include/drm/drm_dp_mst_helper.h - kernel/msm-5.4 - Gitiles

 /*
  * Copyright © 2014 Red Hat.
  *
  * Permission to use, copy, modify, distribute, and sell this software and its
  * documentation for any purpose is hereby granted without fee, provided that
  * the above copyright notice appear in all copies and that both that copyright
  * notice and this permission notice appear in supporting documentation, and
  * that the name of the copyright holders not be used in advertising or
  * publicity pertaining to distribution of the software without specific,
  * written prior permission.  The copyright holders make no representations
  * about the suitability of this software for any purpose.  It is provided "as
  * is" without express or implied warranty.
  *
  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  * OF THIS SOFTWARE.
  */
 #ifndef _DRM_DP_MST_HELPER_H_
 #define _DRM_DP_MST_HELPER_H_

 #include <linux/types.h>
 #include <drm/drm_dp_helper.h>

 struct drm_dp_mst_branch;

 /**
  * struct drm_dp_vcpi - Virtual Channel Payload Identifier
  * @vcpi: Virtual channel ID.
  * @pbn: Payload Bandwidth Number for this channel
  * @aligned_pbn: PBN aligned with slot size
  * @num_slots: number of slots for this PBN
  */
 struct drm_dp_vcpi {
 	int vcpi;
 	int pbn;
 	int aligned_pbn;
 	int num_slots;
 };

 /**
  * struct drm_dp_mst_port - MST port
  * @kref: reference count for this port.
  * @port_num: port number
  * @input: if this port is an input port.
  * @mcs: message capability status - DP 1.2 spec.
  * @ddps: DisplayPort Device Plug Status - DP 1.2
  * @pdt: Peer Device Type
  * @ldps: Legacy Device Plug Status
  * @dpcd_rev: DPCD revision of device on this port
  * @num_sdp_streams: Number of simultaneous streams
  * @num_sdp_stream_sinks: Number of stream sinks
  * @available_pbn: Available bandwidth for this port.
  * @next: link to next port on this branch device
  * @mstb: branch device attach below this port
  * @aux: i2c aux transport to talk to device connected to this port.
  * @parent: branch device parent of this port
  * @vcpi: Virtual Channel Payload info for this port.
  * @connector: DRM connector this port is connected to.
  * @mgr: topology manager this port lives under.
  *
  * This structure represents an MST port endpoint on a device somewhere
  * in the MST topology.
  */
 struct drm_dp_mst_port {
 	struct kref kref;

 	u8 port_num;
 	bool input;
 	bool mcs;
 	bool ddps;
 	u8 pdt;
 	bool ldps;
 	u8 dpcd_rev;
 	u8 num_sdp_streams;
 	u8 num_sdp_stream_sinks;
 	uint16_t available_pbn;
 	struct list_head next;
 	struct drm_dp_mst_branch *mstb; /* pointer to an mstb if this port has one */
 	struct drm_dp_aux aux; /* i2c bus for this port? */
 	struct drm_dp_mst_branch *parent;

 	struct drm_dp_vcpi vcpi;
 	struct drm_connector *connector;
 	struct drm_dp_mst_topology_mgr *mgr;

 	/**
 	 * @cached_edid: for DP logical ports - make tiling work by ensuring
 	 * that the EDID for all connectors is read immediately.
 	 */
 	struct edid *cached_edid;
 	/**
 	 * @has_audio: Tracks whether the sink connector to this port is
 	 * audio-capable.
 	 */
 	bool has_audio;
 };

 /**
  * struct drm_dp_mst_branch - MST branch device.
  * @kref: reference count for this port.
  * @rad: Relative Address to talk to this branch device.
  * @lct: Link count total to talk to this branch device.
  * @num_ports: number of ports on the branch.
  * @msg_slots: one bit per transmitted msg slot.
  * @ports: linked list of ports on this branch.
  * @port_parent: pointer to the port parent, NULL if toplevel.
  * @mgr: topology manager for this branch device.
  * @tx_slots: transmission slots for this device.
  * @last_seqno: last sequence number used to talk to this.
  * @link_address_sent: if a link address message has been sent to this device yet.
  * @guid: guid for DP 1.2 branch device. port under this branch can be
  * identified by port #.
  *
  * This structure represents an MST branch device, there is one
  * primary branch device at the root, along with any other branches connected
  * to downstream port of parent branches.
  */
 struct drm_dp_mst_branch {
 	struct kref kref;
 	u8 rad[8];
 	u8 lct;
 	int num_ports;

 	int msg_slots;
 	struct list_head ports;

 	/* list of tx ops queue for this port */
 	struct drm_dp_mst_port *port_parent;
 	struct drm_dp_mst_topology_mgr *mgr;

 	/* slots are protected by mstb->mgr->qlock */
 	struct drm_dp_sideband_msg_tx *tx_slots[2];
 	int last_seqno;
 	bool link_address_sent;

 	/* global unique identifier to identify branch devices */
 	u8 guid[16];
 };


 /* sideband msg header - not bit struct */
 struct drm_dp_sideband_msg_hdr {
 	u8 lct;
 	u8 lcr;
 	u8 rad[8];
 	bool broadcast;
 	bool path_msg;
 	u8 msg_len;
 	bool somt;
 	bool eomt;
 	bool seqno;
 };

 struct drm_dp_nak_reply {
 	u8 guid[16];
 	u8 reason;
 	u8 nak_data;
 };

 struct drm_dp_link_address_ack_reply {
 	u8 guid[16];
 	u8 nports;
 	struct drm_dp_link_addr_reply_port {
 		bool input_port;
 		u8 peer_device_type;
 		u8 port_number;
 		bool mcs;
 		bool ddps;
 		bool legacy_device_plug_status;
 		u8 dpcd_revision;
 		u8 peer_guid[16];
 		u8 num_sdp_streams;
 		u8 num_sdp_stream_sinks;
 	} ports[16];
 };

 struct drm_dp_remote_dpcd_read_ack_reply {
 	u8 port_number;
 	u8 num_bytes;
 	u8 bytes[255];
 };

 struct drm_dp_remote_dpcd_write_ack_reply {
 	u8 port_number;
 };

 struct drm_dp_remote_dpcd_write_nak_reply {
 	u8 port_number;
 	u8 reason;
 	u8 bytes_written_before_failure;
 };

 struct drm_dp_remote_i2c_read_ack_reply {
 	u8 port_number;
 	u8 num_bytes;
 	u8 bytes[255];
 };

 struct drm_dp_remote_i2c_read_nak_reply {
 	u8 port_number;
 	u8 nak_reason;
 	u8 i2c_nak_transaction;
 };

 struct drm_dp_remote_i2c_write_ack_reply {
 	u8 port_number;
 };


 struct drm_dp_sideband_msg_rx {
 	u8 chunk[48];
 	u8 msg[256];
 	u8 curchunk_len;
 	u8 curchunk_idx; /* chunk we are parsing now */
 	u8 curchunk_hdrlen;
 	u8 curlen; /* total length of the msg */
 	bool have_somt;
 	bool have_eomt;
 	struct drm_dp_sideband_msg_hdr initial_hdr;
 };

 #define DRM_DP_MAX_SDP_STREAMS 16
 struct drm_dp_allocate_payload {
 	u8 port_number;
 	u8 number_sdp_streams;
 	u8 vcpi;
 	u16 pbn;
 	u8 sdp_stream_sink[DRM_DP_MAX_SDP_STREAMS];
 };

 struct drm_dp_allocate_payload_ack_reply {
 	u8 port_number;
 	u8 vcpi;
 	u16 allocated_pbn;
 };

 struct drm_dp_connection_status_notify {
 	u8 guid[16];
 	u8 port_number;
 	bool legacy_device_plug_status;
 	bool displayport_device_plug_status;
 	bool message_capability_status;
 	bool input_port;
 	u8 peer_device_type;
 };

 struct drm_dp_remote_dpcd_read {
 	u8 port_number;
 	u32 dpcd_address;
 	u8 num_bytes;
 };

 struct drm_dp_remote_dpcd_write {
 	u8 port_number;
 	u32 dpcd_address;
 	u8 num_bytes;
 	u8 *bytes;
 };

 #define DP_REMOTE_I2C_READ_MAX_TRANSACTIONS 4
 struct drm_dp_remote_i2c_read {
 	u8 num_transactions;
 	u8 port_number;
 	struct {
 		u8 i2c_dev_id;
 		u8 num_bytes;
 		u8 *bytes;
 		u8 no_stop_bit;
 		u8 i2c_transaction_delay;
 	} transactions[DP_REMOTE_I2C_READ_MAX_TRANSACTIONS];
 	u8 read_i2c_device_id;
 	u8 num_bytes_read;
 };

 struct drm_dp_remote_i2c_write {
 	u8 port_number;
 	u8 write_i2c_device_id;
 	u8 num_bytes;
 	u8 *bytes;
 };

 /* this covers ENUM_RESOURCES, POWER_DOWN_PHY, POWER_UP_PHY */
 struct drm_dp_port_number_req {
 	u8 port_number;
 };

 struct drm_dp_enum_path_resources_ack_reply {
 	u8 port_number;
 	u16 full_payload_bw_number;
 	u16 avail_payload_bw_number;
 };

 /* covers POWER_DOWN_PHY, POWER_UP_PHY */
 struct drm_dp_port_number_rep {
 	u8 port_number;
 };

 struct drm_dp_query_payload {
 	u8 port_number;
 	u8 vcpi;
 };

 struct drm_dp_resource_status_notify {
 	u8 port_number;
 	u8 guid[16];
 	u16 available_pbn;
 };

 struct drm_dp_query_payload_ack_reply {
 	u8 port_number;
 	u8 allocated_pbn;
 };

 struct drm_dp_sideband_msg_req_body {
 	u8 req_type;
 	union ack_req {
 		struct drm_dp_connection_status_notify conn_stat;
 		struct drm_dp_port_number_req port_num;
 		struct drm_dp_resource_status_notify resource_stat;

 		struct drm_dp_query_payload query_payload;
 		struct drm_dp_allocate_payload allocate_payload;

 		struct drm_dp_remote_dpcd_read dpcd_read;
 		struct drm_dp_remote_dpcd_write dpcd_write;

 		struct drm_dp_remote_i2c_read i2c_read;
 		struct drm_dp_remote_i2c_write i2c_write;
 	} u;
 };

 struct drm_dp_sideband_msg_reply_body {
 	u8 reply_type;
 	u8 req_type;
 	union ack_replies {
 		struct drm_dp_nak_reply nak;
 		struct drm_dp_link_address_ack_reply link_addr;
 		struct drm_dp_port_number_rep port_number;

 		struct drm_dp_enum_path_resources_ack_reply path_resources;
 		struct drm_dp_allocate_payload_ack_reply allocate_payload;
 		struct drm_dp_query_payload_ack_reply query_payload;

 		struct drm_dp_remote_dpcd_read_ack_reply remote_dpcd_read_ack;
 		struct drm_dp_remote_dpcd_write_ack_reply remote_dpcd_write_ack;
 		struct drm_dp_remote_dpcd_write_nak_reply remote_dpcd_write_nack;

 		struct drm_dp_remote_i2c_read_ack_reply remote_i2c_read_ack;
 		struct drm_dp_remote_i2c_read_nak_reply remote_i2c_read_nack;
 		struct drm_dp_remote_i2c_write_ack_reply remote_i2c_write_ack;
 	} u;
 };

 /* msg is queued to be put into a slot */
 #define DRM_DP_SIDEBAND_TX_QUEUED 0
 /* msg has started transmitting on a slot - still on msgq */
 #define DRM_DP_SIDEBAND_TX_START_SEND 1
 /* msg has finished transmitting on a slot - removed from msgq only in slot */
 #define DRM_DP_SIDEBAND_TX_SENT 2
 /* msg has received a response - removed from slot */
 #define DRM_DP_SIDEBAND_TX_RX 3
 #define DRM_DP_SIDEBAND_TX_TIMEOUT 4

 struct drm_dp_sideband_msg_tx {
 	u8 msg[256];
 	u8 chunk[48];
 	u8 cur_offset;
 	u8 cur_len;
 	struct drm_dp_mst_branch *dst;
 	struct list_head next;
 	int seqno;
 	int state;
 	bool path_msg;
 	struct drm_dp_sideband_msg_reply_body reply;
 };

 /* sideband msg handler */
 struct drm_dp_mst_topology_mgr;
 struct drm_dp_mst_topology_cbs {
 	/* create a connector for a port */
 	struct drm_connector *(*add_connector)(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, const char *path);
 	void (*register_connector)(struct drm_connector *connector);
 	void (*destroy_connector)(struct drm_dp_mst_topology_mgr *mgr,
 				  struct drm_connector *connector);
 	void (*hotplug)(struct drm_dp_mst_topology_mgr *mgr);

 };

 #define DP_MAX_PAYLOAD (sizeof(unsigned long) * 8)

 #define DP_PAYLOAD_LOCAL 1
 #define DP_PAYLOAD_REMOTE 2
 #define DP_PAYLOAD_DELETE_LOCAL 3

 struct drm_dp_payload {
 	int payload_state;
 	int start_slot;
 	int num_slots;
 	int vcpi;
 };

 /**
  * struct drm_dp_mst_topology_mgr - DisplayPort MST manager
  *
  * This struct represents the toplevel displayport MST topology manager.
  * There should be one instance of this for every MST capable DP connector
  * on the GPU.
  */
 struct drm_dp_mst_topology_mgr {
 	/**
 	 * @dev: device pointer for adding i2c devices etc.
 	 */
 	struct drm_device *dev;
 	/**
 	 * @cbs: callbacks for connector addition and destruction.
 	 */
 	const struct drm_dp_mst_topology_cbs *cbs;
 	/**
 	 * @max_dpcd_transaction_bytes: maximum number of bytes to read/write
 	 * in one go.
 	 */
 	int max_dpcd_transaction_bytes;
 	/**
 	 * @aux: AUX channel for the DP MST connector this topolgy mgr is
 	 * controlling.
 	 */
 	struct drm_dp_aux *aux;
 	/**
 	 * @max_payloads: maximum number of payloads the GPU can generate.
 	 */
 	int max_payloads;
 	/**
 	 * @conn_base_id: DRM connector ID this mgr is connected to. Only used
 	 * to build the MST connector path value.
 	 */
 	int conn_base_id;

 	/**
 	 * @down_rep_recv: Message receiver state for down replies. This and
 	 * @up_req_recv are only ever access from the work item, which is
 	 * serialised.
 	 */
 	struct drm_dp_sideband_msg_rx down_rep_recv;
 	/**
 	 * @up_req_recv: Message receiver state for up requests. This and
 	 * @down_rep_recv are only ever access from the work item, which is
 	 * serialised.
 	 */
 	struct drm_dp_sideband_msg_rx up_req_recv;

 	/**
 	 * @lock: protects mst state, primary, dpcd.
 	 */
 	struct mutex lock;

 	/**
 	 * @mst_state: If this manager is enabled for an MST capable port. False
 	 * if no MST sink/branch devices is connected.
 	 */
 	bool mst_state;
 	/**
 	 * @mst_primary: Pointer to the primary/first branch device.
 	 */
 	struct drm_dp_mst_branch *mst_primary;

 	/**
 	 * @dpcd: Cache of DPCD for primary port.
 	 */
 	u8 dpcd[DP_RECEIVER_CAP_SIZE];
 	/**
 	 * @sink_count: Sink count from DEVICE_SERVICE_IRQ_VECTOR_ESI0.
 	 */
 	u8 sink_count;
 	/**
 	 * @pbn_div: PBN to slots divisor.
 	 */
 	int pbn_div;
 	/**
 	 * @total_slots: Total slots that can be allocated.
 	 */
 	int total_slots;
 	/**
 	 * @avail_slots: Still available slots that can be allocated.
 	 */
 	int avail_slots;
 	/**
 	 * @total_pbn: Total PBN count.
 	 */
 	int total_pbn;

 	/**
 	 * @qlock: protects @tx_msg_downq, the &drm_dp_mst_branch.txslost and
 	 * &drm_dp_sideband_msg_tx.state once they are queued
 	 */
 	struct mutex qlock;
 	/**
 	 * @tx_msg_downq: List of pending down replies.
 	 */
 	struct list_head tx_msg_downq;

 	/**
 	 * @payload_lock: Protect payload information.
 	 */
 	struct mutex payload_lock;
 	/**
 	 * @proposed_vcpis: Array of pointers for the new VCPI allocation. The
 	 * VCPI structure itself is &drm_dp_mst_port.vcpi.
 	 */
 	struct drm_dp_vcpi **proposed_vcpis;
 	/**
 	 * @payloads: Array of payloads.
 	 */
 	struct drm_dp_payload *payloads;
 	/**
 	 * @payload_mask: Elements of @payloads actually in use. Since
 	 * reallocation of active outputs isn't possible gaps can be created by
 	 * disabling outputs out of order compared to how they've been enabled.
 	 */
 	unsigned long payload_mask;
 	/**
 	 * @vcpi_mask: Similar to @payload_mask, but for @proposed_vcpis.
 	 */
 	unsigned long vcpi_mask;

 	/**
 	 * @tx_waitq: Wait to queue stall for the tx worker.
 	 */
 	wait_queue_head_t tx_waitq;
 	/**
 	 * @work: Probe work.
 	 */
 	struct work_struct work;
 	/**
 	 * @tx_work: Sideband transmit worker. This can nest within the main
 	 * @work worker for each transaction @work launches.
 	 */
 	struct work_struct tx_work;

 	/**
 	 * @destroy_connector_list: List of to be destroyed connectors.
 	 */
 	struct list_head destroy_connector_list;
 	/**
 	 * @destroy_connector_lock: Protects @connector_list.
 	 */
 	struct mutex destroy_connector_lock;
 	/**
 	 * @destroy_connector_work: Work item to destroy connectors. Needed to
 	 * avoid locking inversion.
 	 */
 	struct work_struct destroy_connector_work;
 };

 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
 				 struct drm_device *dev, struct drm_dp_aux *aux,
 				 int max_dpcd_transaction_bytes,
 				 int max_payloads, int conn_base_id);

 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr);


 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state);


 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled);


 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);

 bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
 					struct drm_dp_mst_port *port);
 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);


 int drm_dp_calc_pbn_mode(int clock, int bpp);


 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots);

 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);


 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);


 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
 				struct drm_dp_mst_port *port);


 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
 			   int pbn);


 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr);


 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr);

 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr);

 void drm_dp_mst_dump_topology(struct seq_file *m,
 			      struct drm_dp_mst_topology_mgr *mgr);

 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr);
 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr);
 #endif
	/*
	* Copyright © 2014 Red Hat.
	*
	* Permission to use, copy, modify, distribute, and sell this software and its
	* documentation for any purpose is hereby granted without fee, provided that
	* the above copyright notice appear in all copies and that both that copyright
	* notice and this permission notice appear in supporting documentation, and
	* that the name of the copyright holders not be used in advertising or
	* publicity pertaining to distribution of the software without specific,
	* written prior permission. The copyright holders make no representations
	* about the suitability of this software for any purpose. It is provided "as
	* is" without express or implied warranty.
	*
	* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
	* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
	* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
	* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
	* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
	* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
	* OF THIS SOFTWARE.
	*/
	#ifndef _DRM_DP_MST_HELPER_H_
	#define _DRM_DP_MST_HELPER_H_

	#include <linux/types.h>
	#include <drm/drm_dp_helper.h>

	struct drm_dp_mst_branch;

	/**
	* struct drm_dp_vcpi - Virtual Channel Payload Identifier
	* @vcpi: Virtual channel ID.
	* @pbn: Payload Bandwidth Number for this channel
	* @aligned_pbn: PBN aligned with slot size
	* @num_slots: number of slots for this PBN
	*/
	struct drm_dp_vcpi {
	int vcpi;
	int pbn;
	int aligned_pbn;
	int num_slots;
	};

	/**
	* struct drm_dp_mst_port - MST port
	* @kref: reference count for this port.
	* @port_num: port number
	* @input: if this port is an input port.
	* @mcs: message capability status - DP 1.2 spec.
	* @ddps: DisplayPort Device Plug Status - DP 1.2
	* @pdt: Peer Device Type
	* @ldps: Legacy Device Plug Status
	* @dpcd_rev: DPCD revision of device on this port
	* @num_sdp_streams: Number of simultaneous streams
	* @num_sdp_stream_sinks: Number of stream sinks
	* @available_pbn: Available bandwidth for this port.
	* @next: link to next port on this branch device
	* @mstb: branch device attach below this port
	* @aux: i2c aux transport to talk to device connected to this port.
	* @parent: branch device parent of this port
	* @vcpi: Virtual Channel Payload info for this port.
	* @connector: DRM connector this port is connected to.
	* @mgr: topology manager this port lives under.
	*
	* This structure represents an MST port endpoint on a device somewhere
	* in the MST topology.
	*/
	struct drm_dp_mst_port {
	struct kref kref;

	u8 port_num;
	bool input;
	bool mcs;
	bool ddps;
	u8 pdt;
	bool ldps;
	u8 dpcd_rev;
	u8 num_sdp_streams;
	u8 num_sdp_stream_sinks;
	uint16_t available_pbn;
	struct list_head next;
	struct drm_dp_mst_branch mstb; / pointer to an mstb if this port has one */
	struct drm_dp_aux aux; /* i2c bus for this port? */
	struct drm_dp_mst_branch *parent;

	struct drm_dp_vcpi vcpi;
	struct drm_connector *connector;
	struct drm_dp_mst_topology_mgr *mgr;

	/**
	* @cached_edid: for DP logical ports - make tiling work by ensuring
	* that the EDID for all connectors is read immediately.
	*/
	struct edid *cached_edid;
	/**
	* @has_audio: Tracks whether the sink connector to this port is
	* audio-capable.
	*/
	bool has_audio;
	};

	/**
	* struct drm_dp_mst_branch - MST branch device.
	* @kref: reference count for this port.
	* @rad: Relative Address to talk to this branch device.
	* @lct: Link count total to talk to this branch device.
	* @num_ports: number of ports on the branch.
	* @msg_slots: one bit per transmitted msg slot.
	* @ports: linked list of ports on this branch.
	* @port_parent: pointer to the port parent, NULL if toplevel.
	* @mgr: topology manager for this branch device.
	* @tx_slots: transmission slots for this device.
	* @last_seqno: last sequence number used to talk to this.
	* @link_address_sent: if a link address message has been sent to this device yet.
	* @guid: guid for DP 1.2 branch device. port under this branch can be
	* identified by port #.
	*
	* This structure represents an MST branch device, there is one
	* primary branch device at the root, along with any other branches connected
	* to downstream port of parent branches.
	*/
	struct drm_dp_mst_branch {
	struct kref kref;
	u8 rad[8];
	u8 lct;
	int num_ports;

	int msg_slots;
	struct list_head ports;

	/* list of tx ops queue for this port */
	struct drm_dp_mst_port *port_parent;
	struct drm_dp_mst_topology_mgr *mgr;

	/* slots are protected by mstb->mgr->qlock */
	struct drm_dp_sideband_msg_tx *tx_slots[2];
	int last_seqno;
	bool link_address_sent;

	/* global unique identifier to identify branch devices */
	u8 guid[16];
	};


	/* sideband msg header - not bit struct */
	struct drm_dp_sideband_msg_hdr {
	u8 lct;
	u8 lcr;
	u8 rad[8];
	bool broadcast;
	bool path_msg;
	u8 msg_len;
	bool somt;
	bool eomt;
	bool seqno;
	};

	struct drm_dp_nak_reply {
	u8 guid[16];
	u8 reason;
	u8 nak_data;
	};

	struct drm_dp_link_address_ack_reply {
	u8 guid[16];
	u8 nports;
	struct drm_dp_link_addr_reply_port {
	bool input_port;
	u8 peer_device_type;
	u8 port_number;
	bool mcs;
	bool ddps;
	bool legacy_device_plug_status;
	u8 dpcd_revision;
	u8 peer_guid[16];
	u8 num_sdp_streams;
	u8 num_sdp_stream_sinks;
	} ports[16];
	};

	struct drm_dp_remote_dpcd_read_ack_reply {
	u8 port_number;
	u8 num_bytes;
	u8 bytes[255];
	};

	struct drm_dp_remote_dpcd_write_ack_reply {
	u8 port_number;
	};

	struct drm_dp_remote_dpcd_write_nak_reply {
	u8 port_number;
	u8 reason;
	u8 bytes_written_before_failure;
	};

	struct drm_dp_remote_i2c_read_ack_reply {
	u8 port_number;
	u8 num_bytes;
	u8 bytes[255];
	};

	struct drm_dp_remote_i2c_read_nak_reply {
	u8 port_number;
	u8 nak_reason;
	u8 i2c_nak_transaction;
	};

	struct drm_dp_remote_i2c_write_ack_reply {
	u8 port_number;
	};


	struct drm_dp_sideband_msg_rx {
	u8 chunk[48];
	u8 msg[256];
	u8 curchunk_len;
	u8 curchunk_idx; /* chunk we are parsing now */
	u8 curchunk_hdrlen;
	u8 curlen; /* total length of the msg */
	bool have_somt;
	bool have_eomt;
	struct drm_dp_sideband_msg_hdr initial_hdr;
	};

	#define DRM_DP_MAX_SDP_STREAMS 16
	struct drm_dp_allocate_payload {
	u8 port_number;
	u8 number_sdp_streams;
	u8 vcpi;
	u16 pbn;
	u8 sdp_stream_sink[DRM_DP_MAX_SDP_STREAMS];
	};

	struct drm_dp_allocate_payload_ack_reply {
	u8 port_number;
	u8 vcpi;
	u16 allocated_pbn;
	};

	struct drm_dp_connection_status_notify {
	u8 guid[16];
	u8 port_number;
	bool legacy_device_plug_status;
	bool displayport_device_plug_status;
	bool message_capability_status;
	bool input_port;
	u8 peer_device_type;
	};

	struct drm_dp_remote_dpcd_read {
	u8 port_number;
	u32 dpcd_address;
	u8 num_bytes;
	};

	struct drm_dp_remote_dpcd_write {
	u8 port_number;
	u32 dpcd_address;
	u8 num_bytes;
	u8 *bytes;
	};

	#define DP_REMOTE_I2C_READ_MAX_TRANSACTIONS 4
	struct drm_dp_remote_i2c_read {
	u8 num_transactions;
	u8 port_number;
	struct {
	u8 i2c_dev_id;
	u8 num_bytes;
	u8 *bytes;
	u8 no_stop_bit;
	u8 i2c_transaction_delay;
	} transactions[DP_REMOTE_I2C_READ_MAX_TRANSACTIONS];
	u8 read_i2c_device_id;
	u8 num_bytes_read;
	};

	struct drm_dp_remote_i2c_write {
	u8 port_number;
	u8 write_i2c_device_id;
	u8 num_bytes;
	u8 *bytes;
	};

	/* this covers ENUM_RESOURCES, POWER_DOWN_PHY, POWER_UP_PHY */
	struct drm_dp_port_number_req {
	u8 port_number;
	};

	struct drm_dp_enum_path_resources_ack_reply {
	u8 port_number;
	u16 full_payload_bw_number;
	u16 avail_payload_bw_number;
	};

	/* covers POWER_DOWN_PHY, POWER_UP_PHY */
	struct drm_dp_port_number_rep {
	u8 port_number;
	};

	struct drm_dp_query_payload {
	u8 port_number;
	u8 vcpi;
	};

	struct drm_dp_resource_status_notify {
	u8 port_number;
	u8 guid[16];
	u16 available_pbn;
	};

	struct drm_dp_query_payload_ack_reply {
	u8 port_number;
	u8 allocated_pbn;
	};

	struct drm_dp_sideband_msg_req_body {
	u8 req_type;
	union ack_req {
	struct drm_dp_connection_status_notify conn_stat;
	struct drm_dp_port_number_req port_num;
	struct drm_dp_resource_status_notify resource_stat;

	struct drm_dp_query_payload query_payload;
	struct drm_dp_allocate_payload allocate_payload;

	struct drm_dp_remote_dpcd_read dpcd_read;
	struct drm_dp_remote_dpcd_write dpcd_write;

	struct drm_dp_remote_i2c_read i2c_read;
	struct drm_dp_remote_i2c_write i2c_write;
	} u;
	};

	struct drm_dp_sideband_msg_reply_body {
	u8 reply_type;
	u8 req_type;
	union ack_replies {
	struct drm_dp_nak_reply nak;
	struct drm_dp_link_address_ack_reply link_addr;
	struct drm_dp_port_number_rep port_number;

	struct drm_dp_enum_path_resources_ack_reply path_resources;
	struct drm_dp_allocate_payload_ack_reply allocate_payload;
	struct drm_dp_query_payload_ack_reply query_payload;

	struct drm_dp_remote_dpcd_read_ack_reply remote_dpcd_read_ack;
	struct drm_dp_remote_dpcd_write_ack_reply remote_dpcd_write_ack;
	struct drm_dp_remote_dpcd_write_nak_reply remote_dpcd_write_nack;

	struct drm_dp_remote_i2c_read_ack_reply remote_i2c_read_ack;
	struct drm_dp_remote_i2c_read_nak_reply remote_i2c_read_nack;
	struct drm_dp_remote_i2c_write_ack_reply remote_i2c_write_ack;
	} u;
	};

	/* msg is queued to be put into a slot */
	#define DRM_DP_SIDEBAND_TX_QUEUED 0
	/* msg has started transmitting on a slot - still on msgq */
	#define DRM_DP_SIDEBAND_TX_START_SEND 1
	/* msg has finished transmitting on a slot - removed from msgq only in slot */
	#define DRM_DP_SIDEBAND_TX_SENT 2
	/* msg has received a response - removed from slot */
	#define DRM_DP_SIDEBAND_TX_RX 3
	#define DRM_DP_SIDEBAND_TX_TIMEOUT 4

	struct drm_dp_sideband_msg_tx {
	u8 msg[256];
	u8 chunk[48];
	u8 cur_offset;
	u8 cur_len;
	struct drm_dp_mst_branch *dst;
	struct list_head next;
	int seqno;
	int state;
	bool path_msg;
	struct drm_dp_sideband_msg_reply_body reply;
	};

	/* sideband msg handler */
	struct drm_dp_mst_topology_mgr;
	struct drm_dp_mst_topology_cbs {
	/* create a connector for a port */
	struct drm_connector (add_connector)(struct drm_dp_mst_topology_mgr mgr, struct drm_dp_mst_port port, const char *path);
	void (register_connector)(struct drm_connector connector);
	void (destroy_connector)(struct drm_dp_mst_topology_mgr mgr,
	struct drm_connector *connector);
	void (hotplug)(struct drm_dp_mst_topology_mgr mgr);

	};

	#define DP_MAX_PAYLOAD (sizeof(unsigned long) * 8)

	#define DP_PAYLOAD_LOCAL 1
	#define DP_PAYLOAD_REMOTE 2
	#define DP_PAYLOAD_DELETE_LOCAL 3

	struct drm_dp_payload {
	int payload_state;
	int start_slot;
	int num_slots;
	int vcpi;
	};

	/**
	* struct drm_dp_mst_topology_mgr - DisplayPort MST manager
	*
	* This struct represents the toplevel displayport MST topology manager.
	* There should be one instance of this for every MST capable DP connector
	* on the GPU.
	*/
	struct drm_dp_mst_topology_mgr {
	/**
	* @dev: device pointer for adding i2c devices etc.
	*/
	struct drm_device *dev;
	/**
	* @cbs: callbacks for connector addition and destruction.
	*/
	const struct drm_dp_mst_topology_cbs *cbs;
	/**
	* @max_dpcd_transaction_bytes: maximum number of bytes to read/write
	* in one go.
	*/
	int max_dpcd_transaction_bytes;
	/**
	* @aux: AUX channel for the DP MST connector this topolgy mgr is
	* controlling.
	*/
	struct drm_dp_aux *aux;
	/**
	* @max_payloads: maximum number of payloads the GPU can generate.
	*/
	int max_payloads;
	/**
	* @conn_base_id: DRM connector ID this mgr is connected to. Only used
	* to build the MST connector path value.
	*/
	int conn_base_id;

	/**
	* @down_rep_recv: Message receiver state for down replies. This and
	* @up_req_recv are only ever access from the work item, which is
	* serialised.
	*/
	struct drm_dp_sideband_msg_rx down_rep_recv;
	/**
	* @up_req_recv: Message receiver state for up requests. This and
	* @down_rep_recv are only ever access from the work item, which is
	* serialised.
	*/
	struct drm_dp_sideband_msg_rx up_req_recv;

	/**
	* @lock: protects mst state, primary, dpcd.
	*/
	struct mutex lock;

	/**
	* @mst_state: If this manager is enabled for an MST capable port. False
	* if no MST sink/branch devices is connected.
	*/
	bool mst_state;
	/**
	* @mst_primary: Pointer to the primary/first branch device.
	*/
	struct drm_dp_mst_branch *mst_primary;

	/**
	* @dpcd: Cache of DPCD for primary port.
	*/
	u8 dpcd[DP_RECEIVER_CAP_SIZE];
	/**
	* @sink_count: Sink count from DEVICE_SERVICE_IRQ_VECTOR_ESI0.
	*/
	u8 sink_count;
	/**
	* @pbn_div: PBN to slots divisor.
	*/
	int pbn_div;
	/**
	* @total_slots: Total slots that can be allocated.
	*/
	int total_slots;
	/**
	* @avail_slots: Still available slots that can be allocated.
	*/
	int avail_slots;
	/**
	* @total_pbn: Total PBN count.
	*/
	int total_pbn;

	/**
	* @qlock: protects @tx_msg_downq, the &drm_dp_mst_branch.txslost and
	* &drm_dp_sideband_msg_tx.state once they are queued
	*/
	struct mutex qlock;
	/**
	* @tx_msg_downq: List of pending down replies.
	*/
	struct list_head tx_msg_downq;

	/**
	* @payload_lock: Protect payload information.
	*/
	struct mutex payload_lock;
	/**
	* @proposed_vcpis: Array of pointers for the new VCPI allocation. The
	* VCPI structure itself is &drm_dp_mst_port.vcpi.
	*/
	struct drm_dp_vcpi **proposed_vcpis;
	/**
	* @payloads: Array of payloads.
	*/
	struct drm_dp_payload *payloads;
	/**
	* @payload_mask: Elements of @payloads actually in use. Since
	* reallocation of active outputs isn't possible gaps can be created by
	* disabling outputs out of order compared to how they've been enabled.
	*/
	unsigned long payload_mask;
	/**
	* @vcpi_mask: Similar to @payload_mask, but for @proposed_vcpis.
	*/
	unsigned long vcpi_mask;

	/**
	* @tx_waitq: Wait to queue stall for the tx worker.
	*/
	wait_queue_head_t tx_waitq;
	/**
	* @work: Probe work.
	*/
	struct work_struct work;
	/**
	* @tx_work: Sideband transmit worker. This can nest within the main
	* @work worker for each transaction @work launches.
	*/
	struct work_struct tx_work;

	/**
	* @destroy_connector_list: List of to be destroyed connectors.
	*/
	struct list_head destroy_connector_list;
	/**
	* @destroy_connector_lock: Protects @connector_list.
	*/
	struct mutex destroy_connector_lock;
	/**
	* @destroy_connector_work: Work item to destroy connectors. Needed to
	* avoid locking inversion.
	*/
	struct work_struct destroy_connector_work;
	};

	int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
	struct drm_device dev, struct drm_dp_aux aux,
	int max_dpcd_transaction_bytes,
	int max_payloads, int conn_base_id);

	void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr);


	int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state);


	int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr mgr, u8 esi, bool *handled);


	enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector connector, struct drm_dp_mst_topology_mgr mgr, struct drm_dp_mst_port *port);

	bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
	struct drm_dp_mst_port *port);
	struct edid drm_dp_mst_get_edid(struct drm_connector connector, struct drm_dp_mst_topology_mgr mgr, struct drm_dp_mst_port port);


	int drm_dp_calc_pbn_mode(int clock, int bpp);


	bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr mgr, struct drm_dp_mst_port port, int pbn, int *slots);

	int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr mgr, struct drm_dp_mst_port port);


	void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr mgr, struct drm_dp_mst_port port);


	void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
	struct drm_dp_mst_port *port);


	int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
	int pbn);


	int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr);


	int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr);

	int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr);

	void drm_dp_mst_dump_topology(struct seq_file *m,
	struct drm_dp_mst_topology_mgr *mgr);

	void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr);
	int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr);
	#endif