Commit 1c4c215c authored by Dmitry Baryshkov's avatar Dmitry Baryshkov Committed by Artem Bityutskiy
Browse files

mtd: add new API for handling MTD registration 



Lots (nearly all) mtd drivers contain nearly the similar code that
calls parse_mtd_partitions, provides some platform-default values, if
parsing fails, and registers  mtd device.

This is an aim to provide single implementation of this scenario:
mtd_device_parse_register() which will handle all this parsing and
defaults.

Artem: amended comments

Signed-off-by: default avatarDmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: default avatarArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
parent 3761a6dd

drivers/mtd/mtdcore.c

+58 −0
Original line number Diff line number Diff line
@@ -451,6 +451,64 @@ int mtd_device_register(struct mtd_info *master, 
}

EXPORT_SYMBOL_GPL(mtd_device_register);



/**

 * mtd_device_parse_register - parse partitions and register an MTD device.

 *

 * @mtd: the MTD device to register

 * @types: the list of MTD partition probes to try, see

 *         'parse_mtd_partitions()' for more information

 * @origin: start address of MTD device, %0 unless you are sure you need this.

 * @parts: fallback partition information to register, if parsing fails;

 *         only valid if %nr_parts > %0

 * @nr_parts: the number of partitions in parts, if zero then the full

 *            MTD device is registered if no partition info is found

 *

 * This function aggregates MTD partitions parsing (done by

 * 'parse_mtd_partitions()') and MTD device and partitions registering. It

 * basically follows the most common pattern found in many MTD drivers:

 *

 * * It first tries to probe partitions on MTD device @mtd using parsers

 *   specified in @types (if @types is %NULL, then the default list of parsers

 *   is used, see 'parse_mtd_partitions()' for more information). If none are

 *   found this functions tries to fallback to information specified in

 *   @parts/@nr_parts.

 * * If any parititioning info was found, this function registers the found

 *   partitions.

 * * If no partitions were found this function just registers the MTD device

 *   @mtd and exits.

 *

 * Returns zero in case of success and a negative error code in case of failure.

 */

int mtd_device_parse_register(struct mtd_info *mtd, const char **types,

			      unsigned long origin,

			      const struct mtd_partition *parts,

			      int nr_parts)

{

	int err;

	struct mtd_partition *real_parts;



	err = parse_mtd_partitions(mtd, types, &real_parts, origin);

	if (err <= 0 && nr_parts) {

		real_parts = kmemdup(parts, sizeof(*parts) * nr_parts,

				     GFP_KERNEL);

		err = nr_parts;

		if (!parts)

			err = -ENOMEM;

	}



	if (err > 0) {

		err = add_mtd_partitions(mtd, real_parts, err);

		kfree(real_parts);

	} else if (err == 0) {

		err = add_mtd_device(mtd);

		if (err == 1)

			err = -ENODEV;

	}



	return err;

}

EXPORT_SYMBOL_GPL(mtd_device_parse_register);



/**

 * mtd_device_unregister - unregister an existing MTD device.

 *

include/linux/mtd/mtd.h

+5 −0
Original line number Diff line number Diff line
@@ -327,6 +327,11 @@ struct mtd_partition; 
extern int mtd_device_register(struct mtd_info *master,

			       const struct mtd_partition *parts,

			       int nr_parts);

extern int mtd_device_parse_register(struct mtd_info *mtd,

			      const char **part_probe_types,

			      unsigned long origin,

			      const struct mtd_partition *defparts,

			      int defnr_parts);

extern int mtd_device_unregister(struct mtd_info *master);

extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);

extern int __get_mtd_device(struct mtd_info *mtd);