drivers/gpu/drm/amd/display/dc/link/protocols/link_hpd.c

/*
 * Copyright 2022 Advanced Micro Devices, Inc.
 *
 * 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 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 COPYRIGHT HOLDER(S) OR AUTHOR(S) 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: AMD
 *
 */

/* FILE POLICY AND INTENDED USAGE:
 *
 * This file implements functions that manage basic HPD components such as gpio.
 * It also provides wrapper functions to execute HPD related programming. This
 * file only manages basic HPD functionality. It doesn't manage detection or
 * feature or signal specific HPD behaviors.
 */
#include "link_hpd.h"
#include "gpio_service_interface.h"

bool link_get_hpd_state(struct dc_link *link)
{
	uint32_t state;

	dal_gpio_lock_pin(link->hpd_gpio);
	dal_gpio_get_value(link->hpd_gpio, &state);
	dal_gpio_unlock_pin(link->hpd_gpio);

	return state;
}

void link_enable_hpd(const struct dc_link *link)
{
	struct link_encoder *encoder = link->link_enc;

	if (encoder != NULL && encoder->funcs->enable_hpd != NULL)
		encoder->funcs->enable_hpd(encoder);
}

void link_disable_hpd(const struct dc_link *link)
{
	struct link_encoder *encoder = link->link_enc;

	if (encoder != NULL && encoder->funcs->enable_hpd != NULL)
		encoder->funcs->disable_hpd(encoder);
}

void link_enable_hpd_filter(struct dc_link *link, bool enable)
{
	struct gpio *hpd;

	if (enable) {
		link->is_hpd_filter_disabled = false;
		program_hpd_filter(link);
	} else {
		link->is_hpd_filter_disabled = true;
		/* Obtain HPD handle */
		hpd = link_get_hpd_gpio(link->ctx->dc_bios, link->link_id, link->ctx->gpio_service);

		if (!hpd)
			return;

		/* Setup HPD filtering */
		if (dal_gpio_open(hpd, GPIO_MODE_INTERRUPT) == GPIO_RESULT_OK) {
			struct gpio_hpd_config config;

			config.delay_on_connect = 0;
			config.delay_on_disconnect = 0;

			dal_irq_setup_hpd_filter(hpd, &config);

			dal_gpio_close(hpd);
		} else {
			ASSERT_CRITICAL(false);
		}
		/* Release HPD handle */
		dal_gpio_destroy_irq(&hpd);
	}
}

struct gpio *link_get_hpd_gpio(struct dc_bios *dcb,
			  struct graphics_object_id link_id,
			  struct gpio_service *gpio_service)
{
	enum bp_result bp_result;
	struct graphics_object_hpd_info hpd_info;
	struct gpio_pin_info pin_info;

	if (dcb->funcs->get_hpd_info(dcb, link_id, &hpd_info) != BP_RESULT_OK)
		return NULL;

	bp_result = dcb->funcs->get_gpio_pin_info(dcb,
		hpd_info.hpd_int_gpio_uid, &pin_info);

	if (bp_result != BP_RESULT_OK) {
		ASSERT(bp_result == BP_RESULT_NORECORD);
		return NULL;
	}

	return dal_gpio_service_create_irq(gpio_service,
					   pin_info.offset,
					   pin_info.mask);
}

bool query_hpd_status(struct dc_link *link, uint32_t *is_hpd_high)
{
	struct gpio *hpd_pin = link_get_hpd_gpio(
			link->ctx->dc_bios, link->link_id,
			link->ctx->gpio_service);
	if (!hpd_pin)
		return false;

	dal_gpio_open(hpd_pin, GPIO_MODE_INTERRUPT);
	dal_gpio_get_value(hpd_pin, is_hpd_high);
	dal_gpio_close(hpd_pin);
	dal_gpio_destroy_irq(&hpd_pin);
	return true;
}

enum hpd_source_id get_hpd_line(struct dc_link *link)
{
	struct gpio *hpd;
	enum hpd_source_id hpd_id;

		hpd_id = HPD_SOURCEID_UNKNOWN;

	hpd = link_get_hpd_gpio(link->ctx->dc_bios, link->link_id,
			   link->ctx->gpio_service);

	if (hpd) {
		switch (dal_irq_get_source(hpd)) {
		case DC_IRQ_SOURCE_HPD1:
			hpd_id = HPD_SOURCEID1;
		break;
		case DC_IRQ_SOURCE_HPD2:
			hpd_id = HPD_SOURCEID2;
		break;
		case DC_IRQ_SOURCE_HPD3:
			hpd_id = HPD_SOURCEID3;
		break;
		case DC_IRQ_SOURCE_HPD4:
			hpd_id = HPD_SOURCEID4;
		break;
		case DC_IRQ_SOURCE_HPD5:
			hpd_id = HPD_SOURCEID5;
		break;
		case DC_IRQ_SOURCE_HPD6:
			hpd_id = HPD_SOURCEID6;
		break;
		default:
			BREAK_TO_DEBUGGER();
		break;
		}

		dal_gpio_destroy_irq(&hpd);
	}

	return hpd_id;
}

bool program_hpd_filter(const struct dc_link *link)
{
	bool result = false;
	struct gpio *hpd;
	int delay_on_connect_in_ms = 0;
	int delay_on_disconnect_in_ms = 0;

	if (link->is_hpd_filter_disabled)
		return false;
	/* Verify feature is supported */
	switch (link->connector_signal) {
	case SIGNAL_TYPE_DVI_SINGLE_LINK:
	case SIGNAL_TYPE_DVI_DUAL_LINK:
	case SIGNAL_TYPE_HDMI_TYPE_A:
		/* Program hpd filter */
		delay_on_connect_in_ms = 500;
		delay_on_disconnect_in_ms = 100;
		break;
	case SIGNAL_TYPE_DISPLAY_PORT:
	case SIGNAL_TYPE_DISPLAY_PORT_MST:
		/* Program hpd filter to allow DP signal to settle */
		/* 500:	not able to detect MST <-> SST switch as HPD is low for
		 * only 100ms on DELL U2413
		 * 0: some passive dongle still show aux mode instead of i2c
		 * 20-50: not enough to hide bouncing HPD with passive dongle.
		 * also see intermittent i2c read issues.
		 */
		delay_on_connect_in_ms = 80;
		delay_on_disconnect_in_ms = 0;
		break;
	case SIGNAL_TYPE_LVDS:
	case SIGNAL_TYPE_EDP:
	default:
		/* Don't program hpd filter */
		return false;
	}

	/* Obtain HPD handle */
	hpd = link_get_hpd_gpio(link->ctx->dc_bios, link->link_id,
			   link->ctx->gpio_service);

	if (!hpd)
		return result;

	/* Setup HPD filtering */
	if (dal_gpio_open(hpd, GPIO_MODE_INTERRUPT) == GPIO_RESULT_OK) {
		struct gpio_hpd_config config;

		config.delay_on_connect = delay_on_connect_in_ms;
		config.delay_on_disconnect = delay_on_disconnect_in_ms;

		dal_irq_setup_hpd_filter(hpd, &config);

		dal_gpio_close(hpd);

		result = true;
	} else {
		ASSERT_CRITICAL(false);
	}

	/* Release HPD handle */
	dal_gpio_destroy_irq(&hpd);

	return result;
}