nandsim.c

linux-2.6.15.6

{
	int i, num;
	int busdiv = ns->busw == 8 ? 1 : 2;

	action &= ACTION_MASK;

	/* Check that page address input is correct */
	if (action != ACTION_SECERASE && ns->regs.row >= ns->geom.pgnum) {
		NS_WARN("do_state_action: wrong page number (%#x)\n", ns->regs.row);
		return -1;
	}

	switch (action) {

	case ACTION_CPY:
		/*
		 * Copy page data to the internal buffer.
		 */

		/* Column shouldn't be very large */
		if (ns->regs.column >= (ns->geom.pgszoob - ns->regs.off)) {
			NS_ERR("do_state_action: column number is too large\n");
			break;
		}
		num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
		memcpy(ns->buf.byte, ns->mem.byte + NS_RAW_OFFSET(ns) + ns->regs.off, num);

		NS_DBG("do_state_action: (ACTION_CPY:) copy %d bytes to int buf, raw offset %d\n",
			num, NS_RAW_OFFSET(ns) + ns->regs.off);

		if (ns->regs.off == 0)
			NS_LOG("read page %d\n", ns->regs.row);
		else if (ns->regs.off < ns->geom.pgsz)
			NS_LOG("read page %d (second half)\n", ns->regs.row);
		else
			NS_LOG("read OOB of page %d\n", ns->regs.row);

		NS_UDELAY(access_delay);
		NS_UDELAY(input_cycle * ns->geom.pgsz / 1000 / busdiv);

		break;

	case ACTION_SECERASE:
		/*
		 * Erase sector.
		 */

		if (ns->lines.wp) {
			NS_ERR("do_state_action: device is write-protected, ignore sector erase\n");
			return -1;
		}

		if (ns->regs.row >= ns->geom.pgnum - ns->geom.pgsec
			|| (ns->regs.row & ~(ns->geom.secsz - 1))) {
			NS_ERR("do_state_action: wrong sector address (%#x)\n", ns->regs.row);
			return -1;
		}

		ns->regs.row = (ns->regs.row <<
				8 * (ns->geom.pgaddrbytes - ns->geom.secaddrbytes)) | ns->regs.column;
		ns->regs.column = 0;

		NS_DBG("do_state_action: erase sector at address %#x, off = %d\n",
				ns->regs.row, NS_RAW_OFFSET(ns));
		NS_LOG("erase sector %d\n", ns->regs.row >> (ns->geom.secshift - ns->geom.pgshift));

		memset(ns->mem.byte + NS_RAW_OFFSET(ns), 0xFF, ns->geom.secszoob);

		NS_MDELAY(erase_delay);

		break;

	case ACTION_PRGPAGE:
		/*
		 * Programm page - move internal buffer data to the page.
		 */

		if (ns->lines.wp) {
			NS_WARN("do_state_action: device is write-protected, programm\n");
			return -1;
		}

		num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
		if (num != ns->regs.count) {
			NS_ERR("do_state_action: too few bytes were input (%d instead of %d)\n",
					ns->regs.count, num);
			return -1;
		}

		for (i = 0; i < num; i++)
			ns->mem.byte[NS_RAW_OFFSET(ns) + ns->regs.off + i] &= ns->buf.byte[i];

		NS_DBG("do_state_action: copy %d bytes from int buf to (%#x, %#x), raw off = %d\n",
			num, ns->regs.row, ns->regs.column, NS_RAW_OFFSET(ns) + ns->regs.off);
		NS_LOG("programm page %d\n", ns->regs.row);

		NS_UDELAY(programm_delay);
		NS_UDELAY(output_cycle * ns->geom.pgsz / 1000 / busdiv);

		break;

	case ACTION_ZEROOFF:
		NS_DBG("do_state_action: set internal offset to 0\n");
		ns->regs.off = 0;
		break;

	case ACTION_HALFOFF:
		if (!(ns->options & OPT_PAGE512_8BIT)) {
			NS_ERR("do_state_action: BUG! can't skip half of page for non-512"
				"byte page size 8x chips\n");
			return -1;
		}
		NS_DBG("do_state_action: set internal offset to %d\n", ns->geom.pgsz/2);
		ns->regs.off = ns->geom.pgsz/2;
		break;

	case ACTION_OOBOFF:
		NS_DBG("do_state_action: set internal offset to %d\n", ns->geom.pgsz);
		ns->regs.off = ns->geom.pgsz;
		break;

	default:
		NS_DBG("do_state_action: BUG! unknown action\n");
	}

	return 0;
}

/*
 * Switch simulator's state.
 */
static void
switch_state(struct nandsim *ns)
{
	if (ns->op) {
		/*
		 * The current operation have already been identified.
		 * Just follow the states chain.
		 */

		ns->stateidx += 1;
		ns->state = ns->nxstate;
		ns->nxstate = ns->op[ns->stateidx + 1];

		NS_DBG("switch_state: operation is known, switch to the next state, "
			"state: %s, nxstate: %s\n",
			get_state_name(ns->state), get_state_name(ns->nxstate));

		/* See, whether we need to do some action */
		if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
			switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
			return;
		}

	} else {
		/*
		 * We don't yet know which operation we perform.
		 * Try to identify it.
		 */

		/*
		 *  The only event causing the switch_state function to
		 *  be called with yet unknown operation is new command.
		 */
		ns->state = get_state_by_command(ns->regs.command);

		NS_DBG("switch_state: operation is unknown, try to find it\n");

		if (find_operation(ns, 0) != 0)
			return;

		if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
			switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
			return;
		}
	}

	/* For 16x devices column means the page offset in words */
	if ((ns->nxstate & STATE_ADDR_MASK) && ns->busw == 16) {
		NS_DBG("switch_state: double the column number for 16x device\n");
		ns->regs.column <<= 1;
	}

	if (NS_STATE(ns->nxstate) == STATE_READY) {
		/*
		 * The current state is the last. Return to STATE_READY
		 */

		u_char status = NS_STATUS_OK(ns);

		/* In case of data states, see if all bytes were input/output */
		if ((ns->state & (STATE_DATAIN_MASK | STATE_DATAOUT_MASK))
			&& ns->regs.count != ns->regs.num) {
			NS_WARN("switch_state: not all bytes were processed, %d left\n",
					ns->regs.num - ns->regs.count);
			status = NS_STATUS_FAILED(ns);
		}

		NS_DBG("switch_state: operation complete, switch to STATE_READY state\n");

		switch_to_ready_state(ns, status);

		return;
	} else if (ns->nxstate & (STATE_DATAIN_MASK | STATE_DATAOUT_MASK)) {
		/*
		 * If the next state is data input/output, switch to it now
		 */

		ns->state      = ns->nxstate;
		ns->nxstate    = ns->op[++ns->stateidx + 1];
		ns->regs.num   = ns->regs.count = 0;

		NS_DBG("switch_state: the next state is data I/O, switch, "
			"state: %s, nxstate: %s\n",
			get_state_name(ns->state), get_state_name(ns->nxstate));

		/*
		 * Set the internal register to the count of bytes which
		 * are expected to be input or output
		 */
		switch (NS_STATE(ns->state)) {
			case STATE_DATAIN:
			case STATE_DATAOUT:
				ns->regs.num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
				break;

			case STATE_DATAOUT_ID:
				ns->regs.num = ns->geom.idbytes;
				break;

			case STATE_DATAOUT_STATUS:
			case STATE_DATAOUT_STATUS_M:
				ns->regs.count = ns->regs.num = 0;
				break;

			default:
				NS_ERR("switch_state: BUG! unknown data state\n");
		}

	} else if (ns->nxstate & STATE_ADDR_MASK) {
		/*
		 * If the next state is address input, set the internal
		 * register to the number of expected address bytes
		 */

		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:
				NS_ERR("switch_state: BUG! unknown address state\n");
		}
	} else {
		/*
		 * Just reset internal counters.
		 */

		ns->regs.num = 0;
		ns->regs.count = 0;
	}
}

static void
ns_hwcontrol(struct mtd_info *mtd, int cmd)
{
	struct nandsim *ns = (struct nandsim *)((struct nand_chip *)mtd->priv)->priv;

	switch (cmd) {

	/* set CLE line high */
	case NAND_CTL_SETCLE:
		NS_DBG("ns_hwcontrol: start command latch cycles\n");
		ns->lines.cle  = 1;
		break;

	/* set CLE line low */
	case NAND_CTL_CLRCLE:
		NS_DBG("ns_hwcontrol: stop command latch cycles\n");
		ns->lines.cle  = 0;
		break;

	/* set ALE line high */
	case NAND_CTL_SETALE:
		NS_DBG("ns_hwcontrol: start address latch cycles\n");
		ns->lines.ale   = 1;
		break;

	/* set ALE line low */
	case NAND_CTL_CLRALE:
		NS_DBG("ns_hwcontrol: stop address latch cycles\n");
		ns->lines.ale  = 0;
		break;

	/* set WP line high */
	case NAND_CTL_SETWP:
		NS_DBG("ns_hwcontrol: enable write protection\n");
		ns->lines.wp = 1;
		break;

	/* set WP line low */
	case NAND_CTL_CLRWP:
		NS_DBG("ns_hwcontrol: disable write protection\n");
		ns->lines.wp = 0;
		break;

	/* set CE line low */
	case NAND_CTL_SETNCE:
		NS_DBG("ns_hwcontrol: enable chip\n");
		ns->lines.ce = 1;
		break;

	/* set CE line high */
	case NAND_CTL_CLRNCE:
		NS_DBG("ns_hwcontrol: disable chip\n");
		ns->lines.ce = 0;
		break;

	default:
		NS_ERR("hwcontrol: unknown command\n");
        }

	return;
}

static u_char
ns_nand_read_byte(struct mtd_info *mtd)
{
        struct nandsim *ns = (struct nandsim *)((struct nand_chip *)mtd->priv)->priv;
	u_char outb = 0x00;

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

	/* Status register may be read as many times as it is wanted */
	if (NS_STATE(ns->state) == STATE_DATAOUT_STATUS) {
		NS_DBG("read_byte: return %#x status\n", ns->regs.status);
		return ns->regs.status;
	}

	/* Check if there is any data in the internal buffer which may be read */
	if (ns->regs.count == ns->regs.num) {
		NS_WARN("read_byte: no more data to output, return %#x\n", (uint)outb);
		return outb;
	}

	switch (NS_STATE(ns->state)) {
		case STATE_DATAOUT:
			if (ns->busw == 8) {
				outb = ns->buf.byte[ns->regs.count];
				ns->regs.count += 1;
			} else {
				outb = (u_char)cpu_to_le16(ns->buf.word[ns->regs.count >> 1]);
				ns->regs.count += 2;
			}
			break;
		case STATE_DATAOUT_ID:
			NS_DBG("read_byte: read ID byte %d, total = %d\n", ns->regs.count, ns->regs.num);
			outb = ns->ids[ns->regs.count];
			ns->regs.count += 1;
			break;
		default:
			BUG();
	}

	if (ns->regs.count == ns->regs.num) {
		NS_DBG("read_byte: all bytes were read\n");

		/*
		 * The OPT_AUTOINCR allows to read next conseqitive pages without
		 * new read operation cycle.
		 */
		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_byte: switch to the next page (%#x)\n", ns->regs.row);
			do_state_action(ns, ACTION_CPY);