/*
 * Copyright (c) 1986 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 *
 *	@(#)if_css.c	1.2 (2.11BSD) 1997/1/18
 */

#include "css.h"
#if NCSS > 0

/*
 * DEC/CSS IMP11-A ARPAnet IMP interface driver.
 * Since "imp11a" is such a mouthful, it is called
 * "css" after the LH/DH being called "acc".
 *
 * Configuration notes:
 *
 * As delivered from DEC/CSS, it
 * is addressed and vectored as two DR11-B's.  This makes
 * Autoconfig almost IMPOSSIBLE.  To make it work, the
 * interrupt vectors must be restrapped to make the vectors
 * consecutive.  The 020 hole between the CSR addresses is
 * tolerated, althought that could be cleaned-up also.
 *
 * Additionally, the TRANSMIT side of the IMP11-A has the
 * lower address of the two subunits, so the vector ordering
 * in the CONFIG file is reversed from most other devices.
 * It should be:
 *
 * device css0 ....  cssxint cssrint
 *
 * If you get it wrong, it will still autoconfig, but will just
 * sit there with RECIEVE IDLE indicated on the front panel.
 */

#include "param.h"
#include "../machine/seg.h"

#include "systm.h"
#include "mbuf.h"
#include "buf.h"
#include "domain.h"
#include "protosw.h"
#include "socket.h"
#include "pdpuba/ubavar.h"

#include "../net/if.h"

#include "../netinet/in.h"
#include "../netinet/in_systm.h"
#include "../netimp/if_imp.h"

#include "if_css.h"
#include "if_uba.h"

int	cssprobe(), cssattach(), cssrint(), cssxint();
int	cssinit(), cssstart(), cssreset();

struct uba_device *cssinfo[NCSS];
u_short cssstd[] = { 0 };
struct  uba_driver cssdriver =
	{ cssprobe, 0, cssattach, 0, cssstd, "css", cssinfo };
#define CSSUNIT(x)	minor(x)

/*
 * "Lower half" of IMP interface driver.
 *
 * Each IMP interface is handled by a common module which handles
 * the IMP-host protocol and a hardware driver which manages the
 * hardware specific details of talking with the IMP.
 *
 * The hardware portion of the IMP driver handles DMA and related
 * management of UNIBUS resources.  The IMP protocol module interprets
 * contents of these messages and "controls" the actions of the
 * hardware module during IMP resets, but not, for instance, during
 * UNIBUS resets.
 *
 * The two modules are coupled at "attach time", and ever after,
 * through the imp interface structure.  Higher level protocols,
 * e.g. IP, interact with the IMP driver, rather than the CSS.
 */
struct  css_softc {
	struct  ifnet *css_if;		/* pointer to IMP's ifnet struct */
	struct  impcb *css_ic;		/* data structure shared with IMP */
	struct  ifuba css_ifuba;	/* UNIBUS resources */
	struct  mbuf *css_iq;		/* input reassembly queue */
	short   css_olen;		/* size of last message sent */
	char    css_flush;		/* flush remainder of message */
} css_softc[NCSS];

/*
 * Reset the IMP and cause a transmitter interrupt by
 * performing a null DMA.
 */
cssprobe(reg)
	caddr_t reg;
{
#if !pdp11
	register int br, cvec;	  /* r11, r10 value-result */
	register struct cssdevice *addr = (struct cssdevice *)reg;

#ifdef lint
	br = 0; cvec = br; br = cvec;
	cssrint(0); cssxint(0);
#endif

	addr->css_icsr = CSS_CLR;
	addr->css_ocsr = CSS_CLR;
	DELAY(50000L);
	addr->css_icsr = 0;
	addr->css_ocsr = 0;
	DELAY(50000L);

	addr->css_oba = 0;
	addr->css_owc = -1;
	addr->css_ocsr = CSS_IE | CSS_GO;	/* enable interrupts */
	DELAY(50000L);
	addr->css_ocsr = 0;

	return (1);
#endif !pdp11
}

/*
 * Call the IMP module to allow it to set up its internal
 * state, then tie the two modules together by setting up
 * the back pointers to common data structures.
 */
cssattach(ui)
	struct uba_device *ui;
{
	register struct css_softc *sc = &css_softc[ui->ui_unit];
	register struct impcb *ip;
	struct ifimpcb {
		struct  ifnet ifimp_if;
		struct  impcb ifimp_impcb;
	} *ifimp;
	if ((ifimp = (struct ifimpcb *)impattach(ui, cssreset)) == 0)
		panic("cssattach");	     /* XXX */
	sc->css_if = &ifimp->ifimp_if;
	ip = &ifimp->ifimp_impcb;
	sc->css_ic = ip;
	ip->ic_init = cssinit;
	ip->ic_start = cssstart;
	sc->css_ifuba.ifu_flags = UBA_CANTWAIT | UBA_NEED16;
#ifdef notdef
	sc->css_ifuba.ifu_flags |= UBA_NEEDBDP;
#endif
}

/*
 * Reset interface after UNIBUS reset.
 * If interface is on specified uba, reset its state.
 */
cssreset(unit, uban)
	int unit, uban;
{
	register struct uba_device *ui;
	struct css_softc *sc;

	if (unit >= NCSS || (ui = cssinfo[unit]) == 0 || ui->ui_alive == 0 ||
	    ui->ui_ubanum != uban)
		return;
	printf(" css%d", unit);
	sc = &css_softc[unit];
	/* must go through IMP to allow it to set state */
	(*sc->css_if->if_init)(unit);
}

/*
 * Initialize interface: clear recorded pending operations,
 * and retrieve, and reinitialize UNIBUS resources.
 */
cssinit(unit)
	int unit;
{       
	register struct css_softc *sc;
	register struct uba_device *ui;
	register struct cssdevice *addr;
	int x;
	long info;

	if (unit >= NCSS || (ui = cssinfo[unit]) == 0 || ui->ui_alive == 0) {
		printf("css%d: not alive\n", unit);
		return(0);
	}
	sc = &css_softc[unit];

	/*
	 * Header length is 0 to if_ubainit since we have to pass
	 * the IMP leader up to the protocol interpretaion
	 * routines.  If we had the deader length as
	 * sizeof(struct imp_leader), then the if_ routines
	 * would assume we handle it on input and output.
	 */
	
	if (if_ubainit(&sc->css_ifuba, ui->ui_ubanum, 0,(int)btoc(IMPMTU)) == 0) {
		printf("css%d: can't initialize\n", unit);
		ui->ui_alive = 0;
		return(0);
	}
	addr = (struct cssdevice *)ui->ui_addr;

	/* reset the imp interface. */
	x = splimp();
	addr->css_icsr = CSS_CLR;
	addr->css_ocsr = CSS_CLR;
	DELAY(100L);
	addr->css_icsr = 0;
	addr->css_ocsr = 0;
	addr->css_icsr = IN_HRDY;       /* close the relay */
	DELAY(5000L);
	splx(x);

	/*
	 * This may hang if the imp isn't really there.
	 * Will test and verify safe operation.
	 */

	x = 5;
	while (x-- > 0) {
		if ((addr->css_icsr & (IN_HRDY|IN_IMPNR)) == IN_HRDY) 
			break;
		addr->css_icsr = IN_HRDY;	/* close the relay */
		DELAY(5000L);
	}

	if (x <= 0) {
/*
		printf("css%d: imp doesn't respond, icsr=%b\n", unit,
			CSS_INBITS, addr->css_icsr);
*/
		goto down;
	}

	/*
	 * Put up a read.  We can't restart any outstanding writes
	 * until we're back in synch with the IMP (i.e. we've flushed
	 * the NOOPs it throws at us).
	 * Note: IMPMTU includes the leader.
	 */

	x = splimp();
	info = sc->css_ifuba.ifu_r.ifrw_info;
	addr->css_iba = (u_short)info;
	addr->css_iwc = -(IMPMTU >> 1);
	addr->css_icsr = 
		IN_HRDY | CSS_IE | IN_WEN | ((info & 0x30000) >> 12) | CSS_GO;
	splx(x);
	return(1);

down:
	ui->ui_alive = 0;
	return(0);
}

/*
 * Start output on an interface.
 */
cssstart(dev)
	dev_t dev;
{
	int unit = CSSUNIT(dev);
	long info;
	struct uba_device *ui = cssinfo[unit];
	register struct css_softc *sc = &css_softc[unit];
	register struct cssdevice *addr;
	struct mbuf *m;
	u_short cmd;

	if (sc->css_ic->ic_oactive)
		goto restart;
	
	/*
	 * Not already active, deqeue a request and
	 * map it onto the UNIBUS.  If no more
	 * requeusts, just return.
	 */
	IF_DEQUEUE(&sc->css_if->if_snd, m);
	if (m == 0) {
		sc->css_ic->ic_oactive = 0;
		return;
	}
	sc->css_olen = if_wubaput(&sc->css_ifuba, m);

restart:
	addr = (struct cssdevice *)ui->ui_addr;
	info = sc->css_ifuba.ifu_w.ifrw_info;
	addr->css_oba = (u_short)info;
	addr->css_owc = -((sc->css_olen + 1) >> 1);
	cmd = CSS_IE | OUT_ENLB | ((info & 0x30000) >> 12) | CSS_GO;
	addr->css_ocsr = cmd;
	sc->css_ic->ic_oactive = 1;
}

/*
 * Output interrupt handler.
 */
cssxint(unit)
{
	register struct uba_device *ui = cssinfo[unit];
	register struct css_softc *sc = &css_softc[unit];
	register struct cssdevice *addr;

	addr = (struct cssdevice *)ui->ui_addr;
	if (sc->css_ic->ic_oactive == 0) {
		printf("css%d: stray output interrupt csr=%b\n",
			unit, addr->css_ocsr, CSS_OUTBITS);
		goto out;
	}
	sc->css_if->if_opackets++;
	sc->css_ic->ic_oactive = 0;
	if (addr->css_ocsr & CSS_ERR){
		sc->css_if->if_oerrors++;
		printf("css%d: output error, ocsr=%b icsr=%b\n", unit,
			addr->css_ocsr, CSS_OUTBITS,
			addr->css_icsr, CSS_INBITS);
	}
	if (sc->css_ifuba.ifu_xtofree) {
		m_freem(sc->css_ifuba.ifu_xtofree);
		sc->css_ifuba.ifu_xtofree = 0;
	}
	if (sc->css_if->if_snd.ifq_head)
		cssstart(unit);
out:
	return;
}

/*
 * Input interrupt handler
 */
cssrint(unit)
{
	register struct css_softc *sc = &css_softc[unit];
	register struct cssdevice *addr;
	register struct ifqueue *inq;
	struct mbuf *m;
	int len;
	long info;

	sc->css_if->if_ipackets++;

	addr = (struct cssdevice *)cssinfo[unit]->ui_addr;
	if (addr->css_icsr & CSS_ERR) {
		printf("css%d: recv error, csr=%b\n", unit,
		    addr->css_icsr, CSS_INBITS);
		sc->css_if->if_ierrors++;
		sc->css_flush = 1;
		if (addr->css_icsr & IN_IMPNR) {
		    impinput(unit,(struct mbuf *)0);
		    goto out;
		}
	}

	if (sc->css_flush) {
		if (addr->css_icsr & IN_EOM)
			sc->css_flush = 0;
		goto setup;
	}

	len = IMPMTU + (addr->css_iwc << 1);
	if (len < 0 || len > IMPMTU) {
		printf("css%d: bad length=%d\n", len);
		sc->css_if->if_ierrors++;
		goto setup;
	}

	/*
	 * The next to last parameter is always 0 since using
	 * trailers on the ARPAnet is insane.
	 */
	m = if_rubaget(&sc->css_ifuba, len, 0, &sc->css_if);
	if (m == 0)
		goto setup;
	if ((addr->css_icsr & IN_EOM) == 0) {
		if (sc->css_iq)
			m_cat(sc->css_iq, m);
		else
			sc->css_iq = m;
		goto setup;
	}
	if (sc->css_iq) {
		m_cat(sc->css_iq, m);
		m = sc->css_iq;
		sc->css_iq = 0;
	}
	impinput(unit, m);

setup:
	/*
	 * Setup for next message.
	 */
	info = sc->css_ifuba.ifu_r.ifrw_info;
	addr->css_iba = (u_short)info;
	addr->css_iwc = - (IMPMTU >> 1);
	addr->css_icsr =
		IN_HRDY | CSS_IE | IN_WEN | ((info & 0x30000) >> 12) | CSS_GO;
out:
	return;
}
#endif NCSS