C++ DoC_Delay函数代码示例

static int DoC_Command(struct DiskOnChip *doc, unsigned char command,
			      unsigned char xtraflags)
{
	void __iomem *docptr = doc->virtadr;

	if (DoC_is_2000(doc))
		xtraflags |= CDSN_CTRL_FLASH_IO;

	/* Assert the CLE (Command Latch Enable) line to the flash chip */
	WriteDOC(xtraflags | CDSN_CTRL_CLE | CDSN_CTRL_CE, docptr, CDSNControl);
	DoC_Delay(doc, 4);	/* Software requirement 11.4.3 for Millennium */

	if (DoC_is_Millennium(doc))
		WriteDOC(command, docptr, CDSNSlowIO);

	/* Send the command */
	WriteDOC_(command, docptr, doc->ioreg);
	if (DoC_is_Millennium(doc))
		WriteDOC(command, docptr, WritePipeTerm);

	/* Lower the CLE line */
	WriteDOC(xtraflags | CDSN_CTRL_CE, docptr, CDSNControl);
	DoC_Delay(doc, 4);	/* Software requirement 11.4.3 for Millennium */

	/* Wait for the chip to respond - Software requirement 11.4.1 (extended for any command) */
	return DoC_WaitReady(doc);
}

/* DoC_IdentChip: Identify a given NAND chip given {floor,chip} */
static int DoC_IdentChip(struct DiskOnChip *doc, int floor, int chip)
{
	int mfr, id, i, j;
	volatile char dummy;

	/* Page in the required floor/chip
	   FIXME: is this supported by Millennium ?? */
	DoC_SelectFloor(doc->virtadr, floor);
	DoC_SelectChip(doc->virtadr, chip);

	/* Reset the chip, see Software Requirement 11.4 item 1. */
	DoC_Command(doc->virtadr, NAND_CMD_RESET, CDSN_CTRL_WP);
	DoC_WaitReady(doc->virtadr);

	/* Read the NAND chip ID: 1. Send ReadID command */
	DoC_Command(doc->virtadr, NAND_CMD_READID, CDSN_CTRL_WP);

	/* Read the NAND chip ID: 2. Send address byte zero */
	DoC_Address(doc->virtadr, 1, 0x00, CDSN_CTRL_WP, 0x00);

	/* Read the manufacturer and device id codes of the flash device through
	   CDSN IO register see Software Requirement 11.4 item 5.*/
	dummy = ReadDOC(doc->virtadr, ReadPipeInit);
	DoC_Delay(doc->virtadr, 2);
	mfr = ReadDOC(doc->virtadr, Mil_CDSN_IO);

	DoC_Delay(doc->virtadr, 2);
	id  = ReadDOC(doc->virtadr, Mil_CDSN_IO);
	dummy = ReadDOC(doc->virtadr, LastDataRead);

	/* No response - return failure */
	if (mfr == 0xff || mfr == 0)
		return 0;

	/* FIXME: to deal with multi-flash on multi-Millennium case more carefully */
	for (i = 0; nand_flash_ids[i].name != NULL; i++) {
		if ( id == nand_flash_ids[i].id) {
			/* Try to identify manufacturer */
			for (j = 0; nand_manuf_ids[j].id != 0x0; j++) {
				if (nand_manuf_ids[j].id == mfr)
					break;
			}
			printk(KERN_INFO "Flash chip found: Manufacturer ID: %2.2X, "
			       "Chip ID: %2.2X (%s:%s)\n",
			       mfr, id, nand_manuf_ids[j].name, nand_flash_ids[i].name);
			doc->mfr = mfr;
			doc->id = id;
			doc->chipshift = ffs((nand_flash_ids[i].chipsize << 20)) - 1;
			break;
		}
	}

	if (nand_flash_ids[i].name == NULL)
		return 0;
	else
		return 1;
}

static void DoC_Command(void __iomem * docptr, unsigned char command,
			       unsigned char xtraflags)
{
	/* Assert the CLE (Command Latch Enable) line to the flash chip */
	WriteDOC(xtraflags | CDSN_CTRL_CLE | CDSN_CTRL_CE, docptr, CDSNControl);
	DoC_Delay(docptr, 4);

	/* Send the command */
	WriteDOC(command, docptr, Mil_CDSN_IO);
	WriteDOC(0x00, docptr, WritePipeTerm);

	/* Lower the CLE line */
	WriteDOC(xtraflags | CDSN_CTRL_CE, docptr, CDSNControl);
	DoC_Delay(docptr, 4);
}

static int DoC_Address(struct DiskOnChip *doc, int numbytes, unsigned long ofs,
		       unsigned char xtraflags1, unsigned char xtraflags2)
{
	int i;
	void __iomem *docptr = doc->virtadr;

	if (DoC_is_2000(doc))
		xtraflags1 |= CDSN_CTRL_FLASH_IO;

	/* Assert the ALE (Address Latch Enable) line to the flash chip */
	WriteDOC(xtraflags1 | CDSN_CTRL_ALE | CDSN_CTRL_CE, docptr, CDSNControl);

	DoC_Delay(doc, 4);	/* Software requirement 11.4.3 for Millennium */

	/* Send the address */
	/* Devices with 256-byte page are addressed as:
	   Column (bits 0-7), Page (bits 8-15, 16-23, 24-31)
	   * there is no device on the market with page256
	   and more than 24 bits.
	   Devices with 512-byte page are addressed as:
	   Column (bits 0-7), Page (bits 9-16, 17-24, 25-31)
	   * 25-31 is sent only if the chip support it.
	   * bit 8 changes the read command to be sent
	   (NAND_CMD_READ0 or NAND_CMD_READ1).
	 */

	if (numbytes == ADDR_COLUMN || numbytes == ADDR_COLUMN_PAGE) {
		if (DoC_is_Millennium(doc))
			WriteDOC(ofs & 0xff, docptr, CDSNSlowIO);
		WriteDOC_(ofs & 0xff, docptr, doc->ioreg);
	}

	if (doc->page256) {
		ofs = ofs >> 8;
	} else {

/* DoC_SelectChip: Select a given flash chip within the current floor */
static int DoC_SelectChip(void __iomem * docptr, int chip)
{
	/* Select the individual flash chip requested */
	WriteDOC(chip, docptr, CDSNDeviceSelect);
	DoC_Delay(docptr, 4);

	/* Wait for it to be ready */
	return DoC_WaitReady(docptr);
}

static inline int DoC_WaitReady(void __iomem * docptr)
{
	/* This is inline, to optimise the common case, where it's ready instantly */
	int ret = 0;

	/* 4 read form NOP register should be issued in prior to the read from CDSNControl
	   see Software Requirement 11.4 item 2. */
	DoC_Delay(docptr, 4);

	if (!(ReadDOC(docptr, CDSNControl) & CDSN_CTRL_FR_B))
		/* Call the out-of-line routine to wait */
		ret = _DoC_WaitReady(docptr);

	/* issue 2 read from NOP register after reading from CDSNControl register
	   see Software Requirement 11.4 item 2. */
	DoC_Delay(docptr, 2);

	return ret;
}

static inline void DoC_Address(void __iomem * docptr, int numbytes, unsigned long ofs,
			       unsigned char xtraflags1, unsigned char xtraflags2)
{
	/* Assert the ALE (Address Latch Enable) line to the flash chip */
	WriteDOC(xtraflags1 | CDSN_CTRL_ALE | CDSN_CTRL_CE, docptr, CDSNControl);
	DoC_Delay(docptr, 4);

	/* Send the address */
	switch (numbytes)
	    {
	    case 1:
		    /* Send single byte, bits 0-7. */
		    WriteDOC(ofs & 0xff, docptr, Mil_CDSN_IO);
		    WriteDOC(0x00, docptr, WritePipeTerm);
		    break;
	    case 2:
		    /* Send bits 9-16 followed by 17-23 */
		    WriteDOC((ofs >> 9)  & 0xff, docptr, Mil_CDSN_IO);
		    WriteDOC((ofs >> 17) & 0xff, docptr, Mil_CDSN_IO);
		    WriteDOC(0x00, docptr, WritePipeTerm);
		break;
	    case 3:
		    /* Send 0-7, 9-16, then 17-23 */
		    WriteDOC(ofs & 0xff, docptr, Mil_CDSN_IO);
		    WriteDOC((ofs >> 9)  & 0xff, docptr, Mil_CDSN_IO);
		    WriteDOC((ofs >> 17) & 0xff, docptr, Mil_CDSN_IO);
		    WriteDOC(0x00, docptr, WritePipeTerm);
		break;
	    default:
		return;
	    }

	/* Lower the ALE line */
	WriteDOC(xtraflags1 | xtraflags2 | CDSN_CTRL_CE, docptr, CDSNControl);
	DoC_Delay(docptr, 4);
}

static inline int DoC_WaitReady(unsigned long docptr)
{
	/* This is inline, to optimise the common case, where it's ready instantly */
	int ret = 0;

	/* read form NOP register should be issued prior to the read from CDSNControl
	   see Software Requirement 11.4 item 2. */
	DoC_Delay(docptr, 4);

	if ((ReadDOC(docptr, Mplus_FlashControl) & CDSN_CTRL_FR_B_MASK) != CDSN_CTRL_FR_B_MASK)
		/* Call the out-of-line routine to wait */
		ret = _DoC_WaitReady(docptr);

	return ret;
}

/* DOC_WaitReady: Wait for RDY line to be asserted by the flash chip */
static int _DoC_WaitReady(struct DiskOnChip *doc)
{
	void __iomem *docptr = doc->virtadr;
	unsigned long timeo = jiffies + (HZ * 10);

	pr_debug("_DoC_WaitReady called for out-of-line wait\n");

	/* Out-of-line routine to wait for chip response */
	while (!(ReadDOC(docptr, CDSNControl) & CDSN_CTRL_FR_B)) {
		/* issue 2 read from NOP register after reading from CDSNControl register
	   	see Software Requirement 11.4 item 2. */
		DoC_Delay(doc, 2);

		if (time_after(jiffies, timeo)) {
			pr_debug("_DoC_WaitReady timed out.\n");
			return -EIO;
		}
		udelay(1);
		cond_resched();
	}

	return 0;
}