/*	$NetBSD: esp.c,v 1.33 2021/03/05 07:15:53 rin Exp $	*/

/*-
 * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Charles M. Hannum and by Jason R. Thorpe of the Numerical Aerospace
 * Simulation Facility, NASA Ames Research Center.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Copyright (c) 1994 Peter Galbavy
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by Peter Galbavy
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Based on aic6360 by Jarle Greipsland
 *
 * Acknowledgements: Many of the algorithms used in this driver are
 * inspired by the work of Julian Elischer (julian@tfs.com) and
 * Charles Hannum (mycroft@duality.gnu.ai.mit.edu).  Thanks a million!
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: esp.c,v 1.33 2021/03/05 07:15:53 rin Exp $");

#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/device.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/malloc.h>

#include <dev/scsipi/scsi_all.h>
#include <dev/scsipi/scsipi_all.h>
#include <dev/scsipi/scsiconf.h>
#include <dev/scsipi/scsi_message.h>

#include <dev/ofw/openfirm.h>

#include <machine/cpu.h>
#include <machine/autoconf.h>
#include <machine/pio.h>

#include <dev/ic/ncr53c9xreg.h>
#include <dev/ic/ncr53c9xvar.h>

#include <macppc/dev/dbdma.h>
#include <macppc/dev/espvar.h>

int	espmatch(device_t, cfdata_t, void *);
void	espattach(device_t, device_t, void *);

/* Linkup to the rest of the kernel */
CFATTACH_DECL_NEW(esp, sizeof(struct esp_softc),
    espmatch, espattach, NULL, NULL);

/*
 * Functions and the switch for the MI code.
 */
static uint8_t	esp_read_reg(struct ncr53c9x_softc *, int);
static void	esp_write_reg(struct ncr53c9x_softc *, int, uint8_t);
static int	esp_dma_isintr(struct ncr53c9x_softc *);
static void	esp_dma_reset(struct ncr53c9x_softc *);
static int	esp_dma_intr(struct ncr53c9x_softc *);
static int	esp_dma_setup(struct ncr53c9x_softc *, uint8_t **,
		    size_t *, int, size_t *);
static void	esp_dma_go(struct ncr53c9x_softc *);
static void	esp_dma_stop(struct ncr53c9x_softc *);
static int	esp_dma_isactive(struct ncr53c9x_softc *);

static struct ncr53c9x_glue esp_glue = {
	esp_read_reg,
	esp_write_reg,
	esp_dma_isintr,
	esp_dma_reset,
	esp_dma_intr,
	esp_dma_setup,
	esp_dma_go,
	esp_dma_stop,
	esp_dma_isactive,
	NULL,			/* gl_clear_latched_intr */
};

static int espdmaintr(struct esp_softc *);
static bool esp_shutdown(device_t, int);

int
espmatch(device_t parent, cfdata_t cf, void *aux)
{
	struct confargs *ca = aux;

	if (strcmp(ca->ca_name, "53c94") != 0)
		return 0;

	if (ca->ca_nreg != 16)
		return 0;
	if (ca->ca_nintr != 8)
		return 0;

	return 1;
}

/*
 * Attach this instance, and then all the sub-devices
 */
void
espattach(device_t parent, device_t self, void *aux)
{
	struct esp_softc *esc = device_private(self);
	struct ncr53c9x_softc *sc = &esc->sc_ncr53c9x;
	struct confargs *ca = aux;
	u_int *reg;
	int sz;

	/*
	 * Set up glue for MI code early; we use some of it here.
	 */
	sc->sc_dev = self;
	sc->sc_glue = &esp_glue;

	esc->sc_node = ca->ca_node;
	esc->sc_pri = ca->ca_intr[0];
	aprint_normal(" irq %d", esc->sc_pri);

	/*
	 * Map my registers in.
	 */
	reg = ca->ca_reg;
	esc->sc_reg =    mapiodev(ca->ca_baseaddr + reg[0], reg[1], false);
	esc->sc_dmareg = mapiodev(ca->ca_baseaddr + reg[2], reg[3], false);

	/* Allocate 16-byte aligned DMA command space */
	esc->sc_dmacmd = dbdma_alloc(sizeof(dbdma_command_t) * 20, NULL);

	/* Other settings */
	sc->sc_id = 7;
	sz = OF_getprop(ca->ca_node, "clock-frequency",
	    &sc->sc_freq, sizeof(int));
	if (sz != sizeof(int))
		sc->sc_freq = 25000000;

	/* gimme MHz */
	sc->sc_freq /= 1000000;

	/* esc->sc_dma->sc_esp = esc;*/

	/*
	 * XXX More of this should be in ncr53c9x_attach(), but
	 * XXX should we really poke around the chip that much in
	 * XXX the MI code?  Think about this more...
	 */

	/*
	 * Set up static configuration info.
	 */
	sc->sc_cfg1 = sc->sc_id | NCRCFG1_PARENB;
	sc->sc_cfg2 = NCRCFG2_SCSI2; /* | NCRCFG2_FE */
	sc->sc_cfg3 = NCRCFG3_CDB;
	sc->sc_rev = NCR_VARIANT_NCR53C94;

	/*
	 * XXX minsync and maxxfer _should_ be set up in MI code,
	 * XXX but it appears to have some dependency on what sort
	 * XXX of DMA we're hooked up to, etc.
	 */

	/*
	 * This is the value used to start sync negotiations
	 * Note that the NCR register "SYNCTP" is programmed
	 * in "clocks per byte", and has a minimum value of 4.
	 * The SCSI period used in negotiation is one-fourth
	 * of the time (in nanoseconds) needed to transfer one byte.
	 * Since the chip's clock is given in MHz, we have the following
	 * formula: 4 * period = (1000 / freq) * 4
	 */
	sc->sc_minsync = 1000 / sc->sc_freq;

	sc->sc_maxxfer = 64 * 1024;

	/* and the interuppts */
	intr_establish_xname(esc->sc_pri, IST_EDGE, IPL_BIO, ncr53c9x_intr, sc,
	    device_xname(self));

	/* Do the common parts of attachment. */
	sc->sc_adapter.adapt_minphys = minphys;
	sc->sc_adapter.adapt_request = ncr53c9x_scsipi_request;
	ncr53c9x_attach(sc);

	/* Turn on target selection using the `DMA' method */
	sc->sc_features |= NCR_F_DMASELECT;

	/* Reset SCSI bus when halt. */
	if (!pmf_device_register1(self, NULL, NULL, esp_shutdown))
		aprint_error_dev(self, "couldn't establish power handler\n");
}

/*
 * Glue functions.
 */

uint8_t
esp_read_reg(struct ncr53c9x_softc *sc, int reg)
{
	struct esp_softc *esc = (struct esp_softc *)sc;

	return in8(&esc->sc_reg[reg * 16]);
	/*return (esc->sc_reg[reg * 16]);*/
}

void
esp_write_reg(struct ncr53c9x_softc *sc, int reg, uint8_t val)
{
	struct esp_softc *esc = (struct esp_softc *)sc;
	uint8_t v = val;

	out8(&esc->sc_reg[reg * 16], v);
	/*esc->sc_reg[reg * 16] = v;*/
}

int
esp_dma_isintr(struct ncr53c9x_softc *sc)
{

	return esp_read_reg(sc, NCR_STAT) & NCRSTAT_INT;
}

void
esp_dma_reset(struct ncr53c9x_softc *sc)
{
	struct esp_softc *esc = (struct esp_softc *)sc;

	dbdma_stop(esc->sc_dmareg);
	esc->sc_dmaactive = 0;
}

int
esp_dma_intr(struct ncr53c9x_softc *sc)
{
	struct esp_softc *esc = (struct esp_softc *)sc;

	return espdmaintr(esc);
}

int
esp_dma_setup(struct ncr53c9x_softc *sc, uint8_t **addr, size_t *len,
    int datain, size_t *dmasize)
{
	struct esp_softc *esc = (struct esp_softc *)sc;
	dbdma_command_t *cmdp;
	u_int cmd;
	u_int va;
	int count, offset;

	cmdp = esc->sc_dmacmd;
	cmd = datain ? DBDMA_CMD_IN_MORE : DBDMA_CMD_OUT_MORE;

	count = *dmasize;

	if (count / PAGE_SIZE > 32)
		panic("%s: transfer size >= 128k", device_xname(sc->sc_dev));

	esc->sc_dmaaddr = addr;
	esc->sc_dmalen = len;
	esc->sc_dmasize = count;

	va = (u_int)*esc->sc_dmaaddr;
	offset = va & PGOFSET;

	/* if va is not page-aligned, setup the first page */
	if (offset != 0) {
		int rest = PAGE_SIZE - offset;	/* the rest of the page */

		if (count > rest) {		/* if continues to next page */
			DBDMA_BUILD(cmdp, cmd, 0, rest, kvtop((void *)va),
				DBDMA_INT_NEVER, DBDMA_WAIT_NEVER,
				DBDMA_BRANCH_NEVER);
			count -= rest;
			va += rest;
			cmdp++;
		}
	}

	/* now va is page-aligned */
	while (count > PAGE_SIZE) {
		DBDMA_BUILD(cmdp, cmd, 0, PAGE_SIZE, kvtop((void *)va),
		    DBDMA_INT_NEVER, DBDMA_WAIT_NEVER, DBDMA_BRANCH_NEVER);
		count -= PAGE_SIZE;
		va += PAGE_SIZE;
		cmdp++;
	}

	/* the last page (count <= PAGE_SIZE here) */
	cmd = datain ? DBDMA_CMD_IN_LAST : DBDMA_CMD_OUT_LAST;
	DBDMA_BUILD(cmdp, cmd , 0, count, kvtop((void *)va),
	    DBDMA_INT_NEVER, DBDMA_WAIT_NEVER, DBDMA_BRANCH_NEVER);
	cmdp++;

	DBDMA_BUILD(cmdp, DBDMA_CMD_STOP, 0, 0, 0,
	    DBDMA_INT_NEVER, DBDMA_WAIT_NEVER, DBDMA_BRANCH_NEVER);

	esc->sc_dma_direction = datain ? D_WRITE : 0;

	return 0;
}

void
esp_dma_go(struct ncr53c9x_softc *sc)
{
	struct esp_softc *esc = (struct esp_softc *)sc;

	dbdma_start(esc->sc_dmareg, esc->sc_dmacmd);
	esc->sc_dmaactive = 1;
}

void
esp_dma_stop(struct ncr53c9x_softc *sc)
{
	struct esp_softc *esc = (struct esp_softc *)sc;

	dbdma_stop(esc->sc_dmareg);
	esc->sc_dmaactive = 0;
}

int
esp_dma_isactive(struct ncr53c9x_softc *sc)
{
	struct esp_softc *esc = (struct esp_softc *)sc;

	return esc->sc_dmaactive;
}


/*
 * Pseudo (chained) interrupt from the esp driver to kick the
 * current running DMA transfer. I am replying on espintr() to
 * pickup and clean errors for now
 *
 * return 1 if it was a DMA continue.
 */
int
espdmaintr(struct esp_softc *sc)
{
	struct ncr53c9x_softc *nsc = (struct ncr53c9x_softc *)sc;
	int trans, resid;
	u_long csr = sc->sc_dma_direction;

#if 0
	if (csr & D_ERR_PEND) {
		DMACSR(sc) &= ~D_EN_DMA;	/* Stop DMA */
		DMACSR(sc) |= D_INVALIDATE;
		snprintb(bits, sizeof(bits), DMACSRBITS, csr);
		printf("%s: error: csr=%s\n", device_xname(nsc->sc_dev), bits);
		return -1;
	}
#endif

	/* This is an "assertion" :) */
	if (sc->sc_dmaactive == 0)
		panic("%s: DMA wasn't active", __func__);

	/* dbdma_flush(sc->sc_dmareg); */

	/* DMA has stopped */
	dbdma_stop(sc->sc_dmareg);
	sc->sc_dmaactive = 0;

	if (sc->sc_dmasize == 0) {
		/* A "Transfer Pad" operation completed */
		NCR_DMA(("dmaintr: discarded %d bytes (tcl=%d, tcm=%d)\n",
			NCR_READ_REG(nsc, NCR_TCL) |
				(NCR_READ_REG(nsc, NCR_TCM) << 8),
			NCR_READ_REG(nsc, NCR_TCL),
			NCR_READ_REG(nsc, NCR_TCM)));
		return 0;
	}

	resid = 0;
	/*
	 * If a transfer onto the SCSI bus gets interrupted by the device
	 * (e.g. for a SAVEPOINTER message), the data in the FIFO counts
	 * as residual since the ESP counter registers get decremented as
	 * bytes are clocked into the FIFO.
	 */
	if (!(csr & D_WRITE) &&
	    (resid = (NCR_READ_REG(nsc, NCR_FFLAG) & NCRFIFO_FF)) != 0) {
		NCR_DMA(("dmaintr: empty esp FIFO of %d ", resid));
	}

	if ((nsc->sc_espstat & NCRSTAT_TC) == 0) {
		/*
		 * `Terminal count' is off, so read the residue
		 * out of the ESP counter registers.
		 */
		resid += (NCR_READ_REG(nsc, NCR_TCL) |
			  (NCR_READ_REG(nsc, NCR_TCM) << 8) |
			   ((nsc->sc_cfg2 & NCRCFG2_FE)
				? (NCR_READ_REG(nsc, NCR_TCH) << 16)
				: 0));

		if (resid == 0 && sc->sc_dmasize == 65536 &&
		    (nsc->sc_cfg2 & NCRCFG2_FE) == 0)
			/* A transfer of 64K is encoded as `TCL=TCM=0' */
			resid = 65536;
	}

	trans = sc->sc_dmasize - resid;
	if (trans < 0) {			/* transferred < 0 ? */
#if 0
		/*
		 * This situation can happen in perfectly normal operation
		 * if the ESP is reselected while using DMA to select
		 * another target.  As such, don't print the warning.
		 */
		printf("%s: xfer (%d) > req (%d)\n",
		    device_xname(nsc->sc_dev), trans, sc->sc_dmasize);
#endif
		trans = sc->sc_dmasize;
	}

	NCR_DMA(("dmaintr: tcl=%d, tcm=%d, tch=%d; trans=%d, resid=%d\n",
		NCR_READ_REG(nsc, NCR_TCL),
		NCR_READ_REG(nsc, NCR_TCM),
		(nsc->sc_cfg2 & NCRCFG2_FE)
			? NCR_READ_REG(nsc, NCR_TCH) : 0,
		trans, resid));

#if 0
	if (csr & D_WRITE)
		flushcache(*sc->sc_dmaaddr, trans);
#endif

	*sc->sc_dmalen -= trans;
	*sc->sc_dmaaddr += trans;

#if 0	/* this is not normal operation just yet */
	if (*sc->sc_dmalen == 0 ||
	    nsc->sc_phase != nsc->sc_prevphase)
		return 0;

	/* and again */
	dma_start(sc, sc->sc_dmaaddr, sc->sc_dmalen, DMACSR(sc) & D_WRITE);
	return 1;
#endif
	return 0;
}

bool
esp_shutdown(device_t self, int howto)
{
	struct esp_softc *esc;
	struct ncr53c9x_softc *sc;

	esc = device_private(self);
	sc = &esc->sc_ncr53c9x;
	NCRCMD(sc, NCRCMD_RSTSCSI);

	return true;
}