cfi_cmdset_0002.c

带ＳＤ卡的ＬＩＮＵＸ根文件系统． 在ＡＲＭ上应用

		printk(KERN_DEBUG "Wake up to write:\n");
		if(signal_pending(current))
			return -EINTR;
#endif
		timeo = jiffies + HZ;

		goto retry;
	}	

	chip->state = FL_WRITING;

	adr += chip->start;
	DEBUG( MTD_DEBUG_LEVEL3, "MTD %s(): WRITE 0x%.8lx(0x%.8x)\n",
	       __func__, adr, datum );

	ENABLE_VPP(map);
	if (fast) { /* Unlock bypass */
		cfi_send_gen_cmd(0xA0, 0, chip->start, map, cfi, cfi->device_type, NULL);
	}
	else {
	        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);

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

	/*
	 * Polling toggle bits instead of reading back many times
	 * This ensures that write operation is really completed,
	 * or tells us why it failed.
	 *
	 * It appears tha the polling and decoding of error state might
	 * be simplified.  Don't do it unless you really know what you
	 * are doing.  You must remember that JESD21-C 3.5.3 states that
	 * the status must be read back an _additional_ two times before
	 * a failure is determined.  This is because these devices have
	 * internal state machines that are asynchronous to the external
	 * data bus.  During an erase or write the read-back status of the
	 * polling bits might be transitioning internaly when the external
	 * read-back occurs.  This means that the bits aren't in the final
	 * state and they might appear to report an error as they transition
	 * and are in a weird state.  This will produce infrequent errors
	 * that will usually disappear the next time an erase or write
	 * happens (Try tracking those errors down!).  To ensure that
	 * the bits are not in transition the location must be read-back
	 * two more times and compared against what was written - BOTH reads
	 * MUST match what was written - don't think this can be simplified
	 * to only the last read matching.  If the comparison fails, error
	 * state can then be decoded.
	 *
	 * - Thayne Harbaugh
	 */
	dq6 = CMD(1<<6);
	/* See comment above for timeout value. */
	timeo = jiffies + uWriteTimeout; 
		
	oldstatus = cfi_read(map, adr);
	status = cfi_read(map, adr);
	DEBUG( MTD_DEBUG_LEVEL3, "MTD %s(): Check 0x%.8x 0x%.8x\n",
	       __func__, oldstatus, status );

	/*
	 * This only checks if dq6 is still toggling and that our
	 * timer hasn't expired.  We purposefully ignore the chips
	 * internal timer that will assert dq5 and leave dq6 toggling.
	 * This is done for a variety of reasons:
	 * 1) Not all chips support dq5.
	 * 2) Dealing with asynchronous status bit and data updates
	 *    and reading a device two more times creates _messy_
	 *    logic when trying to deal with interleaved devices -
	 *    some may be changing while others are still busy.
	 * 3) Checking dq5 only helps to optimize an error case that
	 *    should at worst be infrequent and at best non-existent.
	 *
	 * If our timeout occurs _then_ we will check dq5 to see
	 * if the device also had an internal timeout.
	 */
	while( ( ( status ^ oldstatus ) & dq6 )
	       && ! ( ta = time_after(jiffies, timeo) ) ) {

		if (need_resched()) {
			cfi_spin_unlock(chip->mutex);
			yield();
			cfi_spin_lock(chip->mutex);
		} else 
			udelay(1);

		oldstatus = cfi_read( map, adr );
		status = cfi_read( map, adr );
		DEBUG( MTD_DEBUG_LEVEL3, "MTD %s(): Check 0x%.8x 0x%.8x\n",
		       __func__, oldstatus, status );
	}

	/*
	 * Something kicked us out of the read-back loop.  We'll
	 * check success befor checking failure.
	 * Even though dq6 might be true data, it is unkown if
	 * all of the other bits have changed to true data due to
	 * the asynchronous nature of the internal state machine.
	 * We will read two more times and use this to either
	 * verify that the write completed successfully or
	 * that something really went wrong.  BOTH reads
	 * must match what was written - this certifies that
	 * bits aren't still changing  and that the status
	 * bits erroneously match the datum that was written.
	 */
	prev_oldstatus = oldstatus;
	prev_status = status;
	oldstatus = cfi_read(map, adr);
	status = cfi_read(map, adr);
	DEBUG( MTD_DEBUG_LEVEL3, "MTD %s(): Check 0x%.8x 0x%.8x\n",
	       __func__, oldstatus, status );

	if ( oldstatus == datum && status == datum ) {
		/* success - do nothing */
		goto write_done;
	}

	if ( ta ) {
		int dq5mask = ( ( status ^ oldstatus ) & dq6 ) >> 1;
		if ( status & dq5mask ) {
			/* dq5 asserted - decode interleave chips */
			printk( KERN_WARNING
				"MTD %s(): FLASH internal timeout: 0x%.8x\n",
				__func__,
				status & dq5mask );
		} else {
			printk( KERN_WARNING
				"MTD %s(): Software timed out during write.\n",
				__func__ );
		}
		goto write_failed;
	}

	/*
	 * If we get to here then it means that something
	 * is wrong and it's not a timeout.  Something
	 * is seriously wacky!  Dump some debug info.
	 */
	printk(KERN_WARNING
	       "MTD %s(): Wacky!  Unable to decode failure status\n",
	       __func__ );

	printk(KERN_WARNING
	       "MTD %s(): 0x%.8lx(0x%.8x): 0x%.8x 0x%.8x 0x%.8x 0x%.8x\n",
	       __func__, adr, datum,
	       prev_oldstatus, prev_status,
	       oldstatus, status);

 write_failed:
	ret = -EIO;
	/* reset on all failures. */
	cfi_write( map, CMD(0xF0), chip->start );

 write_done:
	DISABLE_VPP(map);
	chip->state = FL_READY;
	wake_up(&chip->wq);
	cfi_spin_unlock(chip->mutex);

	return ret;
}

static int cfi_amdstd_write (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;

	*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];
		__u32 datum;

		map->copy_from(map, tmp_buf, bus_ofs + cfi->chips[chipnum].start, CFIDEV_BUSWIDTH);
		while (len && i < CFIDEV_BUSWIDTH)
			tmp_buf[i++] = buf[n++], len--;

		if (cfi_buswidth_is_2()) {
			datum = *(__u16*)tmp_buf;
		} else if (cfi_buswidth_is_4()) {
			datum = *(__u32*)tmp_buf;
		} else {
			return -EINVAL;  /* should never happen, but be safe */
		}

		ret = do_write_oneword(map, &cfi->chips[chipnum], 
				       bus_ofs, datum, 0);
		if (ret) 
			return ret;
		
		ofs += n;
		buf += n;
		(*retlen) += n;

		if (ofs >> cfi->chipshift) {
			chipnum ++; 
			ofs = 0;
			if (chipnum == cfi->numchips)
				return 0;
		}
	}
	
	if (cfi->fast_prog) {
		/* Go into unlock bypass mode */
		cfi_send_gen_cmd(0xAA, cfi->addr_unlock1, chipstart, map, cfi, CFI_DEVICETYPE_X8, NULL);
		cfi_send_gen_cmd(0x55, cfi->addr_unlock2, chipstart, map, cfi, CFI_DEVICETYPE_X8, NULL);
		cfi_send_gen_cmd(0x20, cfi->addr_unlock1, chipstart, map, cfi, CFI_DEVICETYPE_X8, NULL);
	}

	/* We are now aligned, write as much as possible */
	while(len >= CFIDEV_BUSWIDTH) {
		__u32 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;
		} else {
			return -EINVAL;
		}
		ret = do_write_oneword(map, &cfi->chips[chipnum],
				       ofs, datum, cfi->fast_prog);
		if (ret) {
			if (cfi->fast_prog){
				/* Get out of unlock bypass mode */
				cfi_send_gen_cmd(0x90, 0, chipstart, map, cfi, cfi->device_type, NULL);
				cfi_send_gen_cmd(0x00, 0, chipstart, map, cfi, cfi->device_type, NULL);
			}
			return ret;
		}

		ofs += CFIDEV_BUSWIDTH;
		buf += CFIDEV_BUSWIDTH;
		(*retlen) += CFIDEV_BUSWIDTH;
		len -= CFIDEV_BUSWIDTH;

		if (ofs >> cfi->chipshift) {
			if (cfi->fast_prog){
				/* Get out of unlock bypass mode */
				cfi_send_gen_cmd(0x90, 0, chipstart, map, cfi, cfi->device_type, NULL);
				cfi_send_gen_cmd(0x00, 0, chipstart, map, cfi, cfi->device_type, NULL);
			}

			chipnum ++; 
			ofs = 0;
			if (chipnum == cfi->numchips)
				return 0;
			chipstart = cfi->chips[chipnum].start;
			if (cfi->fast_prog){
				/* Go into unlock bypass mode for next set of chips */
				cfi_send_gen_cmd(0xAA, cfi->addr_unlock1, chipstart, map, cfi, CFI_DEVICETYPE_X8, NULL);
				cfi_send_gen_cmd(0x55, cfi->addr_unlock2, chipstart, map, cfi, CFI_DEVICETYPE_X8, NULL);
				cfi_send_gen_cmd(0x20, cfi->addr_unlock1, chipstart, map, cfi, CFI_DEVICETYPE_X8, NULL);
			}
		}
	}

	if (cfi->fast_prog){
		/* Get out of unlock bypass mode */
		cfi_send_gen_cmd(0x90, 0, chipstart, map, cfi, cfi->device_type, NULL);
		cfi_send_gen_cmd(0x00, 0, chipstart, map, cfi, cfi->device_type, NULL);
	}

	/* Write the trailing bytes if any */
	if (len & (CFIDEV_BUSWIDTH-1)) {
		int i = 0, n = 0;
		u_char tmp_buf[8];
		__u32 datum;

		map->copy_from(map, tmp_buf, ofs + cfi->chips[chipnum].start, CFIDEV_BUSWIDTH);
		while (len--)
			tmp_buf[i++] = buf[n++];

		if (cfi_buswidth_is_2()) {
			datum = *(__u16*)tmp_buf;
		} else if (cfi_buswidth_is_4()) {
			datum = *(__u32*)tmp_buf;
		} else {
			return -EINVAL;  /* should never happen, but be safe */
		}

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

	return 0;
}

static inline int do_erase_chip(struct map_info *map, struct flchip *chip)
{
	unsigned int oldstatus, status, prev_oldstatus, prev_status;
	unsigned int dq6;
	unsigned long timeo = jiffies + HZ;
	unsigned long int adr;
	struct cfi_private *cfi = map->fldrv_priv;
	DECLARE_WAITQUEUE(wait, current);
	int ret = 0;
	int ta = 0;
	__u32 ones = 0;

 retry:
	cfi_spin_lock(chip->mutex);

	if (chip->state != FL_READY){
		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;
	}	

	chip->state = FL_ERASING;
	DEBUG( MTD_DEBUG_LEVEL3, "MTD %s(): ERASE 0x%.8lx\n",
	       __func__, chip->start );
	
	/* Handle devices with one erase region, that only implement
	 * the chip erase command.
	 */
	ENABLE_VPP(map);
	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(0x80, cfi->addr_unlock1, chip->start, map, cfi, CFI_DEVICETYPE_X8, NULL);
	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(0x10, cfi->addr_unlock1, chip->start, map, cfi, CFI_DEVICETYPE_X8, NULL);
	timeo = jiffies + (HZ*20);
	adr = cfi->addr_unlock1;

	/* Wait for the end of programing/erasure by using the toggle method.
	 * As long as there is a programming procedure going on, bit 6
	 * is toggling it's state with each consecutive read.
	 * The toggling stops as soon as the procedure is completed.
	 *
	 * If the process has gone on for too long on the chip bit 5 gets.
	 * After bit5 is set you can kill the operation by sending a reset
	 * command to the chip.
	 */
	/* see comments in do_write_oneword */
	dq6 = CMD(1<<6);

	oldstatus = cfi_read(map, adr);
	status = cfi_read(map, adr);
	DEBUG( MTD_DEBUG_LEVEL3, "MTD %s(): Check 0x%.8x 0x%.8x\n",
	       __func__, oldstatus, status );

	while( ( ( status ^ oldstatus ) & dq6 )
	       && ! ( ta = time_after(jiffies, timeo) ) ) {
		int wait_reps;

		/* an initial short sleep */
		cfi_spin_unlock(chip->mutex);
		schedule_timeout(HZ/100);
		cfi_spin_lock(chip->mutex);
		
		if (chip->state != FL_ERASING) {
			/* Someone's suspended the erase. Sleep */
			set_current_state(TASK_UNINTERRUPTIBLE);
			add_wait_queue(&chip->wq, &wait);
			
			cfi_spin_unlock(chip->mutex);
			printk("erase suspended. Sleeping\n");
			
			schedule();
			remove_wait_queue(&chip->wq, &wait);
#if 0			
			if (signal_pending(current))
				return -EINTR;
#endif			
			timeo = jiffies + (HZ*2); /* FIXME */
			cfi_spin_lock(chip->mutex);
			continue;
		}

		/* Busy wait for 1/10 of a milisecond */
		for(wait_reps = 0;
		    (wait_reps < 100)
			    && ( ( status ^ oldstatus ) & dq6 );
		    wait_reps++) {
			
			/* Latency issues. Drop the lock, wait a while and retry */
			cfi_spin_unlock(chip->mutex);

			cfi_udelay(1);

			cfi_spin_lock(chip->mutex);
			oldstatus = cfi_read(map, adr);
			status = cfi_read(map, adr);
			DEBUG( MTD_DEBUG_LEVEL3, "MTD %s(): Check 0x%.8x 0x%.8x\n",
			       __func__, oldstatus, status );
		}
		oldstatus = cfi_read(map, adr);
		status = cfi_read(map, adr);
		DEBUG( MTD_DEBUG_LEVEL3, "MTD %s(): Check 0x%.8x 0x%.8x\n",
		       __func__, oldstatus, status );
	}

	prev_oldstatus = oldstatus;
	prev_status = status;
	oldstatus = cfi_read(map, adr);
	status = cfi_read(map, adr);
	DEBUG( MTD_DEBUG_LEVEL3, "MTD %s(): Check 0x%.8x 0x%.8x\n",
	       __func__, oldstatus, status );

	ones = CMD( (__u8)~0 );
	
	if ( oldstatus == ones && status == ones ) {
		/* success - do nothing */
		goto erase_done;
	}

	if ( ta ) {
		int dq5mask = ( ( status ^ oldstatus ) & dq6 ) >> 1;
		if ( status & dq5mask ) {
			/* dq5 asserted - decode interleave chips */
			printk( KERN_WARNING
				"MTD %s(): FLASH internal timeout: 0x%.8x\n",
				__func__,
				status & dq5mask );
		} else {
			printk( KERN_WARNING
				"MTD %s(): Software timed out during write.\n",
				__func__ );
		}
		goto erase_failed;
	}

	printk(KERN_WARNING
	       "MTD %s(): Wacky!  Unable to decode failure status\n",
	       __func__ );

	printk(KERN_WARNING
	       "MTD %s(): 0x%.8lx(0x%.8x): 0x%.8x 0x%.8x 0x%.8x 0x%.8x\n",
	       __func__, adr, ones,
	       prev_oldstatus, prev_status,
	       oldstatus, status);

 erase_failed:
	ret = -EIO;
	/* reset on all failures. */
	cfi_write( map, CMD(0xF0), chip->start );

 erase_done:
	DISABLE_VPP(map);
	chip->state = FL_READY;
	wake_up(&chip->wq);
	cfi_spin_unlock(chip->mutex);
	return ret;
}


static inline int do_erase_oneblock(struct map_info *map, struct flchip *chip, unsigned long adr)
{
	unsigned int oldstatus, status, prev_oldstatus, prev_status;
	unsigned int dq6;
	unsigned long timeo = jiffies + HZ;
	struct cfi_private *cfi = map->fldrv_priv;
	DECLARE_WAITQUEUE(wait, current);
	int ret = 0;