/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Greybus connections
 *
 * Copyright 2014 Google Inc.
 * Copyright 2014 Linaro Ltd.
 */

#ifndef __CONNECTION_H
#define __CONNECTION_H

#include <linux/bits.h>
#include <linux/list.h>
#include <linux/kfifo.h>
#include <linux/kref.h>
#include <linux/workqueue.h>

#define GB_CONNECTION_FLAG_CSD          BIT(0)
#define GB_CONNECTION_FLAG_NO_FLOWCTRL  BIT(1)
#define GB_CONNECTION_FLAG_OFFLOADED    BIT(2)
#define GB_CONNECTION_FLAG_CDSI1        BIT(3)
#define GB_CONNECTION_FLAG_CONTROL      BIT(4)
#define GB_CONNECTION_FLAG_HIGH_PRIO    BIT(5)

#define GB_CONNECTION_FLAG_CORE_MASK    GB_CONNECTION_FLAG_CONTROL

enum gb_connection_state {
        GB_CONNECTION_STATE_DISABLED            = 0,
        GB_CONNECTION_STATE_ENABLED_TX          = 1,
        GB_CONNECTION_STATE_ENABLED             = 2,
        GB_CONNECTION_STATE_DISCONNECTING       = 3,
};

struct gb_operation;

typedef int (*gb_request_handler_t)(struct gb_operation *);

struct gb_connection {
        struct gb_host_device           *hd;
        struct gb_interface             *intf;
        struct gb_bundle                *bundle;
        struct kref                     kref;
        u16                             hd_cport_id;
        u16                             intf_cport_id;

        struct list_head                hd_links;
        struct list_head                bundle_links;

        gb_request_handler_t            handler;
        unsigned long                   flags;

        struct mutex                    mutex;
        spinlock_t                      lock;
        enum gb_connection_state        state;
        struct list_head                operations;

        char                            name[16];
        struct workqueue_struct         *wq;

        atomic_t                        op_cycle;

        void                            *private;

        bool                            mode_switch;
};

struct gb_connection *gb_connection_create_static(struct gb_host_device *hd,
                                u16 hd_cport_id, gb_request_handler_t handler);
struct gb_connection *gb_connection_create_control(struct gb_interface *intf);
struct gb_connection *gb_connection_create(struct gb_bundle *bundle,
                                u16 cport_id, gb_request_handler_t handler);
struct gb_connection *gb_connection_create_flags(struct gb_bundle *bundle,
                                u16 cport_id, gb_request_handler_t handler,
                                unsigned long flags);
struct gb_connection *gb_connection_create_offloaded(struct gb_bundle *bundle,
                                u16 cport_id, unsigned long flags);
void gb_connection_destroy(struct gb_connection *connection);

static inline bool gb_connection_is_static(struct gb_connection *connection)
{
        return !connection->intf;
}

int gb_connection_enable(struct gb_connection *connection);
int gb_connection_enable_tx(struct gb_connection *connection);
void gb_connection_disable_rx(struct gb_connection *connection);
void gb_connection_disable(struct gb_connection *connection);
void gb_connection_disable_forced(struct gb_connection *connection);

void gb_connection_mode_switch_prepare(struct gb_connection *connection);
void gb_connection_mode_switch_complete(struct gb_connection *connection);

void greybus_data_rcvd(struct gb_host_device *hd, u16 cport_id,
                       u8 *data, size_t length);

void gb_connection_latency_tag_enable(struct gb_connection *connection);
void gb_connection_latency_tag_disable(struct gb_connection *connection);

static inline bool gb_connection_e2efc_enabled(struct gb_connection *connection)
{
        return !(connection->flags & GB_CONNECTION_FLAG_CSD);
}

static inline bool
gb_connection_flow_control_disabled(struct gb_connection *connection)
{
        return connection->flags & GB_CONNECTION_FLAG_NO_FLOWCTRL;
}

static inline bool gb_connection_is_offloaded(struct gb_connection *connection)
{
        return connection->flags & GB_CONNECTION_FLAG_OFFLOADED;
}

static inline bool gb_connection_is_control(struct gb_connection *connection)
{
        return connection->flags & GB_CONNECTION_FLAG_CONTROL;
}

static inline void *gb_connection_get_data(struct gb_connection *connection)
{
        return connection->private;
}

static inline void gb_connection_set_data(struct gb_connection *connection,
                                          void *data)
{
        connection->private = data;
}

#endif /* __CONNECTION_H */