devfs: partitioning: add new helper devfs_create_partitions

Compared to devfs_add_partition which adds a single partition
devfs_create_partitions creates several partitions at once. One nice
benefit is that this simplifies appending partitions because the start
of the latter partition doesn't need to be specified explicitly.
Also dev_add_bb_dev() is called by the new helper if the bbname is
specified for a partition.

Note that adding partitions is also more flexible now (also via
devfs_add_partition) because negative values for offset and size now
have a proper meaning instead of creating broken partitions.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 33 insertions, 0 deletions

diff --git a/include/driver.h b/include/driver.h
index 33b82c3e96..31bdecf6d8 100644
--- a/include/driver.h
+++ b/include/driver.h
@@ -491,6 +491,39 @@ struct cdev *devfs_add_partition(const char *devname, loff_t offset,
 		loff_t size, unsigned int flags, const char *name);
 int devfs_del_partition(const char *name);
 
+#define DEVFS_PARTITION_APPEND		0
+
+/**
+ * struct devfs_partition - defines parameters for a single partition
+ * @offset: start of partition
+ * 	a negative offset requests to start the partition relative to the
+ * 	device's end. DEVFS_PARTITION_APPEND (i.e. 0) means start directly at
+ * 	the end of the previous partition.
+ * @size: size of partition
+ * 	a non-positive value requests to use a size that keeps -size free space
+ * 	after the current partition. A special case of this is passing 0, which
+ * 	means "until end of device".
+ * @flags: flags passed to devfs_add_partition
+ * @name: name passed to devfs_add_partition
+ * @bbname: if non-NULL also dev_add_bb_dev() is called for the partition during
+ * 	devfs_create_partitions().
+ */
+struct devfs_partition {
+	loff_t offset;
+	loff_t size;
+	unsigned int flags;
+	const char *name;
+	const char *bbname;
+};
+/**
+ * devfs_create_partitions - create a set of partitions for a device
+ * @devname: name of the device to partition
+ * @partinfo: array of partition parameters
+ * 	The array is processed until an entry with .name = NULL is found.
+ */
+int devfs_create_partitions(const char *devname,
+		const struct devfs_partition partinfo[]);
+
 #define DRV_OF_COMPAT(compat) \
 	IS_ENABLED(CONFIG_OFDEVICE) ? (compat) : NULL