/*-
 * Copyright (c) 2010 Aleksandr Rybalko.
 * 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.
 *
 * 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.
 */

/*
 * Pseudo driver to copy the NVRAM settings from various sources
 * into the kernel environment.
 *
 * Drivers (such as ethernet devices) can then use environment
 * variables to set default parameters.
 */

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

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/endian.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/rman.h>
#include <sys/malloc.h>

#include <machine/bus.h>

#include <dev/siba/siba_ids.h>
#include <dev/siba/sibareg.h>
#include <dev/siba/sibavar.h>

#define nvram2env_read_1(sc, reg)				\
	bus_space_read_1((sc)->sc_bt, (sc)->sc_bh,(reg))

#define nvram2env_read_2(sc, reg)				\
	bus_space_read_2((sc)->sc_bt, (sc)->sc_bh,(reg))

#define nvram2env_read_4(sc, reg)				\
	bus_space_read_4((sc)->sc_bt, (sc)->sc_bh,(reg))

#define nvram2env_write_1(sc, reg, val)			\
	bus_space_write_1((sc)->sc_bt, (sc)->sc_bh,	\
			 (reg), (val))

#define nvram2env_write_2(sc, reg, val)			\
	bus_space_write_2((sc)->sc_bt, (sc)->sc_bh,	\
			 (reg), (val))

#define nvram2env_write_4(sc, reg, val)			\
	bus_space_write_4((sc)->sc_bt, (sc)->sc_bh,	\
			 (reg), (val))

struct nvram2env_softc {
	bus_space_tag_t bst;
	bus_space_handle_t bsh;
	bus_addr_t addr;
	int need_swap;
	uint32_t sig;
	uint32_t flags;
#define NVRAM_FLAGS_NOCHECK	0x0001	/* Do not check(CRC or somthing else)*/
#define NVRAM_FLAGS_GENERIC	0x0002	/* Format Generic, skip 4b and read */
#define NVRAM_FLAGS_BROADCOM	0x0004	/* Format Broadcom, use struct nvram */
#define NVRAM_FLAGS_UBOOT	0x0008	/* Format Generic, skip 4b of CRC and read */
	uint32_t maxsize;
	uint32_t crc;
};

static int	nvram2env_attach(device_t);
static int	nvram2env_probe(device_t);

#define NVRAM_MAX_SIZE 0x10000

static void
nvram2env_identify(driver_t * drv, device_t parent)
{
	int i, ivar;

	for (i = 0; !resource_int_value("nvram", i, "base", &ivar); i++)
		BUS_ADD_CHILD(parent, 0, "nvram2env", i);
}

static int
nvram2env_probe(device_t dev)
{
	uint32_t i, ivar, sig;
	struct nvram2env_softc * sc = device_get_softc(dev);
	sc->bst = mips_bus_space_generic;

	if (resource_int_value("nvram", device_get_unit(dev), "sig",
	    &sc->sig) != 0 || sc->sig == 0)
		sc->sig = 0x48534c46;

	if (resource_int_value("nvram", device_get_unit(dev), "maxsize",
	    &sc->maxsize) != 0 || sc->maxsize == 0)
		sc->maxsize = NVRAM_MAX_SIZE;

	if (resource_int_value("nvram", device_get_unit(dev), "flags", 
	    &sc->flags) != 0 || sc->flags == 0)
		sc->flags = NVRAM_FLAGS_GENERIC;


	for (i = 0; i < 2; i ++)
	{
		if (resource_int_value("nvram", device_get_unit(dev), 
			(!i)?"base":"fallbackbase", &ivar) != 0 ||
		    ivar == 0)
			continue;

		sc->addr = MIPS_PHYS_TO_KSEG1(ivar);

		if (bootverbose)
			device_printf(dev, "base=0x%08x sig=0x%08x "
			    "maxsize=0x%08x flags=0x%08x\n",
			    sc->addr, sc->sig, sc->maxsize, sc->flags);

		if (bus_space_map(sc->bst, sc->addr, sc->maxsize, 0,
		    &sc->bsh) != 0)
			continue;

		sig = bus_space_read_4(sc->bst, sc->bsh, 0);
		if ( sig == sc->sig /*FLSH*/)
		{
			device_printf(dev, "Found NVRAM at %#x\n", 
			    (uint32_t)ivar);
			sc->need_swap = 0;
			goto unmap_done;
		}
		else if ( htole32(sig) == sc->sig /*HSLF*/)
		{
			device_printf(dev, "Found NVRAM at %#x\n", 
			    (uint32_t)ivar);
			sc->need_swap = 1;
			goto unmap_done;
		} else if (sc->flags & NVRAM_FLAGS_UBOOT) {
			device_printf(dev, "Use NVRAM at %#x\n", 
			    (uint32_t)ivar);
			sc->crc = sig;
			goto unmap_done;
		}
		bus_space_unmap(sc->bst, sc->bsh, NVRAM_MAX_SIZE);
	}
	sc->bst = 0;
	sc->bsh = 0;
	sc->addr = 0;
	return (ENXIO);

unmap_done:
	bus_space_unmap(sc->bst, sc->bsh, NVRAM_MAX_SIZE);
	device_set_desc(dev, "NVRAM to ENV pseudo-device");
	return (BUS_PROBE_SPECIFIC);

}

struct nvram {
	u_int32_t sig;
	u_int32_t size;
	u_int32_t unknown1;
	u_int32_t unknown2;
	u_int32_t unknown3;
	char data[];
};

static uint32_t read_4(struct nvram2env_softc * sc, int offset) 
{
	if (sc->need_swap) 
		return (bswap32(bus_space_read_4(sc->bst, sc->bsh, offset)));
	else
		return (bus_space_read_4(sc->bst, sc->bsh, offset));
}


static int
nvram2env_attach(device_t dev)
{
	struct nvram2env_softc * sc = device_get_softc(dev);
	struct nvram * nv;
	char *pair, *value, *assign;
	uint32_t sig, size, i;

	if (sc->bst == 0 || sc->addr == 0)
		return (ENXIO);

	if (bus_space_map(sc->bst, sc->addr, NVRAM_MAX_SIZE, 0,
		&sc->bsh) != 0)
		return (ENXIO);

	sig  = read_4(sc, 0);
	size = read_4(sc, 4);
#if 1
	if (bootverbose)
		device_printf(dev, " size=0x%05x maxsize=0x%05x\n", size, sc->maxsize);
#endif
	size = (size > sc->maxsize)?sc->maxsize:size;


	if (sig == sc->sig || (sc->flags & NVRAM_FLAGS_UBOOT))
	{

		/* align and shift size to 32bit size*/
		size += 3;
		size >>= 2;

		nv = malloc(size<<2, M_DEVBUF, M_WAITOK | M_ZERO);
		if (!nv)
			return (ENOMEM);

		for (i = 0; i < size; i ++)
			((uint32_t *)nv)[i] = read_4(sc, i<<2);

		if (sc->flags & NVRAM_FLAGS_BROADCOM) {
			device_printf(dev, "sig = %#x\n",  nv->sig);
			device_printf(dev, "size = %#x\n", nv->size);
		}

		if (!(sc->flags & NVRAM_FLAGS_NOCHECK)) {
			/* TODO: need checksum verification */
		}

		if (sc->flags & NVRAM_FLAGS_GENERIC)
			pair = (char*)nv+4;
		if (sc->flags & NVRAM_FLAGS_UBOOT)
			pair = (char*)nv+4;
		else if (sc->flags & NVRAM_FLAGS_BROADCOM)
			pair = (char*)nv+20;
		else
			pair = (char*)nv+4;

		for ( ; 
		    (u_int32_t)pair < ((u_int32_t)nv + size - 4); 
		    pair = pair + strlen(pair) + 1 + strlen(value) + 1 ) {

			if (pair && strlen(pair)) {

#if 0
				printf("ENV: %s\n", pair);
#endif
				/* hint.nvram.0. */
				assign = strchr(pair,'=');
				assign[0] = '\0';
				value = assign+1;
#if 1
				if (bootverbose)
					printf("ENV: %s=%s\n", pair, value);
#endif
				setenv(pair, value);

				if (strcasecmp(pair, "WAN_MAC_ADDR") == 0) {
					/* Alias for MAC address of eth0 */
					if (bootverbose)
						printf("ENV: aliasing "
						    "WAN_MAC_ADDR to ethaddr"
						    " = %s\n",  value);
					setenv("ethaddr", value);
				}
				else if (strcasecmp(pair, "LAN_MAC_ADDR") == 0){
					/* Alias for MAC address of eth1 */
					if (bootverbose)
						printf("ENV: aliasing "
						    "LAN_MAC_ADDR to eth1addr"
						    " = %s\n",  value);
					setenv("eth1addr", value);
				}

				if (strcmp(pair, "bootverbose") == 0)
					bootverbose = strtoul(value, 0, 0);
				if (strcmp(pair, "boothowto"  ) == 0)
					boothowto   = strtoul(value, 0, 0);
			}
			else
				break;
		}
		free(nv, M_DEVBUF);
	}

	bus_space_unmap(sc->bst, sc->bsh, NVRAM_MAX_SIZE);

	return (0);
}

static device_method_t nvram2env_methods[] = {
	/* Device interface */
	DEVMETHOD(device_identify, 	nvram2env_identify),
	DEVMETHOD(device_probe,		nvram2env_probe),
	DEVMETHOD(device_attach,	nvram2env_attach),

	DEVMETHOD_END
};

static driver_t nvram2env_driver = {
	"nvram2env",
	nvram2env_methods,
	sizeof(struct nvram2env_softc),
};
static devclass_t nvram2env_devclass;

DRIVER_MODULE(nvram2env, nexus, nvram2env_driver, nvram2env_devclass, 0, 0);