cfi_cmdset_0002.c

一个2.4.21版本的嵌入式linux内核

			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, __u32 datum, int fast)
{
	unsigned long timeo = jiffies + HZ;
	unsigned int oldstatus, status;
	unsigned int dq6, dq5;	
	struct cfi_private *cfi = map->fldrv_priv;
	DECLARE_WAITQUEUE(wait, current);
	int ret = 0;

 retry:
	cfi_spin_lock(chip->mutex);

	if (chip->state != FL_READY) {
#if 0
	        printk(KERN_DEBUG "Waiting for chip to write, 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
		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;
	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. */        
	dq6 = CMD(1<<6);
	dq5 = CMD(1<<5);
	timeo = jiffies + (HZ/1000); /* setting timeout to 1ms for now */
		
	oldstatus = cfi_read(map, adr);
	status = cfi_read(map, adr);

	while( (status & dq6) != (oldstatus & dq6) && 
	       (status & dq5) != dq5 &&
	       !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 );
	}
	
	if( (status & dq6) != (oldstatus & dq6) ) {
		/* The erasing didn't stop?? */
		if( (status & dq5) == dq5 ) {
			/* When DQ5 raises, we must check once again
			   if DQ6 is toggling.  If not, the erase has been
			   completed OK.  If not, reset chip. */
			oldstatus = cfi_read(map, adr);
			status = cfi_read(map, adr);
		    
			if ( (oldstatus & 0x00FF) == (status & 0x00FF) ) {
				printk(KERN_WARNING "Warning: DQ5 raised while program operation was in progress, however operation completed OK\n" );
			} else { 
				/* DQ5 is active so we can do a reset and stop the erase */
				cfi_write(map, CMD(0xF0), chip->start);
				printk(KERN_WARNING "Internal flash device timeout occurred or write operation was performed while flash was programming.\n" );
			}
		} else {
			printk(KERN_WARNING "Waiting for write to complete timed out in do_write_oneword.");        
			
			chip->state = FL_READY;
			wake_up(&chip->wq);
			cfi_spin_unlock(chip->mutex);
			DISABLE_VPP(map);
			ret = -EIO;
		}
	}

	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[4];
		__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[4];
		__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;
	unsigned int dq6, dq5;
	unsigned long timeo = jiffies + HZ;
	unsigned int adr;
	struct cfi_private *cfi = map->fldrv_priv;
	DECLARE_WAITQUEUE(wait, current);

 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;
	
	/* 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 of the last
	 * written byte is toggling it's state with each consectuve 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.
	 */
	dq6 = CMD(1<<6);
	dq5 = CMD(1<<5);

	oldstatus = cfi_read(map, adr);
	status = cfi_read(map, adr);
	while( ((status & dq6) != (oldstatus & dq6)) && 
		((status & dq5) != dq5) &&
		!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 & dq6) != (oldstatus & dq6)) && 
			((status & dq5) != dq5);
			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);
		}
		oldstatus = cfi_read(map, adr);
		status = cfi_read(map, adr);
	}
	if ((status & dq6) != (oldstatus & dq6)) {
		/* The erasing didn't stop?? */
		if ((status & dq5) == dq5) {
			/* dq5 is active so we can do a reset and stop the erase */
			cfi_write(map, CMD(0xF0), chip->start);
		}
		chip->state = FL_READY;
		wake_up(&chip->wq);
		cfi_spin_unlock(chip->mutex);
		printk("waiting for erase to complete timed out.");
		DISABLE_VPP(map);
		return -EIO;
	}
	DISABLE_VPP(map);
	chip->state = FL_READY;
	wake_up(&chip->wq);
	cfi_spin_unlock(chip->mutex);

	return 0;
}

static inline int do_erase_oneblock(struct map_info *map, struct flchip *chip, unsigned long adr)
{
	unsigned int oldstatus, status;
	unsigned int dq6, dq5;
	unsigned long timeo = jiffies + HZ;
	struct cfi_private *cfi = map->fldrv_priv;
	DECLARE_WAITQUEUE(wait, current);

 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;

	adr += chip->start;
	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);