edp(dev, PORT_D))
			ddi_translations = ddi_translations_edp;
		else
			ddi_translations = ddi_translations_dp;
		break;
	case PORT_E:
		ddi_translations = ddi_translations_fdi;
		break;
	default:
		BUG();
	}

	for (i = 0, reg = DDI_BUF_TRANS(port);
	     i < ARRAY_SIZE(hsw_ddi_translations_fdi); i++) {
		I915_WRITE(reg, ddi_translations[i]);
		reg += 4;
	}
	/* Entry 9 is for HDMI: */
	for (i = 0; i < 2; i++) {
		I915_WRITE(reg, hsw_ddi_translations_hdmi[hdmi_level * 2 + i]);
		reg += 4;
	}
}

/* Program DDI buffers translations for DP. By default, program ports A-D in DP
 * mode and port E for FDI.
 */
void intel_prepare_ddi(struct drm_device *dev)
{
	int port;

	if (!HAS_DDI(dev))
		return;

	for (port = PORT_A; port <= PORT_E; port++)
		intel_prepare_ddi_buffers(dev, port);
}

static const long hsw_ddi_buf_ctl_values[] = {
	DDI_BUF_EMP_400MV_0DB_HSW,
	DDI_BUF_EMP_400MV_3_5DB_HSW,
	DDI_BUF_EMP_400MV_6DB_HSW,
	DDI_BUF_EMP_400MV_9_5DB_HSW,
	DDI_BUF_EMP_600MV_0DB_HSW,
	DDI_BUF_EMP_600MV_3_5DB_HSW,
	DDI_BUF_EMP_600MV_6DB_HSW,
	DDI_BUF_EMP_800MV_0DB_HSW,
	DDI_BUF_EMP_800MV_3_5DB_HSW
};

static void intel_wait_ddi_buf_idle(struct drm_i915_private *dev_priv,
				    enum port port)
{
	uint32_t reg = DDI_BUF_CTL(port);
	int i;

	for (i = 0; i < 8; i++) {
		udelay(1);
		if (I915_READ(reg) & DDI_BUF_IS_IDLE)
			return;
	}
	DRM_ERROR("Timeout waiting for DDI BUF %c idle bit\n", port_name(port));
}

/* Starting with Haswell, different DDI ports can work in FDI mode for
 * connection to the PCH-located connectors. For this, it is necessary to train
 * both the DDI port and PCH receiver for the desired DDI buffer settings.
 *
 * The recommended port to work in FDI mode is DDI E, which we use here. Also,
 * please note that when FDI mode is active on DDI E, it shares 2 lines with
 * DDI A (which is used for eDP)
 */

void hsw_fdi_link_train(struct drm_crtc *crtc)
{
	struct drm_device *dev = crtc->dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
	u32 temp, i, rx_ctl_val;

	/* Set the FDI_RX_MISC pwrdn lanes and the 2 workarounds listed at the
	 * mode set "sequence for CRT port" document:
	 * - TP1 to TP2 time with the default value
	 * - FDI delay to 90h
	 *
	 * WaFDIAutoLinkSetTimingOverrride:hsw
	 */
	I915_WRITE(_FDI_RXA_MISC, FDI_RX_PWRDN_LANE1_VAL(2) |
				  FDI_RX_PWRDN_LANE0_VAL(2) |
				  FDI_RX_TP1_TO_TP2_48 | FDI_RX_FDI_DELAY_90);

	/* Enable the PCH Receiver FDI PLL */
	rx_ctl_val = dev_priv->fdi_rx_config | FDI_RX_ENHANCE_FRAME_ENABLE |
		     FDI_RX_PLL_ENABLE |
		     FDI_DP_PORT_WIDTH(intel_crtc->config.fdi_lanes);
	I915_WRITE(_FDI_RXA_CTL, rx_ctl_val);
	POSTING_READ(_FDI_RXA_CTL);
	udelay(220);

	/* Switch from Rawclk to PCDclk */
	rx_ctl_val |= FDI_PCDCLK;
	I915_WRITE(_FDI_RXA_CTL, rx_ctl_val);

	/* Configure Port Clock Select */
	I915_WRITE(PORT_CLK_SEL(PORT_E), intel_crtc->ddi_pll_sel);

	/* Start the training iterating through available voltages and emphasis,
	 * testing each value twice. */
	for (i = 0; i < ARRAY_SIZE(hsw_ddi_buf_ctl_values) * 2; i++) {
		/* Configure DP_TP_CTL with auto-training */
		I915_WRITE(DP_TP_CTL(PORT_E),
					DP_TP_CTL_FDI_AUTOTRAIN |
					DP_TP_CTL_ENHANCED_FRAME_ENABLE |
					DP_TP_CTL_LINK_TRAIN_PAT1 |
					DP_TP_CTL_ENABLE);

		/* Configure and enable DDI_BUF_CTL for DDI E with next voltage.
		 * DDI E does not support port reversal, the functionality is
		 * achieved on the PCH side in FDI_RX_CTL, so no need to set the
		 * port reversal bit */
		I915_WRITE(DDI_BUF_CTL(PORT_E),
			   DDI_BUF_CTL_ENABLE |
			   ((intel_crtc->config.fdi_lanes - 1) << 1) |
			   hsw_ddi_buf_ctl_values[i / 2]);
		POSTING_READ(DDI_BUF_CTL(PORT_E));

		udelay(600);

		/* Program PCH FDI Receiver TU */
		I915_WRITE(_FDI_RXA_TUSIZE1, TU_SIZE(64));

		/* Enable PCH FDI Receiver with auto-training */
		rx_ctl_val |= FDI_RX_ENABLE | FDI_LINK_TRAIN_AUTO;
		I915_WRITE(_FDI_RXA_CTL, rx_ctl_val);
		POSTING_READ(_FDI_RXA_CTL);

		/* Wait for FDI receiver lane calibration */
		udelay(30);

		/* Unset FDI_RX_MISC pwrdn lanes */
		temp = I915_READ(_FDI_RXA_MISC);
		temp &= ~(FDI_RX_PWRDN_LANE1_MASK | FDI_RX_PWRDN_LANE0_MASK);
		I915_WRITE(_FDI_RXA_MISC, temp);
		POSTING_READ(_FDI_RXA_MISC);

		/* Wait for FDI auto training time */
		udelay(5);

		temp = I915_READ(DP_TP_STATUS(PORT_E));
		if (temp & DP_TP_STATUS_AUTOTRAIN_DONE) {
			DRM_DEBUG_KMS("FDI link training done on step %d\n", i);

			/* Enable normal pixel sending for FDI */
			I915_WRITE(DP_TP_CTL(PORT_E),
				   DP_TP_CTL_FDI_AUTOTRAIN |
				   DP_TP_CTL_LINK_TRAIN_NORMAL |
				   DP_TP_CTL_ENHANCED_FRAME_ENABLE |
				   DP_TP_CTL_ENABLE);

			return;
		}

		temp = I915_READ(DDI_BUF_CTL(PORT_E));
		temp &= ~DDI_BUF_CTL_ENABLE;
		I915_WRITE(DDI_BUF_CTL(PORT_E), temp);
		POSTING_READ(DDI_BUF_CTL(PORT_E));

		/* Disable DP_TP_CTL and FDI_RX_CTL and retry */
		temp = I915_READ(DP_TP_CTL(PORT_E));
		temp &= ~(DP_TP_CTL_ENABLE | DP_TP_CTL_LINK_TRAIN_MASK);
		temp |= DP_TP_CTL_LINK_TRAIN_PAT1;
		I915_WRITE(DP_TP_CTL(PORT_E), temp);
		POSTING_READ(DP_TP_CTL(PORT_E));

		intel_wait_ddi_buf_idle(dev_priv, PORT_E);

		rx_ctl_val &= ~FDI_RX_ENABLE;
		I915_WRITE(_FDI_RXA_CTL, rx_ctl_val);
		POSTING_READ(_FDI_RXA_CTL);

		/* Reset FDI_RX_MISC pwrdn lanes */
		temp = I915_READ(_FDI_RXA_MISC);
		temp &= ~(FDI_RX_PWRDN_LANE1_MASK | FDI_RX_PWRDN_LANE0_MASK);
		temp |= FDI_RX_PWRDN_LANE1_VAL(2) | FDI_RX_PWRDN_LANE0_VAL(2);
		I915_WRITE(_FDI_RXA_MISC, temp);
		POSTING_READ(_FDI_RXA_MISC);
	}

	DRM_ERROR("FDI link training failed!\n");
}

static void intel_ddi_mode_set(struct intel_encoder *encoder)
{
	struct intel_crtc *crtc = to_intel_crtc(encoder->base.crtc);
	int port = intel_ddi_get_encoder_port(encoder);
	int pipe = crtc->pipe;
	int type = encoder->type;
	struct drm_display_mode *adjusted_mode = &crtc->config.adjusted_mode;

	DRM_DEBUG_KMS("Preparing DDI mode on port %c, pipe %c\n",
		      port_name(port), pipe_name(pipe));

	crtc->eld_vld = false;
	if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP) {
		struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
		struct intel_digital_port *intel_dig_port =
			enc_to_dig_port(&encoder->base);

		intel_dp->DP = intel_dig_port->saved_port_bits |
			       DDI_BUF_CTL_ENABLE | DDI_BUF_EMP_400MV_0DB_HSW;
		intel_dp->DP |= DDI_PORT_WIDTH(intel_dp->lane_count);

		if (intel_dp->has_audio) {
			DRM_DEBUG_DRIVER("DP audio on pipe %c on DDI\n",
					 pipe_name(crtc->pipe));

			/* write eld */
			DRM_DEBUG_DRIVER("DP audio: write eld information\n");
			intel_write_eld(&encoder->base, adjusted_mode);
		}
	} else if (type == INTEL_OUTPUT_HDMI) {
		struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(&encoder->base);

		if (intel_hdmi->has_audio) {
			/* Proper support for digital audio needs a new logic
			 * and a new set of registers, so we leave it for future
			 * patch bombing.
			 */
			DRM_DEBUG_DRIVER("HDMI audio on pipe %c on DDI\n",
					 pipe_name(crtc->pipe));

			/* write eld */
			DRM_DEBUG_DRIVER("HDMI audio: write eld information\n");
			intel_write_eld(&encoder->base, adjusted_mode);
		}

		intel_hdmi->set_infoframes(&encoder->base, adjusted_mode);
	}
}

static struct intel_encoder *
intel_ddi_get_crtc_encoder(struct drm_crtc *crtc)
{
	struct drm_device *dev = crtc->dev;
	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
	struct intel_encoder *intel_encoder, *ret = NULL;
	int num_encoders = 0;

	for_each_encoder_on_crtc(dev, crtc, intel_encoder) {
		ret = intel_encoder;
		num_encoders++;
	}

	if (num_encoders != 1)
		WARN(1, "%d encoders on crtc for pipe %c\n", num_encoders,
		     pipe_name(intel_crtc->pipe));

	BUG_ON(ret == NULL);
	return ret;
}

void intel_ddi_put_crtc_pll(struct drm_crtc *crtc)
{
	struct drm_i915_private *dev_priv = crtc->dev->dev_private;
	struct intel_ddi_plls *plls = &dev_priv->ddi_plls;
	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
	uint32_t val;

	switch (intel_crtc->ddi_pll_sel) {
	case PORT_CLK_SEL_SPLL:
		plls->spll_refcount--;
		if (plls->spll_refcount == 0) {
			DRM_DEBUG_KMS("Disabling SPLL\n");
			val = I915_READ(SPLL_CTL);
			WARN_ON(!(val & SPLL_PLL_ENABLE));
			I915_WRITE(SPLL_CTL, val & ~SPLL_PLL_ENABLE);
			POSTING_READ(SPLL_CTL);
		}
		break;
	case PORT_CLK_SEL_WRPLL1:
		plls->wrpll1_refcount--;
		if (plls->wrpll1_refcount == 0) {
			DRM_DEBUG_KMS("Disabling WRPLL 1\n");
			val = I915_READ(WRPLL_CTL1);
			WARN_ON(!(val & WRPLL_PLL_ENABLE));
			I915_WRITE(WRPLL_CTL1, val & ~WRPLL_PLL_ENABLE);
			POSTING_READ(WRPLL_CTL1);
		}
		break;
	case PORT_CLK_SEL_WRPLL2:
		plls->wrpll2_refcount--;
		if (plls->wrpll2_refcount == 0) {
			DRM_DEBUG_KMS("Disabling WRPLL 2\n");
			val = I915_READ(WRPLL_CTL2);
			WARN_ON(!(val & WRPLL_PLL_ENABLE));
			I915_WRITE(WRPLL_CTL2, val & ~WRPLL_PLL_ENABLE);
			POSTING_READ(WRPLL_CTL2);
		}
		break;
	}

	WARN(plls->spll_refcount < 0, "Invalid SPLL refcount\n");
	WARN(plls->wrpll1_refcount < 0, "Invalid WRPLL1 refcount\n");
	WARN(plls->wrpll2_refcount < 0, "Invalid WRPLL2 refcount\n");

	intel_crtc->ddi_pll_sel = PORT_CLK_SEL_NONE;
}

#define LC_FREQ 2700
#define LC_FREQ_2K (LC_FREQ * 2000)

#define P_MIN 2
#define P_MAX 64
#define P_INC 2

/* Constraints for PLL good behavior */
#define REF_MIN 48
#define REF_MAX 400
#define VCO_MIN 2400
#define VCO_MAX 4800

#define ABS_DIFF(a, b) ((a > b) ? (a - b) : (b - a))

struct wrpll_rnp {
	unsigned p, n2, r2;
};

static unsigned wrpll_get_budget_for_freq(int clock)
{
	unsigned budget;

	switch (clock) {
	case 25175000:
	case 25200000:
	case 27000000:
	case 27027000:
	case 37762500:
	case 37800000:
	case 40500000:
	case 40541000:
	case 54000000:
	case 54054000:
	case 59341000:
	case 59400000:
	case 72000000:
	case 74176000:
	case 74250000:
	case 81000000:
	case 81081000:
	case 89012000:
	case 89100000:
	case 108000000:
	case 108108000:
	case 111264000:
	case 111375000:
	case 148352000:
	case 148500000:
	case 162000000:
	case 162162000:
	case 222525000:
	case 222750000:
	case 296703000:
	case 297000000:
		budget = 0;
		break;
	case 233500000:
	case 245250000:
	case 247750000:
	case 253250000:
	case 298000000:
		budget = 1500;
		break;
	case 169128000:
	case 169500000:
	case 179500000:
	case 202000000:
		budget = 2000;
		break;
	case 256250000:
	case 262500000:
	case 270000000:
	case 272500000:
	case 273750000:
	case 280750000:
	case 281250000:
	case 286000000:
	case 291750000:
		budget = 4000;
		break;
	case 267250000:
	case 268500000:
		budget = 5000;
		break;
	default:
		budget = 1000;
		break;
	}

	return budget;
}

static void wrpll_update_rnp(uint64_t freq2k, unsigned budget,
			     unsigned r2, unsigned n2, unsigned p,
			     struct wrpll_rnp *best)
{
	uint64_t a, b, c, d, diff, diff_best;

	/* No best (r,n,p) yet */
	if (best->p == 0) {
		best->p = p;
		best->n2 = n2;
		best->r2 = r2;
		return;
	}

	/*
	 * Output clock is (LC_FREQ_2K / 2000) * N / (P * R), which compares to
	 * freq2k.
	 *
	 * delta = 1e6 *
	 *	   abs(freq2k - (LC_FREQ_2K * n2/(p * r2))) /
	 *	   freq2k;
	 *
	 * and we would like delta <= budget.
	 *
	 * If the discrepancy is above the PPM-based budget, always prefer to
	 * improve upon the previous solution.  However, if you're within the
	 * budget, try to maximize Ref * VCO, that is N / (P * R^2).
	 */
	a = freq2k * budget * p * r2;
	b = freq2k * budget * best->p * best->r2;
	diff = ABS_DIFF((freq2k * p * r2), (LC_FREQ_2K * n2));
	diff_best = ABS_DIFF((freq2k * best->p * best->r2),
			     (LC_FREQ_2K * best->n2));
	c = 1000000 * diff;
	d = 1000000 * diff_best;

	if (a < c && b < d) {
		/* If both are above the budget, pick the closer */
		if (best->p * best->r2 * diff < p * r2 * diff_best) {
			best->p = p;
			best->n2 = n2;
			best->r2 = r2;
		}
	} else if (a >= c && b < d) {
		/* If A is below the threshold but B is above it?  Update. */
		best->p = p;
		best->n2 = n2;
		best->r2 = r2;
	} else if (a >= c && b >= d) {
		/* Both are below the limit, so pick the higher n2/(r2*r2) */
		if (n2 * best->r2 * best->r2 > best->n2 * r2 * r2) {
			best->p = p;
			best->n2 = n2;
			best->r2 = r2;
		}
	}
	/* Otherwise a < c && b >= d, do nothing */
}

static void
intel_ddi_calculate_wrpll(int clock /* in Hz */,
			  unsigned *r2_out, unsigned *n2_out, unsigned *p_out)
{
	uint64_t freq2k;
	unsigned p, n2, r2;
	struct wrpll_rnp best = { 0, 0, 0 };
	unsigned budget;

	freq2k = clock / 100;

	budget = wrpll_get_budget_for_freq(clock);

	/* Special case handling for 540 pixel clock: bypass WR PLL entirely
	 * and directly pass the LC PLL to it. */
	if (freq2k == 5400000) {
		*n2_out = 2;
		*p_out = 1;
		*r2_out = 2;
		return;
	}

	/*
	 * Ref = LC_FREQ / R, where Ref is the actual reference input seen by
	 * the WR PLL.
	 *
	 * We want R so that REF_MIN <= Ref <= REF_MAX.
	 * Injecting R2 = 2 * R gives:
	 *   REF_MAX * r2 > LC_FREQ * 2 and
	 *   REF_MIN * r2 < LC_FREQ * 2
	 *
	 * Which means the desired boundaries for r2 are:
	 *  LC_FREQ * 2 / REF_MAX < r2 < LC_FREQ * 2 / REF_MIN
	 *
	 */
	for (r2 = LC_FREQ * 2 / REF_MAX + 1;
	     r2 <= LC_FREQ * 2 / REF_MIN;
	     r2++) {

		/*
		 * VCO = N * Ref, that is: VCO = N * LC_FREQ / R
		 *
		 * Once again we want VCO_MIN <= VCO <= VCO_MAX.
		 * Injecting R2 = 2 * R and N2 = 2 * N, we get:
		 *   VCO_MAX * r2 > n2 * LC_FREQ and
		 *   VCO_MIN * r2 < n2 * LC_FREQ)
		 *
		 * Which means the desired boundaries for n2 are:
		 * VCO_MIN * r2 / LC_FREQ < n2 < VCO_MAX * r2 / LC_FREQ
		 */
		for (n2 = VCO_MIN * r2 / LC_FREQ + 1;
		     n2 <= VCO_MAX * r2 / LC_FREQ;
		     n2++) {

			for (p = P_MIN; p <= P_MAX; p += P_INC)
				wrpll_update_rnp(freq2k, budget,
						 r2, n2, p, &best);
		}
	}

	*n2_out = best.n2;
	*p_out = best.p;
	*r2_out = best.r2;
}

/*
 * Tries to find a PLL for the CRTC. If it finds, it increases the refcount and
 * stores it in intel_crtc->ddi_pll_sel, so other mode sets won't be able to
 * steal the selected PLL. You need to call intel_ddi_pll_enable to actually
 * enable the PLL.
 */
bool intel_ddi_pll_select(struct intel_crtc *intel_crtc)
{
	struct drm_crtc *crtc = &intel_crtc->base;
	struct intel_encoder *intel_encoder = intel_ddi_get_crtc_encoder(crtc);
	struct drm_encoder *encoder = &intel_encoder->base;
	struct drm_i915_private *dev_priv = crtc->dev->dev_private;
	struct intel_ddi_plls *plls = &dev_priv->ddi_plls;
	int type = intel_encoder->type;
	enum pipe pipe = intel_crtc->pipe;
	int clock = intel_crtc->config.port_clock;

	intel_ddi_put_crtc_pll(crtc);

	if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP) {
		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);

		switch (intel_dp->link_bw) {
		case DP_LINK_BW_1_62:
			intel_crtc->ddi_pll_sel = PORT_CLK_SEL_LCPLL_810;
			break;
		case DP_LINK_BW_2_7:
			intel_crtc->ddi_pll_sel = PORT_CLK_SEL_LCPLL_1350;
			break;
		case DP_LINK_BW_5_4:
			intel_crtc->ddi_pll_sel = PORT_CLK_SEL_LCPLL_2700;
			break;
		default:
			DRM_ERROR("Link bandwidth %d unsupported\n",
				  intel_dp->link_bw);
			return false;
		}

	} else if (type == INTEL_OUTPUT_HDMI) {
		uint32_t reg, val;
		unsigned p, n2, r2;

		intel_ddi_calculate_wrpll(clock * 1000, &r2, &n2, &p);

		val = WRPLL_PLL_ENABLE | WRPLL_PLL_SELECT_LCPLL_2700 |
		      WRPLL_DIVIDER_REFERENCE(r2) | WRPLL_DIVIDER_FEEDBACK(n2) |
		      WRPLL_DIVIDER_POST(p);

		if (val == I915_READ(WRPLL_CTL1)) {
			DRM_DEBUG_KMS("Reusing WRPLL 1 on pipe %c\n",
				      pipe_name(pipe));
			reg = WRPLL_CTL1;
		} else if (val == I915_READ(WRPLL_CTL2)) {
			DRM_DEBUG_KMS("Reusing WRPLL 2 on pipe %c\n",
				      pipe_name(pipe));
			reg = WRPLL_CTL2;
		} else if (plls->wrpll1_refcount == 0) {
			DRM_DEBUG_KMS("Using WRPLL 1 on pipe %c\n",
				      pipe_name(pipe));
			reg = WRPLL_CTL1;
		} else if (plls->wrpll2_refcount == 0) {
			DRM_DEBUG_KMS("Using WRPLL 2 on pipe %c\n",
				      pipe_name(pipe));
			reg = WRPLL_CTL2;
		} else {
			DRM_ERROR("No WRPLLs available!\n");
			return false;
		}

		DRM_DEBUG_KMS("WRPLL: %dKHz refresh rate with p=%d, n2=%d r2=%d\n",
			      clock, p, n2, r2);

		if (reg == WRPLL_CTL1) {
			plls->wrpll1_refcount++;
			intel_crtc->ddi_pll_sel = PORT_CLK_SEL_WRPLL1;
		} else {
			plls->wrpll2_refcount++;
			intel_crtc->ddi_pll_sel = PORT_CLK_SEL_WRPLL2;
		}

	} else if (type == INTEL_OUTPUT_ANALOG) {
		if (plls->spll_refcount == 0) {
			DRM_DEBUG_KMS("Using SPLL on pipe %c\n",
				      pipe_name(pipe));
			plls->spll_refcount++;
			intel_crtc->ddi_pll_sel = PORT_CLK_SEL_SPLL;
		} else {
			DRM_ERROR("SPLL already in use\n");
			return false;
		}

	} else {
		WARN(1, "Invalid DDI encoder type %d\n", type);
		return false;
	}

	return true;
}

/*
 * To be called after intel_ddi_pll_select(). That one selects the PLL to be
 * used, this one actually enables the PLL.
 */
void intel_ddi_pll_enable(struct intel_crtc *crtc)
{
	struct drm_device *dev = crtc->base.dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct intel_ddi_plls *plls = &dev_priv->ddi_plls;
	int clock = crtc->config.port_clock;
	uint32_t reg, cur_val, new_val;
	int refcount;
	const char *pll_name;
	uint32_t enable_bit = (1 << 31);
	unsigned int p, n2, r2;

	BUILD_BUG_ON(enable_bit != SPLL_PLL_ENABLE);
	BUILD_BUG_ON(enable_bit != WRPLL_PLL_ENABLE);

	switch (crtc->ddi_pll_sel) {
	case PORT_CLK_SEL_LCPLL_2700:
	case PORT_CLK_SEL_LCPLL_1350:
	case PORT_CLK_SEL_LCPLL_810:
		/*
		 * LCPLL should always be enabled at this point of the mode set
		 * sequence, so nothing to do.
		 */
		return;

	case PORT_CLK_SEL_SPLL:
		pll_name = "SPLL";
		reg = SPLL_CTL;
		refcount = plls->spll_refcount;
		new_val = SPLL_PLL_ENABLE | SPLL_PLL_FREQ_1350MHz |
			  SPLL_PLL_SSC;
		break;

	case PORT_CLK_SEL_WRPLL1:
	case PORT_CLK_SEL_WRPLL2:
		if (crtc->ddi_pll_sel == PORT_CLK_SEL_WRPLL1) {
			pll_name = "WRPLL1";
			reg = WRPLL_CTL1;
			refcount = plls->wrpll1_refcount;
		} else {
			pll_name = "WRPLL2";
			reg = WRPLL_CTL2;
			refcount = plls->wrpll2_refcount;
		}

		intel_ddi_calculate_wrpll(clock * 1000, &r2, &n2, &p);

		new_val = WRPLL_PLL_ENABLE | WRPLL_PLL_SELECT_LCPLL_2700 |
			  WRPLL_DIVIDER_REFERENCE(r2) |
			  WRPLL_DIVIDER_FEEDBACK(n2) | WRPLL_DIVIDER_POST(p);

		break;

	case PORT_CLK_SEL_NONE:
		WARN(1, "Bad selected pll: PORT_CLK_SEL_NONE\n");
		return;
	default:
		WARN(1, "Bad selected pll: 0x%08x\n", crtc->ddi_pll_sel);
		return;
	}

	cur_val = I915_READ(reg);

	WARN(refcount < 1, "Bad %s refcount: %d\n", pll_name, refcount);
	if (refcount == 1) {
		WARN(cur_val & enable_bit, "%s already enabled\n", pll_name);
		I915_WRITE(reg, new_val);
		POSTING_READ(reg);
		udelay(20);
	} else {
		WARN((cur_val & enable_bit) == 0, "%s disabled\n", pll_name);
	}
}

void intel_ddi_set_pipe_settings(struct drm_crtc *crtc)
{
	struct drm_i915_private *dev_priv = crtc->dev->dev_private;
	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
	struct intel_encoder *intel_encoder = intel_ddi_get_crtc_encoder(crtc);
	enum transcoder cpu_transcoder = intel_crtc->config.cpu_transcoder;
	int type = intel_encoder->type;
	uint32_t temp;

	if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP) {

		temp = TRANS_MSA_SYNC_CLK;
		switch (intel_crtc->config.pipe_bpp) {
		case 18:
			temp |= TRANS_MSA_6_BPC;
			break;
		case 24:
			temp |= TRANS_MSA_8_BPC;
			break;
		case 30:
			temp |= TRANS_MSA_10_BPC;
			break;
		case 36:
			temp |= TRANS_MSA_12_BPC;
			break;
		default:
			BUG();
		}
		I915_WRITE(TRANS_MSA_MISC(cpu_transcoder), temp);
	}
}

void intel_ddi_enable_transcoder_func(struct drm_crtc *crtc)
{
	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
	struct intel_encoder *intel_encoder = intel_ddi_get_crtc_encoder(crtc);
	struct drm_encoder *encoder = &intel_encoder->base;
	struct drm_device *dev = crtc->dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	enum pipe pipe = intel_crtc->pipe;
	enum transcoder cpu_transcoder = intel_crtc->config.cpu_transcoder;
	enum port port = intel_ddi_get_encoder_port(intel_encoder);
	int type = intel_encoder->type;
	uint32_t temp;

	/* Enable TRANS_DDI_FUNC_CTL for the pipe to work in HDMI mode */
	temp = TRANS_DDI_FUNC_ENABLE;
	temp |= TRANS_DDI_SELECT_PORT(port);

	switch (intel_crtc->config.pipe_bpp) {
	case 18:
		temp |= TRANS_DDI_BPC_6;
		break;
	case 24:
		temp |= TRANS_DDI_BPC_8;
		break;
	case 30:
		temp |= TRANS_DDI_BPC_10;
		break;
	case 36:
		temp |= TRANS_DDI_BPC_12;
		break;
	default:
		BUG();
	}

	if (intel_crtc->config.adjusted_mode.flags & DRM_MODE_FLAG_PVSYNC)
		temp |= TRANS_DDI_PVSYNC;
	if (intel_crtc->config.adjusted_mode.flags & DRM_MODE_FLAG_PHSYNC)
		temp |= TRANS_DDI_PHSYNC;

	if (cpu_transcoder == TRANSCODER_EDP) {
		switch (pipe) {
		case PIPE_A:
			/* On Haswell, can only use the always-on power well for
			 * eDP when not using the panel fitter, and when not
			 * using motion blur mitigation (which we don't
			 * support). */
			if (IS_HASWELL(dev) && intel_crtc->config.pch_pfit.enabled)
				temp |= TRANS_DDI_EDP_INPUT_A_ONOFF;
			else
				temp |= TRANS_DDI_EDP_INPUT_A_ON;
			break;
		case PIPE_B:
			temp |= TRANS_DDI_EDP_INPUT_B_ONOFF;
			break;
		case PIPE_C:
			temp |= TRANS_DDI_EDP_INPUT_C_ONOFF;
			break;
		default:
			BUG();
			break;
		}
	}

	if (type == INTEL_OUTPUT_HDMI) {
		struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(encoder);

		if (intel_hdmi->has_hdmi_sink)
			temp |= TRANS_DDI_MODE_SELECT_HDMI;
		else
			temp |= TRANS_DDI_MODE_SELECT_DVI;

	} else if (type == INTEL_OUTPUT_ANALOG) {
		temp |= TRANS_DDI_MODE_SELECT_FDI;
		temp |= (intel_crtc->config.fdi_lanes - 1) << 1;

	} else if (type == INTEL_OUTPUT_DISPLAYPORT ||
		   type == INTEL_OUTPUT_EDP) {
		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);

		temp |= TRANS_DDI_MODE_SELECT_DP_SST;

		temp |= DDI_PORT_WIDTH(intel_dp->lane_count);
	} else {
		WARN(1, "Invalid encoder type %d for pipe %c\n",
		     intel_encoder->type, pipe_name(pipe));
	}

	I915_WRITE(TRANS_DDI_FUNC_CTL(cpu_transcoder), temp);
}

void intel_ddi_disable_transcoder_func(struct drm_i915_private *dev_priv,
				       enum transcoder cpu_transcoder)
{
	uint32_t reg = TRANS_DDI_FUNC_CTL(cpu_transcoder);
	uint32_t val = I915_READ(reg);

	val &= ~(TRANS_DDI_FUNC_ENABLE | TRANS_DDI_PORT_MASK);
	val |= TRANS_DDI_PORT_NONE;
	I915_WRITE(reg, val);
}

bool intel_ddi_connector_get_hw_state(struct intel_connector *intel_connector)
{
	struct drm_device *dev = intel_connector->base.dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct intel_encoder *intel_encoder = intel_connector->encoder;
	int type = intel_connector->base.connector_type;
	enum port port = intel_ddi_get_encoder_port(intel_encoder);
	enum pipe pipe = 0;
	enum transcoder cpu_transcoder;
	uint32_t tmp;

	if (!intel_encoder->get_hw_state(intel_encoder, &pipe))
		return false;

	if (port == PORT_A)
		cpu_transcoder = TRANSCODER_EDP;
	else
		cpu_transcoder = (enum transcoder) pipe;

	tmp = I915_READ(TRANS_DDI_FUNC_CTL(cpu_transcoder));

	switch (tmp & TRANS_DDI_MODE_SELECT_MASK) {
	case TRANS_DDI_MODE_SELECT_HDMI:
	case TRANS_DDI_MODE_SELECT_DVI:
		return (type == DRM_MODE_CONNECTOR_HDMIA);

	case TRANS_DDI_MODE_SELECT_DP_SST:
		if (type == DRM_MODE_CONNECTOR_eDP)
			return true;
	case TRANS_DDI_MODE_SELECT_DP_MST:
		return (type == DRM_MODE_CONNECTOR_DisplayPort);

	case TRANS_DDI_MODE_SELECT_FDI:
		return (type == DRM_MODE_CONNECTOR_VGA);

	default:
		return false;
	}
}

bool intel_ddi_get_hw_state(struct intel_encoder *encoder,
			    enum pipe *pipe)
{
	struct drm_device *dev = encoder->base.dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	enum port port = intel_ddi_get_encoder_port(encoder);
	u32 tmp;
	int i;

	tmp = I915_READ(DDI_BUF_CTL(port));

	if (!(tmp & DDI_BUF_CTL_ENABLE))
		return false;

	if (port == PORT_A) {
		tmp = I915_READ(TRANS_DDI_FUNC_CTL(TRANSCODER_EDP));

		switch (tmp & TRANS_DDI_EDP_INPUT_MASK) {
		case TRANS_DDI_EDP_INPUT_A_ON:
		case TRANS_DDI_EDP_INPUT_A_ONOFF:
			*pipe = PIPE_A;
			break;
		case TRANS_DDI_EDP_INPUT_B_ONOFF:
			*pipe = PIPE_B;
			break;
		case TRANS_DDI_EDP_INPUT_C_ONOFF:
			*pipe = PIPE_C;
			break;
		}

		return true;
	} else {
		for (i = TRANSCODER_A; i <= TRANSCODER_C; i++) {
			tmp = I915_READ(TRANS_DDI_FUNC_CTL(i));

			if ((tmp & TRANS_DDI_PORT_MASK)
			    == TRANS_DDI_SELECT_PORT(port)) {
				*pipe = i;
				return true;
			}
		}
	}

	DRM_DEBUG_KMS("No pipe for ddi port %c found\n", port_name(port));

	return false;
}

static uint32_t intel_ddi_get_crtc_pll(struct drm_i915_private *dev_priv,
				       enum pipe pipe)
{
	uint32_t temp, ret;
	enum port port = I915_MAX_PORTS;
	enum transcoder cpu_transcoder = intel_pipe_to_cpu_transcoder(dev_priv,
								      pipe);
	int i;

	if (cpu_transcoder == TRANSCODER_EDP) {
		port = PORT_A;
	} else {
		temp = I915_READ(TRANS_DDI_FUNC_CTL(cpu_transcoder));
		temp &= TRANS_DDI_PORT_MASK;

		for (i = PORT_B; i <= PORT_E; i++)
			if (temp == TRANS_DDI_SELECT_PORT(i))
				port = i;
	}

	if (port == I915_MAX_PORTS) {
		WARN(1, "Pipe %c enabled on an unknown port\n",
		     pipe_name(pipe));
		ret = PORT_CLK_SEL_NONE;
	} else {
		ret = I915_READ(PORT_CLK_SEL(port));
		DRM_DEBUG_KMS("Pipe %c connected to port %c using clock "
			      "0x%08x\n", pipe_name(pipe), port_name(port),
			      ret);
	}

	return ret;
}

void intel_ddi_setup_hw_pll_state(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	enum pipe pipe;
	struct intel_crtc *intel_crtc;

	dev_priv->ddi_plls.spll_refcount = 0;
	dev_priv->ddi_plls.wrpll1_refcount = 0;
	dev_priv->ddi_plls.wrpll2_refcount = 0;

	for_each_pipe(pipe) {
		intel_crtc =
			to_intel_crtc(dev_priv->pipe_to_crtc_mapping[pipe]);

		if (!intel_crtc->active) {
			intel_crtc->ddi_pll_sel = PORT_CLK_SEL_NONE;
			continue;
		}

		intel_crtc->ddi_pll_sel = intel_ddi_get_crtc_pll(dev_priv,
								 pipe);

		switch (intel_crtc->ddi_pll_sel) {
		case PORT_CLK_SEL_SPLL:
			dev_priv->ddi_plls.spll_refcount++;
			break;
		case PORT_CLK_SEL_WRPLL1:
			dev_priv->ddi_plls.wrpll1_refcount++;
			break;
		case PORT_CLK_SEL_WRPLL2:
			dev_priv->ddi_plls.wrpll2_refcount++;
			break;
		}
	}
}

void intel_ddi_enable_pipe_clock(struct intel_crtc *intel_crtc)
{
	struct drm_crtc *crtc = &intel_crtc->base;
	struct drm_i915_private *dev_priv = crtc->dev->dev_private;
	struct intel_encoder *intel_encoder = intel_ddi_get_crtc_encoder(crtc);
	enum port port = intel_ddi_get_encoder_port(intel_encoder);
	enum transcoder cpu_transcoder = intel_crtc->config.cpu_transcoder;

	if (cpu_transcoder != TRANSCODER_EDP)
		I915_WRITE(TRANS_CLK_SEL(cpu_transcoder),
			   TRANS_CLK_SEL_PORT(port));
}

void intel_ddi_disable_pipe_clock(struct intel_crtc *intel_crtc)
{
	struct drm_i915_private *dev_priv = intel_crtc->base.dev->dev_private;
	enum transcoder cpu_transcoder = intel_crtc->config.cpu_transcoder;

	if (cpu_transcoder != TRANSCODER_EDP)
		I915_WRITE(TRANS_CLK_SEL(cpu_transcoder),
			   TRANS_CLK_SEL_DISABLED);
}

static void intel_ddi_pre_enable(struct intel_encoder *intel_encoder)
{
	struct drm_encoder *encoder = &intel_encoder->base;
	struct drm_crtc *crtc = encoder->crtc;
	struct drm_i915_private *dev_priv = encoder->dev->dev_private;
	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
	enum port port = intel_ddi_get_encoder_port(intel_encoder);
	int type = intel_encoder->type;

	if (type == INTEL_OUTPUT_EDP) {
		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
		ironlake_edp_panel_on(intel_dp);
	}

	WARN_ON(intel_crtc->ddi_pll_sel == PORT_CLK_SEL_NONE);
	I915_WRITE(PORT_CLK_SEL(port), intel_crtc->ddi_pll_sel);

	if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP) {
		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);

		intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON);
		intel_dp_start_link_train(intel_dp);
		intel_dp_complete_link_train(intel_dp);
		if (port != PORT_A)
			intel_dp_stop_link_train(intel_dp);
	}
}

static void intel_ddi_post_disable(struct intel_encoder *intel_encoder)
{
	struct drm_encoder *encoder = &intel_encoder->base;
	struct drm_i915_private *dev_priv = encoder->dev->dev_private;
	enum port port = intel_ddi_get_encoder_port(intel_encoder);
	int type = intel_encoder->type;
	uint32_t val;
	bool wait = false;

	val = I915_READ(DDI_BUF_CTL(port));
	if (val & DDI_BUF_CTL_ENABLE) {
		val &= ~DDI_BUF_CTL_ENABLE;
		I915_WRITE(DDI_BUF_CTL(port), val);
		wait = true;
	}

	val = I915_READ(DP_TP_CTL(port));
	val &= ~(DP_TP_CTL_ENABLE | DP_TP_CTL_LINK_TRAIN_MASK);
	val |= DP_TP_CTL_LINK_TRAIN_PAT1;
	I915_WRITE(DP_TP_CTL(port), val);

	if (wait)
		intel_wait_ddi_buf_idle(dev_priv, port);

	if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP) {
		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
		intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_OFF);
		ironlake_edp_panel_vdd_on(intel_dp);
		ironlake_edp_panel_off(intel_dp);
	}

	I915_WRITE(PORT_CLK_SEL(port), PORT_CLK_SEL_NONE);
}

static void intel_enable_ddi(struct intel_encoder *intel_encoder)
{
	struct drm_encoder *encoder = &intel_encoder->base;
	struct drm_crtc *crtc = encoder->crtc;
	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
	int pipe = intel_crtc->pipe;
	struct drm_device *dev = encoder->dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	enum port port = intel_ddi_get_encoder_port(intel_encoder);
	int type = intel_encoder->type;
	uint32_t tmp;

	if (type == INTEL_OUTPUT_HDMI) {
		struct intel_digital_port *intel_dig_port =
			enc_to_dig_port(encoder);

		/* In HDMI/DVI mode, the port width, and swing/emphasis values
		 * are ignored so nothing special needs to be done besides
		 * enabling the port.
		 */
		I915_WRITE(DDI_BUF_CTL(port),
			   intel_dig_port->saved_port_bits |
			   DDI_BUF_CTL_ENABLE);
	} else if (type == INTEL_OUTPUT_EDP) {
		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);

		if (port == PORT_A)
			intel_dp_stop_link_train(intel_dp);

		ironlake_edp_backlight_on(intel_dp);
		intel_edp_psr_enable(intel_dp);
	}

	if (intel_crtc->eld_vld && type != INTEL_OUTPUT_EDP) {
		tmp = I915_READ(HSW_AUD_PIN_ELD_CP_VLD);
		tmp |= ((AUDIO_OUTPUT_ENABLE_A | AUDIO_ELD_VALID_A) << (pipe * 4));
		I915_WRITE(HSW_AUD_PIN_ELD_CP_VLD, tmp);
	}
}

static void intel_disable_ddi(struct intel_encoder *intel_encoder)
{
	struct drm_encoder *encoder = &intel_encoder->base;
	struct drm_crtc *crtc = encoder->crtc;
	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
	int pipe = intel_crtc->pipe;
	int type = intel_encoder->type;
	struct drm_device *dev = encoder->dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	uint32_t tmp;

	if (intel_crtc->eld_vld && type != INTEL_OUTPUT_EDP) {
		tmp = I915_READ(HSW_AUD_PIN_ELD_CP_VLD);
		tmp &= ~((AUDIO_OUTPUT_ENABLE_A | AUDIO_ELD_VALID_A) <<
			 (pipe * 4));
		I915_WRITE(HSW_AUD_PIN_ELD_CP_VLD, tmp);
	}

	if (type == INTEL_OUTPUT_EDP) {
		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);

		intel_edp_psr_disable(intel_dp);
		ironlake_edp_backlight_off(intel_dp);
	}
}

int intel_ddi_get_cdclk_freq(struct drm_i915_private *dev_priv)
{
	struct drm_device *dev = dev_priv->dev;
	uint32_t lcpll = I915_READ(LCPLL_CTL);
	uint32_t freq = lcpll & LCPLL_CLK_FREQ_MASK;

	if (lcpll & LCPLL_CD_SOURCE_FCLK) {
		return 800000;
	} else if (I915_READ(HSW_FUSE_STRAP) & HSW_CDCLK_LIMIT) {
		return 450000;
	} else if (freq == LCPLL_CLK_FREQ_450) {
		return 450000;
	} else if (IS_HASWELL(dev)) {
		if (IS_ULT(dev))
			return 337500;
		else
			return 540000;
	} else {
		if (freq == LCPLL_CLK_FREQ_54O_BDW)
			return 540000;
		else if (freq == LCPLL_CLK_FREQ_337_5_BDW)
			return 337500;
		else
			return 675000;
	}
}

void intel_ddi_pll_init(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	uint32_t val = I915_READ(LCPLL_CTL);

	/* The LCPLL register should be turned on by the BIOS. For now let's
	 * just check its state and print errors in case something is wrong.
	 * Don't even try to turn it on.
	 */

	DRM_DEBUG_KMS("CDCLK running at %dKHz\n",
		      intel_ddi_get_cdclk_freq(dev_priv));

	if (val & LCPLL_CD_SOURCE_FCLK)
		DRM_ERROR("CDCLK source is not LCPLL\n");

	if (val & LCPLL_PLL_DISABLE)
		DRM_ERROR("LCPLL is disabled\n");
}

void intel_ddi_prepare_link_retrain(struct drm_encoder *encoder)
{
	struct intel_digital_port *intel_dig_port = enc_to_dig_port(encoder);
	struct intel_dp *intel_dp = &intel_dig_port->dp;
	struct drm_i915_private *dev_priv = encoder->dev->dev_private;
	enum port port = intel_dig_port->port;
	uint32_t val;
	bool wait = false;

	if (I915_READ(DP_TP_CTL(port)) & DP_TP_CTL_ENABLE) {
		val = I915_READ(DDI_BUF_CTL(port));
		if (val & DDI_BUF_CTL_ENABLE) {
			val &= ~DDI_BUF_CTL_ENABLE;
			I915_WRITE(DDI_BUF_CTL(port), val);
			wait = true;
		}

		val = I915_READ(DP_TP_CTL(port));
		val &= ~(DP_TP_CTL_ENABLE | DP_TP_CTL_LINK_TRAIN_MASK);
		val |= DP_TP_CTL_LINK_TRAIN_PAT1;
		I915_WRITE(DP_TP_CTL(port), val);
		POSTING_READ(DP_TP_CTL(port));

		if (wait)
			intel_wait_ddi_buf_idle(dev_priv, port);
	}

	val = DP_TP_CTL_ENABLE | DP_TP_CTL_MODE_SST |
	      DP_TP_CTL_LINK_TRAIN_PAT1 | DP_TP_CTL_SCRAMBLE_DISABLE;
	if (drm_dp_enhanced_frame_cap(intel_dp->dpcd))
		val |= DP_TP_CTL_ENHANCED_FRAME_ENABLE;
	I915_WRITE(DP_TP_CTL(port), val);
	POSTING_READ(DP_TP_CTL(port));

	intel_dp->DP |= DDI_BUF_CTL_ENABLE;
	I915_WRITE(DDI_BUF_CTL(port), intel_dp->DP);
	POSTING_READ(DDI_BUF_CTL(port));

	udelay(600);
}

void intel_ddi_fdi_disable(struct drm_crtc *crtc)
{
	struct drm_i915_private *dev_priv = crtc->dev->dev_private;
	struct intel_encoder *intel_encoder = intel_ddi_get_crtc_encoder(crtc);
	uint32_t val;

	intel_ddi_post_disable(intel_encoder);

	val = I915_READ(_FDI_RXA_CTL);
	val &= ~FDI_RX_ENABLE;
	I915_WRITE(_FDI_RXA_CTL, val);

	val = I915_READ(_FDI_RXA_MISC);
	val &= ~(FDI_RX_PWRDN_LANE1_MASK | FDI_RX_PWRDN_LANE0_MASK);
	val |= FDI_RX_PWRDN_LANE1_VAL(2) | FDI_RX_PWRDN_LANE0_VAL(2);
	I915_WRITE(_FDI_RXA_MISC, val);

	val = I915_READ(_FDI_RXA_CTL);
	val &= ~FDI_PCDCLK;
	I915_WRITE(_FDI_RXA_CTL, val);

	val = I915_READ(_FDI_RXA_CTL);
	val &= ~FDI_RX_PLL_ENABLE;
	I915_WRITE(_FDI_RXA_CTL, val);
}

static void intel_ddi_hot_plug(struct intel_encoder *intel_encoder)
{
	struct intel_dp *intel_dp = enc_to_intel_dp(&intel_encoder->base);
	int type = intel_encoder->type;

	if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP)
		intel_dp_check_link_status(intel_dp);
}

void intel_ddi_get_config(struct intel_encoder *encoder,
			  struct intel_crtc_config *pipe_config)
{
	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->base.crtc);
	enum transcoder cpu_transcoder = intel_crtc->config.cpu_transcoder;
	u32 temp, flags = 0;

	temp = I915_READ(TRANS_DDI_FUNC_CTL(cpu_transcoder));
	if (temp & TRANS_DDI_PHSYNC)
		flags |= DRM_MODE_FLAG_PHSYNC;
	else
		flags |= DRM_MODE_FLAG_NHSYNC;
	if (temp & TRANS_DDI_PVSYNC)
		flags |= DRM_MODE_FLAG_PVSYNC;
	else
		flags |= DRM_MODE_FLAG_NVSYNC;

	pipe_config->adjusted_mode.flags |= flags;

	switch (temp & TRANS_DDI_BPC_MASK) {
	case TRANS_DDI_BPC_6:
		pipe_config->pipe_bpp = 18;
		break;
	case TRANS_DDI_BPC_8:
		pipe_config->pipe_bpp = 24;
		break;
	case TRANS_DDI_BPC_10:
		pipe_config->pipe_bpp = 30;
		break;
	case TRANS_DDI_BPC_12:
		pipe_config->pipe_bpp = 36;
		break;
	default:
		break;
	}

	switch (temp & TRANS_DDI_MODE_SELECT_MASK) {
	case TRANS_DDI_MODE_SELECT_HDMI:
	case TRANS_DDI_MODE_SELECT_DVI:
	case TRANS_DDI_MODE_SELECT_FDI:
		break;
	case TRANS_DDI_MODE_SELECT_DP_SST:
	case TRANS_DDI_MODE_SELECT_DP_MST:
		pipe_config->has_dp_encoder = true;
		intel_dp_get_m_n(intel_crtc, pipe_config);
		break;
	default:
		break;
	}

	if (encoder->type == INTEL_OUTPUT_EDP && dev_priv->vbt.edp_bpp &&
	    pipe_config->pipe_bpp > dev_priv->vbt.edp_bpp) {
		/*
		 * This is a big fat ugly hack.
		 *
		 * Some machines in UEFI boot mode provide us a VBT that has 18
		 * bpp and 1.62 GHz link bandwidth for eDP, which for reasons
		 * unknown we fail to light up. Yet the same BIOS boots up with
		 * 24 bpp and 2.7 GHz link. Use the same bpp as the BIOS uses as
		 * max, not what it tells us to use.
		 *
		 * Note: This will still be broken if the eDP panel is not lit
		 * up by the BIOS, and thus we can't get the mode at module
		 * load.
		 */
		DRM_DEBUG_KMS("pipe has %d bpp for eDP panel, overriding BIOS-provided max %d bpp\n",
			      pipe_config->pipe_bpp, dev_priv->vbt.edp_bpp);
		dev_priv->vbt.edp_bpp = pipe_config->pipe_bpp;
	}
}

static void intel_ddi_destroy(struct drm_encoder *encoder)
{
	/* HDMI has nothing special to destroy, so we can go with this. */
	intel_dp_encoder_destroy(encoder);
}

static bool intel_ddi_compute_config(struct intel_encoder *encoder,
				     struct intel_crtc_config *pipe_config)
{
	int type = encoder->type;
	int port = intel_ddi_get_encoder_port(encoder);

	WARN(type == INTEL_OUTPUT_UNKNOWN, "compute_config() on unknown output!\n");

	if (port == PORT_A)
		pipe_config->cpu_transcoder = TRANSCODER_EDP;

	if (type == INTEL_OUTPUT_HDMI)
		return intel_hdmi_compute_config(encoder, pipe_config);
	else
		return intel_dp_compute_config(encoder, pipe_config);
}

static const struct drm_encoder_funcs intel_ddi_funcs = {
	.destroy = intel_ddi_destroy,
};

static struct intel_connector *
intel_ddi_init_dp_connector(struct intel_digital_port *intel_dig_port)
{
	struct intel_connector *connector;
	enum port port = intel_dig_port->port;

	connector = kzalloc(sizeof(*connector), GFP_KERNEL);
	if (!connector)
		return NULL;

	intel_dig_port->dp.output_reg = DDI_BUF_CTL(port);
	if (!intel_dp_init_connector(intel_dig_port, connector)) {
		kfree(connector);
		return NULL;
	}

	return connector;
}

static struct intel_connector *
intel_ddi_init_hdmi_connector(struct intel_digital_port *intel_dig_port)
{
	struct intel_connector *connector;
	enum port port = intel_dig_port->port;

	connector = kzalloc(sizeof(*connector), GFP_KERNEL);
	if (!connector)
		return NULL;

	intel_dig_port->hdmi.hdmi_reg = DDI_BUF_CTL(port);
	intel_hdmi_init_connector(intel_dig_port, connector);

	return connector;
}

void intel_ddi_init(struct drm_device *dev, enum port port)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct intel_digital_port *intel_dig_port;
	struct intel_encoder *intel_encoder;
	struct drm_encoder *encoder;
	struct intel_connector *hdmi_connector = NULL;
	struct intel_connector *dp_connector = NULL;
	bool init_hdmi, init_dp;

	init_hdmi = (dev_priv->vbt.ddi_port_info[port].supports_dvi ||
		     dev_priv->vbt.ddi_port_info[port].supports_hdmi);
	init_dp = dev_priv->vbt.ddi_port_info[port].supports_dp;
	if (!init_dp && !init_hdmi) {
		DRM_DEBUG_KMS("VBT says port %c is not DVI/HDMI/DP compatible\n",
			      port_name(port));
		init_hdmi = true;
		init_dp = true;
	}

	intel_dig_port = kzalloc(sizeof(*intel_dig_port), GFP_KERNEL);
	if (!intel_dig_port)
		return;

	intel_encoder = &intel_dig_port->base;
	encoder = &intel_encoder->base;

	drm_encoder_init(dev, encoder, &intel_ddi_funcs,
			 DRM_MODE_ENCODER_TMDS);

	intel_encoder->compute_config = intel_ddi_compute_config;
	intel_encoder->mode_set = intel_ddi_mode_set;
	intel_encoder->enable = intel_enable_ddi;
	intel_encoder->pre_enable = intel_ddi_pre_enable;
	intel_encoder->disable = intel_disable_ddi;
	intel_encoder->post_disable = intel_ddi_post_disable;
	intel_encoder->get_hw_state = intel_ddi_get_hw_state;
	intel_encoder->get_config = intel_ddi_get_config;

	intel_dig_port->port = port;
	intel_dig_port->saved_port_bits = I915_READ(DDI_BUF_CTL(port)) &
					  (DDI_BUF_PORT_REVERSAL |
					   DDI_A_4_LANES);

	intel_encoder->type = INTEL_OUTPUT_UNKNOWN;
	intel_encoder->crtc_mask =  (1 << 0) | (1 << 1) | (1 << 2);
	intel_encoder->cloneable = false;
	intel_encoder->hot_plug = intel_ddi_hot_plug;

	if (init_dp)
		dp_connector = intel_ddi_init_dp_connector(intel_dig_port);

	/* In theory we don't need the encoder->type check, but leave it just in
	 * case we have some really bad VBTs... */
	if (intel_encoder->type != INTEL_OUTPUT_EDP && init_hdmi)
		hdmi_connector = intel_ddi_init_hdmi_connector(intel_dig_port);

	if (!dp_connector && !hdmi_connector) {
		drm_encoder_cleanup(encoder);
		kfree(intel_dig_port);
	}
}