linux/drivers/mtd/nand/bcm_umi_nand.c
Brian Norris 1fbb938dff mtd: nand: add 'oob_required' argument to NAND {read,write}_page interfaces
New NAND controllers can perform read/write via HW engines which don't expose
OOB data in their DMA mode. To reflect this, we should rework the nand_chip /
nand_ecc_ctrl interfaces that assume that drivers will always read/write OOB
data in the nand_chip.oob_poi buffer. A better interface includes a boolean
argument that explicitly tells the callee when OOB data is requested by the
calling layer (for reading/writing to/from nand_chip.oob_poi).

This patch adds the 'oob_required' parameter to each relevant {read,write}_page
interface; all 'oob_required' parameters are left unused for now. The next
patch will set the parameter properly in the nand_base.c callers, and follow-up
patches will make use of 'oob_required' in some of the callee functions.

Note that currently, there is no harm in ignoring the 'oob_required' parameter
and *always* utilizing nand_chip.oob_poi, but there can be
performance/complexity/design benefits from avoiding filling oob_poi in the
common case. I will try to implement this for some drivers which can be ported
easily.

Note: I couldn't compile-test all of these easily, as some had ARCH
dependencies.

[dwmw2: Merge later 1/0 vs. true/false cleanup]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Acked-by: Jiandong Zheng <jdzheng@broadcom.com>
Acked-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2012-05-13 23:20:00 -05:00

555 lines
13 KiB
C

/*****************************************************************************
* 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 <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";
#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, 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) {
err = -ENXIO;
goto out_free;
}
/* map physical address */
bcm_umi_io_base = ioremap(r->start, resource_size(r));
if (!bcm_umi_io_base) {
printk(KERN_ERR "ioremap to access BCM UMI NAND chip failed\n");
err = -EIO;
goto out_free;
}
/* 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");
err = -EIO;
goto out_unmap;
}
/* 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)
goto out_unmap;
#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);
goto out_unmap;
}
/* 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);
err = -EINVAL;
goto out_unmap;
}
}
#if NAND_ECC_BCH
if (board_mtd->writesize > 512) {
if (this->bbt_options & NAND_BBT_USE_FLASH)
largepage_bbt.options = NAND_BBT_SCAN2NDPAGE;
this->badblock_pattern = &largepage_bbt;
}
this->ecc.strength = 8;
#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);
goto out_unmap;
}
/* Register the partitions */
board_mtd->name = "bcm_umi-nand";
mtd_device_parse_register(board_mtd, NULL, NULL, NULL, 0);
/* Return happy */
return 0;
out_unmap:
iounmap(bcm_umi_io_base);
out_free:
kfree(board_mtd);
return err;
}
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,
};
module_platform_driver(nand_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Broadcom");
MODULE_DESCRIPTION("BCM UMI MTD NAND driver");