nandsim.c

老版本的mtd-snap

			if (ns->regs.row + 1 < ns->geom.pgnum)
				ns->regs.row += 1;
			NS_DBG("read_byte: switch to the next page (%#x)\n", ns->regs.row);
			do_state_action(ns, ACTION_CPY);
		}
		else if (NS_STATE(ns->nxstate) == STATE_READY)
			switch_state(ns);
		
	}
	
	return outb;
}

static void
ns_nand_write_byte(struct mtd_info *mtd, u_char byte)
{
        struct nandsim *ns = (struct nandsim *)((struct nand_chip *)mtd->priv)->priv;
	
	/* Sanity and correctness checks */
	if (!ns->lines.ce) {
		NS_ERR("write_byte: chip is disabled, ignore write\n");
		return;
	}
	if (ns->lines.ale && ns->lines.cle) {
		NS_ERR("write_byte: ALE and CLE pins are high simultaneously, ignore write\n");
		return;
	}
			
	if (ns->lines.cle == 1) {
		/*
		 * The byte written is a command.
		 */

		if (byte == NAND_CMD_RESET) {
			NS_LOG("reset chip\n");
			switch_to_ready_state(ns, NS_STATUS_OK(ns));
			return;
		}

		/* 
		 * Chip might still be in STATE_DATAOUT
		 * (if OPT_AUTOINCR feature is supported), STATE_DATAOUT_STATUS or
		 * STATE_DATAOUT_STATUS_M state. If so, switch state.
		 */
		if (NS_STATE(ns->state) == STATE_DATAOUT_STATUS
			|| NS_STATE(ns->state) == STATE_DATAOUT_STATUS_M
			|| ((ns->options & OPT_AUTOINCR) && NS_STATE(ns->state) == STATE_DATAOUT))
			switch_state(ns);

		/* Check if chip is expecting command */
		if (NS_STATE(ns->nxstate) != STATE_UNKNOWN && !(ns->nxstate & STATE_CMD_MASK)) {
			/*
			 * We are in situation when something else (not command)
			 * was expected but command was input. In this case ignore
			 * previous command(s)/state(s) and accept the last one.
			 */
			NS_WARN("write_byte: command (%#x) wasn't expected, expected state is %s, "
				"ignore previous states\n", (uint)byte, get_state_name(ns->nxstate));
			switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
		}
		
		/* Check that the command byte is correct */
		if (check_command(byte)) {
			NS_ERR("write_byte: unknown command %#x\n", (uint)byte);
			return;
		}
		
		NS_DBG("command byte corresponding to %s state accepted\n",
			get_state_name(get_state_by_command(byte)));
		ns->regs.command = byte;
		switch_state(ns);

	} else if (ns->lines.ale == 1) {
		/*
		 * The byte written is an address.
		 */

		if (NS_STATE(ns->nxstate) == STATE_UNKNOWN) {

			NS_DBG("write_byte: operation isn't known yet, identify it\n");

			if (find_operation(ns, 1) < 0)
				return;
			
			if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
				switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
				return;
			}
				
			ns->regs.count = 0;
			switch (NS_STATE(ns->nxstate)) {
				case STATE_ADDR_PAGE:
					ns->regs.num = ns->geom.pgaddrbytes;
					break;
				case STATE_ADDR_SEC:
					ns->regs.num = ns->geom.secaddrbytes;
					break;
				case STATE_ADDR_ZERO:
					ns->regs.num = 1;
					break;
				default:
					BUG();
			}
		}

		/* Check that chip is expecting address */
		if (!(ns->nxstate & STATE_ADDR_MASK)) {
			NS_ERR("write_byte: address (%#x) isn't expected, expected state is %s, "
				"switch to STATE_READY\n", (uint)byte, get_state_name(ns->nxstate));
			switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
			return;
		}
		
		/* Check if this is expected byte */
		if (ns->regs.count == ns->regs.num) {
			NS_ERR("write_byte: no more address bytes expected\n");
			switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
			return;
		}

		accept_addr_byte(ns, byte);

		ns->regs.count += 1;

		NS_DBG("write_byte: address byte %#x was accepted (%d bytes input, %d expected)\n",
				(uint)byte, ns->regs.count, ns->regs.num);

		if (ns->regs.count == ns->regs.num) {
			NS_DBG("address (%#x, %#x) is accepted\n", ns->regs.row, ns->regs.column);
			switch_state(ns);
		}
		
	} else {
		/*
		 * The byte written is an input data.
		 */
		
		/* Check that chip is expecting data input */
		if (!(ns->state & STATE_DATAIN_MASK)) {
			NS_ERR("write_byte: data input (%#x) isn't expected, state is %s, "
				"switch to %s\n", (uint)byte,
				get_state_name(ns->state), get_state_name(STATE_READY));
			switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
			return;
		}

		/* Check if this is expected byte */
		if (ns->regs.count == ns->regs.num) {
			NS_WARN("write_byte: %u input bytes has already been accepted, ignore write\n",
					ns->regs.num);
			return;
		}

		if (ns->busw == 8) {
			ns->buf.byte[ns->regs.count] = byte;
			ns->regs.count += 1;
		} else {
			ns->buf.word[ns->regs.count >> 1] = cpu_to_le16((uint16_t)byte);
			ns->regs.count += 2;
		}
	}

	return;
}

static int
ns_device_ready(struct mtd_info *mtd)
{
	NS_DBG("device_ready\n");
	return 1;
}

static uint16_t
ns_nand_read_word(struct mtd_info *mtd)
{
	struct nand_chip *chip = (struct nand_chip *)mtd->priv;

	NS_DBG("read_word\n");
	
	return chip->read_byte(mtd) | (chip->read_byte(mtd) << 8);
}

static void
ns_nand_write_word(struct mtd_info *mtd, uint16_t word)
{
	struct nand_chip *chip = (struct nand_chip *)mtd->priv;
	
	NS_DBG("write_word\n");
	
	chip->write_byte(mtd, word & 0xFF);
	chip->write_byte(mtd, word >> 8);
}

static void 
ns_nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
{
        struct nandsim *ns = (struct nandsim *)((struct nand_chip *)mtd->priv)->priv;

	/* Check that chip is expecting data input */
	if (!(ns->state & STATE_DATAIN_MASK)) {
		NS_ERR("write_buf: data input isn't expected, state is %s, "
			"switch to STATE_READY\n", get_state_name(ns->state));
		switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
		return;
	}

	/* Check if these are expected bytes */
	if (ns->regs.count + len > ns->regs.num) {
		NS_ERR("write_buf: too many input bytes\n");
		switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
		return;
	}

	memcpy(ns->buf.byte + ns->regs.count, buf, len);
	ns->regs.count += len;
	
	if (ns->regs.count == ns->regs.num) {
		NS_DBG("write_buf: %d bytes were written\n", ns->regs.count);
	}
}

static void 
ns_nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
{
        struct nandsim *ns = (struct nandsim *)((struct nand_chip *)mtd->priv)->priv;

	/* Sanity and correctness checks */
	if (!ns->lines.ce) {
		NS_ERR("read_buf: chip is disabled\n");
		return;
	}
	if (ns->lines.ale || ns->lines.cle) {
		NS_ERR("read_buf: ALE or CLE pin is high\n");
		return;
	}
	if (!(ns->state & STATE_DATAOUT_MASK)) {
		NS_WARN("read_buf: unexpected data output cycle, current state is %s\n",
			get_state_name(ns->state));
		return;
	}

	if (NS_STATE(ns->state) != STATE_DATAOUT) {
		int i;

		for (i = 0; i < len; i++)
			buf[i] = ((struct nand_chip *)mtd->priv)->read_byte(mtd);

		return;
	}

	/* Check if these are expected bytes */
	if (ns->regs.count + len > ns->regs.num) {
		NS_ERR("read_buf: too many bytes to read\n");
		switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
		return;
	}

	memcpy(buf, ns->buf.byte + ns->regs.count, len);
	ns->regs.count += len;
	
	if (ns->regs.count == ns->regs.num) {
		if ((ns->options & OPT_AUTOINCR) && NS_STATE(ns->state) == STATE_DATAOUT) {
			ns->regs.count = 0;
			if (ns->regs.row + 1 < ns->geom.pgnum)
				ns->regs.row += 1;
			NS_DBG("read_buf: switch to the next page (%#x)\n", ns->regs.row);
			do_state_action(ns, ACTION_CPY);
		}
		else if (NS_STATE(ns->nxstate) == STATE_READY)
			switch_state(ns);
	}
	
	return;
}

static int 
ns_nand_verify_buf(struct mtd_info *mtd, const u_char *buf, int len)
{
	ns_nand_read_buf(mtd, (u_char *)&ns_verify_buf[0], len);

	if (!memcmp(buf, &ns_verify_buf[0], len)) {
		NS_DBG("verify_buf: the buffer is OK\n");
		return 0;
	} else {
		NS_DBG("verify_buf: the buffer is wrong\n");
		return -EFAULT;
	}
}

/*
 * Module initialization function
 */
int __init ns_init_module(void)
{
	struct nand_chip *chip;
	struct nandsim *nand;
	int retval = -ENOMEM;

	if (bus_width != 8 && bus_width != 16) {
		NS_ERR("wrong bus width (%d), use only 8 or 16\n", bus_width);
		return -EINVAL;
	}
	
	/* Allocate and initialize mtd_info, nand_chip and nandsim structures */
	nsmtd = kmalloc(sizeof(struct mtd_info) + sizeof(struct nand_chip)
				+ sizeof(struct nandsim), GFP_KERNEL);
	if (!nsmtd) {
		NS_ERR("unable to allocate core structures.\n");
		return -ENOMEM;
	}
	memset(nsmtd, 0, sizeof(struct mtd_info) + sizeof(struct nand_chip) +
			sizeof(struct nandsim));
	chip        = (struct nand_chip *)(nsmtd + 1);
        nsmtd->priv = (void *)chip;
	nand        = (struct nandsim *)(chip + 1);
	chip->priv  = (void *)nand;	

	/*
	 * Register simulator's callbacks.
	 */
	chip->hwcontrol  = ns_hwcontrol;
	chip->read_byte  = ns_nand_read_byte;
	chip->dev_ready  = ns_device_ready;
	chip->write_byte = ns_nand_write_byte;
	chip->write_buf  = ns_nand_write_buf;
	chip->read_buf   = ns_nand_read_buf;
	chip->verify_buf = ns_nand_verify_buf;
	chip->write_word = ns_nand_write_word;
	chip->read_word  = ns_nand_read_word;
	chip->eccmode    = NAND_ECC_SOFT;
	chip->options   |= NAND_SKIP_BBTSCAN;

	/* 
	 * Perform minimum nandsim structure initialization to handle
	 * the initial ID read command correctly 
	 */
	if (third_id_byte != 0xFF || fourth_id_byte != 0xFF)
		nand->geom.idbytes = 4;
	else
		nand->geom.idbytes = 2;
	nand->regs.status = NS_STATUS_OK(nand);
	nand->nxstate = STATE_UNKNOWN;
	nand->options |= OPT_PAGE256; /* temporary value */
	nand->ids[0] = first_id_byte;
	nand->ids[1] = second_id_byte;
	nand->ids[2] = third_id_byte;
	nand->ids[3] = fourth_id_byte;
	if (bus_width == 16) {
		nand->busw = 16;
		chip->options |= NAND_BUSWIDTH_16;
	}

	if ((retval = nand_scan(nsmtd, 1)) != 0) {
		NS_ERR("can't register NAND Simulator\n");
		if (retval > 0)
			retval = -ENXIO;
		goto error;
	}

	if ((retval = init_nandsim(nsmtd)) != 0) {
		NS_ERR("scan_bbt: can't initialize the nandsim structure\n");
		goto error;
	}
	
	if ((retval = nand_default_bbt(nsmtd)) != 0) {
		free_nandsim(nand);
		goto error;
	}

	/* Register NAND as one big partition */
	add_mtd_partitions(nsmtd, &nand->part, 1);

        return 0;

error:
	kfree(nsmtd);

	return retval;
}

module_init(ns_init_module);

/*
 * Module clean-up function
 */
static void __exit ns_cleanup_module(void)
{
	struct nandsim *ns = (struct nandsim *)(((struct nand_chip *)nsmtd->priv)->priv);

	free_nandsim(ns);    /* Free nandsim private resources */
	nand_release(nsmtd); /* Unregisterd drived */
	kfree(nsmtd);        /* Free other structures */
}

module_exit(ns_cleanup_module);

MODULE_LICENSE ("GPL");
MODULE_AUTHOR ("Artem B. Bityuckiy");
MODULE_DESCRIPTION ("The NAND flash simulator");