V9/sys/sun3/zsreg.h

/*	@(#)zsreg.h 1.1 86/02/03 SMI	*/

/*
 * Copyright (c) 1983 by Sun Microsystems, Inc.
 */

/*
 * Zilog 8530 SCC Serial Communications Controller
 *
 * This is a dual uart chip with on-chip baud rate generators.
 * It is about as brain-damaged as the typical modern uart chip,
 * but it does have a lot of features as well as the usual lot of
 * brain damage around addressing, write-onlyness, etc.
 */

/*
 * Uart registers:
 *
 * There are 16 write registers and 9 read registers in each channel.
 * As usual, the two channels are ALMOST orthogonal, not exactly.  Most regs
 * can only be written to, or read, but not both.  To access one, you must
 * first write to register 0 with the number of the register you
 * are interested in, then read/write the actual value, and hope that
 * nobody interrupts you in between.
 *
 * Note that the register&bit assignment is suspiciously like the Intel 8274.
 * Do you think they read each others' data sheets?  Can they decode them?
 */

/* bits in RR0 */
#define	ZSRR0_RX_READY		0x01	/* received character available */
#define ZSRR0_TIMER		0x02	/* if R15_TIMER, timer reached 0 */
#define	ZSRR0_TX_READY		0x04	/* transmit buffer empty */
#define	ZSRR0_CD		0x08	/* CD input (latched if R15_CD) */
#define ZSRR0_SYNC		0x10	/* SYNC input (latched if R15_SYNC) */
#define	ZSRR0_CTS		0x20	/* CTS input (latched if R15_CTS) */
#define ZSRR0_TXUNDER		0x40	/* (SYNC) Xmitter underran */
#define	ZSRR0_BREAK		0x80	/* received break detected */

/* bits in RR1 */
#define	ZSRR1_ALL_SENT		0x01	/* all chars fully transmitted */
#define	ZSRR1_PE		0x10	/* parity error (latched, must reset) */
#define	ZSRR1_DO		0x20	/* data overrun (latched, must reset) */
#define	ZSRR1_FE		0x40	/* framing/CRC error (not latched) */
#define	ZSRR1_RXEOF		0x80	/* end of recv sdlc frame */

/* bits in R/WR2 -- interrupt vector number. */
/* NOTE that RR2 in channel A is unmodified, while in channel B it is
   modified by the current status of the UARTs.  (This is independent
   of the setting of WR9_VIS.)  If no interrupts are pending, the modified
   status is Channel B Special Receive.  It can be written from
   either channel. */

/* bits in RR3 -- Interrupt Pending flags for both channels (this reg can
   only be read in Channel A, tho.  Thanks guys.) */
#define ZSRR3_IP_B_STAT		0x01	/* Ext/status int pending, chan B */
#define ZSRR3_IP_B_TX		0x02	/* Transmit int pending, chan B */
#define ZSRR3_IP_B_RX		0x04	/* Receive int pending, chan B */
#define ZSRR3_IP_A_STAT		0x08	/* Ditto for channel A */
#define ZSRR3_IP_A_TX		0x10
#define ZSRR3_IP_A_RX		0x20

/* bits in RR8 -- this is the same as reading the Data port */

/* bits in RR10 -- DPLL and SDLC Loop Mode status -- not entered*/

/* bits in R/WR12 -- lower byte of time constant for baud rate generator */
/*
 * The following macro can be used to generate the baud rate generator's
 * time constants.  The parameters are the input clock to the BRG (eg,
 * 5000000 for 5MHz) and the desired baud rate.  This macro assumes that
 * the clock needed is 16x the desired baud rate.
 */
#define ZSTimeConst(InputClock, BaudRate) (( InputClock / (2*BaudRate*16)) - 2)

/* bits in R/WR13 -- upper byte of time constant for baud rate generator */

/* bits in R/WR15 -- interrupt enables for status conditions */
#define ZSR15_TIMER		0x02	/* ie if baud rate generator = 0 */
#define ZSR15_CD		0x08	/* ie transition on CD (car. det.) */
#define ZSR15_SYNC		0x10	/* ie transition on SYNC (gen purp) */
#define ZSR15_CTS		0x20	/* ie transition on CTS (clr to send) */
#define ZSR15_TX_UNDER		0x40	/* (SYNC) ie transmit underrun */
#define ZSR15_BREAK		0x80	/* ie on start, and end, of break */

/* Write register 0 -- common commands and Register Pointers */
#define ZSWR0_REG		0x0F	/* mask: next reg to read/write */
#define	ZSWR0_RESET_STATUS	0x10	/* reset status bit latches */
#define ZSWR0_FIRST_RX		0x20	/* in WR1_RX_FIRST_IE, enab next int */
#define	ZSWR0_RESET_TXINT	0x28	/* reset transmitter interrupt */
#define	ZSWR0_RESET_ERRORS	0x30	/* reset read character errors */
#define	ZSWR0_CLR_INTR		0x38	/* Reset Interrupt In Service */
#define ZSWR0_RESET_RXCRC       0x40    /*  Reset Rx CRC generator.     */
#define ZSWR0_RESET_TXCRC       0x80    /*  Reset Tx CRC generator.     */
#define ZSWR0_RESET_EOM         0xC0    /*  Reset Tx underrun / EOM.    */

/* bits in WR1 */
#define	ZSWR1_SIE		0x01	/* status change master int enable */
					/* Also see R15 for individual enabs */
#define	ZSWR1_TIE		0x02	/* transmitter interrupt enable */
#define	ZSWR1_PARITY_SPECIAL	0x04	/* parity err causes special rx int */
#define ZSWR1_RX_FIRST_IE	0x08	/* r.i.e. on 1st char of msg */
#define	ZSWR1_RIE		0x10	/* receiver interrupt enable */
/* There are other Receive interrupt options defined, see data sheet. */

/* bits in WR2 are defined above as R/WR2. */

/* bits in WR3 */
#define	ZSWR3_RX_ENABLE		0x01	/* receiver enable */
#define	ZSWR3_RXCRC_ENABLE	0x08	/* receiver CRC enable */
#define	ZSWR3_HUNT		0x10	/* enter hunt mode */
#define	ZSWR3_AUTO_CD_CTS	0x20	/* auto-enable CD&CTS rcv&xmit ctl */
#define ZSWR3_RX_5		0x00	/* receive 5-bit characters */
#define	ZSWR3_RX_6		0x80	/* receive 6 bit characters */
#define	ZSWR3_RX_7		0x40	/* receive 7 bit characters */
#define	ZSWR3_RX_8		0xC0	/* receive 8 bit characters */

/* bits in WR4 */
#define	ZSWR4_PARITY_ENABLE	0x01	/* Gen/check parity bit */
#define	ZSWR4_PARITY_EVEN	0x02	/* Gen/check even parity */
#define	ZSWR4_1_STOP		0x04	/* 1 stop bit */
#define	ZSWR4_1_5_STOP		0x08	/* 1.5 stop bits */
#define	ZSWR4_2_STOP		0x0C	/* 2 stop bits */
#define	ZSWR4_SDLC		0x20	/* SDLC mode */
#define ZSWR4_X1_CLK		0x00	/* clock is 1x */
#define	ZSWR4_X16_CLK		0x40	/* clock is 16x */
#define ZSWR4_X32_CLK		0x80	/* clock is 32x */
#define ZSWR4_X64_CLK		0xC0	/* clock is 64x */

/* bits in WR5 */
#define	ZSWR5_TXCRC_ENABLE	0x01	/* transmitter CRC enable */
#define	ZSWR5_RTS		0x02	/* RTS output */
#define	ZSWR5_TX_ENABLE		0x08	/* transmitter enable */
#define	ZSWR5_BREAK		0x10	/* send break continuously */
#define	ZSWR5_TX_5		0x00	/* transmit 5 bit chars or less */
#define	ZSWR5_TX_6		0x40	/* transmit 6 bit characters */
#define	ZSWR5_TX_7		0x20	/* transmit 7 bit characters */
#define	ZSWR5_TX_8		0x60	/* transmit 8 bit characters */
#define	ZSWR5_DTR		0x80	/* DTR output */

/* bits in WR6 -- Sync characters or SDLC address field. */

/* bits in WR7 -- Sync character or SDLC flag */

/* bits in WR8 -- transmit buffer.  Same as writing to data port. */

/* bits in WR9 -- Master interrupt control and reset.  Accessible thru
   either channel, there's only one of them. */
#define ZSWR9_VECTOR_INCL_STAT	0x01	/* Include status bits in int vector */
#define ZSWR9_NO_VECTOR		0x02	/* Do not respond to int ack cycles */
#define ZSWR9_DIS_LOWER_CHAIN	0x04	/* Disable ints lower in daisy chain */
#define ZSWR9_MASTER_IE		0x08	/* Master interrupt enable */
#define ZSWR9_STAT_HIGH		0x10	/* Modify ivec bits 6-4, not 1-3 */
#define ZSWR9_RESET_CHAN_B	0x40	/* Reset just channel B */
#define ZSWR9_RESET_CHAN_A	0x80	/* Reset just channel A */
#define ZSWR9_RESET_WORLD	0xC0	/* Force hardware reset */

/* bits in WR10 -- SDLC, NRZI, FM control bits */
#define	ZSWR10_UNDERRUN_ABORT	0x04	/* send abort on TX underrun */
#define	ZSWR10_PRESET_ONES	0x80	/* preset CRC to ones (SDLC) */

/* bits in WR11 -- clock mode control */
#define ZSWR11_TRXC_XTAL	0x00	/* TRxC output = xtal osc */
#define ZSWR11_TRXC_XMIT	0x01	/* TRxC output = xmitter clk */
#define ZSWR11_TRXC_BAUD	0x02	/* TRxC output = baud rate gen */
#define ZSWR11_TRXC_DPLL	0x03	/* TRxC output = Phase Locked Loop */
#define ZSWR11_TRXC_OUT_ENA	0x04	/* TRxC output enable (unless input) */
#define ZSWR11_TXCLK_RTXC	0x00	/* Tx clock is RTxC pin */
#define ZSWR11_TXCLK_TRXC	0x08	/* Tx clock is TRxC pin */
#define ZSWR11_TXCLK_BAUD	0x10	/* Tx clock is baud rate gen output */
#define ZSWR11_TXCLK_DPLL	0x18	/* Tx clock is Phase Locked Loop o/p */
#define ZSWR11_RXCLK_RTXC	0x00	/* Rx clock is RTxC pin */
#define ZSWR11_RXCLK_TRXC	0x20	/* Rx clock is TRxC pin */
#define ZSWR11_RXCLK_BAUD	0x40	/* Rx clock is baud rate gen output */
#define ZSWR11_RXCLK_DPLL	0x60	/* Rx clock is Phase Locked Loop o/p */
#define ZSWR11_RTXC_XTAL	0x80	/* RTxC uses crystal, not TTL signal */

/* bits in WR12 -- described above as R/WR12 */

/* bits in WR13 -- described above as R/WR13 */

/* bits in WR14 -- misc control bits, and DPLL control */
#define ZSWR14_BAUD_ENA		0x01	/* enables baud rate counter */
#define ZSWR14_BAUD_FROM_PCLK	0x02	/* Baud rate gen src = PCLK not RTxC */
#define ZSWR14_DTR_IS_REQUEST	0x04	/* Changes DTR line to DMA Request */
#define ZSWR14_AUTO_ECHO	0x08	/* Echoes RXD to TXD */
#define ZSWR14_LOCAL_LOOPBACK	0x10	/* Echoes TX to RX in chip */
#define ZSWR14_DPLL_NOP		0x00	/* These 8 commands are mut. exclu. */
#define ZSWR14_DPLL_SEARCH	0x20	/* Enter search mode in DPLL */
#define ZSWR14_DPLL_RESET	0x40	/* Reset missing clock in DPLL */
#define ZSWR14_DPLL_DISABLE	0x60	/* Disable DPLL */
#define ZSWR14_DPLL_SRC_BAUD	0x80	/* Source for DPLL is baud rate gen */
#define ZSWR14_DPLL_SRC_RTXC	0xA0	/* Source for DPLL is RTxC pin */
#define ZSWR14_DPLL_FM		0xC0	/* DPLL should run in FM mode */
#define ZSWR14_DPLL_NRZI	0xE0	/* DPLL should run in NRZI mode */

/* bits in WR15 -- described above as R/WR15 */

/*
 * UART register addressing
 *
 * It would be nice if they used 4 address pins to address 15 registers,
 * but they only used 1.  So you have to write to the control port then
 * read or write it; the 2nd cycle is done to whatever register number
 * you wrote in the first cycle.
 *
 * The data register can also be accessed as Read/Write register 8.
 */
#ifndef LOCORE
struct zscc_device {
	unsigned char	zscc_control;
	unsigned char	:8;		/* Filler */
	unsigned char	zscc_data;
	unsigned char	:8;		/* Filler */
};
#endif