cfi_cmdset_0001.c

linux下的MTD设备驱动源代码,配合jffs2 yaffss2文件系统.

/*
 * Common Flash Interface support:
 *   Intel Extended Vendor Command Set (ID 0x0001)
 *
 * (C) 2000 Red Hat. GPL'd
 *
 * $Id: cfi_cmdset_0001.c,v 1.135 2004/03/25 13:24:40 dwmw2 Exp $
 *
 * 
 * 10/10/2000	Nicolas Pitre <[e-mail]>
 * 	- completely revamped method functions so they are aware and
 * 	  independent of the flash geometry (buswidth, interleave, etc.)
 * 	- scalability vs code size is completely set at compile-time
 * 	  (see include/linux/mtd/cfi.h for selection)
 *	- optimized write buffer method
 * 02/05/2002	Christopher Hoover <[e-mail]>/<[e-mail]>
 *	- reworked lock/unlock/erase support for var size flash
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <asm/io.h>
#include <asm/byteorder.h>

#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/mtd/map.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/compatmac.h>
#include <linux/mtd/cfi.h>

/* #define CMDSET0001_DISABLE_ERASE_SUSPEND_ON_WRITE */

// debugging, turns off buffer write mode if set to 1
#define FORCE_WORD_WRITE 0

static int cfi_intelext_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *);
static int cfi_intelext_read_user_prot_reg (struct mtd_info *, loff_t, size_t, size_t *, u_char *);
static int cfi_intelext_read_fact_prot_reg (struct mtd_info *, loff_t, size_t, size_t *, u_char *);
static int cfi_intelext_write_words(struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
static int cfi_intelext_write_buffers(struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
static int cfi_intelext_erase_varsize(struct mtd_info *, struct erase_info *);
static void cfi_intelext_sync (struct mtd_info *);
static int cfi_intelext_lock(struct mtd_info *mtd, loff_t ofs, size_t len);
static int cfi_intelext_unlock(struct mtd_info *mtd, loff_t ofs, size_t len);
static int cfi_intelext_suspend (struct mtd_info *);
static void cfi_intelext_resume (struct mtd_info *);

static void cfi_intelext_destroy(struct mtd_info *);

struct mtd_info *cfi_cmdset_0001(struct map_info *, int);

static struct mtd_info *cfi_intelext_setup (struct map_info *);

static int cfi_intelext_point (struct mtd_info *mtd, loff_t from, size_t len,
		     size_t *retlen, u_char **mtdbuf);
static void cfi_intelext_unpoint (struct mtd_info *mtd, u_char *addr, loff_t from,
			size_t len);


/*
 *  *********** SETUP AND PROBE BITS  ***********
 */

static struct mtd_chip_driver cfi_intelext_chipdrv = {
	.probe		= NULL, /* Not usable directly */
	.destroy	= cfi_intelext_destroy,
	.name		= "cfi_cmdset_0001",
	.module		= THIS_MODULE
};

/* #define DEBUG_LOCK_BITS */
/* #define DEBUG_CFI_FEATURES */

#ifdef DEBUG_CFI_FEATURES
static void cfi_tell_features(struct cfi_pri_intelext *extp)
{
	int i;
	printk("  Feature/Command Support: %4.4X\n", extp->FeatureSupport);
	printk("     - Chip Erase:         %s\n", extp->FeatureSupport&1?"supported":"unsupported");
	printk("     - Suspend Erase:      %s\n", extp->FeatureSupport&2?"supported":"unsupported");
	printk("     - Suspend Program:    %s\n", extp->FeatureSupport&4?"supported":"unsupported");
	printk("     - Legacy Lock/Unlock: %s\n", extp->FeatureSupport&8?"supported":"unsupported");
	printk("     - Queued Erase:       %s\n", extp->FeatureSupport&16?"supported":"unsupported");
	printk("     - Instant block lock: %s\n", extp->FeatureSupport&32?"supported":"unsupported");
	printk("     - Protection Bits:    %s\n", extp->FeatureSupport&64?"supported":"unsupported");
	printk("     - Page-mode read:     %s\n", extp->FeatureSupport&128?"supported":"unsupported");
	printk("     - Synchronous read:   %s\n", extp->FeatureSupport&256?"supported":"unsupported");
	for (i=9; i<32; i++) {
		if (extp->FeatureSupport & (1<<i)) 
			printk("     - Unknown Bit %X:      supported\n", i);
	}
	
	printk("  Supported functions after Suspend: %2.2X\n", extp->SuspendCmdSupport);
	printk("     - Program after Erase Suspend: %s\n", extp->SuspendCmdSupport&1?"supported":"unsupported");
	for (i=1; i<8; i++) {
		if (extp->SuspendCmdSupport & (1<<i))
			printk("     - Unknown Bit %X:               supported\n", i);
	}
	
	printk("  Block Status Register Mask: %4.4X\n", extp->BlkStatusRegMask);
	printk("     - Lock Bit Active:      %s\n", extp->BlkStatusRegMask&1?"yes":"no");
	printk("     - Valid Bit Active:     %s\n", extp->BlkStatusRegMask&2?"yes":"no");
	for (i=2; i<16; i++) {
		if (extp->BlkStatusRegMask & (1<<i))
			printk("     - Unknown Bit %X Active: yes\n",i);
	}
	
	printk("  Vcc Logic Supply Optimum Program/Erase Voltage: %d.%d V\n", 
	       extp->VccOptimal >> 4, extp->VccOptimal & 0xf);
	if (extp->VppOptimal)
		printk("  Vpp Programming Supply Optimum Program/Erase Voltage: %d.%d V\n", 
		       extp->VppOptimal >> 4, extp->VppOptimal & 0xf);
}
#endif

#ifdef CMDSET0001_DISABLE_ERASE_SUSPEND_ON_WRITE
/* Some Intel Strata Flash prior to FPO revision C has bugs in this area */ 
static void fixup_intel_strataflash(struct map_info *map, void* param)
{
	struct cfi_private *cfi = map->fldrv_priv;
	struct cfi_pri_amdstd *extp = cfi->cmdset_priv;

	printk(KERN_WARNING "cfi_cmdset_0001: Suspend "
	                    "erase on write disabled.\n");
	extp->SuspendCmdSupport &= ~1;
}
#endif

static void fixup_st_m28w320ct(struct map_info *map, void* param)
{
	struct cfi_private *cfi = map->fldrv_priv;
	
	cfi->cfiq->BufWriteTimeoutTyp = 0;	/* Not supported */
	cfi->cfiq->BufWriteTimeoutMax = 0;	/* Not supported */
}

static void fixup_st_m28w320cb(struct map_info *map, void* param)
{
	struct cfi_private *cfi = map->fldrv_priv;
	
	/* Note this is done after the region info is endian swapped */
	cfi->cfiq->EraseRegionInfo[1] =
		(cfi->cfiq->EraseRegionInfo[1] & 0xffff0000) | 0x3e;
};

static struct cfi_fixup fixup_table[] = {
#ifdef CMDSET0001_DISABLE_ERASE_SUSPEND_ON_WRITE
	{
		CFI_MFR_ANY, CFI_ID_ANY,
		fixup_intel_strataflash, NULL
	}, 
#endif
	{
		0x0020,	/* STMicroelectronics */
		0x00ba,	/* M28W320CT */
		fixup_st_m28w320ct, NULL
	}, {
		0x0020,	/* STMicroelectronics */
		0x00bb,	/* M28W320CB */
		fixup_st_m28w320cb, NULL
	}, {
		0, 0, NULL, NULL
	}
};

/* This routine is made available to other mtd code via
 * inter_module_register.  It must only be accessed through
 * inter_module_get which will bump the use count of this module.  The
 * addresses passed back in cfi are valid as long as the use count of
 * this module is non-zero, i.e. between inter_module_get and
 * inter_module_put.  Keith Owens <[e-mail]> 29 Oct 2000.
 */
struct mtd_info *cfi_cmdset_0001(struct map_info *map, int primary)
{
	struct cfi_private *cfi = map->fldrv_priv;
	int i;

	if (cfi->cfi_mode == CFI_MODE_CFI) {
		/* 
		 * It's a real CFI chip, not one for which the probe
		 * routine faked a CFI structure. So we read the feature
		 * table from it.
		 */
		__u16 adr = primary?cfi->cfiq->P_ADR:cfi->cfiq->A_ADR;
		struct cfi_pri_intelext *extp;

		extp = (struct cfi_pri_intelext*)cfi_read_pri(map, adr, sizeof(*extp), "Intel/Sharp");
		if (!extp)
			return NULL;
		
		/* Do some byteswapping if necessary */
		extp->FeatureSupport = le32_to_cpu(extp->FeatureSupport);
		extp->BlkStatusRegMask = le16_to_cpu(extp->BlkStatusRegMask);
		extp->ProtRegAddr = le16_to_cpu(extp->ProtRegAddr);

		/* Install our own private info structure */
		cfi->cmdset_priv = extp;	

		cfi_fixup(map, fixup_table);
			
#ifdef DEBUG_CFI_FEATURES
		/* Tell the user about it in lots of lovely detail */
		cfi_tell_features(extp);
#endif	

		if(extp->SuspendCmdSupport & 1) {
			printk(KERN_NOTICE "cfi_cmdset_0001: Erase suspend on write enabled\n");
		}
	}

	for (i=0; i< cfi->numchips; i++) {
		cfi->chips[i].word_write_time = 1<<cfi->cfiq->WordWriteTimeoutTyp;
		cfi->chips[i].buffer_write_time = 1<<cfi->cfiq->BufWriteTimeoutTyp;
		cfi->chips[i].erase_time = 1<<cfi->cfiq->BlockEraseTimeoutTyp;
		cfi->chips[i].ref_point_counter = 0;
	}		

	map->fldrv = &cfi_intelext_chipdrv;
	
	return cfi_intelext_setup(map);
}

static struct mtd_info *cfi_intelext_setup(struct map_info *map)
{
	struct cfi_private *cfi = map->fldrv_priv;
	struct mtd_info *mtd;
	unsigned long offset = 0;
	int i,j;
	unsigned long devsize = (1<<cfi->cfiq->DevSize) * cfi->interleave;

	mtd = kmalloc(sizeof(*mtd), GFP_KERNEL);
	//printk(KERN_DEBUG "number of CFI chips: %d\n", cfi->numchips);

	if (!mtd) {
		printk(KERN_ERR "Failed to allocate memory for MTD device\n");
		goto setup_err;
	}

	memset(mtd, 0, sizeof(*mtd));
	mtd->priv = map;
	mtd->type = MTD_NORFLASH;
	mtd->size = devsize * cfi->numchips;

	mtd->numeraseregions = cfi->cfiq->NumEraseRegions * cfi->numchips;
	mtd->eraseregions = kmalloc(sizeof(struct mtd_erase_region_info) 
			* mtd->numeraseregions, GFP_KERNEL);
	if (!mtd->eraseregions) { 
		printk(KERN_ERR "Failed to allocate memory for MTD erase region info\n");
		goto setup_err;
	}
	
	for (i=0; i<cfi->cfiq->NumEraseRegions; i++) {
		unsigned long ernum, ersize;
		ersize = ((cfi->cfiq->EraseRegionInfo[i] >> 8) & ~0xff) * cfi->interleave;
		ernum = (cfi->cfiq->EraseRegionInfo[i] & 0xffff) + 1;

		if (mtd->erasesize < ersize) {
			mtd->erasesize = ersize;
		}
		for (j=0; j<cfi->numchips; j++) {
			mtd->eraseregions[(j*cfi->cfiq->NumEraseRegions)+i].offset = (j*devsize)+offset;
			mtd->eraseregions[(j*cfi->cfiq->NumEraseRegions)+i].erasesize = ersize;
			mtd->eraseregions[(j*cfi->cfiq->NumEraseRegions)+i].numblocks = ernum;
		}
		offset += (ersize * ernum);
	}

	if (offset != devsize) {
		/* Argh */
		printk(KERN_WARNING "Sum of regions (%lx) != total size of set of interleaved chips (%lx)\n", offset, devsize);
		goto setup_err;
	}

	for (i=0; i<mtd->numeraseregions;i++){
		printk(KERN_DEBUG "%d: offset=0x%x,size=0x%x,blocks=%d\n",
		       i,mtd->eraseregions[i].offset,
		       mtd->eraseregions[i].erasesize,
		       mtd->eraseregions[i].numblocks);
	}

	/* Also select the correct geometry setup too */ 
	mtd->erase = cfi_intelext_erase_varsize;
	mtd->read = cfi_intelext_read;

	if (map_is_linear(map)) {
		mtd->point = cfi_intelext_point;
		mtd->unpoint = cfi_intelext_unpoint;
	}

	if ( cfi->cfiq->BufWriteTimeoutTyp && !FORCE_WORD_WRITE) {
		printk(KERN_INFO "Using buffer write method\n" );
		mtd->write = cfi_intelext_write_buffers;
	} else {
		printk(KERN_INFO "Using word write method\n" );
		mtd->write = cfi_intelext_write_words;
	}
	mtd->read_user_prot_reg = cfi_intelext_read_user_prot_reg;
	mtd->read_fact_prot_reg = cfi_intelext_read_fact_prot_reg;
	mtd->sync = cfi_intelext_sync;
	mtd->lock = cfi_intelext_lock;
	mtd->unlock = cfi_intelext_unlock;
	mtd->suspend = cfi_intelext_suspend;
	mtd->resume = cfi_intelext_resume;
	mtd->flags = MTD_CAP_NORFLASH;
	map->fldrv = &cfi_intelext_chipdrv;
	mtd->name = map->name;
	__module_get(THIS_MODULE);
	return mtd;

 setup_err:
	if(mtd) {
		if(mtd->eraseregions)
			kfree(mtd->eraseregions);
		kfree(mtd);
	}
	kfree(cfi->cmdset_priv);
	kfree(cfi->cfiq);
	return NULL;
}

/*
 *  *********** CHIP ACCESS FUNCTIONS ***********
 */

static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr, int mode)
{
	DECLARE_WAITQUEUE(wait, current);
	struct cfi_private *cfi = map->fldrv_priv;
	cfi_word status, status_OK = CMD(0x80);
	unsigned long timeo;
	struct cfi_pri_intelext *cfip = (struct cfi_pri_intelext *)cfi->cmdset_priv;

 resettime:
	timeo = jiffies + HZ;
 retry:
	switch (chip->state) {

	case FL_STATUS:
		for (;;) {
			status = cfi_read(map, adr);
			if ((status & status_OK) == status_OK)
				break;

			if (time_after(jiffies, timeo)) {
				printk(KERN_ERR "Waiting for chip to be ready timed out. Status %llx\n", 
				       (long long)status);
				spin_unlock(chip->mutex);
				return -EIO;
			}
			spin_unlock(chip->mutex);
			cfi_udelay(1);
			spin_lock(chip->mutex);
			/* Someone else might have been playing with it. */
			goto retry;
		}
				
	case FL_READY:
	case FL_CFI_QUERY:
	case FL_JEDEC_QUERY:
		return 0;

	case FL_ERASING:
		if (!(cfip->FeatureSupport & 2) ||
		    !(mode == FL_READY || mode == FL_POINT ||
		     (mode == FL_WRITING && (cfip->SuspendCmdSupport & 1))))
			goto sleep;


		/* Erase suspend */
		cfi_write(map, CMD(0xB0), adr);

		/* If the flash has finished erasing, then 'erase suspend'
		 * appears to make some (28F320) flash devices switch to
		 * 'read' mode.  Make sure that we switch to 'read status'
		 * mode so we get the right data. --rmk
		 */
		cfi_write(map, CMD(0x70), adr);
		chip->oldstate = FL_ERASING;
		chip->state = FL_ERASE_SUSPENDING;
		chip->erase_suspended = 1;
		for (;;) {
			status = cfi_read(map, adr);
			if ((status & status_OK) == status_OK)
			        break;

			if (time_after(jiffies, timeo)) {
				/* Urgh. Resume and pretend we weren't here.  */
				cfi_write(map, CMD(0xd0), adr);
				/* Make sure we're in 'read status' mode if it had finished */
				cfi_write(map, CMD(0x70), adr);
				chip->state = FL_ERASING;
				chip->oldstate = FL_READY;
				printk(KERN_ERR "Chip not ready after erase "
				       "suspended: status = 0x%llx\n", (__u64)status);
				return -EIO;
			}

			spin_unlock(chip->mutex);
			cfi_udelay(1);
			spin_lock(chip->mutex);
			/* Nobody will touch it while it's in state FL_ERASE_SUSPENDING.
			   So we can just loop here. */
		}
		chip->state = FL_STATUS;
		return 0;

	case FL_POINT:
		/* Only if there's no operation suspended... */
		if (mode == FL_READY && chip->oldstate == FL_READY)
			return 0;

	default:
	sleep:
		set_current_state(TASK_UNINTERRUPTIBLE);
		add_wait_queue(&chip->wq, &wait);
		spin_unlock(chip->mutex);
		schedule();
		remove_wait_queue(&chip->wq, &wait);
		spin_lock(chip->mutex);
		goto resettime;
	}
}

static void put_chip(struct map_info *map, struct flchip *chip, unsigned long adr)
{
	struct cfi_private *cfi = map->fldrv_priv;

	switch(chip->oldstate) {
	case FL_ERASING:
		chip->state = chip->oldstate;
		/* What if one interleaved chip has finished and the 
		   other hasn't? The old code would leave the finished
		   one in READY mode. That's bad, and caused -EROFS 
		   errors to be returned from do_erase_oneblock because
		   that's the only bit it checked for at the time.
		   As the state machine appears to explicitly allow 
		   sending the 0x70 (Read Status) command to an erasing
		   chip and expecting it to be ignored, that's what we 
		   do. */
		cfi_write(map, CMD(0xd0), adr);
		cfi_write(map, CMD(0x70), adr);
		chip->oldstate = FL_READY;
		chip->state = FL_ERASING;
		break;

	case FL_READY:
	case FL_STATUS:
	case FL_JEDEC_QUERY:
		/* We should really make set_vpp() count, rather than doing this */
		DISABLE_VPP(map);
		break;
	default:
		printk(KERN_ERR "put_chip() called with oldstate %d!!\n", chip->oldstate);
	}
	wake_up(&chip->wq);
}

static int do_point_onechip (struct map_info *map, struct flchip *chip, loff_t adr, size_t len)
{
	unsigned long cmd_addr;
	struct cfi_private *cfi = map->fldrv_priv;
	int ret = 0;

	adr += chip->start;

	/* Ensure cmd read/writes are aligned. */ 
	cmd_addr = adr & ~(CFIDEV_BUSWIDTH-1); 

	spin_lock(chip->mutex);

	ret = get_chip(map, chip, cmd_addr, FL_POINT);

	if (!ret) {
		if (chip->state != FL_POINT && chip->state != FL_READY)
			cfi_write(map, CMD(0xff), cmd_addr);

		chip->state = FL_POINT;
		chip->ref_point_counter++;
	}
	spin_unlock(chip->mutex);

	return ret;
}