/*-
 * Copyright (c) 2007, Juniper Networks, Inc.
 * 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. Neither the name of the author nor the names of any co-contributors
 *    may 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.
 */

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

#include "opt_cfi.h"

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

#include <machine/bus.h>

#include <dev/cfi/cfi_reg.h>
#include <dev/cfi/cfi_var.h>

extern struct cdevsw cfi_cdevsw;

char cfi_driver_name[] = "cfi";
devclass_t cfi_devclass;

uint32_t
cfi_read(struct cfi_softc *sc, u_int ofs)
{
	uint32_t val;

	ofs &= ~(sc->sc_width - 1);
	switch (sc->sc_width) {
	case 1:
		val = bus_space_read_1(sc->sc_tag, sc->sc_handle, ofs);
		break;
	case 2:
		val = bus_space_read_2(sc->sc_tag, sc->sc_handle, ofs);
		break;
	case 4:
		val = bus_space_read_4(sc->sc_tag, sc->sc_handle, ofs);
		break;
	default:
		val = ~0;
		break;
	}
	return (val);
}

static void
cfi_write(struct cfi_softc *sc, u_int ofs, u_int val)
{

	ofs &= ~(sc->sc_width - 1);
	switch (sc->sc_width) {
	case 1:
		bus_space_write_1(sc->sc_tag, sc->sc_handle, ofs, val);
		break;
	case 2:
		bus_space_write_2(sc->sc_tag, sc->sc_handle, ofs, val);
		break;
	case 4:
		bus_space_write_4(sc->sc_tag, sc->sc_handle, ofs, val);
		break;
	}
}

uint8_t
cfi_read_qry(struct cfi_softc *sc, u_int ofs)
{
	uint8_t val;
 
	cfi_write(sc, CFI_QRY_CMD_ADDR * sc->sc_width, CFI_QRY_CMD_DATA); 
	val = cfi_read(sc, ofs * sc->sc_width);
	cfi_write(sc, 0, CFI_BCS_READ_ARRAY);
	return (val);
} 

static void
cfi_amd_write(struct cfi_softc *sc, u_int ofs, u_int addr, u_int data)
{

	cfi_write(sc, ofs + AMD_ADDR_START, CFI_AMD_UNLOCK);
	cfi_write(sc, ofs + AMD_ADDR_ACK, CFI_AMD_UNLOCK_ACK);
	cfi_write(sc, ofs + addr, data);
}

static char *
cfi_fmtsize(uint32_t sz)
{
	static char buf[8];
	static const char *sfx[] = { "", "K", "M", "G" };
	int sfxidx;

	sfxidx = 0;
	while (sfxidx < 3 && sz > 1023) {
		sz /= 1024;
		sfxidx++;
	}

	sprintf(buf, "%u%sB", sz, sfx[sfxidx]);
	return (buf);
}

int
cfi_probe(device_t dev)
{
	char desc[80];
	struct cfi_softc *sc;
	char *vend_str;
	int error;
	uint16_t iface, vend;

	sc = device_get_softc(dev);
	sc->sc_dev = dev;

	sc->sc_rid = 0;
	sc->sc_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &sc->sc_rid,
	    RF_ACTIVE);
	if (sc->sc_res == NULL)
		return (ENXIO);

	sc->sc_tag = rman_get_bustag(sc->sc_res);
	sc->sc_handle = rman_get_bushandle(sc->sc_res);

	if (sc->sc_width == 0) {
		sc->sc_width = 1;
		while (sc->sc_width <= 4) {
			if (cfi_read_qry(sc, CFI_QRY_IDENT) == 'Q')
				break;
			sc->sc_width <<= 1;
		}
	} else if (cfi_read_qry(sc, CFI_QRY_IDENT) != 'Q') {
		error = ENXIO;
		goto out;
	}
	if (sc->sc_width > 4) {
		error = ENXIO;
		goto out;
	}

	/* We got a Q. Check if we also have the R and the Y. */
	if (cfi_read_qry(sc, CFI_QRY_IDENT + 1) != 'R' ||
	    cfi_read_qry(sc, CFI_QRY_IDENT + 2) != 'Y') {
		error = ENXIO;
		goto out;
	}

	/* Get the vendor and command set. */
	vend = cfi_read_qry(sc, CFI_QRY_VEND) |
	    (cfi_read_qry(sc, CFI_QRY_VEND + 1) << 8);

	sc->sc_cmdset = vend;

	switch (vend) {
	case CFI_VEND_AMD_ECS:
	case CFI_VEND_AMD_SCS:
		vend_str = "AMD/Fujitsu";
		break;
	case CFI_VEND_INTEL_ECS:
		vend_str = "Intel/Sharp";
		break;
	case CFI_VEND_INTEL_SCS:
		vend_str = "Intel";
		break;
	case CFI_VEND_MITSUBISHI_ECS:
	case CFI_VEND_MITSUBISHI_SCS:
		vend_str = "Mitsubishi";
		break;
	default:
		vend_str = "Unknown vendor";
		break;
	}

	/* Get the device size. */
	sc->sc_size = 1U << cfi_read_qry(sc, CFI_QRY_SIZE);

	/* Sanity-check the I/F */
	iface = cfi_read_qry(sc, CFI_QRY_IFACE) |
	    (cfi_read_qry(sc, CFI_QRY_IFACE + 1) << 8);

	/*
	 * Adding 1 to iface will give us a bit-wise "switch"
	 * that allows us to test for the interface width by
	 * testing a single bit.
	 */
	iface++;

	error = (iface & sc->sc_width) ? 0 : EINVAL;
	if (error)
		goto out;

	snprintf(desc, sizeof(desc), "%s - %s", vend_str,
	    cfi_fmtsize(sc->sc_size));
	device_set_desc_copy(dev, desc);

 out:
	bus_release_resource(dev, SYS_RES_MEMORY, sc->sc_rid, sc->sc_res);
	return (error);
}

int
cfi_attach(device_t dev) 
{
	struct cfi_softc *sc;
	u_int blksz, blocks;
	u_int r, u;

	sc = device_get_softc(dev);
	sc->sc_dev = dev;

	sc->sc_rid = 0;
	sc->sc_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &sc->sc_rid,
	    RF_ACTIVE);
	if (sc->sc_res == NULL)
		return (ENXIO);

	sc->sc_tag = rman_get_bustag(sc->sc_res);
	sc->sc_handle = rman_get_bushandle(sc->sc_res);

	/* Get time-out values for erase and write. */
	sc->sc_write_timeout = 1 << cfi_read_qry(sc, CFI_QRY_TTO_WRITE);
	sc->sc_erase_timeout = 1 << cfi_read_qry(sc, CFI_QRY_TTO_ERASE);
	sc->sc_write_timeout *= 1 << cfi_read_qry(sc, CFI_QRY_MTO_WRITE);
	sc->sc_erase_timeout *= 1 << cfi_read_qry(sc, CFI_QRY_MTO_ERASE);

	/* Get erase regions. */
	sc->sc_regions = cfi_read_qry(sc, CFI_QRY_NREGIONS);
	sc->sc_region = malloc(sc->sc_regions * sizeof(struct cfi_region),
	    M_TEMP, M_WAITOK | M_ZERO);
	for (r = 0; r < sc->sc_regions; r++) {
		blocks = cfi_read_qry(sc, CFI_QRY_REGION(r)) |
		    (cfi_read_qry(sc, CFI_QRY_REGION(r) + 1) << 8);
		sc->sc_region[r].r_blocks = blocks + 1;

		blksz = cfi_read_qry(sc, CFI_QRY_REGION(r) + 2) |
		    (cfi_read_qry(sc, CFI_QRY_REGION(r) + 3) << 8);
		sc->sc_region[r].r_blksz = (blksz == 0) ? 128 :
		    blksz * 256;
	}

	/* Reset the device to a default state. */
	cfi_write(sc, 0, CFI_BCS_CLEAR_STATUS);

	if (bootverbose) {
		device_printf(dev, "[");
		for (r = 0; r < sc->sc_regions; r++) {
			printf("%ux%s%s", sc->sc_region[r].r_blocks,
			    cfi_fmtsize(sc->sc_region[r].r_blksz),
			    (r == sc->sc_regions - 1) ? "]\n" : ",");
		}
	}

	u = device_get_unit(dev);
	sc->sc_nod = make_dev(&cfi_cdevsw, u, UID_ROOT, GID_WHEEL, 0600,
	    "%s%u", cfi_driver_name, u);
	sc->sc_nod->si_drv1 = sc;

	return (0);
}

int
cfi_detach(device_t dev)
{
	struct cfi_softc *sc;

	sc = device_get_softc(dev);

	destroy_dev(sc->sc_nod);
	free(sc->sc_region, M_TEMP);
	bus_release_resource(dev, SYS_RES_MEMORY, sc->sc_rid, sc->sc_res);
	return (0);
}

static int
cfi_wait_ready(struct cfi_softc *sc, u_int ofs, u_int timeout)
{
	int done, error;
	uint32_t st0 = 0, st = 0;

	done = 0;
	error = 0;
	timeout *= 10;
	while (!done && !error && timeout) {
		DELAY(100);
		timeout--;

		switch (sc->sc_cmdset) {
		case CFI_VEND_INTEL_ECS:
		case CFI_VEND_INTEL_SCS:
			st = cfi_read(sc, ofs);
			done = (st & CFI_INTEL_STATUS_WSMS);
			if (done) {
				/* NB: bit 0 is reserved */
				st &= ~(CFI_INTEL_XSTATUS_RSVD |
					CFI_INTEL_STATUS_WSMS |
					CFI_INTEL_STATUS_RSVD);
				if (st & CFI_INTEL_STATUS_DPS)
					error = EPERM;
				else if (st & CFI_INTEL_STATUS_PSLBS)
					error = EIO;
				else if (st & CFI_INTEL_STATUS_ECLBS)
					error = ENXIO;
				else if (st)
					error = EACCES;
			}
			break;
		case CFI_VEND_AMD_SCS:
		case CFI_VEND_AMD_ECS:
			st0 = cfi_read(sc, ofs);
			st = cfi_read(sc, ofs);
			done = ((st & 0x40) == (st0 & 0x40)) ? 1 : 0;
			break;
		}
	}
	if (!done && !error)
		error = ETIMEDOUT;
	if (error)
		printf("\nerror=%d (st 0x%x st0 0x%x)\n", error, st, st0);
	return (error);
}

int
cfi_write_block(struct cfi_softc *sc)
{
	union {
		uint8_t		*x8;
		uint16_t	*x16;
		uint32_t	*x32;
	} ptr;
	register_t intr;
	int error, i;

	/* Erase the block. */
	switch (sc->sc_cmdset) {
	case CFI_VEND_INTEL_ECS:
	case CFI_VEND_INTEL_SCS:
		cfi_write(sc, sc->sc_wrofs, CFI_BCS_BLOCK_ERASE);
		cfi_write(sc, sc->sc_wrofs, CFI_BCS_CONFIRM);
		break;
	case CFI_VEND_AMD_SCS:
	case CFI_VEND_AMD_ECS:
		cfi_amd_write(sc, sc->sc_wrofs, AMD_ADDR_START,
		    CFI_AMD_ERASE_SECTOR);
		cfi_amd_write(sc, sc->sc_wrofs, 0, CFI_AMD_BLOCK_ERASE);
		break;
	default:
		/* Better safe than sorry... */
		return (ENODEV);
	}
	error = cfi_wait_ready(sc, sc->sc_wrofs, sc->sc_erase_timeout);
	if (error)
		goto out;

	/* Write the block. */
	ptr.x8 = sc->sc_wrbuf;
	for (i = 0; i < sc->sc_wrbufsz; i += sc->sc_width) {

		/*
		 * Make sure the command to start a write and the
		 * actual write happens back-to-back without any
		 * excessive delays.
		 */
		intr = intr_disable();

		switch (sc->sc_cmdset) {
		case CFI_VEND_INTEL_ECS:
		case CFI_VEND_INTEL_SCS:
			cfi_write(sc, sc->sc_wrofs + i, CFI_BCS_PROGRAM);
			break;
		case CFI_VEND_AMD_SCS:
		case CFI_VEND_AMD_ECS:
			cfi_amd_write(sc, 0, AMD_ADDR_START, CFI_AMD_PROGRAM);
			break;
		}
		switch (sc->sc_width) {
		case 1:
			bus_space_write_1(sc->sc_tag, sc->sc_handle,
			    sc->sc_wrofs + i, *(ptr.x8)++);
			break;
		case 2:
			bus_space_write_2(sc->sc_tag, sc->sc_handle,
			    sc->sc_wrofs + i, *(ptr.x16)++);
			break;
		case 4:
			bus_space_write_4(sc->sc_tag, sc->sc_handle,
			    sc->sc_wrofs + i, *(ptr.x32)++);
			break;
		}

		intr_restore(intr);

		error = cfi_wait_ready(sc, sc->sc_wrofs, sc->sc_write_timeout);
		if (error)
			goto out;
	}

	/* error is 0. */

 out:
	cfi_write(sc, 0, CFI_BCS_READ_ARRAY);
	return (error);
}

#ifdef CFI_SUPPORT_STRATAFLASH
/*
 * Intel StrataFlash Protection Register Support.
 *
 * The memory includes a 128-bit Protection Register that can be
 * used for security.  There are two 64-bit segments; one is programmed
 * at the factory with a unique 64-bit number which is immutable.
 * The other segment is left blank for User (OEM) programming.
 * The User/OEM segment is One Time Programmable (OTP).  It can also
 * be locked to prevent any firther writes by setting bit 0 of the
 * Protection Lock Register (PLR).  The PLR can written only once.
 */

static uint16_t
cfi_get16(struct cfi_softc *sc, int off)
{
	uint16_t v = bus_space_read_2(sc->sc_tag, sc->sc_handle, off<<1);
	return v;
}

#ifdef CFI_ARMEDANDDANGEROUS
static void
cfi_put16(struct cfi_softc *sc, int off, uint16_t v)
{
	bus_space_write_2(sc->sc_tag, sc->sc_handle, off<<1, v);
}
#endif

/*
 * Read the factory-defined 64-bit segment of the PR.
 */
int 
cfi_intel_get_factory_pr(struct cfi_softc *sc, uint64_t *id)
{
	if (sc->sc_cmdset != CFI_VEND_INTEL_ECS)
		return EOPNOTSUPP;
	KASSERT(sc->sc_width == 2, ("sc_width %d", sc->sc_width));

	cfi_write(sc, 0, CFI_INTEL_READ_ID);
	*id = ((uint64_t)cfi_get16(sc, CFI_INTEL_PR(0)))<<48 |
	      ((uint64_t)cfi_get16(sc, CFI_INTEL_PR(1)))<<32 |
	      ((uint64_t)cfi_get16(sc, CFI_INTEL_PR(2)))<<16 |
	      ((uint64_t)cfi_get16(sc, CFI_INTEL_PR(3)));
	cfi_write(sc, 0, CFI_BCS_READ_ARRAY);
	return 0;
}

/*
 * Read the User/OEM 64-bit segment of the PR.
 */
int 
cfi_intel_get_oem_pr(struct cfi_softc *sc, uint64_t *id)
{
	if (sc->sc_cmdset != CFI_VEND_INTEL_ECS)
		return EOPNOTSUPP;
	KASSERT(sc->sc_width == 2, ("sc_width %d", sc->sc_width));

	cfi_write(sc, 0, CFI_INTEL_READ_ID);
	*id = ((uint64_t)cfi_get16(sc, CFI_INTEL_PR(4)))<<48 |
	      ((uint64_t)cfi_get16(sc, CFI_INTEL_PR(5)))<<32 |
	      ((uint64_t)cfi_get16(sc, CFI_INTEL_PR(6)))<<16 |
	      ((uint64_t)cfi_get16(sc, CFI_INTEL_PR(7)));
	cfi_write(sc, 0, CFI_BCS_READ_ARRAY);
	return 0;
}

/*
 * Write the User/OEM 64-bit segment of the PR.
 * XXX should allow writing individual words/bytes
 */
int
cfi_intel_set_oem_pr(struct cfi_softc *sc, uint64_t id)
{
#ifdef CFI_ARMEDANDDANGEROUS
	register_t intr;
	int i, error;
#endif

	if (sc->sc_cmdset != CFI_VEND_INTEL_ECS)
		return EOPNOTSUPP;
	KASSERT(sc->sc_width == 2, ("sc_width %d", sc->sc_width));

#ifdef CFI_ARMEDANDDANGEROUS
	for (i = 7; i >= 4; i--, id >>= 16) {
		intr = intr_disable();
		cfi_write(sc, 0, CFI_INTEL_PP_SETUP);
		cfi_put16(sc, CFI_INTEL_PR(i), id&0xffff);
		intr_restore(intr);
		error = cfi_wait_ready(sc, CFI_BCS_READ_STATUS,
		    sc->sc_write_timeout);
		if (error)
			break;
	}
	cfi_write(sc, 0, CFI_BCS_READ_ARRAY);
	return error;
#else
	device_printf(sc->sc_dev, "%s: OEM PR not set, "
	    "CFI_ARMEDANDDANGEROUS not configured\n", __func__);
	return ENXIO;
#endif
}

/*
 * Read the contents of the Protection Lock Register.
 */
int 
cfi_intel_get_plr(struct cfi_softc *sc, uint32_t *plr)
{
	if (sc->sc_cmdset != CFI_VEND_INTEL_ECS)
		return EOPNOTSUPP;
	KASSERT(sc->sc_width == 2, ("sc_width %d", sc->sc_width));

	cfi_write(sc, 0, CFI_INTEL_READ_ID);
	*plr = cfi_get16(sc, CFI_INTEL_PLR);
	cfi_write(sc, 0, CFI_BCS_READ_ARRAY);
	return 0;
}

/*
 * Write the Protection Lock Register to lock down the
 * user-settable segment of the Protection Register.
 * NOTE: this operation is not reversible.
 */
int 
cfi_intel_set_plr(struct cfi_softc *sc)
{
#ifdef CFI_ARMEDANDDANGEROUS
	register_t intr;
	int error;
#endif
	if (sc->sc_cmdset != CFI_VEND_INTEL_ECS)
		return EOPNOTSUPP;
	KASSERT(sc->sc_width == 2, ("sc_width %d", sc->sc_width));

#ifdef CFI_ARMEDANDDANGEROUS
	/* worthy of console msg */
	device_printf(sc->sc_dev, "set PLR\n");
	intr = intr_disable();
	cfi_write(sc, 0, CFI_INTEL_PP_SETUP);
	cfi_put16(sc, CFI_INTEL_PLR, 0xFFFD);
	intr_restore(intr);
	error = cfi_wait_ready(sc, CFI_BCS_READ_STATUS, sc->sc_write_timeout);
	cfi_write(sc, 0, CFI_BCS_READ_ARRAY);
	return error;
#else
	device_printf(sc->sc_dev, "%s: PLR not set, "
	    "CFI_ARMEDANDDANGEROUS not configured\n", __func__);
	return ENXIO;
#endif
}
#endif /* CFI_SUPPORT_STRATAFLASH */