cfi_cmdset_0002.c

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

		if (!(mode == FL_READY || mode == FL_POINT
		      || (mode == FL_WRITING && (cfip->EraseSuspend & 0x2))
		      || (mode == FL_WRITING && (cfip->EraseSuspend & 0x1))))
			goto sleep;

		/* We could check to see if we're trying to access the sector
		 * that is currently being erased. However, no user will try
		 * anything like that so we just wait for the timeout. */

		/* Erase suspend */
		/* It's harmless to issue the Erase-Suspend and Erase-Resume
		 * commands when the erase algorithm isn't in progress. */
		cfi_write(map, CMD(0xB0), chip->in_progress_block_addr);
		chip->oldstate = FL_ERASING;
		chip->state = FL_ERASE_SUSPENDING;
		chip->erase_suspended = 1;
		for (;;) {
			if (chip_ready(map, adr))
				break;

			if (time_after(jiffies, timeo)) {
				/* Should have suspended the erase by now.
				 * Send an Erase-Resume command as either
				 * there was an error (so leave the erase
				 * routine to recover from it) or we trying to
				 * use the erase-in-progress sector. */
				cfi_write(map, CMD(0x30), chip->in_progress_block_addr);
				chip->state = FL_ERASING;
				chip->oldstate = FL_READY;
				printk(KERN_ERR "MTD %s(): chip not ready after erase suspend\n", __func__);
				return -EIO;
			}
			
			cfi_spin_unlock(chip->mutex);
			cfi_udelay(1);
			cfi_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_READY;
		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);
		cfi_spin_unlock(chip->mutex);
		schedule();
		remove_wait_queue(&chip->wq, &wait);
		cfi_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;
		cfi_write(map, CMD(0x30), chip->in_progress_block_addr);
		chip->oldstate = FL_READY;
		chip->state = FL_ERASING;
		break;

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


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

	adr += chip->start;

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

	cfi_spin_lock(chip->mutex);
	ret = get_chip(map, chip, cmd_addr, FL_READY);
	if (ret) {
		cfi_spin_unlock(chip->mutex);
		return ret;
	}

	if (chip->state != FL_POINT && chip->state != FL_READY) {
		cfi_write(map, CMD(0xf0), cmd_addr);
		chip->state = FL_READY;
	}

	map_copy_from(map, buf, adr, len);

	put_chip(map, chip, cmd_addr);

	cfi_spin_unlock(chip->mutex);
	return 0;
}


static int cfi_amdstd_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf)
{
	struct map_info *map = mtd->priv;
	struct cfi_private *cfi = map->fldrv_priv;
	unsigned long ofs;
	int chipnum;
	int ret = 0;

	/* ofs: offset within the first chip that the first read should start */

	chipnum = (from >> cfi->chipshift);
	ofs = from - (chipnum <<  cfi->chipshift);


	*retlen = 0;

	while (len) {
		unsigned long thislen;

		if (chipnum >= cfi->numchips)
			break;

		if ((len + ofs -1) >> cfi->chipshift)
			thislen = (1<<cfi->chipshift) - ofs;
		else
			thislen = len;

		ret = do_read_onechip(map, &cfi->chips[chipnum], ofs, thislen, buf);
		if (ret)
			break;

		*retlen += thislen;
		len -= thislen;
		buf += thislen;

		ofs = 0;
		chipnum++;
	}
	return ret;
}


static inline int do_read_secsi_onechip(struct map_info *map, struct flchip *chip, loff_t adr, size_t len, u_char *buf)
{
	DECLARE_WAITQUEUE(wait, current);
	unsigned long timeo = jiffies + HZ;
	struct cfi_private *cfi = map->fldrv_priv;

 retry:
	cfi_spin_lock(chip->mutex);

	if (chip->state != FL_READY){
#if 0
		printk(KERN_DEBUG "Waiting for chip to read, status = %d\n", chip->state);
#endif
		set_current_state(TASK_UNINTERRUPTIBLE);
		add_wait_queue(&chip->wq, &wait);
		
		cfi_spin_unlock(chip->mutex);

		schedule();
		remove_wait_queue(&chip->wq, &wait);
#if 0
		if(signal_pending(current))
			return -EINTR;
#endif
		timeo = jiffies + HZ;

		goto retry;
	}	

	adr += chip->start;

	chip->state = FL_READY;

	/* should these be CFI_DEVICETYPE_X8 instead of cfi->device_type? */
	cfi_send_gen_cmd(0xAA, cfi->addr_unlock1, chip->start, map, cfi, cfi->device_type, NULL);
	cfi_send_gen_cmd(0x55, cfi->addr_unlock2, chip->start, map, cfi, cfi->device_type, NULL);
	cfi_send_gen_cmd(0x88, cfi->addr_unlock1, chip->start, map, cfi, cfi->device_type, NULL);
	
	map_copy_from(map, buf, adr, len);

	/* should these be CFI_DEVICETYPE_X8 instead of cfi->device_type? */
	cfi_send_gen_cmd(0xAA, cfi->addr_unlock1, chip->start, map, cfi, cfi->device_type, NULL);
	cfi_send_gen_cmd(0x55, cfi->addr_unlock2, chip->start, map, cfi, cfi->device_type, NULL);
	cfi_send_gen_cmd(0x90, cfi->addr_unlock1, chip->start, map, cfi, cfi->device_type, NULL);
	cfi_send_gen_cmd(0x00, cfi->addr_unlock1, chip->start, map, cfi, cfi->device_type, NULL);
	
	wake_up(&chip->wq);
	cfi_spin_unlock(chip->mutex);

	return 0;
}

static int cfi_amdstd_secsi_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf)
{
	struct map_info *map = mtd->priv;
	struct cfi_private *cfi = map->fldrv_priv;
	unsigned long ofs;
	int chipnum;
	int ret = 0;


	/* ofs: offset within the first chip that the first read should start */

	/* 8 secsi bytes per chip */
	chipnum=from>>3;
	ofs=from & 7;


	*retlen = 0;

	while (len) {
		unsigned long thislen;

		if (chipnum >= cfi->numchips)
			break;

		if ((len + ofs -1) >> 3)
			thislen = (1<<3) - ofs;
		else
			thislen = len;

		ret = do_read_secsi_onechip(map, &cfi->chips[chipnum], ofs, thislen, buf);
		if (ret)
			break;

		*retlen += thislen;
		len -= thislen;
		buf += thislen;

		ofs = 0;
		chipnum++;
	}
	return ret;
}


static int do_write_oneword(struct map_info *map, struct flchip *chip, unsigned long adr, cfi_word datum)
{
	struct cfi_private *cfi = map->fldrv_priv;
	unsigned long timeo = jiffies + HZ;
	/*
	 * We use a 1ms + 1 jiffies generic timeout for writes (most devices
	 * have a max write time of a few hundreds usec). However, we should
	 * use the maximum timeout value given by the chip at probe time
	 * instead.  Unfortunately, struct flchip does have a field for
	 * maximum timeout, only for typical which can be far too short
	 * depending of the conditions.	 The ' + 1' is to avoid having a
	 * timeout of 0 jiffies if HZ is smaller than 1000.
	 */
	unsigned long uWriteTimeout = ( HZ / 1000 ) + 1;
	int ret = 0;

	adr += chip->start;

	cfi_spin_lock(chip->mutex);
	ret = get_chip(map, chip, adr, FL_WRITING);
	if (ret) {
		cfi_spin_unlock(chip->mutex);
		return ret;
	}

	DEBUG( MTD_DEBUG_LEVEL3, "MTD %s(): WRITE 0x%.8lx(0x%.8x)\n",
	       __func__, adr, datum );

	/*
	 * Check for a NOP for the case when the datum to write is already
	 * present - it saves time and works around buggy chips that corrupt
	 * data at other locations when 0xff is written to a location that
	 * already contains 0xff.
	 */
	if (cfi_read(map, adr) == datum) {
		DEBUG( MTD_DEBUG_LEVEL3, "MTD %s(): NOP\n",
		       __func__);
		goto op_done;
	}

	ENABLE_VPP(map);
	/*
	 * The CFI_DEVICETYPE_X8 argument is needed even when
	 * cfi->device_type != CFI_DEVICETYPE_X8.  The addresses for
	 * command sequences don't scale even when the device is
	 * wider.  This is the case for many of the cfi_send_gen_cmd()
	 * below.  I'm not sure, however, why some use
	 * cfi->device_type.
	 */
	cfi_send_gen_cmd(0xAA, cfi->addr_unlock1, chip->start, map, cfi, CFI_DEVICETYPE_X8, NULL);
	cfi_send_gen_cmd(0x55, cfi->addr_unlock2, chip->start, map, cfi, CFI_DEVICETYPE_X8, NULL);
	cfi_send_gen_cmd(0xA0, cfi->addr_unlock1, chip->start, map, cfi, CFI_DEVICETYPE_X8, NULL);
	cfi_write(map, datum, adr);
	chip->state = FL_WRITING;

	cfi_spin_unlock(chip->mutex);
	cfi_udelay(chip->word_write_time);
	cfi_spin_lock(chip->mutex);

	/* See comment above for timeout value. */
	timeo = jiffies + uWriteTimeout; 
	for (;;) {
		if (chip->state != FL_WRITING) {
			/* Someone's suspended the write. Sleep */
			DECLARE_WAITQUEUE(wait, current);

			set_current_state(TASK_UNINTERRUPTIBLE);
			add_wait_queue(&chip->wq, &wait);
			cfi_spin_unlock(chip->mutex);
			schedule();
			remove_wait_queue(&chip->wq, &wait);
			timeo = jiffies + (HZ / 2); /* FIXME */
			cfi_spin_lock(chip->mutex);
			continue;
		}

		if (chip_ready(map, adr))
			goto op_done;

		if (time_after(jiffies, timeo))
			break;

		/* Latency issues. Drop the lock, wait a while and retry */
		cfi_spin_unlock(chip->mutex);
		cfi_udelay(1);
		cfi_spin_lock(chip->mutex);
	}

	printk(KERN_WARNING "MTD %s(): software timeout\n",
	       __func__ );

	/* reset on all failures. */
	cfi_write( map, CMD(0xF0), chip->start );
	/* FIXME - should have reset delay before continuing */
	ret = -EIO;

 op_done:
	chip->state = FL_READY;
	put_chip(map, chip, adr);
	cfi_spin_unlock(chip->mutex);

	return ret;
}


static int cfi_amdstd_write_words(struct mtd_info *mtd, loff_t to, size_t len,
				  size_t *retlen, const u_char *buf)
{
	struct map_info *map = mtd->priv;
	struct cfi_private *cfi = map->fldrv_priv;
	int ret = 0;
	int chipnum;
	unsigned long ofs, chipstart;
	DECLARE_WAITQUEUE(wait, current);

	*retlen = 0;
	if (!len)
		return 0;

	chipnum = to >> cfi->chipshift;
	ofs = to  - (chipnum << cfi->chipshift);
	chipstart = cfi->chips[chipnum].start;

	/* If it's not bus-aligned, do the first byte write */
	if (ofs & (CFIDEV_BUSWIDTH-1)) {
		unsigned long bus_ofs = ofs & ~(CFIDEV_BUSWIDTH-1);
		int i = ofs - bus_ofs;
		int n = 0;
		u_char tmp_buf[8];
		cfi_word datum;

 retry:
		cfi_spin_lock(cfi->chips[chipnum].mutex);

		if (cfi->chips[chipnum].state != FL_READY) {
#if 0
			printk(KERN_DEBUG "Waiting for chip to write, status = %d\n", cfi->chips[chipnum].state);
#endif
			set_current_state(TASK_UNINTERRUPTIBLE);
			add_wait_queue(&cfi->chips[chipnum].wq, &wait);

			cfi_spin_unlock(cfi->chips[chipnum].mutex);

			schedule();
			remove_wait_queue(&cfi->chips[chipnum].wq, &wait);
#if 0
			if(signal_pending(current))
				return -EINTR;
#endif
			goto retry;
		}

		map_copy_from(map, tmp_buf, bus_ofs + cfi->chips[chipnum].start, CFIDEV_BUSWIDTH);

		cfi_spin_unlock(cfi->chips[chipnum].mutex);

		while (len && i < CFIDEV_BUSWIDTH) {
			tmp_buf[i++] = buf[n++];
			len--;
		}

		/* already know that buswidth > 1 */
		if (cfi_buswidth_is_2()) {
			datum = *(__u16*)tmp_buf;
		} else if (cfi_buswidth_is_4()) {
			datum = *(__u32*)tmp_buf;
#ifdef CFI_WORD_64
		} else if (cfi_buswidth_is_8()) {
			datum = *(__u64*)tmp_buf;
#endif
		} else {
			printk(KERN_WARNING "MTD %s(): Unsupported buswidth %d\n",
			       __func__, CFIDEV_BUSWIDTH);
			return -EINVAL;
		}

		ret = do_write_oneword(map, &cfi->chips[chipnum], 
				       bus_ofs, datum);
		if (ret) 
			return ret;
		
		ofs += n;
		buf += n;
		(*retlen) += n;

		if (ofs >> cfi->chipshift) {
			chipnum ++; 
			ofs = 0;
			if (chipnum == cfi->numchips)
				return 0;
		}
	}
	
	/* We are now aligned, write as much as possible */
	while(len >= CFIDEV_BUSWIDTH) {
		cfi_word datum;

		if (cfi_buswidth_is_1()) {
			datum = *(__u8*)buf;
		} else if (cfi_buswidth_is_2()) {
			datum = *(__u16*)buf;
		} else if (cfi_buswidth_is_4()) {
			datum = *(__u32*)buf;
#ifdef CFI_WORD_64
		} else if (cfi_buswidth_is_8()) {
			datum = *(__u64*)buf;
#endif
		} else {
			printk(KERN_WARNING "MTD %s(): Unsupported buswidth %d\n",
			       __func__, CFIDEV_BUSWIDTH);
			return -EINVAL;
		}