mtdchar.c

基于linux-2.6.28的mtd驱动

		struct region_info_user *ur = (struct region_info_user *) argp;

		if (get_user(ur_idx, &(ur->regionindex)))
			return -EFAULT;

		kr = &(mtd->eraseregions[ur_idx]);

		if (put_user(kr->offset, &(ur->offset))
		    || put_user(kr->erasesize, &(ur->erasesize))
		    || put_user(kr->numblocks, &(ur->numblocks)))
			return -EFAULT;

		break;
	}

	case MEMGETINFO:
		info.type	= mtd->type;
		info.flags	= mtd->flags;
		info.size	= mtd->size;
		info.erasesize	= mtd->erasesize;
		info.writesize	= mtd->writesize;
		info.oobsize	= mtd->oobsize;
		/* The below fields are obsolete */
		info.ecctype	= -1;
		info.eccsize	= 0;
		if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
			return -EFAULT;
		break;

	case MEMERASE:
	{
		struct erase_info *erase;

		if(!(file->f_mode & FMODE_WRITE))
			return -EPERM;

		erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
		if (!erase)
			ret = -ENOMEM;
		else {
			wait_queue_head_t waitq;
			DECLARE_WAITQUEUE(wait, current);

			init_waitqueue_head(&waitq);

			if (copy_from_user(&erase->addr, argp,
				    sizeof(struct erase_info_user))) {
				kfree(erase);
				return -EFAULT;
			}
			erase->mtd = mtd;
			erase->callback = mtdchar_erase_callback;
			erase->priv = (unsigned long)&waitq;

			/*
			  FIXME: Allow INTERRUPTIBLE. Which means
			  not having the wait_queue head on the stack.

			  If the wq_head is on the stack, and we
			  leave because we got interrupted, then the
			  wq_head is no longer there when the
			  callback routine tries to wake us up.
			*/
			ret = mtd->erase(mtd, erase);
			if (!ret) {
				set_current_state(TASK_UNINTERRUPTIBLE);
				add_wait_queue(&waitq, &wait);
				if (erase->state != MTD_ERASE_DONE &&
				    erase->state != MTD_ERASE_FAILED)
					schedule();
				remove_wait_queue(&waitq, &wait);
				set_current_state(TASK_RUNNING);

				ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
			}
			kfree(erase);
		}
		break;
	}

	case MEMWRITEOOB:
	{
		struct mtd_oob_buf buf;
		struct mtd_oob_ops ops;
		struct mtd_oob_buf __user *user_buf = argp;
	        uint32_t retlen;

		if(!(file->f_mode & FMODE_WRITE))
			return -EPERM;

		if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
			return -EFAULT;

		if (buf.length > 4096)
			return -EINVAL;

		if (!mtd->write_oob)
			ret = -EOPNOTSUPP;
		else
			ret = access_ok(VERIFY_READ, buf.ptr,
					buf.length) ? 0 : EFAULT;

		if (ret)
			return ret;

		ops.ooblen = buf.length;
		ops.ooboffs = buf.start & (mtd->oobsize - 1);
		ops.datbuf = NULL;
		ops.mode = MTD_OOB_PLACE;

		if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
			return -EINVAL;

		ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
		if (!ops.oobbuf)
			return -ENOMEM;

		if (copy_from_user(ops.oobbuf, buf.ptr, buf.length)) {
			kfree(ops.oobbuf);
			return -EFAULT;
		}

		buf.start &= ~(mtd->oobsize - 1);
		ret = mtd->write_oob(mtd, buf.start, &ops);

		if (ops.oobretlen > 0xFFFFFFFFU)
			ret = -EOVERFLOW;
		retlen = ops.oobretlen;
		if (copy_to_user(&user_buf->length, &retlen, sizeof(buf.length)))
			ret = -EFAULT;

		kfree(ops.oobbuf);
		break;

	}

	case MEMREADOOB:
	{
		struct mtd_oob_buf buf;
		struct mtd_oob_ops ops;

		if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
			return -EFAULT;

		if (buf.length > 4096)
			return -EINVAL;

		if (!mtd->read_oob)
			ret = -EOPNOTSUPP;
		else
			ret = access_ok(VERIFY_WRITE, buf.ptr,
					buf.length) ? 0 : -EFAULT;
		if (ret)
			return ret;

		ops.ooblen = buf.length;
		ops.ooboffs = buf.start & (mtd->oobsize - 1);
		ops.datbuf = NULL;
		ops.mode = MTD_OOB_PLACE;

		if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
			return -EINVAL;

		ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
		if (!ops.oobbuf)
			return -ENOMEM;

		buf.start &= ~(mtd->oobsize - 1);
		ret = mtd->read_oob(mtd, buf.start, &ops);

		if (put_user(ops.oobretlen, (uint32_t __user *)argp))
			ret = -EFAULT;
		else if (ops.oobretlen && copy_to_user(buf.ptr, ops.oobbuf,
						    ops.oobretlen))
			ret = -EFAULT;

		kfree(ops.oobbuf);
		break;
	}

	case MEMLOCK:
	{
		struct erase_info_user einfo;

		if (copy_from_user(&einfo, argp, sizeof(einfo)))
			return -EFAULT;

		if (!mtd->lock)
			ret = -EOPNOTSUPP;
		else
			ret = mtd->lock(mtd, einfo.start, einfo.length);
		break;
	}

	case MEMUNLOCK:
	{
		struct erase_info_user einfo;

		if (copy_from_user(&einfo, argp, sizeof(einfo)))
			return -EFAULT;

		if (!mtd->unlock)
			ret = -EOPNOTSUPP;
		else
			ret = mtd->unlock(mtd, einfo.start, einfo.length);
		break;
	}

	/* Legacy interface */
	case MEMGETOOBSEL:
	{
		struct nand_oobinfo oi;

		if (!mtd->ecclayout)
			return -EOPNOTSUPP;
		if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
			return -EINVAL;

		oi.useecc = MTD_NANDECC_AUTOPLACE;
		memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
		memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
		       sizeof(oi.oobfree));
		oi.eccbytes = mtd->ecclayout->eccbytes;

		if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
			return -EFAULT;
		break;
	}

	case MEMGETBADBLOCK:
	{
		loff_t offs;

		if (copy_from_user(&offs, argp, sizeof(loff_t)))
			return -EFAULT;
		if (!mtd->block_isbad)
			ret = -EOPNOTSUPP;
		else
			return mtd->block_isbad(mtd, offs);
		break;
	}

	case MEMSETBADBLOCK:
	{
		loff_t offs;

		if (copy_from_user(&offs, argp, sizeof(loff_t)))
			return -EFAULT;
		if (!mtd->block_markbad)
			ret = -EOPNOTSUPP;
		else
			return mtd->block_markbad(mtd, offs);
		break;
	}

#ifdef CONFIG_HAVE_MTD_OTP
	case OTPSELECT:
	{
		int mode;
		if (copy_from_user(&mode, argp, sizeof(int)))
			return -EFAULT;

		mfi->mode = MTD_MODE_NORMAL;

		ret = otp_select_filemode(mfi, mode);

		file->f_pos = 0;
		break;
	}

	case OTPGETREGIONCOUNT:
	case OTPGETREGIONINFO:
	{
		struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
		if (!buf)
			return -ENOMEM;
		ret = -EOPNOTSUPP;
		switch (mfi->mode) {
		case MTD_MODE_OTP_FACTORY:
			if (mtd->get_fact_prot_info)
				ret = mtd->get_fact_prot_info(mtd, buf, 4096);
			break;
		case MTD_MODE_OTP_USER:
			if (mtd->get_user_prot_info)
				ret = mtd->get_user_prot_info(mtd, buf, 4096);
			break;
		default:
			break;
		}
		if (ret >= 0) {
			if (cmd == OTPGETREGIONCOUNT) {
				int nbr = ret / sizeof(struct otp_info);
				ret = copy_to_user(argp, &nbr, sizeof(int));
			} else
				ret = copy_to_user(argp, buf, ret);
			if (ret)
				ret = -EFAULT;
		}
		kfree(buf);
		break;
	}

	case OTPLOCK:
	{
		struct otp_info oinfo;

		if (mfi->mode != MTD_MODE_OTP_USER)
			return -EINVAL;
		if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
			return -EFAULT;
		if (!mtd->lock_user_prot_reg)
			return -EOPNOTSUPP;
		ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
		break;
	}
#endif

	case ECCGETLAYOUT:
	{
		if (!mtd->ecclayout)
			return -EOPNOTSUPP;

		if (copy_to_user(argp, mtd->ecclayout,
				 sizeof(struct nand_ecclayout)))
			return -EFAULT;
		break;
	}

	case ECCGETSTATS:
	{
		if (copy_to_user(argp, &mtd->ecc_stats,
				 sizeof(struct mtd_ecc_stats)))
			return -EFAULT;
		break;
	}

	case MTDFILEMODE:
	{
		mfi->mode = 0;

		switch(arg) {
		case MTD_MODE_OTP_FACTORY:
		case MTD_MODE_OTP_USER:
			ret = otp_select_filemode(mfi, arg);
			break;

		case MTD_MODE_RAW:
			if (!mtd->read_oob || !mtd->write_oob)
				return -EOPNOTSUPP;
			mfi->mode = arg;

		case MTD_MODE_NORMAL:
			break;
		default:
			ret = -EINVAL;
		}
		file->f_pos = 0;
		break;
	}

	default:
		ret = -ENOTTY;
	}

	return ret;
} /* memory_ioctl */

static const struct file_operations mtd_fops = {
	.owner		= THIS_MODULE,
	.llseek		= mtd_lseek,
	.read		= mtd_read,
	.write		= mtd_write,
	.ioctl		= mtd_ioctl,
	.open		= mtd_open,
	.release	= mtd_close,
};

static int __init init_mtdchar(void)
{
	if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
		printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
		       MTD_CHAR_MAJOR);
		return -EAGAIN;
	}

	mtd_class = class_create(THIS_MODULE, "mtd");

	if (IS_ERR(mtd_class)) {
		printk(KERN_ERR "Error creating mtd class.\n");
		unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
		return PTR_ERR(mtd_class);
	}

	register_mtd_user(&notifier);
	return 0;
}

static void __exit cleanup_mtdchar(void)
{
	unregister_mtd_user(&notifier);
	class_destroy(mtd_class);
	unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
}

module_init(init_mtdchar);
module_exit(cleanup_mtdchar);


MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <[e-mail]>");
MODULE_DESCRIPTION("Direct character-device access to MTD devices");