drivers/gpu/drm/i915/intel_lspcon.c - arm/linux - Git at Google

 /*
  * Copyright © 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 <drm/drm_edid.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_dp_dual_mode_helper.h>
 #include "intel_drv.h"

 static struct intel_dp *lspcon_to_intel_dp(struct intel_lspcon *lspcon)
 {
 	struct intel_digital_port *dig_port =
 		container_of(lspcon, struct intel_digital_port, lspcon);

 	return &dig_port->dp;
 }

 static const char *lspcon_mode_name(enum drm_lspcon_mode mode)
 {
 	switch (mode) {
 	case DRM_LSPCON_MODE_PCON:
 		return "PCON";
 	case DRM_LSPCON_MODE_LS:
 		return "LS";
 	case DRM_LSPCON_MODE_INVALID:
 		return "INVALID";
 	default:
 		MISSING_CASE(mode);
 		return "INVALID";
 	}
 }

 static enum drm_lspcon_mode lspcon_get_current_mode(struct intel_lspcon *lspcon)
 {
 	enum drm_lspcon_mode current_mode;
 	struct i2c_adapter *adapter = &lspcon_to_intel_dp(lspcon)->aux.ddc;

 	if (drm_lspcon_get_mode(adapter, &current_mode)) {
 		DRM_ERROR("Error reading LSPCON mode\n");
 		return DRM_LSPCON_MODE_INVALID;
 	}
 	return current_mode;
 }

 static enum drm_lspcon_mode lspcon_wait_mode(struct intel_lspcon *lspcon,
 					     enum drm_lspcon_mode mode)
 {
 	enum drm_lspcon_mode current_mode;

 	current_mode = lspcon_get_current_mode(lspcon);
 	if (current_mode == mode || current_mode == DRM_LSPCON_MODE_INVALID)
 		goto out;

 	DRM_DEBUG_KMS("Waiting for LSPCON mode %s to settle\n",
 		      lspcon_mode_name(mode));

 	wait_for((current_mode = lspcon_get_current_mode(lspcon)) == mode ||
 		 current_mode == DRM_LSPCON_MODE_INVALID, 100);
 	if (current_mode != mode)
 		DRM_DEBUG_KMS("LSPCON mode hasn't settled\n");

 out:
 	DRM_DEBUG_KMS("Current LSPCON mode %s\n",
 		      lspcon_mode_name(current_mode));

 	return current_mode;
 }

 static int lspcon_change_mode(struct intel_lspcon *lspcon,
 			      enum drm_lspcon_mode mode)
 {
 	int err;
 	enum drm_lspcon_mode current_mode;
 	struct i2c_adapter *adapter = &lspcon_to_intel_dp(lspcon)->aux.ddc;

 	err = drm_lspcon_get_mode(adapter, &current_mode);
 	if (err) {
 		DRM_ERROR("Error reading LSPCON mode\n");
 		return err;
 	}

 	if (current_mode == mode) {
 		DRM_DEBUG_KMS("Current mode = desired LSPCON mode\n");
 		return 0;
 	}

 	err = drm_lspcon_set_mode(adapter, mode);
 	if (err < 0) {
 		DRM_ERROR("LSPCON mode change failed\n");
 		return err;
 	}

 	lspcon->mode = mode;
 	DRM_DEBUG_KMS("LSPCON mode changed done\n");
 	return 0;
 }

 static bool lspcon_wake_native_aux_ch(struct intel_lspcon *lspcon)
 {
 	uint8_t rev;

 	if (drm_dp_dpcd_readb(&lspcon_to_intel_dp(lspcon)->aux, DP_DPCD_REV,
 			      &rev) != 1) {
 		DRM_DEBUG_KMS("Native AUX CH down\n");
 		return false;
 	}

 	DRM_DEBUG_KMS("Native AUX CH up, DPCD version: %d.%d\n",
 		      rev >> 4, rev & 0xf);

 	return true;
 }

 static bool lspcon_probe(struct intel_lspcon *lspcon)
 {
 	enum drm_dp_dual_mode_type adaptor_type;
 	struct i2c_adapter *adapter = &lspcon_to_intel_dp(lspcon)->aux.ddc;
 	enum drm_lspcon_mode expected_mode;

 	expected_mode = lspcon_wake_native_aux_ch(lspcon) ?
 			DRM_LSPCON_MODE_PCON : DRM_LSPCON_MODE_LS;

 	/* Lets probe the adaptor and check its type */
 	adaptor_type = drm_dp_dual_mode_detect(adapter);
 	if (adaptor_type != DRM_DP_DUAL_MODE_LSPCON) {
 		DRM_DEBUG_KMS("No LSPCON detected, found %s\n",
 			drm_dp_get_dual_mode_type_name(adaptor_type));
 		return false;
 	}

 	/* Yay ... got a LSPCON device */
 	DRM_DEBUG_KMS("LSPCON detected\n");
 	lspcon->mode = lspcon_wait_mode(lspcon, expected_mode);
 	lspcon->active = true;
 	return true;
 }

 static void lspcon_resume_in_pcon_wa(struct intel_lspcon *lspcon)
 {
 	struct intel_dp *intel_dp = lspcon_to_intel_dp(lspcon);
 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
 	struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
 	unsigned long start = jiffies;

 	while (1) {
 		if (intel_digital_port_connected(dev_priv, dig_port)) {
 			DRM_DEBUG_KMS("LSPCON recovering in PCON mode after %u ms\n",
 				      jiffies_to_msecs(jiffies - start));
 			return;
 		}

 		if (time_after(jiffies, start + msecs_to_jiffies(1000)))
 			break;

 		usleep_range(10000, 15000);
 	}

 	DRM_DEBUG_KMS("LSPCON DP descriptor mismatch after resume\n");
 }

 void lspcon_resume(struct intel_lspcon *lspcon)
 {
 	enum drm_lspcon_mode expected_mode;

 	if (lspcon_wake_native_aux_ch(lspcon)) {
 		expected_mode = DRM_LSPCON_MODE_PCON;
 		lspcon_resume_in_pcon_wa(lspcon);
 	} else {
 		expected_mode = DRM_LSPCON_MODE_LS;
 	}

 	if (lspcon_wait_mode(lspcon, expected_mode) == DRM_LSPCON_MODE_PCON)
 		return;

 	if (lspcon_change_mode(lspcon, DRM_LSPCON_MODE_PCON))
 		DRM_ERROR("LSPCON resume failed\n");
 	else
 		DRM_DEBUG_KMS("LSPCON resume success\n");
 }

 void lspcon_wait_pcon_mode(struct intel_lspcon *lspcon)
 {
 	lspcon_wait_mode(lspcon, DRM_LSPCON_MODE_PCON);
 }

 bool lspcon_init(struct intel_digital_port *intel_dig_port)
 {
 	struct intel_dp *dp = &intel_dig_port->dp;
 	struct intel_lspcon *lspcon = &intel_dig_port->lspcon;
 	struct drm_device *dev = intel_dig_port->base.base.dev;
 	struct drm_i915_private *dev_priv = to_i915(dev);

 	if (!HAS_LSPCON(dev_priv)) {
 		DRM_ERROR("LSPCON is not supported on this platform\n");
 		return false;
 	}

 	lspcon->active = false;
 	lspcon->mode = DRM_LSPCON_MODE_INVALID;

 	if (!lspcon_probe(lspcon)) {
 		DRM_ERROR("Failed to probe lspcon\n");
 		return false;
 	}

 	/*
 	* In the SW state machine, lets Put LSPCON in PCON mode only.
 	* In this way, it will work with both HDMI 1.4 sinks as well as HDMI
 	* 2.0 sinks.
 	*/
 	if (lspcon->active && lspcon->mode != DRM_LSPCON_MODE_PCON) {
 		if (lspcon_change_mode(lspcon, DRM_LSPCON_MODE_PCON) < 0) {
 			DRM_ERROR("LSPCON mode change to PCON failed\n");
 			return false;
 		}
 	}

 	if (!intel_dp_read_dpcd(dp)) {
 		DRM_ERROR("LSPCON DPCD read failed\n");
 		return false;
 	}

 	drm_dp_read_desc(&dp->aux, &dp->desc, drm_dp_is_branch(dp->dpcd));

 	DRM_DEBUG_KMS("Success: LSPCON init\n");
 	return true;
 }
	/*
	* Copyright © 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 <drm/drm_edid.h>
	#include <drm/drm_atomic_helper.h>
	#include <drm/drm_dp_dual_mode_helper.h>
	#include "intel_drv.h"

	static struct intel_dp lspcon_to_intel_dp(struct intel_lspcon lspcon)
	{
	struct intel_digital_port *dig_port =
	container_of(lspcon, struct intel_digital_port, lspcon);

	return &dig_port->dp;
	}

	static const char *lspcon_mode_name(enum drm_lspcon_mode mode)
	{
	switch (mode) {
	case DRM_LSPCON_MODE_PCON:
	return "PCON";
	case DRM_LSPCON_MODE_LS:
	return "LS";
	case DRM_LSPCON_MODE_INVALID:
	return "INVALID";
	default:
	MISSING_CASE(mode);
	return "INVALID";
	}
	}

	static enum drm_lspcon_mode lspcon_get_current_mode(struct intel_lspcon *lspcon)
	{
	enum drm_lspcon_mode current_mode;
	struct i2c_adapter *adapter = &lspcon_to_intel_dp(lspcon)->aux.ddc;

	if (drm_lspcon_get_mode(adapter, &current_mode)) {
	DRM_ERROR("Error reading LSPCON mode\n");
	return DRM_LSPCON_MODE_INVALID;
	}
	return current_mode;
	}

	static enum drm_lspcon_mode lspcon_wait_mode(struct intel_lspcon *lspcon,
	enum drm_lspcon_mode mode)
	{
	enum drm_lspcon_mode current_mode;

	current_mode = lspcon_get_current_mode(lspcon);
	if (current_mode == mode \|\| current_mode == DRM_LSPCON_MODE_INVALID)
	goto out;

	DRM_DEBUG_KMS("Waiting for LSPCON mode %s to settle\n",
	lspcon_mode_name(mode));

	wait_for((current_mode = lspcon_get_current_mode(lspcon)) == mode \|\|
	current_mode == DRM_LSPCON_MODE_INVALID, 100);
	if (current_mode != mode)
	DRM_DEBUG_KMS("LSPCON mode hasn't settled\n");

	out:
	DRM_DEBUG_KMS("Current LSPCON mode %s\n",
	lspcon_mode_name(current_mode));

	return current_mode;
	}

	static int lspcon_change_mode(struct intel_lspcon *lspcon,
	enum drm_lspcon_mode mode)
	{
	int err;
	enum drm_lspcon_mode current_mode;
	struct i2c_adapter *adapter = &lspcon_to_intel_dp(lspcon)->aux.ddc;

	err = drm_lspcon_get_mode(adapter, &current_mode);
	if (err) {
	DRM_ERROR("Error reading LSPCON mode\n");
	return err;
	}

	if (current_mode == mode) {
	DRM_DEBUG_KMS("Current mode = desired LSPCON mode\n");
	return 0;
	}

	err = drm_lspcon_set_mode(adapter, mode);
	if (err < 0) {
	DRM_ERROR("LSPCON mode change failed\n");
	return err;
	}

	lspcon->mode = mode;
	DRM_DEBUG_KMS("LSPCON mode changed done\n");
	return 0;
	}

	static bool lspcon_wake_native_aux_ch(struct intel_lspcon *lspcon)
	{
	uint8_t rev;

	if (drm_dp_dpcd_readb(&lspcon_to_intel_dp(lspcon)->aux, DP_DPCD_REV,
	&rev) != 1) {
	DRM_DEBUG_KMS("Native AUX CH down\n");
	return false;
	}

	DRM_DEBUG_KMS("Native AUX CH up, DPCD version: %d.%d\n",
	rev >> 4, rev & 0xf);

	return true;
	}

	static bool lspcon_probe(struct intel_lspcon *lspcon)
	{
	enum drm_dp_dual_mode_type adaptor_type;
	struct i2c_adapter *adapter = &lspcon_to_intel_dp(lspcon)->aux.ddc;
	enum drm_lspcon_mode expected_mode;

	expected_mode = lspcon_wake_native_aux_ch(lspcon) ?
	DRM_LSPCON_MODE_PCON : DRM_LSPCON_MODE_LS;

	/* Lets probe the adaptor and check its type */
	adaptor_type = drm_dp_dual_mode_detect(adapter);
	if (adaptor_type != DRM_DP_DUAL_MODE_LSPCON) {
	DRM_DEBUG_KMS("No LSPCON detected, found %s\n",
	drm_dp_get_dual_mode_type_name(adaptor_type));
	return false;
	}

	/* Yay ... got a LSPCON device */
	DRM_DEBUG_KMS("LSPCON detected\n");
	lspcon->mode = lspcon_wait_mode(lspcon, expected_mode);
	lspcon->active = true;
	return true;
	}

	static void lspcon_resume_in_pcon_wa(struct intel_lspcon *lspcon)
	{
	struct intel_dp *intel_dp = lspcon_to_intel_dp(lspcon);
	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
	struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
	unsigned long start = jiffies;

	while (1) {
	if (intel_digital_port_connected(dev_priv, dig_port)) {
	DRM_DEBUG_KMS("LSPCON recovering in PCON mode after %u ms\n",
	jiffies_to_msecs(jiffies - start));
	return;
	}

	if (time_after(jiffies, start + msecs_to_jiffies(1000)))
	break;

	usleep_range(10000, 15000);
	}

	DRM_DEBUG_KMS("LSPCON DP descriptor mismatch after resume\n");
	}

	void lspcon_resume(struct intel_lspcon *lspcon)
	{
	enum drm_lspcon_mode expected_mode;

	if (lspcon_wake_native_aux_ch(lspcon)) {
	expected_mode = DRM_LSPCON_MODE_PCON;
	lspcon_resume_in_pcon_wa(lspcon);
	} else {
	expected_mode = DRM_LSPCON_MODE_LS;
	}

	if (lspcon_wait_mode(lspcon, expected_mode) == DRM_LSPCON_MODE_PCON)
	return;

	if (lspcon_change_mode(lspcon, DRM_LSPCON_MODE_PCON))
	DRM_ERROR("LSPCON resume failed\n");
	else
	DRM_DEBUG_KMS("LSPCON resume success\n");
	}

	void lspcon_wait_pcon_mode(struct intel_lspcon *lspcon)
	{
	lspcon_wait_mode(lspcon, DRM_LSPCON_MODE_PCON);
	}

	bool lspcon_init(struct intel_digital_port *intel_dig_port)
	{
	struct intel_dp *dp = &intel_dig_port->dp;
	struct intel_lspcon *lspcon = &intel_dig_port->lspcon;
	struct drm_device *dev = intel_dig_port->base.base.dev;
	struct drm_i915_private *dev_priv = to_i915(dev);

	if (!HAS_LSPCON(dev_priv)) {
	DRM_ERROR("LSPCON is not supported on this platform\n");
	return false;
	}

	lspcon->active = false;
	lspcon->mode = DRM_LSPCON_MODE_INVALID;

	if (!lspcon_probe(lspcon)) {
	DRM_ERROR("Failed to probe lspcon\n");
	return false;
	}

	/*
	* In the SW state machine, lets Put LSPCON in PCON mode only.
	* In this way, it will work with both HDMI 1.4 sinks as well as HDMI
	* 2.0 sinks.
	*/
	if (lspcon->active && lspcon->mode != DRM_LSPCON_MODE_PCON) {
	if (lspcon_change_mode(lspcon, DRM_LSPCON_MODE_PCON) < 0) {
	DRM_ERROR("LSPCON mode change to PCON failed\n");
	return false;
	}
	}

	if (!intel_dp_read_dpcd(dp)) {
	DRM_ERROR("LSPCON DPCD read failed\n");
	return false;
	}

	drm_dp_read_desc(&dp->aux, &dp->desc, drm_dp_is_branch(dp->dpcd));

	DRM_DEBUG_KMS("Success: LSPCON init\n");
	return true;
	}