/*
 * Copyright 2015 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
 *
 */

#include "dm_services_types.h"
#include "dc.h"

#include "amdgpu.h"
#include "amdgpu_dm.h"
#include "amdgpu_dm_irq.h"

/**
 * DOC: overview
 *
 * DM provides another layer of IRQ management on top of what the base driver
 * already provides. This is something that could be cleaned up, and is a
 * future TODO item.
 *
 * The base driver provides IRQ source registration with DRM, handler
 * registration into the base driver's IRQ table, and a handler callback
 * amdgpu_irq_handler(), with which DRM calls on interrupts. This generic
 * handler looks up the IRQ table, and calls the respective
 * &amdgpu_irq_src_funcs.process hookups.
 *
 * What DM provides on top are two IRQ tables specifically for top-half and
 * bottom-half IRQ handling, with the bottom-half implementing workqueues:
 *
 * - &amdgpu_display_manager.irq_handler_list_high_tab
 * - &amdgpu_display_manager.irq_handler_list_low_tab
 *
 * They override the base driver's IRQ table, and the effect can be seen
 * in the hooks that DM provides for &amdgpu_irq_src_funcs.process. They
 * are all set to the DM generic handler amdgpu_dm_irq_handler(), which looks up
 * DM's IRQ tables. However, in order for base driver to recognize this hook, DM
 * still needs to register the IRQ with the base driver. See
 * dce110_register_irq_handlers() and dcn10_register_irq_handlers().
 *
 * To expose DC's hardware interrupt toggle to the base driver, DM implements
 * &amdgpu_irq_src_funcs.set hooks. Base driver calls it through
 * amdgpu_irq_update() to enable or disable the interrupt.
 */

/******************************************************************************
 * Private declarations.
 *****************************************************************************/

/**
 * struct amdgpu_dm_irq_handler_data - Data for DM interrupt handlers.
 *
 * @list: Linked list entry referencing the next/previous handler
 * @handler: Handler function
 * @handler_arg: Argument passed to the handler when triggered
 * @dm: DM which this handler belongs to
 * @irq_source: DC interrupt source that this handler is registered for
 */
struct amdgpu_dm_irq_handler_data {
	struct list_head list;
	interrupt_handler handler;
	void *handler_arg;

	struct amdgpu_display_manager *dm;
	/* DAL irq source which registered for this interrupt. */
	enum dc_irq_source irq_source;
};

#define DM_IRQ_TABLE_LOCK(adev, flags) \
	spin_lock_irqsave(&adev->dm.irq_handler_list_table_lock, flags)

#define DM_IRQ_TABLE_UNLOCK(adev, flags) \
	spin_unlock_irqrestore(&adev->dm.irq_handler_list_table_lock, flags)

/******************************************************************************
 * Private functions.
 *****************************************************************************/

static void init_handler_common_data(struct amdgpu_dm_irq_handler_data *hcd,
				     void (*ih)(void *),
				     void *args,
				     struct amdgpu_display_manager *dm)
{
	hcd->handler = ih;
	hcd->handler_arg = args;
	hcd->dm = dm;
}

/**
 * dm_irq_work_func() - Handle an IRQ outside of the interrupt handler proper.
 *
 * @work: work struct
 */
static void dm_irq_work_func(struct work_struct *work)
{
	struct irq_list_head *irq_list_head =
		container_of(work, struct irq_list_head, work);
	struct list_head *handler_list = &irq_list_head->head;
	struct amdgpu_dm_irq_handler_data *handler_data;

	list_for_each_entry(handler_data, handler_list, list) {
		DRM_DEBUG_KMS("DM_IRQ: work_func: for dal_src=%d\n",
				handler_data->irq_source);

		DRM_DEBUG_KMS("DM_IRQ: schedule_work: for dal_src=%d\n",
			handler_data->irq_source);

		handler_data->handler(handler_data->handler_arg);
	}

	/* Call a DAL subcomponent which registered for interrupt notification
	 * at INTERRUPT_LOW_IRQ_CONTEXT.
	 * (The most common use is HPD interrupt) */
}

/*
 * Remove a handler and return a pointer to handler list from which the
 * handler was removed.
 */
static struct list_head *remove_irq_handler(struct amdgpu_device *adev,
					    void *ih,
					    const struct dc_interrupt_params *int_params)
{
	struct list_head *hnd_list;
	struct list_head *entry, *tmp;
	struct amdgpu_dm_irq_handler_data *handler;
	unsigned long irq_table_flags;
	bool handler_removed = false;
	enum dc_irq_source irq_source;

	DM_IRQ_TABLE_LOCK(adev, irq_table_flags);

	irq_source = int_params->irq_source;

	switch (int_params->int_context) {
	case INTERRUPT_HIGH_IRQ_CONTEXT:
		hnd_list = &adev->dm.irq_handler_list_high_tab[irq_source];
		break;
	case INTERRUPT_LOW_IRQ_CONTEXT:
	default:
		hnd_list = &adev->dm.irq_handler_list_low_tab[irq_source].head;
		break;
	}

	list_for_each_safe(entry, tmp, hnd_list) {

		handler = list_entry(entry, struct amdgpu_dm_irq_handler_data,
				     list);

		if (ih == handler) {
			/* Found our handler. Remove it from the list. */
			list_del(&handler->list);
			handler_removed = true;
			break;
		}
	}

	DM_IRQ_TABLE_UNLOCK(adev, irq_table_flags);

	if (handler_removed == false) {
		/* Not necessarily an error - caller may not
		 * know the context. */
		return NULL;
	}

	kfree(handler);

	DRM_DEBUG_KMS(
	"DM_IRQ: removed irq handler: %p for: dal_src=%d, irq context=%d\n",
		ih, int_params->irq_source, int_params->int_context);

	return hnd_list;
}

static bool
validate_irq_registration_params(struct dc_interrupt_params *int_params,
				 void (*ih)(void *))
{
	if (NULL == int_params || NULL == ih) {
		DRM_ERROR("DM_IRQ: invalid input!\n");
		return false;
	}

	if (int_params->int_context >= INTERRUPT_CONTEXT_NUMBER) {
		DRM_ERROR("DM_IRQ: invalid context: %d!\n",
				int_params->int_context);
		return false;
	}

	if (!DAL_VALID_IRQ_SRC_NUM(int_params->irq_source)) {
		DRM_ERROR("DM_IRQ: invalid irq_source: %d!\n",
				int_params->irq_source);
		return false;
	}

	return true;
}

static bool validate_irq_unregistration_params(enum dc_irq_source irq_source,
					       irq_handler_idx handler_idx)
{
	if (DAL_INVALID_IRQ_HANDLER_IDX == handler_idx) {
		DRM_ERROR("DM_IRQ: invalid handler_idx==NULL!\n");
		return false;
	}

	if (!DAL_VALID_IRQ_SRC_NUM(irq_source)) {
		DRM_ERROR("DM_IRQ: invalid irq_source:%d!\n", irq_source);
		return false;
	}

	return true;
}
/******************************************************************************
 * Public functions.
 *
 * Note: caller is responsible for input validation.
 *****************************************************************************/

/**
 * amdgpu_dm_irq_register_interrupt() - Register a handler within DM.
 * @adev: The base driver device containing the DM device.
 * @int_params: Interrupt parameters containing the source, and handler context
 * @ih: Function pointer to the interrupt handler to register
 * @handler_args: Arguments passed to the handler when the interrupt occurs
 *
 * Register an interrupt handler for the given IRQ source, under the given
 * context. The context can either be high or low. High context handlers are
 * executed directly within ISR context, while low context is executed within a
 * workqueue, thereby allowing operations that sleep.
 *
 * Registered handlers are called in a FIFO manner, i.e. the most recently
 * registered handler will be called first.
 *
 * Return: Handler data &struct amdgpu_dm_irq_handler_data containing the IRQ
 *         source, handler function, and args
 */
void *amdgpu_dm_irq_register_interrupt(struct amdgpu_device *adev,
				       struct dc_interrupt_params *int_params,
				       void (*ih)(void *),
				       void *handler_args)
{
	struct list_head *hnd_list;
	struct amdgpu_dm_irq_handler_data *handler_data;
	unsigned long irq_table_flags;
	enum dc_irq_source irq_source;

	if (false == validate_irq_registration_params(int_params, ih))
		return DAL_INVALID_IRQ_HANDLER_IDX;

	handler_data = kzalloc(sizeof(*handler_data), GFP_KERNEL);
	if (!handler_data) {
		DRM_ERROR("DM_IRQ: failed to allocate irq handler!\n");
		return DAL_INVALID_IRQ_HANDLER_IDX;
	}

	init_handler_common_data(handler_data, ih, handler_args, &adev->dm);

	irq_source = int_params->irq_source;

	handler_data->irq_source = irq_source;

	/* Lock the list, add the handler. */
	DM_IRQ_TABLE_LOCK(adev, irq_table_flags);

	switch (int_params->int_context) {
	case INTERRUPT_HIGH_IRQ_CONTEXT:
		hnd_list = &adev->dm.irq_handler_list_high_tab[irq_source];
		break;
	case INTERRUPT_LOW_IRQ_CONTEXT:
	default:
		hnd_list = &adev->dm.irq_handler_list_low_tab[irq_source].head;
		break;
	}

	list_add_tail(&handler_data->list, hnd_list);

	DM_IRQ_TABLE_UNLOCK(adev, irq_table_flags);

	/* This pointer will be stored by code which requested interrupt
	 * registration.
	 * The same pointer will be needed in order to unregister the
	 * interrupt. */

	DRM_DEBUG_KMS(
		"DM_IRQ: added irq handler: %p for: dal_src=%d, irq context=%d\n",
		handler_data,
		irq_source,
		int_params->int_context);

	return handler_data;
}

/**
 * amdgpu_dm_irq_unregister_interrupt() - Remove a handler from the DM IRQ table
 * @adev: The base driver device containing the DM device
 * @irq_source: IRQ source to remove the given handler from
 * @ih: Function pointer to the interrupt handler to unregister
 *
 * Go through both low and high context IRQ tables, and find the given handler
 * for the given irq source. If found, remove it. Otherwise, do nothing.
 */
void amdgpu_dm_irq_unregister_interrupt(struct amdgpu_device *adev,
					enum dc_irq_source irq_source,
					void *ih)
{
	struct list_head *handler_list;
	struct dc_interrupt_params int_params;
	int i;

	if (false == validate_irq_unregistration_params(irq_source, ih))
		return;

	memset(&int_params, 0, sizeof(int_params));

	int_params.irq_source = irq_source;

	for (i = 0; i < INTERRUPT_CONTEXT_NUMBER; i++) {

		int_params.int_context = i;

		handler_list = remove_irq_handler(adev, ih, &int_params);

		if (handler_list != NULL)
			break;
	}

	if (handler_list == NULL) {
		/* If we got here, it means we searched all irq contexts
		 * for this irq source, but the handler was not found. */
		DRM_ERROR(
		"DM_IRQ: failed to find irq handler:%p for irq_source:%d!\n",
			ih, irq_source);
	}
}

/**
 * amdgpu_dm_irq_init() - Initialize DM IRQ management
 * @adev:  The base driver device containing the DM device
 *
 * Initialize DM's high and low context IRQ tables.
 *
 * The N by M table contains N IRQ sources, with M
 * &struct amdgpu_dm_irq_handler_data hooked together in a linked list. The
 * list_heads are initialized here. When an interrupt n is triggered, all m
 * handlers are called in sequence, FIFO according to registration order.
 *
 * The low context table requires special steps to initialize, since handlers
 * will be deferred to a workqueue. See &struct irq_list_head.
 */
int amdgpu_dm_irq_init(struct amdgpu_device *adev)
{
	int src;
	struct irq_list_head *lh;

	DRM_DEBUG_KMS("DM_IRQ\n");

	spin_lock_init(&adev->dm.irq_handler_list_table_lock);

	for (src = 0; src < DAL_IRQ_SOURCES_NUMBER; src++) {
		/* low context handler list init */
		lh = &adev->dm.irq_handler_list_low_tab[src];
		INIT_LIST_HEAD(&lh->head);
		INIT_WORK(&lh->work, dm_irq_work_func);

		/* high context handler init */
		INIT_LIST_HEAD(&adev->dm.irq_handler_list_high_tab[src]);
	}

	return 0;
}

/**
 * amdgpu_dm_irq_fini() - Tear down DM IRQ management
 * @adev: The base driver device containing the DM device
 *
 * Flush all work within the low context IRQ table.
 */
void amdgpu_dm_irq_fini(struct amdgpu_device *adev)
{
	int src;
	struct irq_list_head *lh;
	unsigned long irq_table_flags;
	DRM_DEBUG_KMS("DM_IRQ: releasing resources.\n");
	for (src = 0; src < DAL_IRQ_SOURCES_NUMBER; src++) {
		DM_IRQ_TABLE_LOCK(adev, irq_table_flags);
		/* The handler was removed from the table,
		 * it means it is safe to flush all the 'work'
		 * (because no code can schedule a new one). */
		lh = &adev->dm.irq_handler_list_low_tab[src];
		DM_IRQ_TABLE_UNLOCK(adev, irq_table_flags);
		flush_work(&lh->work);
	}
}

int amdgpu_dm_irq_suspend(struct amdgpu_device *adev)
{
	int src;
	struct list_head *hnd_list_h;
	struct list_head *hnd_list_l;
	unsigned long irq_table_flags;

	DM_IRQ_TABLE_LOCK(adev, irq_table_flags);

	DRM_DEBUG_KMS("DM_IRQ: suspend\n");

	/**
	 * Disable HW interrupt  for HPD and HPDRX only since FLIP and VBLANK
	 * will be disabled from manage_dm_interrupts on disable CRTC.
	 */
	for (src = DC_IRQ_SOURCE_HPD1; src <= DC_IRQ_SOURCE_HPD6RX; src++) {
		hnd_list_l = &adev->dm.irq_handler_list_low_tab[src].head;
		hnd_list_h = &adev->dm.irq_handler_list_high_tab[src];
		if (!list_empty(hnd_list_l) || !list_empty(hnd_list_h))
			dc_interrupt_set(adev->dm.dc, src, false);

		DM_IRQ_TABLE_UNLOCK(adev, irq_table_flags);
		flush_work(&adev->dm.irq_handler_list_low_tab[src].work);

		DM_IRQ_TABLE_LOCK(adev, irq_table_flags);
	}

	DM_IRQ_TABLE_UNLOCK(adev, irq_table_flags);
	return 0;
}

int amdgpu_dm_irq_resume_early(struct amdgpu_device *adev)
{
	int src;
	struct list_head *hnd_list_h, *hnd_list_l;
	unsigned long irq_table_flags;

	DM_IRQ_TABLE_LOCK(adev, irq_table_flags);

	DRM_DEBUG_KMS("DM_IRQ: early resume\n");

	/* re-enable short pulse interrupts HW interrupt */
	for (src = DC_IRQ_SOURCE_HPD1RX; src <= DC_IRQ_SOURCE_HPD6RX; src++) {
		hnd_list_l = &adev->dm.irq_handler_list_low_tab[src].head;
		hnd_list_h = &adev->dm.irq_handler_list_high_tab[src];
		if (!list_empty(hnd_list_l) || !list_empty(hnd_list_h))
			dc_interrupt_set(adev->dm.dc, src, true);
	}

	DM_IRQ_TABLE_UNLOCK(adev, irq_table_flags);

	return 0;
}

int amdgpu_dm_irq_resume_late(struct amdgpu_device *adev)
{
	int src;
	struct list_head *hnd_list_h, *hnd_list_l;
	unsigned long irq_table_flags;

	DM_IRQ_TABLE_LOCK(adev, irq_table_flags);

	DRM_DEBUG_KMS("DM_IRQ: resume\n");

	/**
	 * Renable HW interrupt  for HPD and only since FLIP and VBLANK
	 * will be enabled from manage_dm_interrupts on enable CRTC.
	 */
	for (src = DC_IRQ_SOURCE_HPD1; src <= DC_IRQ_SOURCE_HPD6; src++) {
		hnd_list_l = &adev->dm.irq_handler_list_low_tab[src].head;
		hnd_list_h = &adev->dm.irq_handler_list_high_tab[src];
		if (!list_empty(hnd_list_l) || !list_empty(hnd_list_h))
			dc_interrupt_set(adev->dm.dc, src, true);
	}

	DM_IRQ_TABLE_UNLOCK(adev, irq_table_flags);
	return 0;
}

/*
 * amdgpu_dm_irq_schedule_work - schedule all work items registered for the
 * "irq_source".
 */
static void amdgpu_dm_irq_schedule_work(struct amdgpu_device *adev,
					enum dc_irq_source irq_source)
{
	unsigned long irq_table_flags;
	struct work_struct *work = NULL;

	DM_IRQ_TABLE_LOCK(adev, irq_table_flags);

	if (!list_empty(&adev->dm.irq_handler_list_low_tab[irq_source].head))
		work = &adev->dm.irq_handler_list_low_tab[irq_source].work;

	DM_IRQ_TABLE_UNLOCK(adev, irq_table_flags);

	if (work) {
		if (!schedule_work(work))
			DRM_INFO("amdgpu_dm_irq_schedule_work FAILED src %d\n",
						irq_source);
	}

}

/*
 * amdgpu_dm_irq_immediate_work
 * Callback high irq work immediately, don't send to work queue
 */
static void amdgpu_dm_irq_immediate_work(struct amdgpu_device *adev,
					 enum dc_irq_source irq_source)
{
	struct amdgpu_dm_irq_handler_data *handler_data;
	unsigned long irq_table_flags;

	DM_IRQ_TABLE_LOCK(adev, irq_table_flags);

	list_for_each_entry(handler_data,
			    &adev->dm.irq_handler_list_high_tab[irq_source],
			    list) {
		/* Call a subcomponent which registered for immediate
		 * interrupt notification */
		handler_data->handler(handler_data->handler_arg);
	}

	DM_IRQ_TABLE_UNLOCK(adev, irq_table_flags);
}

/**
 * amdgpu_dm_irq_handler - Generic DM IRQ handler
 * @adev: amdgpu base driver device containing the DM device
 * @source: Unused
 * @entry: Data about the triggered interrupt
 *
 * Calls all registered high irq work immediately, and schedules work for low
 * irq. The DM IRQ table is used to find the corresponding handlers.
 */
static int amdgpu_dm_irq_handler(struct amdgpu_device *adev,
				 struct amdgpu_irq_src *source,
				 struct amdgpu_iv_entry *entry)
{

	enum dc_irq_source src =
		dc_interrupt_to_irq_source(
			adev->dm.dc,
			entry->src_id,
			entry->src_data[0]);

	dc_interrupt_ack(adev->dm.dc, src);

	/* Call high irq work immediately */
	amdgpu_dm_irq_immediate_work(adev, src);
	/*Schedule low_irq work */
	amdgpu_dm_irq_schedule_work(adev, src);

	return 0;
}

static enum dc_irq_source amdgpu_dm_hpd_to_dal_irq_source(unsigned type)
{
	switch (type) {
	case AMDGPU_HPD_1:
		return DC_IRQ_SOURCE_HPD1;
	case AMDGPU_HPD_2:
		return DC_IRQ_SOURCE_HPD2;
	case AMDGPU_HPD_3:
		return DC_IRQ_SOURCE_HPD3;
	case AMDGPU_HPD_4:
		return DC_IRQ_SOURCE_HPD4;
	case AMDGPU_HPD_5:
		return DC_IRQ_SOURCE_HPD5;
	case AMDGPU_HPD_6:
		return DC_IRQ_SOURCE_HPD6;
	default:
		return DC_IRQ_SOURCE_INVALID;
	}
}

static int amdgpu_dm_set_hpd_irq_state(struct amdgpu_device *adev,
				       struct amdgpu_irq_src *source,
				       unsigned type,
				       enum amdgpu_interrupt_state state)
{
	enum dc_irq_source src = amdgpu_dm_hpd_to_dal_irq_source(type);
	bool st = (state == AMDGPU_IRQ_STATE_ENABLE);

	dc_interrupt_set(adev->dm.dc, src, st);
	return 0;
}

static inline int dm_irq_state(struct amdgpu_device *adev,
			       struct amdgpu_irq_src *source,
			       unsigned crtc_id,
			       enum amdgpu_interrupt_state state,
			       const enum irq_type dal_irq_type,
			       const char *func)
{
	bool st;
	enum dc_irq_source irq_source;

	struct amdgpu_crtc *acrtc = adev->mode_info.crtcs[crtc_id];

	if (!acrtc) {
		DRM_ERROR(
			"%s: crtc is NULL at id :%d\n",
			func,
			crtc_id);
		return 0;
	}

	if (acrtc->otg_inst == -1)
		return 0;

	irq_source = dal_irq_type + acrtc->otg_inst;

	st = (state == AMDGPU_IRQ_STATE_ENABLE);

	dc_interrupt_set(adev->dm.dc, irq_source, st);
	return 0;
}

static int amdgpu_dm_set_pflip_irq_state(struct amdgpu_device *adev,
					 struct amdgpu_irq_src *source,
					 unsigned crtc_id,
					 enum amdgpu_interrupt_state state)
{
	return dm_irq_state(
		adev,
		source,
		crtc_id,
		state,
		IRQ_TYPE_PFLIP,
		__func__);
}

static int amdgpu_dm_set_crtc_irq_state(struct amdgpu_device *adev,
					struct amdgpu_irq_src *source,
					unsigned crtc_id,
					enum amdgpu_interrupt_state state)
{
	return dm_irq_state(
		adev,
		source,
		crtc_id,
		state,
		IRQ_TYPE_VBLANK,
		__func__);
}

static int amdgpu_dm_set_vupdate_irq_state(struct amdgpu_device *adev,
					   struct amdgpu_irq_src *source,
					   unsigned int crtc_id,
					   enum amdgpu_interrupt_state state)
{
	return dm_irq_state(
		adev,
		source,
		crtc_id,
		state,
		IRQ_TYPE_VUPDATE,
		__func__);
}

static const struct amdgpu_irq_src_funcs dm_crtc_irq_funcs = {
	.set = amdgpu_dm_set_crtc_irq_state,
	.process = amdgpu_dm_irq_handler,
};

static const struct amdgpu_irq_src_funcs dm_vupdate_irq_funcs = {
	.set = amdgpu_dm_set_vupdate_irq_state,
	.process = amdgpu_dm_irq_handler,
};

static const struct amdgpu_irq_src_funcs dm_pageflip_irq_funcs = {
	.set = amdgpu_dm_set_pflip_irq_state,
	.process = amdgpu_dm_irq_handler,
};

static const struct amdgpu_irq_src_funcs dm_hpd_irq_funcs = {
	.set = amdgpu_dm_set_hpd_irq_state,
	.process = amdgpu_dm_irq_handler,
};

void amdgpu_dm_set_irq_funcs(struct amdgpu_device *adev)
{

	adev->crtc_irq.num_types = adev->mode_info.num_crtc;
	adev->crtc_irq.funcs = &dm_crtc_irq_funcs;

	adev->vupdate_irq.num_types = adev->mode_info.num_crtc;
	adev->vupdate_irq.funcs = &dm_vupdate_irq_funcs;

	adev->pageflip_irq.num_types = adev->mode_info.num_crtc;
	adev->pageflip_irq.funcs = &dm_pageflip_irq_funcs;

	adev->hpd_irq.num_types = adev->mode_info.num_hpd;
	adev->hpd_irq.funcs = &dm_hpd_irq_funcs;
}

/**
 * amdgpu_dm_hpd_init - hpd setup callback.
 *
 * @adev: amdgpu_device pointer
 *
 * Setup the hpd pins used by the card (evergreen+).
 * Enable the pin, set the polarity, and enable the hpd interrupts.
 */
void amdgpu_dm_hpd_init(struct amdgpu_device *adev)
{
	struct drm_device *dev = adev->ddev;
	struct drm_connector *connector;
	struct drm_connector_list_iter iter;

	drm_connector_list_iter_begin(dev, &iter);
	drm_for_each_connector_iter(connector, &iter) {
		struct amdgpu_dm_connector *amdgpu_dm_connector =
				to_amdgpu_dm_connector(connector);

		const struct dc_link *dc_link = amdgpu_dm_connector->dc_link;

		if (DC_IRQ_SOURCE_INVALID != dc_link->irq_source_hpd) {
			dc_interrupt_set(adev->dm.dc,
					dc_link->irq_source_hpd,
					true);
		}

		if (DC_IRQ_SOURCE_INVALID != dc_link->irq_source_hpd_rx) {
			dc_interrupt_set(adev->dm.dc,
					dc_link->irq_source_hpd_rx,
					true);
		}
	}
	drm_connector_list_iter_end(&iter);
}

/**
 * amdgpu_dm_hpd_fini - hpd tear down callback.
 *
 * @adev: amdgpu_device pointer
 *
 * Tear down the hpd pins used by the card (evergreen+).
 * Disable the hpd interrupts.
 */
void amdgpu_dm_hpd_fini(struct amdgpu_device *adev)
{
	struct drm_device *dev = adev->ddev;
	struct drm_connector *connector;
	struct drm_connector_list_iter iter;

	drm_connector_list_iter_begin(dev, &iter);
	drm_for_each_connector_iter(connector, &iter) {
		struct amdgpu_dm_connector *amdgpu_dm_connector =
				to_amdgpu_dm_connector(connector);
		const struct dc_link *dc_link = amdgpu_dm_connector->dc_link;

		dc_interrupt_set(adev->dm.dc, dc_link->irq_source_hpd, false);

		if (DC_IRQ_SOURCE_INVALID != dc_link->irq_source_hpd_rx) {
			dc_interrupt_set(adev->dm.dc,
					dc_link->irq_source_hpd_rx,
					false);
		}
	}
	drm_connector_list_iter_end(&iter);
}