/* SPDX-License-Identifier: ISC */
/*
 * Copyright (c) 2005-2011 Atheros Communications Inc.
 * Copyright (c) 2011-2016 Qualcomm Atheros, Inc.
 */

#ifndef _HTC_H_
#define _HTC_H_

#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/bug.h>
#include <linux/skbuff.h>
#include <linux/timer.h>
#include <linux/bitfield.h>

struct ath10k;

/****************/
/* HTC protocol */
/****************/

/*
 * HTC - host-target control protocol
 *
 * tx packets are generally <htc_hdr><payload>
 * rx packets are more complex: <htc_hdr><payload><trailer>
 *
 * The payload + trailer length is stored in len.
 * To get payload-only length one needs to payload - trailer_len.
 *
 * Trailer contains (possibly) multiple <htc_record>.
 * Each record is a id-len-value.
 *
 * HTC header flags, control_byte0, control_byte1
 * have different meaning depending whether its tx
 * or rx.
 *
 * Alignment: htc_hdr, payload and trailer are
 * 4-byte aligned.
 */

#define HTC_HOST_MAX_MSG_PER_RX_BUNDLE        32

enum ath10k_htc_tx_flags {
        ATH10K_HTC_FLAG_NEED_CREDIT_UPDATE = 0x01,
        ATH10K_HTC_FLAG_SEND_BUNDLE        = 0x02
};

enum ath10k_htc_rx_flags {
        ATH10K_HTC_FLAGS_RECV_1MORE_BLOCK = 0x01,
        ATH10K_HTC_FLAG_TRAILER_PRESENT = 0x02,
};

#define ATH10K_HTC_FLAG_BUNDLE_MASK GENMASK(7, 4)

/* bits 2-3 are for extra bundle count bits 4-5 */
#define ATH10K_HTC_BUNDLE_EXTRA_MASK GENMASK(3, 2)
#define ATH10K_HTC_BUNDLE_EXTRA_SHIFT 4

static inline unsigned int ath10k_htc_get_bundle_count(u8 max_msgs, u8 flags)
{
        unsigned int count, extra_count = 0;

        count = FIELD_GET(ATH10K_HTC_FLAG_BUNDLE_MASK, flags);

        if (max_msgs > 16)
                extra_count = FIELD_GET(ATH10K_HTC_BUNDLE_EXTRA_MASK, flags) <<
                        ATH10K_HTC_BUNDLE_EXTRA_SHIFT;

        return count + extra_count;
}

struct ath10k_htc_hdr {
        u8 eid; /* @enum ath10k_htc_ep_id */
        u8 flags; /* @enum ath10k_htc_tx_flags, ath10k_htc_rx_flags */
        __le16 len;
        union {
                u8 trailer_len; /* for rx */
                u8 control_byte0;
        } __packed;
        union {
                u8 seq_no; /* for tx */
                u8 control_byte1;
        } __packed;
        union {
                __le16 pad_len;
                struct {
                        u8 pad0;
                        u8 pad1;
                } __packed;
        } __packed;

} __packed __aligned(4);

enum ath10k_ath10k_htc_msg_id {
        ATH10K_HTC_MSG_READY_ID                = 1,
        ATH10K_HTC_MSG_CONNECT_SERVICE_ID      = 2,
        ATH10K_HTC_MSG_CONNECT_SERVICE_RESP_ID = 3,
        ATH10K_HTC_MSG_SETUP_COMPLETE_ID       = 4,
        ATH10K_HTC_MSG_SETUP_COMPLETE_EX_ID    = 5,
        ATH10K_HTC_MSG_SEND_SUSPEND_COMPLETE   = 6
};

enum ath10k_htc_version {
        ATH10K_HTC_VERSION_2P0 = 0x00, /* 2.0 */
        ATH10K_HTC_VERSION_2P1 = 0x01, /* 2.1 */
};

enum ath10k_htc_conn_flags {
        ATH10K_HTC_CONN_FLAGS_THRESHOLD_LEVEL_ONE_FOURTH    = 0x0,
        ATH10K_HTC_CONN_FLAGS_THRESHOLD_LEVEL_ONE_HALF      = 0x1,
        ATH10K_HTC_CONN_FLAGS_THRESHOLD_LEVEL_THREE_FOURTHS = 0x2,
        ATH10K_HTC_CONN_FLAGS_THRESHOLD_LEVEL_UNITY         = 0x3,
#define ATH10K_HTC_CONN_FLAGS_THRESHOLD_LEVEL_MASK 0x3
        ATH10K_HTC_CONN_FLAGS_REDUCE_CREDIT_DRIBBLE    = 1 << 2,
        ATH10K_HTC_CONN_FLAGS_DISABLE_CREDIT_FLOW_CTRL = 1 << 3
#define ATH10K_HTC_CONN_FLAGS_RECV_ALLOC_MASK 0xFF00
#define ATH10K_HTC_CONN_FLAGS_RECV_ALLOC_LSB  8
};

#define ATH10K_HTC_MSG_READY_EXT_ALT_DATA_MASK 0xFFF

enum ath10k_htc_conn_svc_status {
        ATH10K_HTC_CONN_SVC_STATUS_SUCCESS      = 0,
        ATH10K_HTC_CONN_SVC_STATUS_NOT_FOUND    = 1,
        ATH10K_HTC_CONN_SVC_STATUS_FAILED       = 2,
        ATH10K_HTC_CONN_SVC_STATUS_NO_RESOURCES = 3,
        ATH10K_HTC_CONN_SVC_STATUS_NO_MORE_EP   = 4
};

#define ATH10K_MAX_MSG_PER_HTC_TX_BUNDLE        32
#define ATH10K_MIN_MSG_PER_HTC_TX_BUNDLE        2
#define ATH10K_MIN_CREDIT_PER_HTC_TX_BUNDLE     2

enum ath10k_htc_setup_complete_flags {
        ATH10K_HTC_SETUP_COMPLETE_FLAGS_RX_BNDL_EN = 1
};

struct ath10k_ath10k_htc_msg_hdr {
        __le16 message_id; /* @enum htc_message_id */
} __packed;

struct ath10k_htc_unknown {
        u8 pad0;
        u8 pad1;
} __packed;

struct ath10k_htc_ready {
        __le16 credit_count;
        __le16 credit_size;
        u8 max_endpoints;
        u8 pad0;
} __packed;

struct ath10k_htc_ready_extended {
        struct ath10k_htc_ready base;
        u8 htc_version; /* @enum ath10k_htc_version */
        u8 max_msgs_per_htc_bundle;
        union {
                __le16 reserved;
                struct {
                        u8 pad0;
                        u8 pad1;
                } __packed;
        } __packed;

} __packed;

struct ath10k_htc_conn_svc {
        __le16 service_id;
        __le16 flags; /* @enum ath10k_htc_conn_flags */
        u8 pad0;
        u8 pad1;
} __packed;

struct ath10k_htc_conn_svc_response {
        __le16 service_id;
        u8 status; /* @enum ath10k_htc_conn_svc_status */
        u8 eid;
        __le16 max_msg_size;
} __packed;

struct ath10k_htc_setup_complete_extended {
        u8 pad0;
        u8 pad1;
        __le32 flags; /* @enum htc_setup_complete_flags */
        u8 max_msgs_per_bundled_recv;
        u8 pad2;
        u8 pad3;
        u8 pad4;
} __packed;

struct ath10k_htc_msg {
        struct ath10k_ath10k_htc_msg_hdr hdr;
        union {
                /* host-to-target */
                struct ath10k_htc_conn_svc connect_service;
                struct ath10k_htc_ready ready;
                struct ath10k_htc_ready_extended ready_ext;
                struct ath10k_htc_unknown unknown;
                struct ath10k_htc_setup_complete_extended setup_complete_ext;

                /* target-to-host */
                struct ath10k_htc_conn_svc_response connect_service_response;
        };
} __packed __aligned(4);

enum ath10k_ath10k_htc_record_id {
        ATH10K_HTC_RECORD_NULL             = 0,
        ATH10K_HTC_RECORD_CREDITS          = 1,
        ATH10K_HTC_RECORD_LOOKAHEAD        = 2,
        ATH10K_HTC_RECORD_LOOKAHEAD_BUNDLE = 3,
};

struct ath10k_ath10k_htc_record_hdr {
        u8 id; /* @enum ath10k_ath10k_htc_record_id */
        u8 len;
        u8 pad0;
        u8 pad1;
} __packed;

struct ath10k_htc_credit_report {
        u8 eid; /* @enum ath10k_htc_ep_id */
        u8 credits;
        u8 pad0;
        u8 pad1;
} __packed;

struct ath10k_htc_lookahead_report {
        u8 pre_valid;
        u8 pad0;
        u8 pad1;
        u8 pad2;
        u8 lookahead[4];
        u8 post_valid;
        u8 pad3;
        u8 pad4;
        u8 pad5;
} __packed;

struct ath10k_htc_lookahead_bundle {
        u8 lookahead[4];
} __packed;

struct ath10k_htc_record {
        struct ath10k_ath10k_htc_record_hdr hdr;
        union {
                DECLARE_FLEX_ARRAY(struct ath10k_htc_credit_report, credit_report);
                DECLARE_FLEX_ARRAY(struct ath10k_htc_lookahead_report, lookahead_report);
                DECLARE_FLEX_ARRAY(struct ath10k_htc_lookahead_bundle, lookahead_bundle);
        };
} __packed __aligned(4);

/*******************/
/* Host-side stuff */
/*******************/

enum ath10k_htc_svc_gid {
        ATH10K_HTC_SVC_GRP_RSVD = 0,
        ATH10K_HTC_SVC_GRP_WMI = 1,
        ATH10K_HTC_SVC_GRP_NMI = 2,
        ATH10K_HTC_SVC_GRP_HTT = 3,
        ATH10K_LOG_SERVICE_GROUP = 6,

        ATH10K_HTC_SVC_GRP_TEST = 254,
        ATH10K_HTC_SVC_GRP_LAST = 255,
};

#define SVC(group, idx) \
        (int)(((int)(group) << 8) | (int)(idx))

enum ath10k_htc_svc_id {
        /* NOTE: service ID of 0x0000 is reserved and should never be used */
        ATH10K_HTC_SVC_ID_RESERVED      = 0x0000,
        ATH10K_HTC_SVC_ID_UNUSED        = ATH10K_HTC_SVC_ID_RESERVED,

        ATH10K_HTC_SVC_ID_RSVD_CTRL     = SVC(ATH10K_HTC_SVC_GRP_RSVD, 1),
        ATH10K_HTC_SVC_ID_WMI_CONTROL   = SVC(ATH10K_HTC_SVC_GRP_WMI, 0),
        ATH10K_HTC_SVC_ID_WMI_DATA_BE   = SVC(ATH10K_HTC_SVC_GRP_WMI, 1),
        ATH10K_HTC_SVC_ID_WMI_DATA_BK   = SVC(ATH10K_HTC_SVC_GRP_WMI, 2),
        ATH10K_HTC_SVC_ID_WMI_DATA_VI   = SVC(ATH10K_HTC_SVC_GRP_WMI, 3),
        ATH10K_HTC_SVC_ID_WMI_DATA_VO   = SVC(ATH10K_HTC_SVC_GRP_WMI, 4),

        ATH10K_HTC_SVC_ID_NMI_CONTROL   = SVC(ATH10K_HTC_SVC_GRP_NMI, 0),
        ATH10K_HTC_SVC_ID_NMI_DATA      = SVC(ATH10K_HTC_SVC_GRP_NMI, 1),

        ATH10K_HTC_SVC_ID_HTT_DATA_MSG  = SVC(ATH10K_HTC_SVC_GRP_HTT, 0),

        ATH10K_HTC_SVC_ID_HTT_DATA2_MSG = SVC(ATH10K_HTC_SVC_GRP_HTT, 1),
        ATH10K_HTC_SVC_ID_HTT_DATA3_MSG = SVC(ATH10K_HTC_SVC_GRP_HTT, 2),
        ATH10K_HTC_SVC_ID_HTT_LOG_MSG = SVC(ATH10K_LOG_SERVICE_GROUP, 0),
        /* raw stream service (i.e. flash, tcmd, calibration apps) */
        ATH10K_HTC_SVC_ID_TEST_RAW_STREAMS = SVC(ATH10K_HTC_SVC_GRP_TEST, 0),
};

#undef SVC

enum ath10k_htc_ep_id {
        ATH10K_HTC_EP_UNUSED = -1,
        ATH10K_HTC_EP_0 = 0,
        ATH10K_HTC_EP_1 = 1,
        ATH10K_HTC_EP_2,
        ATH10K_HTC_EP_3,
        ATH10K_HTC_EP_4,
        ATH10K_HTC_EP_5,
        ATH10K_HTC_EP_6,
        ATH10K_HTC_EP_7,
        ATH10K_HTC_EP_8,
        ATH10K_HTC_EP_COUNT,
};

struct ath10k_htc_ops {
        void (*target_send_suspend_complete)(struct ath10k *ar);
};

struct ath10k_htc_ep_ops {
        void (*ep_tx_complete)(struct ath10k *, struct sk_buff *);
        void (*ep_rx_complete)(struct ath10k *, struct sk_buff *);
        void (*ep_tx_credits)(struct ath10k *);
};

/* service connection information */
struct ath10k_htc_svc_conn_req {
        u16 service_id;
        struct ath10k_htc_ep_ops ep_ops;
        int max_send_queue_depth;
};

/* service connection response information */
struct ath10k_htc_svc_conn_resp {
        u8 buffer_len;
        u8 actual_len;
        enum ath10k_htc_ep_id eid;
        unsigned int max_msg_len;
        u8 connect_resp_code;
};

#define ATH10K_NUM_CONTROL_TX_BUFFERS 2
#define ATH10K_HTC_MAX_LEN 4096
#define ATH10K_HTC_MAX_CTRL_MSG_LEN 256
#define ATH10K_HTC_WAIT_TIMEOUT_HZ (1 * HZ)
#define ATH10K_HTC_CONTROL_BUFFER_SIZE (ATH10K_HTC_MAX_CTRL_MSG_LEN + \
                                        sizeof(struct ath10k_htc_hdr))
#define ATH10K_HTC_CONN_SVC_TIMEOUT_HZ (1 * HZ)

struct ath10k_htc_ep {
        struct ath10k_htc *htc;
        enum ath10k_htc_ep_id eid;
        enum ath10k_htc_svc_id service_id;
        struct ath10k_htc_ep_ops ep_ops;

        int max_tx_queue_depth;
        int max_ep_message_len;
        u8 ul_pipe_id;
        u8 dl_pipe_id;

        u8 seq_no; /* for debugging */
        int tx_credits;
        int tx_credit_size;
        bool tx_credit_flow_enabled;
        bool bundle_tx;
        struct sk_buff_head tx_req_head;
        struct sk_buff_head tx_complete_head;

};

struct ath10k_htc_svc_tx_credits {
        u16 service_id;
        u8  credit_allocation;
};

struct ath10k_htc {
        struct ath10k *ar;
        struct ath10k_htc_ep endpoint[ATH10K_HTC_EP_COUNT];

        /* protects endpoints */
        spinlock_t tx_lock;

        struct ath10k_htc_ops htc_ops;

        u8 control_resp_buffer[ATH10K_HTC_MAX_CTRL_MSG_LEN];
        int control_resp_len;

        struct completion ctl_resp;

        int total_transmit_credits;
        int target_credit_size;
        u8 max_msgs_per_htc_bundle;
        int alt_data_credit_size;
};

int ath10k_htc_init(struct ath10k *ar);
int ath10k_htc_wait_target(struct ath10k_htc *htc);
void ath10k_htc_setup_tx_req(struct ath10k_htc_ep *ep);
int ath10k_htc_start(struct ath10k_htc *htc);
int ath10k_htc_connect_service(struct ath10k_htc *htc,
                               struct ath10k_htc_svc_conn_req  *conn_req,
                               struct ath10k_htc_svc_conn_resp *conn_resp);
void ath10k_htc_change_tx_credit_flow(struct ath10k_htc *htc,
                                      enum ath10k_htc_ep_id eid,
                                      bool enable);
int ath10k_htc_send(struct ath10k_htc *htc, enum ath10k_htc_ep_id eid,
                    struct sk_buff *packet);
void ath10k_htc_stop_hl(struct ath10k *ar);

int ath10k_htc_send_hl(struct ath10k_htc *htc, enum ath10k_htc_ep_id eid,
                       struct sk_buff *packet);
struct sk_buff *ath10k_htc_alloc_skb(struct ath10k *ar, int size);
void ath10k_htc_tx_completion_handler(struct ath10k *ar, struct sk_buff *skb);
void ath10k_htc_rx_completion_handler(struct ath10k *ar, struct sk_buff *skb);
void ath10k_htc_notify_tx_completion(struct ath10k_htc_ep *ep,
                                     struct sk_buff *skb);
int ath10k_htc_process_trailer(struct ath10k_htc *htc,
                               u8 *buffer,
                               int length,
                               enum ath10k_htc_ep_id src_eid,
                               void *next_lookaheads,
                               int *next_lookaheads_len);

#endif