linux/drivers/gpu/drm/i915/intel_dpio_phy.c

/*
 * Copyright © 2014-2016 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.
 */

#include "intel_drv.h"

void chv_set_phy_signal_level(struct intel_encoder *encoder,
			      u32 deemph_reg_value, u32 margin_reg_value,
			      bool uniq_trans_scale)
{
	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
	struct intel_digital_port *dport = enc_to_dig_port(&encoder->base);
	struct intel_crtc *intel_crtc = to_intel_crtc(dport->base.base.crtc);
	enum dpio_channel ch = vlv_dport_to_channel(dport);
	enum pipe pipe = intel_crtc->pipe;
	u32 val;
	int i;

	mutex_lock(&dev_priv->sb_lock);

	/* Clear calc init */
	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW10(ch));
	val &= ~(DPIO_PCS_SWING_CALC_TX0_TX2 | DPIO_PCS_SWING_CALC_TX1_TX3);
	val &= ~(DPIO_PCS_TX1DEEMP_MASK | DPIO_PCS_TX2DEEMP_MASK);
	val |= DPIO_PCS_TX1DEEMP_9P5 | DPIO_PCS_TX2DEEMP_9P5;
	vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW10(ch), val);

	if (intel_crtc->config->lane_count > 2) {
		val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW10(ch));
		val &= ~(DPIO_PCS_SWING_CALC_TX0_TX2 | DPIO_PCS_SWING_CALC_TX1_TX3);
		val &= ~(DPIO_PCS_TX1DEEMP_MASK | DPIO_PCS_TX2DEEMP_MASK);
		val |= DPIO_PCS_TX1DEEMP_9P5 | DPIO_PCS_TX2DEEMP_9P5;
		vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW10(ch), val);
	}

	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW9(ch));
	val &= ~(DPIO_PCS_TX1MARGIN_MASK | DPIO_PCS_TX2MARGIN_MASK);
	val |= DPIO_PCS_TX1MARGIN_000 | DPIO_PCS_TX2MARGIN_000;
	vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW9(ch), val);

	if (intel_crtc->config->lane_count > 2) {
		val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW9(ch));
		val &= ~(DPIO_PCS_TX1MARGIN_MASK | DPIO_PCS_TX2MARGIN_MASK);
		val |= DPIO_PCS_TX1MARGIN_000 | DPIO_PCS_TX2MARGIN_000;
		vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW9(ch), val);
	}

	/* Program swing deemph */
	for (i = 0; i < intel_crtc->config->lane_count; i++) {
		val = vlv_dpio_read(dev_priv, pipe, CHV_TX_DW4(ch, i));
		val &= ~DPIO_SWING_DEEMPH9P5_MASK;
		val |= deemph_reg_value << DPIO_SWING_DEEMPH9P5_SHIFT;
		vlv_dpio_write(dev_priv, pipe, CHV_TX_DW4(ch, i), val);
	}

	/* Program swing margin */
	for (i = 0; i < intel_crtc->config->lane_count; i++) {
		val = vlv_dpio_read(dev_priv, pipe, CHV_TX_DW2(ch, i));

		val &= ~DPIO_SWING_MARGIN000_MASK;
		val |= margin_reg_value << DPIO_SWING_MARGIN000_SHIFT;

		/*
		 * Supposedly this value shouldn't matter when unique transition
		 * scale is disabled, but in fact it does matter. Let's just
		 * always program the same value and hope it's OK.
		 */
		val &= ~(0xff << DPIO_UNIQ_TRANS_SCALE_SHIFT);
		val |= 0x9a << DPIO_UNIQ_TRANS_SCALE_SHIFT;

		vlv_dpio_write(dev_priv, pipe, CHV_TX_DW2(ch, i), val);
	}

	/*
	 * The document said it needs to set bit 27 for ch0 and bit 26
	 * for ch1. Might be a typo in the doc.
	 * For now, for this unique transition scale selection, set bit
	 * 27 for ch0 and ch1.
	 */
	for (i = 0; i < intel_crtc->config->lane_count; i++) {
		val = vlv_dpio_read(dev_priv, pipe, CHV_TX_DW3(ch, i));
		if (uniq_trans_scale)
			val |= DPIO_TX_UNIQ_TRANS_SCALE_EN;
		else
			val &= ~DPIO_TX_UNIQ_TRANS_SCALE_EN;
		vlv_dpio_write(dev_priv, pipe, CHV_TX_DW3(ch, i), val);
	}

	/* Start swing calculation */
	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW10(ch));
	val |= DPIO_PCS_SWING_CALC_TX0_TX2 | DPIO_PCS_SWING_CALC_TX1_TX3;
	vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW10(ch), val);

	if (intel_crtc->config->lane_count > 2) {
		val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW10(ch));
		val |= DPIO_PCS_SWING_CALC_TX0_TX2 | DPIO_PCS_SWING_CALC_TX1_TX3;
		vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW10(ch), val);
	}

	mutex_unlock(&dev_priv->sb_lock);

}