/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * CAN driver for PEAK System micro-CAN based adapters
 *
 * Copyright (C) 2003-2025 PEAK System-Technik GmbH
 * Author: Stéphane Grosjean <stephane.grosjean@hms-networks.com>
 */
#ifndef PUCAN_H
#define PUCAN_H

/* uCAN commands opcodes list (low-order 10 bits) */
#define PUCAN_CMD_NOP                   0x000
#define PUCAN_CMD_RESET_MODE            0x001
#define PUCAN_CMD_NORMAL_MODE           0x002
#define PUCAN_CMD_LISTEN_ONLY_MODE      0x003
#define PUCAN_CMD_TIMING_SLOW           0x004
#define PUCAN_CMD_TIMING_FAST           0x005
#define PUCAN_CMD_SET_STD_FILTER        0x006
#define PUCAN_CMD_RESERVED2             0x007
#define PUCAN_CMD_FILTER_STD            0x008
#define PUCAN_CMD_TX_ABORT              0x009
#define PUCAN_CMD_WR_ERR_CNT            0x00a
#define PUCAN_CMD_SET_EN_OPTION         0x00b
#define PUCAN_CMD_CLR_DIS_OPTION        0x00c
#define PUCAN_CMD_RX_BARRIER            0x010
#define PUCAN_CMD_END_OF_COLLECTION     0x3ff

/* uCAN received messages list */
#define PUCAN_MSG_CAN_RX                0x0001
#define PUCAN_MSG_ERROR                 0x0002
#define PUCAN_MSG_STATUS                0x0003
#define PUCAN_MSG_BUSLOAD               0x0004

#define PUCAN_MSG_CACHE_CRITICAL        0x0102

/* uCAN transmitted messages */
#define PUCAN_MSG_CAN_TX                0x1000

/* uCAN command common header */
struct __packed pucan_command {
        __le16  opcode_channel;
        u16     args[3];
};

/* return the opcode from the opcode_channel field of a command */
static inline u16 pucan_cmd_get_opcode(struct pucan_command *c)
{
        return le16_to_cpu(c->opcode_channel) & 0x3ff;
}

#define PUCAN_TSLOW_BRP_BITS            10
#define PUCAN_TSLOW_TSGEG1_BITS         8
#define PUCAN_TSLOW_TSGEG2_BITS         7
#define PUCAN_TSLOW_SJW_BITS            7

#define PUCAN_TSLOW_BRP_MASK            ((1 << PUCAN_TSLOW_BRP_BITS) - 1)
#define PUCAN_TSLOW_TSEG1_MASK          ((1 << PUCAN_TSLOW_TSGEG1_BITS) - 1)
#define PUCAN_TSLOW_TSEG2_MASK          ((1 << PUCAN_TSLOW_TSGEG2_BITS) - 1)
#define PUCAN_TSLOW_SJW_MASK            ((1 << PUCAN_TSLOW_SJW_BITS) - 1)

/* uCAN TIMING_SLOW command fields */
#define PUCAN_TSLOW_SJW_T(s, t)         (((s) & PUCAN_TSLOW_SJW_MASK) | \
                                                                ((!!(t)) << 7))
#define PUCAN_TSLOW_TSEG2(t)            ((t) & PUCAN_TSLOW_TSEG2_MASK)
#define PUCAN_TSLOW_TSEG1(t)            ((t) & PUCAN_TSLOW_TSEG1_MASK)
#define PUCAN_TSLOW_BRP(b)              ((b) & PUCAN_TSLOW_BRP_MASK)

struct __packed pucan_timing_slow {
        __le16  opcode_channel;

        u8      ewl;            /* Error Warning limit */
        u8      sjw_t;          /* Sync Jump Width + Triple sampling */
        u8      tseg2;          /* Timing SEGment 2 */
        u8      tseg1;          /* Timing SEGment 1 */

        __le16  brp;            /* BaudRate Prescaler */
};

#define PUCAN_TFAST_BRP_BITS            10
#define PUCAN_TFAST_TSGEG1_BITS         5
#define PUCAN_TFAST_TSGEG2_BITS         4
#define PUCAN_TFAST_SJW_BITS            4

#define PUCAN_TFAST_BRP_MASK            ((1 << PUCAN_TFAST_BRP_BITS) - 1)
#define PUCAN_TFAST_TSEG1_MASK          ((1 << PUCAN_TFAST_TSGEG1_BITS) - 1)
#define PUCAN_TFAST_TSEG2_MASK          ((1 << PUCAN_TFAST_TSGEG2_BITS) - 1)
#define PUCAN_TFAST_SJW_MASK            ((1 << PUCAN_TFAST_SJW_BITS) - 1)

/* uCAN TIMING_FAST command fields */
#define PUCAN_TFAST_SJW(s)              ((s) & PUCAN_TFAST_SJW_MASK)
#define PUCAN_TFAST_TSEG2(t)            ((t) & PUCAN_TFAST_TSEG2_MASK)
#define PUCAN_TFAST_TSEG1(t)            ((t) & PUCAN_TFAST_TSEG1_MASK)
#define PUCAN_TFAST_BRP(b)              ((b) & PUCAN_TFAST_BRP_MASK)

struct __packed pucan_timing_fast {
        __le16  opcode_channel;

        u8      unused;
        u8      sjw;            /* Sync Jump Width */
        u8      tseg2;          /* Timing SEGment 2 */
        u8      tseg1;          /* Timing SEGment 1 */

        __le16  brp;            /* BaudRate Prescaler */
};

/* uCAN FILTER_STD command fields */
#define PUCAN_FLTSTD_ROW_IDX_BITS       6

struct __packed pucan_filter_std {
        __le16  opcode_channel;

        __le16  idx;
        __le32  mask;           /* CAN-ID bitmask in idx range */
};

#define PUCAN_FLTSTD_ROW_IDX_MAX        ((1 << PUCAN_FLTSTD_ROW_IDX_BITS) - 1)

/* uCAN SET_STD_FILTER command fields */
struct __packed pucan_std_filter {
        __le16  opcode_channel;

        u8      unused;
        u8      idx;
        __le32  mask;           /* CAN-ID bitmask in idx range */
};

/* uCAN TX_ABORT commands fields */
#define PUCAN_TX_ABORT_FLUSH            0x0001

struct __packed pucan_tx_abort {
        __le16  opcode_channel;

        __le16  flags;
        u32     unused;
};

/* uCAN WR_ERR_CNT command fields */
#define PUCAN_WRERRCNT_TE               0x4000  /* Tx error cntr write Enable */
#define PUCAN_WRERRCNT_RE               0x8000  /* Rx error cntr write Enable */

struct __packed pucan_wr_err_cnt {
        __le16  opcode_channel;

        __le16  sel_mask;
        u8      tx_counter;     /* Tx error counter new value */
        u8      rx_counter;     /* Rx error counter new value */

        u16     unused;
};

/* uCAN SET_EN/CLR_DIS _OPTION command fields */
#define PUCAN_OPTION_ERROR              0x0001
#define PUCAN_OPTION_BUSLOAD            0x0002
#define PUCAN_OPTION_CANDFDISO          0x0004

struct __packed pucan_options {
        __le16  opcode_channel;

        __le16  options;
        u32     unused;
};

/* uCAN received messages global format */
struct __packed pucan_msg {
        __le16  size;
        __le16  type;
        __le32  ts_low;
        __le32  ts_high;
};

/* uCAN flags for CAN/CANFD messages */
#define PUCAN_MSG_SELF_RECEIVE          0x80
#define PUCAN_MSG_ERROR_STATE_IND       0x40    /* error state indicator */
#define PUCAN_MSG_BITRATE_SWITCH        0x20    /* bitrate switch */
#define PUCAN_MSG_EXT_DATA_LEN          0x10    /* extended data length */
#define PUCAN_MSG_SINGLE_SHOT           0x08
#define PUCAN_MSG_LOOPED_BACK           0x04
#define PUCAN_MSG_EXT_ID                0x02
#define PUCAN_MSG_RTR                   0x01

struct __packed pucan_rx_msg {
        __le16  size;
        __le16  type;
        __le32  ts_low;
        __le32  ts_high;
        __le32  tag_low;
        __le32  tag_high;
        u8      channel_dlc;
        u8      client;
        __le16  flags;
        __le32  can_id;
        u8      d[];
};

/* uCAN error types */
#define PUCAN_ERMSG_BIT_ERROR           0
#define PUCAN_ERMSG_FORM_ERROR          1
#define PUCAN_ERMSG_STUFF_ERROR         2
#define PUCAN_ERMSG_OTHER_ERROR         3
#define PUCAN_ERMSG_ERR_CNT_DEC         4

struct __packed pucan_error_msg {
        __le16  size;
        __le16  type;
        __le32  ts_low;
        __le32  ts_high;
        u8      channel_type_d;
        u8      code_g;
        u8      tx_err_cnt;
        u8      rx_err_cnt;
};

static inline int pucan_error_get_channel(const struct pucan_error_msg *msg)
{
        return msg->channel_type_d & 0x0f;
}

#define PUCAN_RX_BARRIER                0x10
#define PUCAN_BUS_PASSIVE               0x20
#define PUCAN_BUS_WARNING               0x40
#define PUCAN_BUS_BUSOFF                0x80

struct __packed pucan_status_msg {
        __le16  size;
        __le16  type;
        __le32  ts_low;
        __le32  ts_high;
        u8      channel_p_w_b;
        u8      unused[3];
};

static inline int pucan_status_get_channel(const struct pucan_status_msg *msg)
{
        return msg->channel_p_w_b & 0x0f;
}

static inline int pucan_status_is_rx_barrier(const struct pucan_status_msg *msg)
{
        return msg->channel_p_w_b & PUCAN_RX_BARRIER;
}

static inline int pucan_status_is_passive(const struct pucan_status_msg *msg)
{
        return msg->channel_p_w_b & PUCAN_BUS_PASSIVE;
}

static inline int pucan_status_is_warning(const struct pucan_status_msg *msg)
{
        return msg->channel_p_w_b & PUCAN_BUS_WARNING;
}

static inline int pucan_status_is_busoff(const struct pucan_status_msg *msg)
{
        return msg->channel_p_w_b & PUCAN_BUS_BUSOFF;
}

/* uCAN transmitted message format */
#define PUCAN_MSG_CHANNEL_DLC(c, d)     (((c) & 0xf) | ((d) << 4))

struct __packed pucan_tx_msg {
        __le16  size;
        __le16  type;
        __le32  tag_low;
        __le32  tag_high;
        u8      channel_dlc;
        u8      client;
        __le16  flags;
        __le32  can_id;
        u8      d[];
};

/* build the cmd opcode_channel field with respect to the correct endianness */
static inline __le16 pucan_cmd_opcode_channel(int index, int opcode)
{
        return cpu_to_le16(((index) << 12) | ((opcode) & 0x3ff));
}

/* return the channel number part from any received message channel_dlc field */
static inline int pucan_msg_get_channel(const struct pucan_rx_msg *msg)
{
        return msg->channel_dlc & 0xf;
}

/* return the dlc value from any received message channel_dlc field */
static inline u8 pucan_msg_get_dlc(const struct pucan_rx_msg *msg)
{
        return msg->channel_dlc >> 4;
}

static inline int pucan_ermsg_get_channel(const struct pucan_error_msg *msg)
{
        return msg->channel_type_d & 0x0f;
}

static inline int pucan_stmsg_get_channel(const struct pucan_status_msg *msg)
{
        return msg->channel_p_w_b & 0x0f;
}

#endif