/* SPDX-License-Identifier: GPL-2.0 */
/*
 *	Description of Z8530 Z85C30 and Z85230 communications chips
 *
 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
 * Copyright (C) 1998 Alan Cox <alan@lxorguk.ukuu.org.uk>
 */

#ifndef _Z8530_H
#define _Z8530_H

#include <linux/tty.h>
#include <linux/interrupt.h>

/* Conversion routines to/from brg time constants from/to bits
 * per second.
 */
#define BRG_TO_BPS(brg, freq) ((freq) / 2 / ((brg) + 2))
#define BPS_TO_BRG(bps, freq) ((((freq) + (bps)) / (2 * (bps))) - 2)

/* The Zilog register set */

#define	FLAG	0x7e

/* Write Register 0 */
#define	R0	0		/* Register selects */
#define	R1	1
#define	R2	2
#define	R3	3
#define	R4	4
#define	R5	5
#define	R6	6
#define	R7	7
#define	R8	8
#define	R9	9
#define	R10	10
#define	R11	11
#define	R12	12
#define	R13	13
#define	R14	14
#define	R15	15

#define RPRIME	16		/* Indicate a prime register access on 230 */

#define	NULLCODE	0	/* Null Code */
#define	POINT_HIGH	0x8	/* Select upper half of registers */
#define	RES_EXT_INT	0x10	/* Reset Ext. Status Interrupts */
#define	SEND_ABORT	0x18	/* HDLC Abort */
#define	RES_RxINT_FC	0x20	/* Reset RxINT on First Character */
#define	RES_Tx_P	0x28	/* Reset TxINT Pending */
#define	ERR_RES		0x30	/* Error Reset */
#define	RES_H_IUS	0x38	/* Reset highest IUS */

#define	RES_Rx_CRC	0x40	/* Reset Rx CRC Checker */
#define	RES_Tx_CRC	0x80	/* Reset Tx CRC Checker */
#define	RES_EOM_L	0xC0	/* Reset EOM latch */

/* Write Register 1 */

#define	EXT_INT_ENAB	0x1	/* Ext Int Enable */
#define	TxINT_ENAB	0x2	/* Tx Int Enable */
#define	PAR_SPEC	0x4	/* Parity is special condition */

#define	RxINT_DISAB	0	/* Rx Int Disable */
#define	RxINT_FCERR	0x8	/* Rx Int on First Character Only or Error */
#define	INT_ALL_Rx	0x10	/* Int on all Rx Characters or error */
#define	INT_ERR_Rx	0x18	/* Int on error only */

#define	WT_RDY_RT	0x20	/* Wait/Ready on R/T */
#define	WT_FN_RDYFN	0x40	/* Wait/FN/Ready FN */
#define	WT_RDY_ENAB	0x80	/* Wait/Ready Enable */

/* Write Register #2 (Interrupt Vector) */

/* Write Register 3 */

#define	RxENABLE	0x1	/* Rx Enable */
#define	SYNC_L_INH	0x2	/* Sync Character Load Inhibit */
#define	ADD_SM		0x4	/* Address Search Mode (SDLC) */
#define	RxCRC_ENAB	0x8	/* Rx CRC Enable */
#define	ENT_HM		0x10	/* Enter Hunt Mode */
#define	AUTO_ENAB	0x20	/* Auto Enables */
#define	Rx5		0x0	/* Rx 5 Bits/Character */
#define	Rx7		0x40	/* Rx 7 Bits/Character */
#define	Rx6		0x80	/* Rx 6 Bits/Character */
#define	Rx8		0xc0	/* Rx 8 Bits/Character */

/* Write Register 4 */

#define	PAR_ENA		0x1	/* Parity Enable */
#define	PAR_EVEN	0x2	/* Parity Even/Odd* */

#define	SYNC_ENAB	0	/* Sync Modes Enable */
#define	SB1		0x4	/* 1 stop bit/char */
#define	SB15		0x8	/* 1.5 stop bits/char */
#define	SB2		0xc	/* 2 stop bits/char */

#define	MONSYNC		0	/* 8 Bit Sync character */
#define	BISYNC		0x10	/* 16 bit sync character */
#define	SDLC		0x20	/* SDLC Mode (01111110 Sync Flag) */
#define	EXTSYNC		0x30	/* External Sync Mode */

#define	X1CLK		0x0	/* x1 clock mode */
#define	X16CLK		0x40	/* x16 clock mode */
#define	X32CLK		0x80	/* x32 clock mode */
#define	X64CLK		0xC0	/* x64 clock mode */

/* Write Register 5 */

#define	TxCRC_ENAB	0x1	/* Tx CRC Enable */
#define	RTS		0x2	/* RTS */
#define	SDLC_CRC	0x4	/* SDLC/CRC-16 */
#define	TxENAB		0x8	/* Tx Enable */
#define	SND_BRK		0x10	/* Send Break */
#define	Tx5		0x0	/* Tx 5 bits (or less)/character */
#define	Tx7		0x20	/* Tx 7 bits/character */
#define	Tx6		0x40	/* Tx 6 bits/character */
#define	Tx8		0x60	/* Tx 8 bits/character */
#define	DTR		0x80	/* DTR */

/* Write Register 6 (Sync bits 0-7/SDLC Address Field) */

/* Write Register 7 (Sync bits 8-15/SDLC 01111110) */

/* Write Register 8 (transmit buffer) */

/* Write Register 9 (Master interrupt control) */
#define	VIS	1	/* Vector Includes Status */
#define	NV	2	/* No Vector */
#define	DLC	4	/* Disable Lower Chain */
#define	MIE	8	/* Master Interrupt Enable */
#define	STATHI	0x10	/* Status high */
#define	NORESET	0	/* No reset on write to R9 */
#define	CHRB	0x40	/* Reset channel B */
#define	CHRA	0x80	/* Reset channel A */
#define	FHWRES	0xc0	/* Force hardware reset */

/* Write Register 10 (misc control bits) */
#define	BIT6	1	/* 6 bit/8bit sync */
#define	LOOPMODE 2	/* SDLC Loop mode */
#define	ABUNDER	4	/* Abort/flag on SDLC xmit underrun */
#define	MARKIDLE 8	/* Mark/flag on idle */
#define	GAOP	0x10	/* Go active on poll */
#define	NRZ	0	/* NRZ mode */
#define	NRZI	0x20	/* NRZI mode */
#define	FM1	0x40	/* FM1 (transition = 1) */
#define	FM0	0x60	/* FM0 (transition = 0) */
#define	CRCPS	0x80	/* CRC Preset I/O */

/* Write Register 11 (Clock Mode control) */
#define	TRxCXT	0	/* TRxC = Xtal output */
#define	TRxCTC	1	/* TRxC = Transmit clock */
#define	TRxCBR	2	/* TRxC = BR Generator Output */
#define	TRxCDP	3	/* TRxC = DPLL output */
#define	TRxCOI	4	/* TRxC O/I */
#define	TCRTxCP	0	/* Transmit clock = RTxC pin */
#define	TCTRxCP	8	/* Transmit clock = TRxC pin */
#define	TCBR	0x10	/* Transmit clock = BR Generator output */
#define	TCDPLL	0x18	/* Transmit clock = DPLL output */
#define	RCRTxCP	0	/* Receive clock = RTxC pin */
#define	RCTRxCP	0x20	/* Receive clock = TRxC pin */
#define	RCBR	0x40	/* Receive clock = BR Generator output */
#define	RCDPLL	0x60	/* Receive clock = DPLL output */
#define	RTxCX	0x80	/* RTxC Xtal/No Xtal */

/* Write Register 12 (lower byte of baud rate generator time constant) */

/* Write Register 13 (upper byte of baud rate generator time constant) */

/* Write Register 14 (Misc control bits) */
#define	BRENABL	1	/* Baud rate generator enable */
#define	BRSRC	2	/* Baud rate generator source */
#define	DTRREQ	4	/* DTR/Request function */
#define	AUTOECHO 8	/* Auto Echo */
#define	LOOPBAK	0x10	/* Local loopback */
#define	SEARCH	0x20	/* Enter search mode */
#define	RMC	0x40	/* Reset missing clock */
#define	DISDPLL	0x60	/* Disable DPLL */
#define	SSBR	0x80	/* Set DPLL source = BR generator */
#define	SSRTxC	0xa0	/* Set DPLL source = RTxC */
#define	SFMM	0xc0	/* Set FM mode */
#define	SNRZI	0xe0	/* Set NRZI mode */

/* Write Register 15 (external/status interrupt control) */
#define PRIME	1	/* R5' etc register access (Z85C30/230 only) */
#define	ZCIE	2	/* Zero count IE */
#define FIFOE	4	/* Z85230 only */
#define	DCDIE	8	/* DCD IE */
#define	SYNCIE	0x10	/* Sync/hunt IE */
#define	CTSIE	0x20	/* CTS IE */
#define	TxUIE	0x40	/* Tx Underrun/EOM IE */
#define	BRKIE	0x80	/* Break/Abort IE */


/* Read Register 0 */
#define	Rx_CH_AV	0x1	/* Rx Character Available */
#define	ZCOUNT		0x2	/* Zero count */
#define	Tx_BUF_EMP	0x4	/* Tx Buffer empty */
#define	DCD		0x8	/* DCD */
#define	SYNC_HUNT	0x10	/* Sync/hunt */
#define	CTS		0x20	/* CTS */
#define	TxEOM		0x40	/* Tx underrun */
#define	BRK_ABRT	0x80	/* Break/Abort */

/* Read Register 1 */
#define	ALL_SNT		0x1	/* All sent */
/* Residue Data for 8 Rx bits/char programmed */
#define	RES3		0x8	/* 0/3 */
#define	RES4		0x4	/* 0/4 */
#define	RES5		0xc	/* 0/5 */
#define	RES6		0x2	/* 0/6 */
#define	RES7		0xa	/* 0/7 */
#define	RES8		0x6	/* 0/8 */
#define	RES18		0xe	/* 1/8 */
#define	RES28		0x0	/* 2/8 */
/* Special Rx Condition Interrupts */
#define	PAR_ERR		0x10	/* Parity error */
#define	Rx_OVR		0x20	/* Rx Overrun Error */
#define	CRC_ERR		0x40	/* CRC/Framing Error */
#define	END_FR		0x80	/* End of Frame (SDLC) */

/* Read Register 2 (channel b only) - Interrupt vector */

/* Read Register 3 (interrupt pending register) ch a only */
#define	CHBEXT	0x1		/* Channel B Ext/Stat IP */
#define	CHBTxIP	0x2		/* Channel B Tx IP */
#define	CHBRxIP	0x4		/* Channel B Rx IP */
#define	CHAEXT	0x8		/* Channel A Ext/Stat IP */
#define	CHATxIP	0x10		/* Channel A Tx IP */
#define	CHARxIP	0x20		/* Channel A Rx IP */

/* Read Register 8 (receive data register) */

/* Read Register 10  (misc status bits) */
#define	ONLOOP	2		/* On loop */
#define	LOOPSEND 0x10		/* Loop sending */
#define	CLK2MIS	0x40		/* Two clocks missing */
#define	CLK1MIS	0x80		/* One clock missing */

/* Read Register 12 (lower byte of baud rate generator constant) */

/* Read Register 13 (upper byte of baud rate generator constant) */

/* Read Register 15 (value of WR 15) */


/*
 *	Interrupt handling functions for this SCC
 */

struct z8530_channel;
 
struct z8530_irqhandler
{
	void (*rx)(struct z8530_channel *);
	void (*tx)(struct z8530_channel *);
	void (*status)(struct z8530_channel *);
};

/*
 *	A channel of the Z8530
 */

struct z8530_channel
{
	struct		z8530_irqhandler *irqs;		/* IRQ handlers */
	/*
	 *	Synchronous
	 */
	u16		count;		/* Buyes received */
	u16		max;		/* Most we can receive this frame */
	u16		mtu;		/* MTU of the device */
	u8		*dptr;		/* Pointer into rx buffer */
	struct sk_buff	*skb;		/* Buffer dptr points into */
	struct sk_buff	*skb2;		/* Pending buffer */
	u8		status;		/* Current DCD */
	u8		dcdcheck;	/* which bit to check for line */
	u8		sync;		/* Set if in sync mode */

	u8		regs[32];	/* Register map for the chip */
	u8		pendregs[32];	/* Pending register values */
	
	struct sk_buff 	*tx_skb;	/* Buffer being transmitted */
	struct sk_buff  *tx_next_skb;	/* Next transmit buffer */
	u8		*tx_ptr;	/* Byte pointer into the buffer */
	u8		*tx_next_ptr;	/* Next pointer to use */
	u8		*tx_dma_buf[2];	/* TX flip buffers for DMA */
	u8		tx_dma_used;	/* Flip buffer usage toggler */
	u16		txcount;	/* Count of bytes to transmit */
	
	void		(*rx_function)(struct z8530_channel *, struct sk_buff *);
	
	/*
	 *	Sync DMA
	 */
	
	u8		rxdma;		/* DMA channels */
	u8		txdma;		
	u8		rxdma_on;	/* DMA active if flag set */
	u8		txdma_on;
	u8		dma_num;	/* Buffer we are DMAing into */
	u8		dma_ready;	/* Is the other buffer free */
	u8		dma_tx;		/* TX is to use DMA */
	u8		*rx_buf[2];	/* The flip buffers */
	
	/*
	 *	System
	 */
	 
	struct z8530_dev *dev;		/* Z85230 chip instance we are from */
	unsigned long	ctrlio;		/* I/O ports */
	unsigned long	dataio;

	/*
	 *	For PC we encode this way.
	 */	
#define Z8530_PORT_SLEEP	0x80000000
#define Z8530_PORT_OF(x)	((x)&0xFFFF)

	u32		rx_overrun;		/* Overruns - not done yet */
	u32		rx_crc_err;

	/*
	 *	Bound device pointers
	 */

	void		*private;	/* For our owner */
	struct net_device	*netdevice;	/* Network layer device */

	/*
	 *	Async features
	 */

	struct tty_struct 	*tty;		/* Attached terminal */
	int			line;		/* Minor number */
	wait_queue_head_t	open_wait;	/* Tasks waiting to open */
	wait_queue_head_t	close_wait;	/* and for close to end */
	unsigned long		event;		/* Pending events */
	int			fdcount;    	/* # of fd on device */
	int			blocked_open;	/* # of blocked opens */
	int			x_char;		/* XON/XOF char */
	unsigned char 		*xmit_buf;	/* Transmit pointer */
	int			xmit_head;	/* Transmit ring */
	int			xmit_tail;
	int			xmit_cnt;
	int			flags;	
	int			timeout;
	int			xmit_fifo_size;	/* Transmit FIFO info */

	int			close_delay;	/* Do we wait for drain on close ? */
	unsigned short		closing_wait;

	/* We need to know the current clock divisor
	 * to read the bps rate the chip has currently
	 * loaded.
	 */

	unsigned char		clk_divisor;  /* May be 1, 16, 32, or 64 */
	int			zs_baud;

	int			magic;
	int			baud_base;		/* Baud parameters */
	int			custom_divisor;


	unsigned char		tx_active; /* character is being xmitted */
	unsigned char		tx_stopped; /* output is suspended */

	spinlock_t		*lock;	  /* Device lock */
};

/*
 *	Each Z853x0 device.
 */

struct z8530_dev
{
	char *name;	/* Device instance name */
	struct z8530_channel chanA;	/* SCC channel A */
	struct z8530_channel chanB;	/* SCC channel B */
	int type;
#define Z8530	0	/* NMOS dinosaur */	
#define Z85C30	1	/* CMOS - better */
#define Z85230	2	/* CMOS with real FIFO */
	int irq;	/* Interrupt for the device */
	int active;	/* Soft interrupt enable - the Mac doesn't 
			   always have a hard disable on its 8530s... */
	spinlock_t lock;
};


/*
 *	Functions
 */
 
extern u8 z8530_dead_port[];
extern u8 z8530_hdlc_kilostream_85230[];
extern u8 z8530_hdlc_kilostream[];
irqreturn_t z8530_interrupt(int, void *);
void z8530_describe(struct z8530_dev *, char *mapping, unsigned long io);
int z8530_init(struct z8530_dev *);
int z8530_shutdown(struct z8530_dev *);
int z8530_sync_open(struct net_device *, struct z8530_channel *);
int z8530_sync_close(struct net_device *, struct z8530_channel *);
int z8530_sync_dma_open(struct net_device *, struct z8530_channel *);
int z8530_sync_dma_close(struct net_device *, struct z8530_channel *);
int z8530_sync_txdma_open(struct net_device *, struct z8530_channel *);
int z8530_sync_txdma_close(struct net_device *, struct z8530_channel *);
int z8530_channel_load(struct z8530_channel *, u8 *);
netdev_tx_t z8530_queue_xmit(struct z8530_channel *c, struct sk_buff *skb);
void z8530_null_rx(struct z8530_channel *c, struct sk_buff *skb);


/*
 *	Standard interrupt vector sets
 */
 
extern struct z8530_irqhandler z8530_sync, z8530_async, z8530_nop;

/*
 *	Asynchronous Interfacing
 */

#define SERIAL_MAGIC 0x5301

/*
 * The size of the serial xmit buffer is 1 page, or 4096 bytes
 */

#define SERIAL_XMIT_SIZE 4096
#define WAKEUP_CHARS	256

/*
 * Events are used to schedule things to happen at timer-interrupt
 * time, instead of at rs interrupt time.
 */
#define RS_EVENT_WRITE_WAKEUP	0

/* Internal flags used only by kernel/chr_drv/serial.c */
#define ZILOG_INITIALIZED	0x80000000 /* Serial port was initialized */
#define ZILOG_CALLOUT_ACTIVE	0x40000000 /* Call out device is active */
#define ZILOG_NORMAL_ACTIVE	0x20000000 /* Normal device is active */
#define ZILOG_BOOT_AUTOCONF	0x10000000 /* Autoconfigure port on bootup */
#define ZILOG_CLOSING		0x08000000 /* Serial port is closing */
#define ZILOG_CTS_FLOW		0x04000000 /* Do CTS flow control */
#define ZILOG_CHECK_CD		0x02000000 /* i.e., CLOCAL */

#endif /* !(_Z8530_H) */