path: root/drivers/mtd/devices/doc2000.c

/*
 * Linux driver for Disk-On-Chip 2000 and Millennium
 * (c) 1999 Machine Vision Holdings, Inc.
 * (c) 1999, 2000 David Woodhouse <dwmw2@infradead.org>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <asm/errno.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <linux/miscdevice.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/bitops.h>
#include <linux/mutex.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/doc2000.h>

#define DOC_SUPPORT_2000
#define DOC_SUPPORT_2000TSOP
#define DOC_SUPPORT_MILLENNIUM

#ifdef DOC_SUPPORT_2000
#define DoC_is_2000(doc) (doc->ChipID == DOC_ChipID_Doc2k)
#else
#define DoC_is_2000(doc) (0)
#endif

#if defined(DOC_SUPPORT_2000TSOP) || defined(DOC_SUPPORT_MILLENNIUM)
#define DoC_is_Millennium(doc) (doc->ChipID == DOC_ChipID_DocMil)
#else
#define DoC_is_Millennium(doc) (0)
#endif

/* #define ECC_DEBUG */

/* I have no idea why some DoC chips can not use memcpy_from|to_io().
 * This may be due to the different revisions of the ASIC controller built-in or
 * simplily a QA/Bug issue. Who knows ?? If you have trouble, please uncomment
 * this:
 #undef USE_MEMCPY
*/

static int doc_read(struct mtd_info *mtd, loff_t from, size_t len,
		    size_t *retlen, u_char *buf);
static int doc_write(struct mtd_info *mtd, loff_t to, size_t len,
		     size_t *retlen, const u_char *buf);
static int doc_read_oob(struct mtd_info *mtd, loff_t ofs,
			struct mtd_oob_ops *ops);
static int doc_write_oob(struct mtd_info *mtd, loff_t ofs,
			 struct mtd_oob_ops *ops);
static int doc_write_oob_nolock(struct mtd_info *mtd, loff_t ofs, size_t len,
			 size_t *retlen, const u_char *buf);
static int doc_erase (struct mtd_info *mtd, struct erase_info *instr);

static struct mtd_info *doc2klist = NULL;

/* Perform the required delay cycles by reading from the appropriate register */
static void DoC_Delay(struct DiskOnChip *doc, unsigned short cycles)
{
	volatile char dummy;
	int i;

	for (i = 0; i < cycles; i++) {
		if (DoC_is_Millennium(doc))
			dummy = ReadDOC(doc->virtadr, NOP);
		else
			dummy = ReadDOC(doc->virtadr, DOCStatus);
	}

}

/* 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);

	DEBUG(MTD_DEBUG_LEVEL3,
	      "_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)) {
			DEBUG(MTD_DEBUG_LEVEL2, "_DoC_WaitReady timed out.\n");
			return -EIO;
		}
		udelay(1);
		cond_resched();
	}

	return 0;
}

static inline int DoC_WaitReady(struct DiskOnChip *doc)
{
	void __iomem *docptr = doc-><