cfi_cmdset_0002.c

linux 下的coldfire cpu的 nor flash 驱动程序

	switch(chip->oldstate) {
	case FL_ERASING:
		chip->state = chip->oldstate;
		map_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 & ~(map_bankwidth(map)-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) {
		map_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;

	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);

	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, map_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;
	map_word oldd;
	int retry_cnt = 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%.8lx)\n",
	       __func__, adr, datum.x[0] );

	/*
	 * 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.
	 */
	oldd = map_read(map, adr);
	if (map_word_equal(map, oldd, datum)) {
		DEBUG( MTD_DEBUG_LEVEL3, "MTD %s(): NOP\n",
		       __func__);
		goto op_done;
	}

	ENABLE_VPP(map);
 retry:
	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(0xA0, cfi->addr_unlock1, chip->start, map, cfi, cfi->device_type, NULL);
	map_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. */
	map_write( map, CMD(0xF0), chip->start );
	/* FIXME - should have reset delay before continuing */
	if (++retry_cnt <= MAX_WORD_RETRIES) 
		goto retry;

	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 & (map_bankwidth(map)-1)) {
		unsigned long bus_ofs = ofs & ~(map_bankwidth(map)-1);
		int i = ofs - bus_ofs;
		int n = 0;
		map_word tmp_buf;

 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;
		}

		/* Load 'tmp_buf' with old contents of flash */
		tmp_buf = map_read(map, bus_ofs+chipstart);

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

		/* Number of bytes to copy from buffer */
		n = min_t(int, len, map_bankwidth(map)-i);
		
		tmp_buf = map_word_load_partial(map, tmp_buf, buf, i, n);

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

		datum = map_word_load(map, buf);

		ret = do_write_oneword(map, &cfi->chips[chipnum],
				       ofs, datum);
		if (ret)
			return ret;

		ofs += map_bankwidth(map);
		buf += map_bankwidth(map);
		(*retlen) += map_bankwidth(map);
		len -= map_bankwidth(map);

		if (ofs >> cfi->chipshift) {
			chipnum ++; 
			ofs = 0;
			if (chipnum == cfi->numchips)
				return 0;
			chipstart = cfi->chips[chipnum].start;
		}
	}

	/* Write the trailing bytes if any */
	if (len & (map_bankwidth(map)-1)) {
		map_word tmp_buf;

 retry1:
		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 retry1;
		}

		tmp_buf = map_read(map, ofs + chipstart);

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

		tmp_buf = map_word_load_partial(map, tmp_buf, buf, 0, len);
	
		ret = do_write_oneword(map, &cfi->chips[chipnum], 
				ofs, tmp_buf);
		if (ret) 
			return ret;
		
		(*retlen) += len;
	}

	return 0;
}


/*
 * FIXME: interleaved mode not tested, and probably not supported!
 */
static inline int do_write_buffer(struct map_info *map, struct flchip *chip, 
				  unsigned long adr, const u_char *buf, int len)
{
	struct cfi_private *cfi = map->fldrv_priv;
	unsigned long timeo = jiffies + HZ;
	/* see comments in do_write_oneword() regarding uWriteTimeo. */
	unsigned long uWriteTimeout = ( HZ / 1000 ) + 1;
	int ret = -EIO;
	unsigned long cmd_adr;
	int z, words;
	map_word datum;

	adr += chip->start;
	cmd_adr = adr;

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

	datum = map_word_load(map, buf);

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

	ENABLE_VPP(map);
	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(0xA0, cfi->addr_unlock1, chip->start, map, cfi, cfi->device_type, NULL);

	/* Write Buffer Load */
	map_write(map, CMD(0x25), cmd_adr);

	chip->state = FL_WRITING_TO_BUFFER;

	/* Write length of data to come */
	words = len / map_bankwidth(map);
	map_write(map, CMD(words - 1), cmd_adr);
	/* Write data */
	z = 0;
	while(z < words * map_bankwidth(map)) {
		datum = map_word_load(map, buf);
		map_write(map, datum, adr + z);

		z += map_bankwidth(map);
		buf += map_bankwidth(map);
	}
	z -= map_bankwidth(map);

	adr += z;

	/* Write Buffer Program Confirm: GO GO GO */
	map_write(map, CMD(0x29), cmd_adr);
	chip->state = FL_WRITING;

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

	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);