/* 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__ */