mtd: Add partition device node to mtd partition devices

The user visible change here is that mtd partitions get an of_node link
in sysfs.

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

drivers/mtd/mtdpart.c

@@ -432,6 +432,7 @@ static struct mtd_part *allocate_partition(struct mtd_info *master,
 	slave->mtd.dev.parent = IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) ?
 				&master->dev :
 				master->dev.parent;
+	slave->mtd.dev.of_node = part->of_node;
 
 	slave->mtd._read = part_read;
 	slave->mtd._write = part_write;

drivers/mtd/ofpart.c

@@ -108,6 +108,7 @@ static int parse_ofpart_partitions(struct mtd_info *master,
 
 		parts[i].offset = of_read_number(reg, a_cells);
 		parts[i].size = of_read_number(reg + a_cells, s_cells);
+		parts[i].of_node = pp;
 
 		partname = of_get_property(pp, "label", &len);
 		if (!partname)

include/linux/mtd/partitions.h

@@ -41,6 +41,7 @@ struct mtd_partition {
 	uint64_t size;			/* partition size */
 	uint64_t offset;		/* offset within the master MTD space */
 	uint32_t mask_flags;		/* master MTD flags to mask out for this partition */
+	struct device_node *of_node;
 };
 
 #define MTDPART_OFS_RETAIN	(-3)