/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _FIREWIRE_CORE_H
#define _FIREWIRE_CORE_H

#include <linux/compiler.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/fs.h>
#include <linux/list.h>
#include <linux/xarray.h>
#include <linux/mm_types.h>
#include <linux/rwsem.h>
#include <linux/slab.h>
#include <linux/types.h>

#include <linux/refcount.h>

struct device;
struct fw_card;
struct fw_device;
struct fw_iso_buffer;
struct fw_iso_context;
struct fw_iso_packet;
struct fw_node;
struct fw_packet;


/* -card */

// This is the arbitrary value we use to indicate a mismatched gap count.
#define GAP_COUNT_MISMATCHED    0

#define isoc_cycles_to_jiffies(cycles) usecs_to_jiffies((u32)div_u64((u64)cycles * USEC_PER_SEC, 8000))

extern __printf(2, 3)
void fw_err(const struct fw_card *card, const char *fmt, ...);
extern __printf(2, 3)
void fw_notice(const struct fw_card *card, const char *fmt, ...);

/* bitfields within the PHY registers */
#define PHY_LINK_ACTIVE         0x80
#define PHY_CONTENDER           0x40
#define PHY_BUS_RESET           0x40
#define PHY_EXTENDED_REGISTERS  0xe0
#define PHY_BUS_SHORT_RESET     0x40
#define PHY_INT_STATUS_BITS     0x3c
#define PHY_ENABLE_ACCEL        0x02
#define PHY_ENABLE_MULTI        0x01
#define PHY_PAGE_SELECT         0xe0

#define BANDWIDTH_AVAILABLE_INITIAL     4915
#define BROADCAST_CHANNEL_INITIAL       (1 << 31 | 31)
#define BROADCAST_CHANNEL_VALID         (1 << 30)

#define CSR_STATE_BIT_CMSTR     (1 << 8)
#define CSR_STATE_BIT_ABDICATE  (1 << 10)

struct fw_card_driver {
        /*
         * Enable the given card with the given initial config rom.
         * This function is expected to activate the card, and either
         * enable the PHY or set the link_on bit and initiate a bus
         * reset.
         */
        int (*enable)(struct fw_card *card,
                      const __be32 *config_rom, size_t length);

        // After returning the call, any function is no longer triggered to handle hardware event.
        void (*disable)(struct fw_card *card);

        int (*read_phy_reg)(struct fw_card *card, int address);
        int (*update_phy_reg)(struct fw_card *card, int address,
                              int clear_bits, int set_bits);

        /*
         * Update the config rom for an enabled card.  This function
         * should change the config rom that is presented on the bus
         * and initiate a bus reset.
         */
        int (*set_config_rom)(struct fw_card *card,
                              const __be32 *config_rom, size_t length);

        void (*send_request)(struct fw_card *card, struct fw_packet *packet);
        void (*send_response)(struct fw_card *card, struct fw_packet *packet);
        /* Calling cancel is valid once a packet has been submitted. */
        int (*cancel_packet)(struct fw_card *card, struct fw_packet *packet);

        /*
         * Allow the specified node ID to do direct DMA out and in of
         * host memory.  The card will disable this for all node when
         * a bus reset happens, so driver need to re-enable this after
         * bus reset.  Returns 0 on success, -ENODEV if the card
         * doesn't support this, -ESTALE if the generation doesn't
         * match.
         */
        int (*enable_phys_dma)(struct fw_card *card,
                               int node_id, int generation);

        u32 (*read_csr)(struct fw_card *card, int csr_offset);
        void (*write_csr)(struct fw_card *card, int csr_offset, u32 value);

        struct fw_iso_context *
        (*allocate_iso_context)(struct fw_card *card, int type, int channel, size_t header_size,
                                size_t header_storage_size);
        void (*free_iso_context)(struct fw_iso_context *ctx);

        int (*start_iso)(struct fw_iso_context *ctx,
                         s32 cycle, u32 sync, u32 tags);

        int (*set_iso_channels)(struct fw_iso_context *ctx, u64 *channels);

        int (*queue_iso)(struct fw_iso_context *ctx,
                         struct fw_iso_packet *packet,
                         struct fw_iso_buffer *buffer,
                         unsigned long payload);

        void (*flush_queue_iso)(struct fw_iso_context *ctx);

        int (*flush_iso_completions)(struct fw_iso_context *ctx);

        int (*stop_iso)(struct fw_iso_context *ctx);
};

void fw_card_initialize(struct fw_card *card,
                const struct fw_card_driver *driver, struct device *device);
int fw_card_add(struct fw_card *card, u32 max_receive, u32 link_speed, u64 guid,
                unsigned int supported_isoc_contexts);
void fw_core_remove_card(struct fw_card *card);
int fw_compute_block_crc(__be32 *block);
void fw_schedule_bm_work(struct fw_card *card, unsigned long delay);

/* -cdev */

extern const struct file_operations fw_device_ops;

void fw_device_cdev_update(struct fw_device *device);
void fw_device_cdev_remove(struct fw_device *device);
void fw_cdev_handle_phy_packet(struct fw_card *card, struct fw_packet *p);


/* -device */

extern struct rw_semaphore fw_device_rwsem;
extern struct xarray fw_device_xa;
extern int fw_cdev_major;

static inline struct fw_device *fw_device_get(struct fw_device *device)
{
        get_device(&device->device);

        return device;
}

static inline void fw_device_put(struct fw_device *device)
{
        put_device(&device->device);
}

struct fw_device *fw_device_get_by_devt(dev_t devt);
int fw_device_set_broadcast_channel(struct device *dev, void *gen);
void fw_node_event(struct fw_card *card, struct fw_node *node, int event);


/* -iso */

int fw_iso_buffer_alloc(struct fw_iso_buffer *buffer, int page_count);
int fw_iso_buffer_map_dma(struct fw_iso_buffer *buffer, struct fw_card *card,
                          enum dma_data_direction direction);
size_t fw_iso_buffer_lookup(struct fw_iso_buffer *buffer, dma_addr_t completed);

static inline void fw_iso_context_init_work(struct fw_iso_context *ctx, work_func_t func)
{
        INIT_WORK(&ctx->work, func);
}

static inline struct fw_iso_context *fw_iso_mc_context_create(struct fw_card *card,
                fw_iso_mc_callback_t callback, void *callback_data)
{
        union fw_iso_callback cb = { .mc = callback };

        return __fw_iso_context_create(card, FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL, 0, 0, 0, 0, cb,
                                       callback_data);
}


/* -topology */

// The initial value of BUS_MANAGER_ID register, to express nothing registered.
#define BUS_MANAGER_ID_NOT_REGISTERED   0x3f

enum {
        FW_NODE_CREATED,
        FW_NODE_UPDATED,
        FW_NODE_DESTROYED,
        FW_NODE_LINK_ON,
        FW_NODE_LINK_OFF,
        FW_NODE_INITIATED_RESET,
};

struct fw_node {
        u16 node_id;
        u8 color;
        u8 port_count;
        u8 link_on:1;
        u8 initiated_reset:1;
        u8 b_path:1;
        u8 phy_speed:2; /* As in the self ID packet. */
        u8 max_speed:2; /* Minimum of all phy-speeds on the path from the
                         * local node to this node. */
        u8 max_depth:4; /* Maximum depth to any leaf node */
        u8 max_hops:4;  /* Max hops in this sub tree */

        struct kref kref;

        /* For serializing node topology into a list. */
        struct list_head link;

        // The device when already associated, else NULL.
        struct fw_device *device;

        struct fw_node *ports[] __counted_by(port_count);
};

static inline struct fw_node *fw_node_get(struct fw_node *node)
{
        kref_get(&node->kref);

        return node;
}

static void release_node(struct kref *kref)
{
        struct fw_node *node = container_of(kref, struct fw_node, kref);

        kfree(node);
}

static inline void fw_node_put(struct fw_node *node)
{
        kref_put(&node->kref, release_node);
}

static inline struct fw_device *fw_node_get_device(struct fw_node *node)
{
        return node->device;
}

static inline void fw_node_set_device(struct fw_node *node, struct fw_device *device)
{
        node->device = device;
}

void fw_core_handle_bus_reset(struct fw_card *card, int node_id,
        int generation, int self_id_count, u32 *self_ids, bool bm_abdicate);
void fw_destroy_nodes(struct fw_card *card);

/*
 * Check whether new_generation is the immediate successor of old_generation.
 * Take counter roll-over at 255 (as per OHCI) into account.
 */
static inline bool is_next_generation(int new_generation, int old_generation)
{
        return (new_generation & 0xff) == ((old_generation + 1) & 0xff);
}


/* -transaction */

#define TCODE_LINK_INTERNAL             0xe

static inline bool tcode_is_read_request(unsigned int tcode)
{
        return (tcode & ~1u) == 4u;
}

static inline bool tcode_is_block_packet(unsigned int tcode)
{
        return (tcode & 1u) != 0u;
}

static inline bool tcode_is_link_internal(unsigned int tcode)
{
        return (tcode == TCODE_LINK_INTERNAL);
}

#define LOCAL_BUS 0xffc0

/* OHCI-1394's default upper bound for physical DMA: 4 GB */
#define FW_MAX_PHYSICAL_RANGE           (1ULL << 32)

void fw_core_handle_request(struct fw_card *card, struct fw_packet *request);
void fw_core_handle_response(struct fw_card *card, struct fw_packet *packet);
int fw_get_response_length(struct fw_request *request);
void fw_fill_response(struct fw_packet *response, u32 *request_header,
                      int rcode, void *payload, size_t length);

void fw_request_get(struct fw_request *request);
void fw_request_put(struct fw_request *request);

void fw_cancel_pending_transactions(struct fw_card *card);

// Convert the value of IEEE 1394 CYCLE_TIME register to the format of timeStamp field in
// descriptors of 1394 OHCI.
static inline u32 cycle_time_to_ohci_tstamp(u32 tstamp)
{
        return (tstamp & 0x0ffff000) >> 12;
}

#define FW_PHY_CONFIG_NO_NODE_ID        -1
#define FW_PHY_CONFIG_CURRENT_GAP_COUNT -1
void fw_send_phy_config(struct fw_card *card,
                        int node_id, int generation, int gap_count);

static inline bool is_ping_packet(u32 *data)
{
        return (data[0] & 0xc0ffffff) == 0 && ~data[0] == data[1];
}

static inline bool is_in_fcp_region(u64 offset, size_t length)
{
        return offset >= (CSR_REGISTER_BASE | CSR_FCP_COMMAND) &&
                offset + length <= (CSR_REGISTER_BASE | CSR_FCP_END);
}

#endif /* _FIREWIRE_CORE_H */