drivers/mtd/nand/bcm_umi_nand.c - third_party/linux - Git at Google

 /*****************************************************************************
 * Copyright 2004 - 2009 Broadcom Corporation.  All rights reserved.
 *
 * Unless you and Broadcom execute a separate written software license
 * agreement governing use of this software, this software is licensed to you
 * under the terms of the GNU General Public License version 2, available at
 * http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
 *
 * Notwithstanding the above, under no circumstances may you combine this
 * software in any way with any other Broadcom software provided under a
 * license other than the GPL, without Broadcom's express prior written
 * consent.
 *****************************************************************************/

 /* ---- Include Files ---------------------------------------------------- */
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/ioport.h>
 #include <linux/device.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/platform_device.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/nand.h>
 #include <linux/mtd/nand_ecc.h>
 #include <linux/mtd/partitions.h>

 #include <asm/mach-types.h>
 #include <asm/system.h>

 #include <mach/reg_nand.h>
 #include <mach/reg_umi.h>

 #include "nand_bcm_umi.h"

 #include <mach/memory_settings.h>

 #define USE_DMA 1
 #include <mach/dma.h>
 #include <linux/dma-mapping.h>
 #include <linux/completion.h>

 /* ---- External Variable Declarations ----------------------------------- */
 /* ---- External Function Prototypes ------------------------------------- */
 /* ---- Public Variables ------------------------------------------------- */
 /* ---- Private Constants and Types -------------------------------------- */
 static const __devinitconst char gBanner[] = KERN_INFO \
 	"BCM UMI MTD NAND Driver: 1.00\n";

 #ifdef CONFIG_MTD_PARTITIONS
 const char *part_probes[] = { "cmdlinepart", NULL };
 #endif

 #if NAND_ECC_BCH
 static uint8_t scan_ff_pattern[] = { 0xff };

 static struct nand_bbt_descr largepage_bbt = {
 	.options = 0,
 	.offs = 0,
 	.len = 1,
 	.pattern = scan_ff_pattern
 };
 #endif

 /*
 ** Preallocate a buffer to avoid having to do this every dma operation.
 ** This is the size of the preallocated coherent DMA buffer.
 */
 #if USE_DMA
 #define DMA_MIN_BUFLEN	512
 #define DMA_MAX_BUFLEN	PAGE_SIZE
 #define USE_DIRECT_IO(len)	(((len) < DMA_MIN_BUFLEN) || \
 	((len) > DMA_MAX_BUFLEN))

 /*
  * The current NAND data space goes from 0x80001900 to 0x80001FFF,
  * which is only 0x700 = 1792 bytes long. This is too small for 2K, 4K page
  * size NAND flash. Need to break the DMA down to multiple 1Ks.
  *
  * Need to make sure REG_NAND_DATA_PADDR + DMA_MAX_LEN < 0x80002000
  */
 #define DMA_MAX_LEN             1024

 #else /* !USE_DMA */
 #define DMA_MIN_BUFLEN          0
 #define DMA_MAX_BUFLEN          0
 #define USE_DIRECT_IO(len)      1
 #endif
 /* ---- Private Function Prototypes -------------------------------------- */
 static void bcm_umi_nand_read_buf(struct mtd_info *mtd, u_char * buf, int len);
 static void bcm_umi_nand_write_buf(struct mtd_info *mtd, const u_char * buf,
 				   int len);

 /* ---- Private Variables ------------------------------------------------ */
 static struct mtd_info *board_mtd;
 static void __iomem *bcm_umi_io_base;
 static void *virtPtr;
 static dma_addr_t physPtr;
 static struct completion nand_comp;

 /* ---- Private Functions ------------------------------------------------ */
 #if NAND_ECC_BCH
 #include "bcm_umi_bch.c"
 #else
 #include "bcm_umi_hamming.c"
 #endif

 #if USE_DMA

 /* Handler called when the DMA finishes. */
 static void nand_dma_handler(DMA_Device_t dev, int reason, void *userData)
 {
 	complete(&nand_comp);
 }

 static int nand_dma_init(void)
 {
 	int rc;

 	rc = dma_set_device_handler(DMA_DEVICE_NAND_MEM_TO_MEM,
 		nand_dma_handler, NULL);
 	if (rc != 0) {
 		printk(KERN_ERR "dma_set_device_handler failed: %d\n", rc);
 		return rc;
 	}

 	virtPtr =
 	    dma_alloc_coherent(NULL, DMA_MAX_BUFLEN, &physPtr, GFP_KERNEL);
 	if (virtPtr == NULL) {
 		printk(KERN_ERR "NAND - Failed to allocate memory for DMA buffer\n");
 		return -ENOMEM;
 	}

 	return 0;
 }

 static void nand_dma_term(void)
 {
 	if (virtPtr != NULL)
 		dma_free_coherent(NULL, DMA_MAX_BUFLEN, virtPtr, physPtr);
 }

 static void nand_dma_read(void *buf, int len)
 {
 	int offset = 0;
 	int tmp_len = 0;
 	int len_left = len;
 	DMA_Handle_t hndl;

 	if (virtPtr == NULL)
 		panic("nand_dma_read: virtPtr == NULL\n");

 	if ((void *)physPtr == NULL)
 		panic("nand_dma_read: physPtr == NULL\n");

 	hndl = dma_request_channel(DMA_DEVICE_NAND_MEM_TO_MEM);
 	if (hndl < 0) {
 		printk(KERN_ERR
 		       "nand_dma_read: unable to allocate dma channel: %d\n",
 		       (int)hndl);
 		panic("\n");
 	}

 	while (len_left > 0) {
 		if (len_left > DMA_MAX_LEN) {
 			tmp_len = DMA_MAX_LEN;
 			len_left -= DMA_MAX_LEN;
 		} else {
 			tmp_len = len_left;
 			len_left = 0;
 		}

 		init_completion(&nand_comp);
 		dma_transfer_mem_to_mem(hndl, REG_NAND_DATA_PADDR,
 					physPtr + offset, tmp_len);
 		wait_for_completion(&nand_comp);

 		offset += tmp_len;
 	}

 	dma_free_channel(hndl);

 	if (buf != NULL)
 		memcpy(buf, virtPtr, len);
 }

 static void nand_dma_write(const void *buf, int len)
 {
 	int offset = 0;
 	int tmp_len = 0;
 	int len_left = len;
 	DMA_Handle_t hndl;

 	if (buf == NULL)
 		panic("nand_dma_write: buf == NULL\n");

 	if (virtPtr == NULL)
 		panic("nand_dma_write: virtPtr == NULL\n");

 	if ((void *)physPtr == NULL)
 		panic("nand_dma_write: physPtr == NULL\n");

 	memcpy(virtPtr, buf, len);


 	hndl = dma_request_channel(DMA_DEVICE_NAND_MEM_TO_MEM);
 	if (hndl < 0) {
 		printk(KERN_ERR
 		       "nand_dma_write: unable to allocate dma channel: %d\n",
 		       (int)hndl);
 		panic("\n");
 	}

 	while (len_left > 0) {
 		if (len_left > DMA_MAX_LEN) {
 			tmp_len = DMA_MAX_LEN;
 			len_left -= DMA_MAX_LEN;
 		} else {
 			tmp_len = len_left;
 			len_left = 0;
 		}

 		init_completion(&nand_comp);
 		dma_transfer_mem_to_mem(hndl, physPtr + offset,
 					REG_NAND_DATA_PADDR, tmp_len);
 		wait_for_completion(&nand_comp);

 		offset += tmp_len;
 	}

 	dma_free_channel(hndl);
 }

 #endif

 static int nand_dev_ready(struct mtd_info *mtd)
 {
 	return nand_bcm_umi_dev_ready();
 }

 /****************************************************************************
 *
 *  bcm_umi_nand_inithw
 *
 *   This routine does the necessary hardware (board-specific)
 *   initializations.  This includes setting up the timings, etc.
 *
 ***************************************************************************/
 int bcm_umi_nand_inithw(void)
 {
 	/* Configure nand timing parameters */
 	REG_UMI_NAND_TCR &= ~0x7ffff;
 	REG_UMI_NAND_TCR |= HW_CFG_NAND_TCR;

 #if !defined(CONFIG_MTD_NAND_BCM_UMI_HWCS)
 	/* enable software control of CS */
 	REG_UMI_NAND_TCR |= REG_UMI_NAND_TCR_CS_SWCTRL;
 #endif

 	/* keep NAND chip select asserted */
 	REG_UMI_NAND_RCSR |= REG_UMI_NAND_RCSR_CS_ASSERTED;

 	REG_UMI_NAND_TCR &= ~REG_UMI_NAND_TCR_WORD16;
 	/* enable writes to flash */
 	REG_UMI_MMD_ICR |= REG_UMI_MMD_ICR_FLASH_WP;

 	writel(NAND_CMD_RESET, bcm_umi_io_base + REG_NAND_CMD_OFFSET);
 	nand_bcm_umi_wait_till_ready();

 #if NAND_ECC_BCH
 	nand_bcm_umi_bch_config_ecc(NAND_ECC_NUM_BYTES);
 #endif

 	return 0;
 }

 /* Used to turn latch the proper register for access. */
 static void bcm_umi_nand_hwcontrol(struct mtd_info *mtd, int cmd,
 				   unsigned int ctrl)
 {
 	/* send command to hardware */
 	struct nand_chip *chip = mtd->priv;
 	if (ctrl & NAND_CTRL_CHANGE) {
 		if (ctrl & NAND_CLE) {
 			chip->IO_ADDR_W = bcm_umi_io_base + REG_NAND_CMD_OFFSET;
 			goto CMD;
 		}
 		if (ctrl & NAND_ALE) {
 			chip->IO_ADDR_W =
 			    bcm_umi_io_base + REG_NAND_ADDR_OFFSET;
 			goto CMD;
 		}
 		chip->IO_ADDR_W = bcm_umi_io_base + REG_NAND_DATA8_OFFSET;
 	}

 CMD:
 	/* Send command to chip directly */
 	if (cmd != NAND_CMD_NONE)
 		writeb(cmd, chip->IO_ADDR_W);
 }

 static void bcm_umi_nand_write_buf(struct mtd_info *mtd, const u_char * buf,
 				   int len)
 {
 	if (USE_DIRECT_IO(len)) {
 		/* Do it the old way if the buffer is small or too large.
 		 * Probably quicker than starting and checking dma. */
 		int i;
 		struct nand_chip *this = mtd->priv;

 		for (i = 0; i < len; i++)
 			writeb(buf[i], this->IO_ADDR_W);
 	}
 #if USE_DMA
 	else
 		nand_dma_write(buf, len);
 #endif
 }

 static void bcm_umi_nand_read_buf(struct mtd_info *mtd, u_char * buf, int len)
 {
 	if (USE_DIRECT_IO(len)) {
 		int i;
 		struct nand_chip *this = mtd->priv;

 		for (i = 0; i < len; i++)
 			buf[i] = readb(this->IO_ADDR_R);
 	}
 #if USE_DMA
 	else
 		nand_dma_read(buf, len);
 #endif
 }

 static uint8_t readbackbuf[NAND_MAX_PAGESIZE];
 static int bcm_umi_nand_verify_buf(struct mtd_info *mtd, const u_char * buf,
 				   int len)
 {
 	/*
 	 * Try to readback page with ECC correction. This is necessary
 	 * for MLC parts which may have permanently stuck bits.
 	 */
 	struct nand_chip *chip = mtd->priv;
 	int ret = chip->ecc.read_page(mtd, chip, readbackbuf, 0);
 	if (ret < 0)
 		return -EFAULT;
 	else {
 		if (memcmp(readbackbuf, buf, len) == 0)
 			return 0;

 		return -EFAULT;
 	}
 	return 0;
 }

 static int __devinit bcm_umi_nand_probe(struct platform_device *pdev)
 {
 	struct nand_chip *this;
 	struct resource *r;
 	int err = 0;

 	printk(gBanner);

 	/* Allocate memory for MTD device structure and private data */
 	board_mtd =
 	    kmalloc(sizeof(struct mtd_info) + sizeof(struct nand_chip),
 		    GFP_KERNEL);
 	if (!board_mtd) {
 		printk(KERN_WARNING
 		       "Unable to allocate NAND MTD device structure.\n");
 		return -ENOMEM;
 	}

 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);

 	if (!r)
 		return -ENXIO;

 	/* map physical address */
 	bcm_umi_io_base = ioremap(r->start, r->end - r->start + 1);

 	if (!bcm_umi_io_base) {
 		printk(KERN_ERR "ioremap to access BCM UMI NAND chip failed\n");
 		kfree(board_mtd);
 		return -EIO;
 	}

 	/* Get pointer to private data */
 	this = (struct nand_chip *)(&board_mtd[1]);

 	/* Initialize structures */
 	memset((char *)board_mtd, 0, sizeof(struct mtd_info));
 	memset((char *)this, 0, sizeof(struct nand_chip));

 	/* Link the private data with the MTD structure */
 	board_mtd->priv = this;

 	/* Initialize the NAND hardware.  */
 	if (bcm_umi_nand_inithw() < 0) {
 		printk(KERN_ERR "BCM UMI NAND chip could not be initialized\n");
 		iounmap(bcm_umi_io_base);
 		kfree(board_mtd);
 		return -EIO;
 	}

 	/* Set address of NAND IO lines */
 	this->IO_ADDR_W = bcm_umi_io_base + REG_NAND_DATA8_OFFSET;
 	this->IO_ADDR_R = bcm_umi_io_base + REG_NAND_DATA8_OFFSET;

 	/* Set command delay time, see datasheet for correct value */
 	this->chip_delay = 0;
 	/* Assign the device ready function, if available */
 	this->dev_ready = nand_dev_ready;
 	this->options = 0;

 	this->write_buf = bcm_umi_nand_write_buf;
 	this->read_buf = bcm_umi_nand_read_buf;
 	this->verify_buf = bcm_umi_nand_verify_buf;

 	this->cmd_ctrl = bcm_umi_nand_hwcontrol;
 	this->ecc.mode = NAND_ECC_HW;
 	this->ecc.size = 512;
 	this->ecc.bytes = NAND_ECC_NUM_BYTES;
 #if NAND_ECC_BCH
 	this->ecc.read_page = bcm_umi_bch_read_page_hwecc;
 	this->ecc.write_page = bcm_umi_bch_write_page_hwecc;
 #else
 	this->ecc.correct = nand_correct_data512;
 	this->ecc.calculate = bcm_umi_hamming_get_hw_ecc;
 	this->ecc.hwctl = bcm_umi_hamming_enable_hwecc;
 #endif

 #if USE_DMA
 	err = nand_dma_init();
 	if (err != 0)
 		return err;
 #endif

 	/* Figure out the size of the device that we have.
 	 * We need to do this to figure out which ECC
 	 * layout we'll be using.
 	 */

 	err = nand_scan_ident(board_mtd, 1, NULL);
 	if (err) {
 		printk(KERN_ERR "nand_scan failed: %d\n", err);
 		iounmap(bcm_umi_io_base);
 		kfree(board_mtd);
 		return err;
 	}

 	/* Now that we know the nand size, we can setup the ECC layout */

 	switch (board_mtd->writesize) {	/* writesize is the pagesize */
 	case 4096:
 		this->ecc.layout = &nand_hw_eccoob_4096;
 		break;
 	case 2048:
 		this->ecc.layout = &nand_hw_eccoob_2048;
 		break;
 	case 512:
 		this->ecc.layout = &nand_hw_eccoob_512;
 		break;
 	default:
 		{
 			printk(KERN_ERR "NAND - Unrecognized pagesize: %d\n",
 					 board_mtd->writesize);
 			return -EINVAL;
 		}
 	}

 #if NAND_ECC_BCH
 	if (board_mtd->writesize > 512) {
 		if (this->options & NAND_USE_FLASH_BBT)
 			largepage_bbt.options = NAND_BBT_SCAN2NDPAGE;
 		this->badblock_pattern = &largepage_bbt;
 	}
 #endif

 	/* Now finish off the scan, now that ecc.layout has been initialized. */

 	err = nand_scan_tail(board_mtd);
 	if (err) {
 		printk(KERN_ERR "nand_scan failed: %d\n", err);
 		iounmap(bcm_umi_io_base);
 		kfree(board_mtd);
 		return err;
 	}

 	/* Register the partitions */
 	{
 		int nr_partitions;
 		struct mtd_partition *partition_info;

 		board_mtd->name = "bcm_umi-nand";
 		nr_partitions =
 		    parse_mtd_partitions(board_mtd, part_probes,
 					 &partition_info, 0);

 		if (nr_partitions <= 0) {
 			printk(KERN_ERR "BCM UMI NAND: Too few partitions - %d\n",
 			       nr_partitions);
 			iounmap(bcm_umi_io_base);
 			kfree(board_mtd);
 			return -EIO;
 		}
 		add_mtd_partitions(board_mtd, partition_info, nr_partitions);
 	}

 	/* Return happy */
 	return 0;
 }

 static int bcm_umi_nand_remove(struct platform_device *pdev)
 {
 #if USE_DMA
 	nand_dma_term();
 #endif

 	/* Release resources, unregister device */
 	nand_release(board_mtd);

 	/* unmap physical address */
 	iounmap(bcm_umi_io_base);

 	/* Free the MTD device structure */
 	kfree(board_mtd);

 	return 0;
 }

 #ifdef CONFIG_PM
 static int bcm_umi_nand_suspend(struct platform_device *pdev,
 				pm_message_t state)
 {
 	printk(KERN_ERR "MTD NAND suspend is being called\n");
 	return 0;
 }

 static int bcm_umi_nand_resume(struct platform_device *pdev)
 {
 	printk(KERN_ERR "MTD NAND resume is being called\n");
 	return 0;
 }
 #else
 #define bcm_umi_nand_suspend   NULL
 #define bcm_umi_nand_resume    NULL
 #endif

 static struct platform_driver nand_driver = {
 	.driver = {
 		   .name = "bcm-nand",
 		   .owner = THIS_MODULE,
 		   },
 	.probe = bcm_umi_nand_probe,
 	.remove = bcm_umi_nand_remove,
 	.suspend = bcm_umi_nand_suspend,
 	.resume = bcm_umi_nand_resume,
 };

 static int __init nand_init(void)
 {
 	return platform_driver_register(&nand_driver);
 }

 static void __exit nand_exit(void)
 {
 	platform_driver_unregister(&nand_driver);
 }

 module_init(nand_init);
 module_exit(nand_exit);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Broadcom");
 MODULE_DESCRIPTION("BCM UMI MTD NAND driver");
	/*****************************************************************************
	* Copyright 2004 - 2009 Broadcom Corporation. All rights reserved.
	*
	* Unless you and Broadcom execute a separate written software license
	* agreement governing use of this software, this software is licensed to you
	* under the terms of the GNU General Public License version 2, available at
	* http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
	*
	* Notwithstanding the above, under no circumstances may you combine this
	* software in any way with any other Broadcom software provided under a
	* license other than the GPL, without Broadcom's express prior written
	* consent.
	*****************************************************************************/

	/* ---- Include Files ---------------------------------------------------- */
	#include <linux/module.h>
	#include <linux/types.h>
	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/slab.h>
	#include <linux/string.h>
	#include <linux/ioport.h>
	#include <linux/device.h>
	#include <linux/delay.h>
	#include <linux/err.h>
	#include <linux/io.h>
	#include <linux/platform_device.h>
	#include <linux/mtd/mtd.h>
	#include <linux/mtd/nand.h>
	#include <linux/mtd/nand_ecc.h>
	#include <linux/mtd/partitions.h>

	#include <asm/mach-types.h>
	#include <asm/system.h>

	#include <mach/reg_nand.h>
	#include <mach/reg_umi.h>

	#include "nand_bcm_umi.h"

	#include <mach/memory_settings.h>

	#define USE_DMA 1
	#include <mach/dma.h>
	#include <linux/dma-mapping.h>
	#include <linux/completion.h>

	/* ---- External Variable Declarations ----------------------------------- */
	/* ---- External Function Prototypes ------------------------------------- */
	/* ---- Public Variables ------------------------------------------------- */
	/* ---- Private Constants and Types -------------------------------------- */
	static const __devinitconst char gBanner[] = KERN_INFO \
	"BCM UMI MTD NAND Driver: 1.00\n";

	#ifdef CONFIG_MTD_PARTITIONS
	const char *part_probes[] = { "cmdlinepart", NULL };
	#endif

	#if NAND_ECC_BCH
	static uint8_t scan_ff_pattern[] = { 0xff };

	static struct nand_bbt_descr largepage_bbt = {
	.options = 0,
	.offs = 0,
	.len = 1,
	.pattern = scan_ff_pattern
	};
	#endif

	/*
	** Preallocate a buffer to avoid having to do this every dma operation.
	** This is the size of the preallocated coherent DMA buffer.
	*/
	#if USE_DMA
	#define DMA_MIN_BUFLEN 512
	#define DMA_MAX_BUFLEN PAGE_SIZE
	#define USE_DIRECT_IO(len) (((len) < DMA_MIN_BUFLEN) \|\| \
	((len) > DMA_MAX_BUFLEN))

	/*
	* The current NAND data space goes from 0x80001900 to 0x80001FFF,
	* which is only 0x700 = 1792 bytes long. This is too small for 2K, 4K page
	* size NAND flash. Need to break the DMA down to multiple 1Ks.
	*
	* Need to make sure REG_NAND_DATA_PADDR + DMA_MAX_LEN < 0x80002000
	*/
	#define DMA_MAX_LEN 1024

	#else /* !USE_DMA */
	#define DMA_MIN_BUFLEN 0
	#define DMA_MAX_BUFLEN 0
	#define USE_DIRECT_IO(len) 1
	#endif
	/* ---- Private Function Prototypes -------------------------------------- */
	static void bcm_umi_nand_read_buf(struct mtd_info mtd, u_char buf, int len);
	static void bcm_umi_nand_write_buf(struct mtd_info mtd, const u_char buf,
	int len);

	/* ---- Private Variables ------------------------------------------------ */
	static struct mtd_info *board_mtd;
	static void __iomem *bcm_umi_io_base;
	static void *virtPtr;
	static dma_addr_t physPtr;
	static struct completion nand_comp;

	/* ---- Private Functions ------------------------------------------------ */
	#if NAND_ECC_BCH
	#include "bcm_umi_bch.c"
	#else
	#include "bcm_umi_hamming.c"
	#endif

	#if USE_DMA

	/* Handler called when the DMA finishes. */
	static void nand_dma_handler(DMA_Device_t dev, int reason, void *userData)
	{
	complete(&nand_comp);
	}

	static int nand_dma_init(void)
	{
	int rc;

	rc = dma_set_device_handler(DMA_DEVICE_NAND_MEM_TO_MEM,
	nand_dma_handler, NULL);
	if (rc != 0) {
	printk(KERN_ERR "dma_set_device_handler failed: %d\n", rc);
	return rc;
	}

	virtPtr =
	dma_alloc_coherent(NULL, DMA_MAX_BUFLEN, &physPtr, GFP_KERNEL);
	if (virtPtr == NULL) {
	printk(KERN_ERR "NAND - Failed to allocate memory for DMA buffer\n");
	return -ENOMEM;
	}

	return 0;
	}

	static void nand_dma_term(void)
	{
	if (virtPtr != NULL)
	dma_free_coherent(NULL, DMA_MAX_BUFLEN, virtPtr, physPtr);
	}

	static void nand_dma_read(void *buf, int len)
	{
	int offset = 0;
	int tmp_len = 0;
	int len_left = len;
	DMA_Handle_t hndl;

	if (virtPtr == NULL)
	panic("nand_dma_read: virtPtr == NULL\n");

	if ((void *)physPtr == NULL)
	panic("nand_dma_read: physPtr == NULL\n");

	hndl = dma_request_channel(DMA_DEVICE_NAND_MEM_TO_MEM);
	if (hndl < 0) {
	printk(KERN_ERR
	"nand_dma_read: unable to allocate dma channel: %d\n",
	(int)hndl);
	panic("\n");
	}

	while (len_left > 0) {
	if (len_left > DMA_MAX_LEN) {
	tmp_len = DMA_MAX_LEN;
	len_left -= DMA_MAX_LEN;
	} else {
	tmp_len = len_left;
	len_left = 0;
	}

	init_completion(&nand_comp);
	dma_transfer_mem_to_mem(hndl, REG_NAND_DATA_PADDR,
	physPtr + offset, tmp_len);
	wait_for_completion(&nand_comp);

	offset += tmp_len;
	}

	dma_free_channel(hndl);

	if (buf != NULL)
	memcpy(buf, virtPtr, len);
	}

	static void nand_dma_write(const void *buf, int len)
	{
	int offset = 0;
	int tmp_len = 0;
	int len_left = len;
	DMA_Handle_t hndl;

	if (buf == NULL)
	panic("nand_dma_write: buf == NULL\n");

	if (virtPtr == NULL)
	panic("nand_dma_write: virtPtr == NULL\n");

	if ((void *)physPtr == NULL)
	panic("nand_dma_write: physPtr == NULL\n");

	memcpy(virtPtr, buf, len);


	hndl = dma_request_channel(DMA_DEVICE_NAND_MEM_TO_MEM);
	if (hndl < 0) {
	printk(KERN_ERR
	"nand_dma_write: unable to allocate dma channel: %d\n",
	(int)hndl);
	panic("\n");
	}

	while (len_left > 0) {
	if (len_left > DMA_MAX_LEN) {
	tmp_len = DMA_MAX_LEN;
	len_left -= DMA_MAX_LEN;
	} else {
	tmp_len = len_left;
	len_left = 0;
	}

	init_completion(&nand_comp);
	dma_transfer_mem_to_mem(hndl, physPtr + offset,
	REG_NAND_DATA_PADDR, tmp_len);
	wait_for_completion(&nand_comp);

	offset += tmp_len;
	}

	dma_free_channel(hndl);
	}

	#endif

	static int nand_dev_ready(struct mtd_info *mtd)
	{
	return nand_bcm_umi_dev_ready();
	}

	/****************************************************************************
	*
	* bcm_umi_nand_inithw
	*
	* This routine does the necessary hardware (board-specific)
	* initializations. This includes setting up the timings, etc.
	*
	***************************************************************************/
	int bcm_umi_nand_inithw(void)
	{
	/* Configure nand timing parameters */
	REG_UMI_NAND_TCR &= ~0x7ffff;
	REG_UMI_NAND_TCR \|= HW_CFG_NAND_TCR;

	#if !defined(CONFIG_MTD_NAND_BCM_UMI_HWCS)
	/* enable software control of CS */
	REG_UMI_NAND_TCR \|= REG_UMI_NAND_TCR_CS_SWCTRL;
	#endif

	/* keep NAND chip select asserted */
	REG_UMI_NAND_RCSR \|= REG_UMI_NAND_RCSR_CS_ASSERTED;

	REG_UMI_NAND_TCR &= ~REG_UMI_NAND_TCR_WORD16;
	/* enable writes to flash */
	REG_UMI_MMD_ICR \|= REG_UMI_MMD_ICR_FLASH_WP;

	writel(NAND_CMD_RESET, bcm_umi_io_base + REG_NAND_CMD_OFFSET);
	nand_bcm_umi_wait_till_ready();

	#if NAND_ECC_BCH
	nand_bcm_umi_bch_config_ecc(NAND_ECC_NUM_BYTES);
	#endif

	return 0;
	}

	/* Used to turn latch the proper register for access. */
	static void bcm_umi_nand_hwcontrol(struct mtd_info *mtd, int cmd,
	unsigned int ctrl)
	{
	/* send command to hardware */
	struct nand_chip *chip = mtd->priv;
	if (ctrl & NAND_CTRL_CHANGE) {
	if (ctrl & NAND_CLE) {
	chip->IO_ADDR_W = bcm_umi_io_base + REG_NAND_CMD_OFFSET;
	goto CMD;
	}
	if (ctrl & NAND_ALE) {
	chip->IO_ADDR_W =
	bcm_umi_io_base + REG_NAND_ADDR_OFFSET;
	goto CMD;
	}
	chip->IO_ADDR_W = bcm_umi_io_base + REG_NAND_DATA8_OFFSET;
	}

	CMD:
	/* Send command to chip directly */
	if (cmd != NAND_CMD_NONE)
	writeb(cmd, chip->IO_ADDR_W);
	}

	static void bcm_umi_nand_write_buf(struct mtd_info mtd, const u_char buf,
	int len)
	{
	if (USE_DIRECT_IO(len)) {
	/* Do it the old way if the buffer is small or too large.
	* Probably quicker than starting and checking dma. */
	int i;
	struct nand_chip *this = mtd->priv;

	for (i = 0; i < len; i++)
	writeb(buf[i], this->IO_ADDR_W);
	}
	#if USE_DMA
	else
	nand_dma_write(buf, len);
	#endif
	}

	static void bcm_umi_nand_read_buf(struct mtd_info mtd, u_char buf, int len)
	{
	if (USE_DIRECT_IO(len)) {
	int i;
	struct nand_chip *this = mtd->priv;

	for (i = 0; i < len; i++)
	buf[i] = readb(this->IO_ADDR_R);
	}
	#if USE_DMA
	else
	nand_dma_read(buf, len);
	#endif
	}

	static uint8_t readbackbuf[NAND_MAX_PAGESIZE];
	static int bcm_umi_nand_verify_buf(struct mtd_info mtd, const u_char buf,
	int len)
	{
	/*
	* Try to readback page with ECC correction. This is necessary
	* for MLC parts which may have permanently stuck bits.
	*/
	struct nand_chip *chip = mtd->priv;
	int ret = chip->ecc.read_page(mtd, chip, readbackbuf, 0);
	if (ret < 0)
	return -EFAULT;
	else {
	if (memcmp(readbackbuf, buf, len) == 0)
	return 0;

	return -EFAULT;
	}
	return 0;
	}

	static int __devinit bcm_umi_nand_probe(struct platform_device *pdev)
	{
	struct nand_chip *this;
	struct resource *r;
	int err = 0;

	printk(gBanner);

	/* Allocate memory for MTD device structure and private data */
	board_mtd =
	kmalloc(sizeof(struct mtd_info) + sizeof(struct nand_chip),
	GFP_KERNEL);
	if (!board_mtd) {
	printk(KERN_WARNING
	"Unable to allocate NAND MTD device structure.\n");
	return -ENOMEM;
	}

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	if (!r)
	return -ENXIO;

	/* map physical address */
	bcm_umi_io_base = ioremap(r->start, r->end - r->start + 1);

	if (!bcm_umi_io_base) {
	printk(KERN_ERR "ioremap to access BCM UMI NAND chip failed\n");
	kfree(board_mtd);
	return -EIO;
	}

	/* Get pointer to private data */
	this = (struct nand_chip *)(&board_mtd[1]);

	/* Initialize structures */
	memset((char *)board_mtd, 0, sizeof(struct mtd_info));
	memset((char *)this, 0, sizeof(struct nand_chip));

	/* Link the private data with the MTD structure */
	board_mtd->priv = this;

	/* Initialize the NAND hardware. */
	if (bcm_umi_nand_inithw() < 0) {
	printk(KERN_ERR "BCM UMI NAND chip could not be initialized\n");
	iounmap(bcm_umi_io_base);
	kfree(board_mtd);
	return -EIO;
	}

	/* Set address of NAND IO lines */
	this->IO_ADDR_W = bcm_umi_io_base + REG_NAND_DATA8_OFFSET;
	this->IO_ADDR_R = bcm_umi_io_base + REG_NAND_DATA8_OFFSET;

	/* Set command delay time, see datasheet for correct value */
	this->chip_delay = 0;
	/* Assign the device ready function, if available */
	this->dev_ready = nand_dev_ready;
	this->options = 0;

	this->write_buf = bcm_umi_nand_write_buf;
	this->read_buf = bcm_umi_nand_read_buf;
	this->verify_buf = bcm_umi_nand_verify_buf;

	this->cmd_ctrl = bcm_umi_nand_hwcontrol;
	this->ecc.mode = NAND_ECC_HW;
	this->ecc.size = 512;
	this->ecc.bytes = NAND_ECC_NUM_BYTES;
	#if NAND_ECC_BCH
	this->ecc.read_page = bcm_umi_bch_read_page_hwecc;
	this->ecc.write_page = bcm_umi_bch_write_page_hwecc;
	#else
	this->ecc.correct = nand_correct_data512;
	this->ecc.calculate = bcm_umi_hamming_get_hw_ecc;
	this->ecc.hwctl = bcm_umi_hamming_enable_hwecc;
	#endif

	#if USE_DMA
	err = nand_dma_init();
	if (err != 0)
	return err;
	#endif

	/* Figure out the size of the device that we have.
	* We need to do this to figure out which ECC
	* layout we'll be using.
	*/

	err = nand_scan_ident(board_mtd, 1, NULL);
	if (err) {
	printk(KERN_ERR "nand_scan failed: %d\n", err);
	iounmap(bcm_umi_io_base);
	kfree(board_mtd);
	return err;
	}

	/* Now that we know the nand size, we can setup the ECC layout */

	switch (board_mtd->writesize) { /* writesize is the pagesize */
	case 4096:
	this->ecc.layout = &nand_hw_eccoob_4096;
	break;
	case 2048:
	this->ecc.layout = &nand_hw_eccoob_2048;
	break;
	case 512:
	this->ecc.layout = &nand_hw_eccoob_512;
	break;
	default:
	{
	printk(KERN_ERR "NAND - Unrecognized pagesize: %d\n",
	board_mtd->writesize);
	return -EINVAL;
	}
	}

	#if NAND_ECC_BCH
	if (board_mtd->writesize > 512) {
	if (this->options & NAND_USE_FLASH_BBT)
	largepage_bbt.options = NAND_BBT_SCAN2NDPAGE;
	this->badblock_pattern = &largepage_bbt;
	}
	#endif

	/* Now finish off the scan, now that ecc.layout has been initialized. */

	err = nand_scan_tail(board_mtd);
	if (err) {
	printk(KERN_ERR "nand_scan failed: %d\n", err);
	iounmap(bcm_umi_io_base);
	kfree(board_mtd);
	return err;
	}

	/* Register the partitions */
	{
	int nr_partitions;
	struct mtd_partition *partition_info;

	board_mtd->name = "bcm_umi-nand";
	nr_partitions =
	parse_mtd_partitions(board_mtd, part_probes,
	&partition_info, 0);

	if (nr_partitions <= 0) {
	printk(KERN_ERR "BCM UMI NAND: Too few partitions - %d\n",
	nr_partitions);
	iounmap(bcm_umi_io_base);
	kfree(board_mtd);
	return -EIO;
	}
	add_mtd_partitions(board_mtd, partition_info, nr_partitions);
	}

	/* Return happy */
	return 0;
	}

	static int bcm_umi_nand_remove(struct platform_device *pdev)
	{
	#if USE_DMA
	nand_dma_term();
	#endif

	/* Release resources, unregister device */
	nand_release(board_mtd);

	/* unmap physical address */
	iounmap(bcm_umi_io_base);

	/* Free the MTD device structure */
	kfree(board_mtd);

	return 0;
	}

	#ifdef CONFIG_PM
	static int bcm_umi_nand_suspend(struct platform_device *pdev,
	pm_message_t state)
	{
	printk(KERN_ERR "MTD NAND suspend is being called\n");
	return 0;
	}

	static int bcm_umi_nand_resume(struct platform_device *pdev)
	{
	printk(KERN_ERR "MTD NAND resume is being called\n");
	return 0;
	}
	#else
	#define bcm_umi_nand_suspend NULL
	#define bcm_umi_nand_resume NULL
	#endif

	static struct platform_driver nand_driver = {
	.driver = {
	.name = "bcm-nand",
	.owner = THIS_MODULE,
	},
	.probe = bcm_umi_nand_probe,
	.remove = bcm_umi_nand_remove,
	.suspend = bcm_umi_nand_suspend,
	.resume = bcm_umi_nand_resume,
	};

	static int __init nand_init(void)
	{
	return platform_driver_register(&nand_driver);
	}

	static void __exit nand_exit(void)
	{
	platform_driver_unregister(&nand_driver);
	}

	module_init(nand_init);
	module_exit(nand_exit);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Broadcom");
	MODULE_DESCRIPTION("BCM UMI MTD NAND driver");