1 files changed, 240 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_hpd.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_hpd.c
new file mode 100644
index 000000000000..5f39dfe06e9a
--- /dev/null
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_hpd.c
@@ -0,0 +1,240 @@
+/*
+ * 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 dc_link_get_hpd_state(struct dc_link *dc_link)
+{
+	uint32_t state;
+
+	dal_gpio_lock_pin(dc_link->hpd_gpio);
+	dal_gpio_get_value(dc_link->hpd_gpio, &state);
+	dal_gpio_unlock_pin(dc_link->hpd_gpio);
+
+	return state;
+}
+
+void dc_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 dc_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 dc_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;
+}