/* SPDX-License-Identifier: GPL-2.0 */
/*
 * hfcsusb.h, HFC-S USB mISDN driver
 */

#ifndef __HFCSUSB_H__
#define __HFCSUSB_H__


#define DRIVER_NAME "HFC-S_USB"

#define DBG_HFC_CALL_TRACE      0x00010000
#define DBG_HFC_FIFO_VERBOSE    0x00020000
#define DBG_HFC_USB_VERBOSE     0x00100000
#define DBG_HFC_URB_INFO        0x00200000
#define DBG_HFC_URB_ERROR       0x00400000

#define DEFAULT_TRANSP_BURST_SZ 128

#define HFC_CTRL_TIMEOUT        20      /* 5ms timeout writing/reading regs */
#define CLKDEL_TE               0x0f    /* CLKDEL in TE mode */
#define CLKDEL_NT               0x6c    /* CLKDEL in NT mode */

/* hfcsusb Layer1 commands */
#define HFC_L1_ACTIVATE_TE              1
#define HFC_L1_ACTIVATE_NT              2
#define HFC_L1_DEACTIVATE_NT            3
#define HFC_L1_FORCE_DEACTIVATE_TE      4

/* cmd FLAGS in HFCUSB_STATES register */
#define HFCUSB_LOAD_STATE       0x10
#define HFCUSB_ACTIVATE         0x20
#define HFCUSB_DO_ACTION        0x40
#define HFCUSB_NT_G2_G3         0x80

/* timers */
#define NT_ACTIVATION_TIMER     0x01    /* enables NT mode activation Timer */
#define NT_T1_COUNT             10

#define MAX_BCH_SIZE            2048    /* allowed B-channel packet size */

#define HFCUSB_RX_THRESHOLD     64      /* threshold for fifo report bit rx */
#define HFCUSB_TX_THRESHOLD     96      /* threshold for fifo report bit tx */

#define HFCUSB_CHIP_ID          0x16    /* Chip ID register index */
#define HFCUSB_CIRM             0x00    /* cirm register index */
#define HFCUSB_USB_SIZE         0x07    /* int length register */
#define HFCUSB_USB_SIZE_I       0x06    /* iso length register */
#define HFCUSB_F_CROSS          0x0b    /* bit order register */
#define HFCUSB_CLKDEL           0x37    /* bit delay register */
#define HFCUSB_CON_HDLC         0xfa    /* channel connect register */
#define HFCUSB_HDLC_PAR         0xfb
#define HFCUSB_SCTRL            0x31    /* S-bus control register (tx) */
#define HFCUSB_SCTRL_E          0x32    /* same for E and special funcs */
#define HFCUSB_SCTRL_R          0x33    /* S-bus control register (rx) */
#define HFCUSB_F_THRES          0x0c    /* threshold register */
#define HFCUSB_FIFO             0x0f    /* fifo select register */
#define HFCUSB_F_USAGE          0x1a    /* fifo usage register */
#define HFCUSB_MST_MODE0        0x14
#define HFCUSB_MST_MODE1        0x15
#define HFCUSB_P_DATA           0x1f
#define HFCUSB_INC_RES_F        0x0e
#define HFCUSB_B1_SSL           0x20
#define HFCUSB_B2_SSL           0x21
#define HFCUSB_B1_RSL           0x24
#define HFCUSB_B2_RSL           0x25
#define HFCUSB_STATES           0x30


#define HFCUSB_CHIPID           0x40    /* ID value of HFC-S USB */

/* fifo registers */
#define HFCUSB_NUM_FIFOS        8       /* maximum number of fifos */
#define HFCUSB_B1_TX            0       /* index for B1 transmit bulk/int */
#define HFCUSB_B1_RX            1       /* index for B1 receive bulk/int */
#define HFCUSB_B2_TX            2
#define HFCUSB_B2_RX            3
#define HFCUSB_D_TX             4
#define HFCUSB_D_RX             5
#define HFCUSB_PCM_TX           6
#define HFCUSB_PCM_RX           7


#define USB_INT         0
#define USB_BULK        1
#define USB_ISOC        2

#define ISOC_PACKETS_D  8
#define ISOC_PACKETS_B  8
#define ISO_BUFFER_SIZE 128

/* defines how much ISO packets are handled in one URB */
static int iso_packets[8] =
{ ISOC_PACKETS_B, ISOC_PACKETS_B, ISOC_PACKETS_B, ISOC_PACKETS_B,
  ISOC_PACKETS_D, ISOC_PACKETS_D, ISOC_PACKETS_D, ISOC_PACKETS_D
};


/* Fifo flow Control for TX ISO */
#define SINK_MAX        68
#define SINK_MIN        48
#define SINK_DMIN       12
#define SINK_DMAX       18
#define BITLINE_INF     (-96 * 8)

/* HFC-S USB register access by Control-URSs */
#define write_reg_atomic(a, b, c)                                       \
        usb_control_msg((a)->dev, (a)->ctrl_out_pipe, 0, 0x40, (c), (b), \
                        0, 0, HFC_CTRL_TIMEOUT)
#define read_reg_atomic(a, b, c)                                        \
        usb_control_msg((a)->dev, (a)->ctrl_in_pipe, 1, 0xC0, 0, (b), (c), \
                        1, HFC_CTRL_TIMEOUT)
#define HFC_CTRL_BUFSIZE 64

struct ctrl_buf {
        __u8 hfcs_reg;          /* register number */
        __u8 reg_val;           /* value to be written (or read) */
};

/*
 * URB error codes
 * Used to represent a list of values and their respective symbolic names
 */
struct hfcusb_symbolic_list {
        const int num;
        const char *name;
};

static struct hfcusb_symbolic_list urb_errlist[] = {
        {-ENOMEM, "No memory for allocation of internal structures"},
        {-ENOSPC, "The host controller's bandwidth is already consumed"},
        {-ENOENT, "URB was canceled by unlink_urb"},
        {-EXDEV, "ISO transfer only partially completed"},
        {-EAGAIN, "Too match scheduled for the future"},
        {-ENXIO, "URB already queued"},
        {-EFBIG, "Too much ISO frames requested"},
        {-ENOSR, "Buffer error (overrun)"},
        {-EPIPE, "Specified endpoint is stalled (device not responding)"},
        {-EOVERFLOW, "Babble (bad cable?)"},
        {-EPROTO, "Bit-stuff error (bad cable?)"},
        {-EILSEQ, "CRC/Timeout"},
        {-ETIMEDOUT, "NAK (device does not respond)"},
        {-ESHUTDOWN, "Device unplugged"},
        {-1, NULL}
};

static inline const char *
symbolic(struct hfcusb_symbolic_list list[], const int num)
{
        int i;
        for (i = 0; list[i].name != NULL; i++)
                if (list[i].num == num)
                        return list[i].name;
        return "<unknown USB Error>";
}

/* USB descriptor need to contain one of the following EndPoint combination: */
#define CNF_4INT3ISO    1       /* 4 INT IN, 3 ISO OUT */
#define CNF_3INT3ISO    2       /* 3 INT IN, 3 ISO OUT */
#define CNF_4ISO3ISO    3       /* 4 ISO IN, 3 ISO OUT */
#define CNF_3ISO3ISO    4       /* 3 ISO IN, 3 ISO OUT */

#define EP_NUL 1        /* Endpoint at this position not allowed */
#define EP_NOP 2        /* all type of endpoints allowed at this position */
#define EP_ISO 3        /* Isochron endpoint mandatory at this position */
#define EP_BLK 4        /* Bulk endpoint mandatory at this position */
#define EP_INT 5        /* Interrupt endpoint mandatory at this position */

#define HFC_CHAN_B1     0
#define HFC_CHAN_B2     1
#define HFC_CHAN_D      2
#define HFC_CHAN_E      3


/*
 * List of all supported endpoint configuration sets, used to find the
 * best matching endpoint configuration within a device's USB descriptor.
 * We need at least 3 RX endpoints, and 3 TX endpoints, either
 * INT-in and ISO-out, or ISO-in and ISO-out)
 * with 4 RX endpoints even E-Channel logging is possible
 */
static int
validconf[][19] = {
        /* INT in, ISO out config */
        {EP_NUL, EP_INT, EP_NUL, EP_INT, EP_NUL, EP_INT, EP_NOP, EP_INT,
         EP_ISO, EP_NUL, EP_ISO, EP_NUL, EP_ISO, EP_NUL, EP_NUL, EP_NUL,
         CNF_4INT3ISO, 2, 1},
        {EP_NUL, EP_INT, EP_NUL, EP_INT, EP_NUL, EP_INT, EP_NUL, EP_NUL,
         EP_ISO, EP_NUL, EP_ISO, EP_NUL, EP_ISO, EP_NUL, EP_NUL, EP_NUL,
         CNF_3INT3ISO, 2, 0},
        /* ISO in, ISO out config */
        {EP_NOP, EP_NOP, EP_NOP, EP_NOP, EP_NOP, EP_NOP, EP_NOP, EP_NOP,
         EP_ISO, EP_ISO, EP_ISO, EP_ISO, EP_ISO, EP_ISO, EP_NOP, EP_ISO,
         CNF_4ISO3ISO, 2, 1},
        {EP_NUL, EP_NUL, EP_NUL, EP_NUL, EP_NUL, EP_NUL, EP_NUL, EP_NUL,
         EP_ISO, EP_ISO, EP_ISO, EP_ISO, EP_ISO, EP_ISO, EP_NUL, EP_NUL,
         CNF_3ISO3ISO, 2, 0},
        {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} /* EOL element */
};

/* string description of chosen config */
static char *conf_str[] = {
        "4 Interrupt IN + 3 Isochron OUT",
        "3 Interrupt IN + 3 Isochron OUT",
        "4 Isochron IN + 3 Isochron OUT",
        "3 Isochron IN + 3 Isochron OUT"
};


#define LED_OFF         0       /* no LED support */
#define LED_SCHEME1     1       /* LED standard scheme */
#define LED_SCHEME2     2       /* not used yet... */

#define LED_POWER_ON    1
#define LED_POWER_OFF   2
#define LED_S0_ON       3
#define LED_S0_OFF      4
#define LED_B1_ON       5
#define LED_B1_OFF      6
#define LED_B1_DATA     7
#define LED_B2_ON       8
#define LED_B2_OFF      9
#define LED_B2_DATA     10

#define LED_NORMAL      0       /* LEDs are normal */
#define LED_INVERTED    1       /* LEDs are inverted */

/* time in ms to perform a Flashing LED when B-Channel has traffic */
#define LED_TIME      250



struct hfcsusb;
struct usb_fifo;

/* structure defining input+output fifos (interrupt/bulk mode) */
struct iso_urb {
        struct urb *urb;
        __u8 buffer[ISO_BUFFER_SIZE];   /* buffer rx/tx USB URB data */
        struct usb_fifo *owner_fifo;    /* pointer to owner fifo */
        __u8 indx; /* Fifos's ISO double buffer 0 or 1 ? */
#ifdef ISO_FRAME_START_DEBUG
        int start_frames[ISO_FRAME_START_RING_COUNT];
        __u8 iso_frm_strt_pos; /* index in start_frame[] */
#endif
};

struct usb_fifo {
        int fifonum;            /* fifo index attached to this structure */
        int active;             /* fifo is currently active */
        struct hfcsusb *hw;     /* pointer to main structure */
        int pipe;               /* address of endpoint */
        __u8 usb_packet_maxlen; /* maximum length for usb transfer */
        unsigned int max_size;  /* maximum size of receive/send packet */
        __u8 intervall;         /* interrupt interval */
        struct urb *urb;        /* transfer structure for usb routines */
        __u8 buffer[128];       /* buffer USB INT OUT URB data */
        int bit_line;           /* how much bits are in the fifo? */

        __u8 usb_transfer_mode; /* switched between ISO and INT */
        struct iso_urb  iso[2]; /* two urbs to have one always
                                   one pending */

        struct dchannel *dch;   /* link to hfcsusb_t->dch */
        struct bchannel *bch;   /* link to hfcsusb_t->bch */
        struct dchannel *ech;   /* link to hfcsusb_t->ech, TODO: E-CHANNEL */
        int last_urblen;        /* remember length of last packet */
        __u8 stop_gracefull;    /* stops URB retransmission */
};

struct hfcsusb {
        struct list_head        list;
        struct dchannel         dch;
        struct bchannel         bch[2];
        struct dchannel         ech; /* TODO : wait for struct echannel ;) */

        struct usb_device       *dev;           /* our device */
        struct usb_interface    *intf;          /* used interface */
        int                     if_used;        /* used interface number */
        int                     alt_used;       /* used alternate config */
        int                     cfg_used;       /* configuration index used */
        int                     vend_idx;       /* index in hfcsusb_idtab */
        int                     packet_size;
        int                     iso_packet_size;
        struct usb_fifo         fifos[HFCUSB_NUM_FIFOS];

        /* control pipe background handling */
        struct ctrl_buf         ctrl_buff[HFC_CTRL_BUFSIZE];
        int                     ctrl_in_idx, ctrl_out_idx, ctrl_cnt;
        struct urb              *ctrl_urb;
        struct usb_ctrlrequest  ctrl_write;
        struct usb_ctrlrequest  ctrl_read;
        int                     ctrl_paksize;
        int                     ctrl_in_pipe, ctrl_out_pipe;
        spinlock_t              ctrl_lock; /* lock for ctrl */
        spinlock_t              lock;

        __u8                    threshold_mask;
        __u8                    led_state;

        __u8                    protocol;
        int                     nt_timer;
        int                     open;
        __u8                    timers;
        __u8                    initdone;
        char                    name[MISDN_MAX_IDLEN];
};

/* private vendor specific data */
struct hfcsusb_vdata {
        __u8            led_scheme;  /* led display scheme */
        signed short    led_bits[8]; /* array of 8 possible LED bitmask */
        char            *vend_name;  /* device name */
};


#define HFC_MAX_TE_LAYER1_STATE 8
#define HFC_MAX_NT_LAYER1_STATE 4

static const char *HFC_TE_LAYER1_STATES[HFC_MAX_TE_LAYER1_STATE + 1] = {
        "TE F0 - Reset",
        "TE F1 - Reset",
        "TE F2 - Sensing",
        "TE F3 - Deactivated",
        "TE F4 - Awaiting signal",
        "TE F5 - Identifying input",
        "TE F6 - Synchronized",
        "TE F7 - Activated",
        "TE F8 - Lost framing",
};

static const char *HFC_NT_LAYER1_STATES[HFC_MAX_NT_LAYER1_STATE + 1] = {
        "NT G0 - Reset",
        "NT G1 - Deactive",
        "NT G2 - Pending activation",
        "NT G3 - Active",
        "NT G4 - Pending deactivation",
};

/* supported devices */
static const struct usb_device_id hfcsusb_idtab[] = {
        {
                USB_DEVICE(0x0959, 0x2bd0),
                .driver_info = (unsigned long) &((struct hfcsusb_vdata)
                        {LED_OFF, {4, 0, 2, 1},
                                        "ISDN USB TA (Cologne Chip HFC-S USB based)"}),
        },
        {
                USB_DEVICE(0x0675, 0x1688),
                .driver_info = (unsigned long) &((struct hfcsusb_vdata)
                        {LED_SCHEME1, {1, 2, 0, 0},
                                        "DrayTek miniVigor 128 USB ISDN TA"}),
        },
        {
                USB_DEVICE(0x07b0, 0x0007),
                .driver_info = (unsigned long) &((struct hfcsusb_vdata)
                        {LED_SCHEME1, {0x80, -64, -32, -16},
                                        "Billion tiny USB ISDN TA 128"}),
        },
        {
                USB_DEVICE(0x0742, 0x2008),
                .driver_info = (unsigned long) &((struct hfcsusb_vdata)
                        {LED_SCHEME1, {4, 0, 2, 1},
                                        "Stollmann USB TA"}),
        },
        {
                USB_DEVICE(0x0742, 0x2009),
                .driver_info = (unsigned long) &((struct hfcsusb_vdata)
                        {LED_SCHEME1, {4, 0, 2, 1},
                                        "Aceex USB ISDN TA"}),
        },
        {
                USB_DEVICE(0x0742, 0x200A),
                .driver_info = (unsigned long) &((struct hfcsusb_vdata)
                        {LED_SCHEME1, {4, 0, 2, 1},
                                        "OEM USB ISDN TA"}),
        },
        {
                USB_DEVICE(0x08e3, 0x0301),
                .driver_info = (unsigned long) &((struct hfcsusb_vdata)
                        {LED_SCHEME1, {2, 0, 1, 4},
                                        "Olitec USB RNIS"}),
        },
        {
                USB_DEVICE(0x07fa, 0x0846),
                .driver_info = (unsigned long) &((struct hfcsusb_vdata)
                        {LED_SCHEME1, {0x80, -64, -32, -16},
                                        "Bewan Modem RNIS USB"}),
        },
        {
                USB_DEVICE(0x07fa, 0x0847),
                .driver_info = (unsigned long) &((struct hfcsusb_vdata)
                        {LED_SCHEME1, {0x80, -64, -32, -16},
                                        "Djinn Numeris USB"}),
        },
        {
                USB_DEVICE(0x07b0, 0x0006),
                .driver_info = (unsigned long) &((struct hfcsusb_vdata)
                        {LED_SCHEME1, {0x80, -64, -32, -16},
                                        "Twister ISDN TA"}),
        },
        {
                USB_DEVICE(0x071d, 0x1005),
                .driver_info = (unsigned long) &((struct hfcsusb_vdata)
                        {LED_SCHEME1, {0x02, 0, 0x01, 0x04},
                                        "Eicon DIVA USB 4.0"}),
        },
        {
                USB_DEVICE(0x0586, 0x0102),
                .driver_info = (unsigned long) &((struct hfcsusb_vdata)
                        {LED_SCHEME1, {0x88, -64, -32, -16},
                                        "ZyXEL OMNI.NET USB II"}),
        },
        {
                USB_DEVICE(0x1ae7, 0x0525),
                .driver_info = (unsigned long) &((struct hfcsusb_vdata)
                        {LED_SCHEME1, {0x88, -64, -32, -16},
                                        "X-Tensions USB ISDN TA XC-525"}),
        },
        { }
};

MODULE_DEVICE_TABLE(usb, hfcsusb_idtab);

#endif  /* __HFCSUSB_H__ */