/*-
 * Copyright (c) 2012 Robert N. M. Watson
 * All rights reserved.
 *
 * This software was developed by SRI International and the University of
 * Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
 * ("CTSRD"), as part of the DARPA CRASH research programme.
 *
 * 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 AUTHOR 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 AUTHOR 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.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/consio.h>				/* struct vt_mode */
#include <sys/endian.h>
#include <sys/fbio.h>				/* video_adapter_t */
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/rman.h>
#include <sys/systm.h>
#include <sys/uio.h>

#include <machine/bus.h>
#include <machine/resource.h>
#include <machine/vm.h>

#include <dev/terasic/mtl/terasic_mtl.h>

static d_mmap_t terasic_mtl_text_mmap;
static d_read_t terasic_mtl_text_read;
static d_write_t terasic_mtl_text_write;

static struct cdevsw terasic_mtl_text_cdevsw = {
	.d_version =	D_VERSION,
	.d_mmap =	terasic_mtl_text_mmap,
	.d_read =	terasic_mtl_text_read,
	.d_write =	terasic_mtl_text_write,
	.d_name =	"terasic_mtl_text",
};

/*
 * All I/O to/from the mtl device must be 16-bit, and aligned to 16-bit.
 */
static int
terasic_mtl_text_read(struct cdev *dev, struct uio *uio, int flag)
{
	struct terasic_mtl_softc *sc;
	u_long offset, size;
	uint16_t v;
	int error;

	if (uio->uio_offset < 0 || uio->uio_offset % 2 != 0 ||
	    uio->uio_resid % 2 != 0)
		return (ENODEV);
	sc = dev->si_drv1;
	size = rman_get_size(sc->mtl_text_res);
	error = 0;
	if ((uio->uio_offset + uio->uio_resid < 0) ||
	    (uio->uio_offset + uio->uio_resid > size))
		return (ENODEV);
	while (uio->uio_resid > 0) {
		offset = uio->uio_offset;
		if (offset + sizeof(v) > size)
			return (ENODEV);
		v = bus_read_2(sc->mtl_text_res, offset);
		error = uiomove(&v, sizeof(v), uio);
		if (error)
			return (error);
	}
	return (error);
}

static int
terasic_mtl_text_write(struct cdev *dev, struct uio *uio, int flag)
{
	struct terasic_mtl_softc *sc;
	u_long offset, size;
	uint16_t v;
	int error;

	if (uio->uio_offset < 0 || uio->uio_offset % 2 != 0 ||
	    uio->uio_resid % 2 != 0)
		return (ENODEV);
	sc = dev->si_drv1;
	size = rman_get_size(sc->mtl_text_res);
	error = 0;
	while (uio->uio_resid > 0) {
		offset = uio->uio_offset;
		if (offset + sizeof(v) > size)
			return (ENODEV);
		error = uiomove(&v, sizeof(v), uio);
		if (error)
			return (error);
		bus_write_2(sc->mtl_text_res, offset, v);
	}
	return (error);
}

static int
terasic_mtl_text_mmap(struct cdev *dev, vm_ooffset_t offset,
    vm_paddr_t *paddr, int nprot, vm_memattr_t *memattr)
{
	struct terasic_mtl_softc *sc;
	int error;

	sc = dev->si_drv1;
	error = 0;
	if (trunc_page(offset) == offset &&
	    rman_get_size(sc->mtl_text_res) >= offset + PAGE_SIZE) {
		*paddr = rman_get_start(sc->mtl_text_res) + offset;
		*memattr = VM_MEMATTR_UNCACHEABLE;
	} else
		error = ENODEV;
	return (error);
}

void
terasic_mtl_text_putc(struct terasic_mtl_softc *sc, u_int x, u_int y,
    uint8_t c, uint8_t a)
{
	u_int offset;
	uint16_t v;

	KASSERT(x < TERASIC_MTL_COLS, ("%s: TERASIC_MTL_COLS", __func__));
	KASSERT(y < TERASIC_MTL_ROWS, ("%s: TERASIC_MTL_ROWS", __func__));

	offset = sizeof(uint16_t) * (x + y * TERASIC_MTL_COLS);
	v = (c << TERASIC_MTL_TEXTFRAMEBUF_CHAR_SHIFT) |
	    (a << TERASIC_MTL_TEXTFRAMEBUF_ATTR_SHIFT);
	v = htole16(v);
	bus_write_2(sc->mtl_text_res, offset, v);
}

int
terasic_mtl_text_attach(struct terasic_mtl_softc *sc)
{
	uint32_t v;

	terasic_mtl_reg_textframebufaddr_get(sc, &v);
	if (v != TERASIC_MTL_TEXTFRAMEBUF_EXPECTED_ADDR) {
		device_printf(sc->mtl_dev, "%s: unexpected text frame buffer "
		    "address (%08x); cannot attach\n", __func__, v);
		return (ENXIO);
	}

	sc->mtl_text_cdev = make_dev(&terasic_mtl_text_cdevsw, sc->mtl_unit,
	    UID_ROOT, GID_WHEEL, 0400, "mtl_text%d", sc->mtl_unit);
	if (sc->mtl_text_cdev == NULL) {
		device_printf(sc->mtl_dev, "%s: make_dev failed\n", __func__);
		return (ENXIO);
	}
	/* XXXRW: Slight race between make_dev(9) and here. */
	TERASIC_MTL_LOCK_INIT(sc);
	sc->mtl_text_cdev->si_drv1 = sc;
	return (0);
}

void
terasic_mtl_text_detach(struct terasic_mtl_softc *sc)
{

	if (sc->mtl_text_cdev != NULL) {
		destroy_dev(sc->mtl_text_cdev);
		TERASIC_MTL_LOCK_DESTROY(sc);
	}
}