[PATCH V4 1/2] mtd: allow getting MTD device associated with a specific DT node
From: Rafał Miłecki <zajec5@gmail.com>
Date: 2022-06-15 19:43:17
Also in:
linux-devicetree, lkml, u-boot
Subsystem:
memory technology devices (mtd), the rest · Maintainers:
Miquel Raynal, Richard Weinberger, Vignesh Raghavendra, Linus Torvalds
From: Rafał Miłecki <rafal@milecki.pl> MTD subsystem API allows interacting with MTD devices (e.g. reading, writing, handling bad blocks). So far a random driver could get MTD device only by its name (get_mtd_device_nm()). This change allows getting them also by a DT node. This API is required for drivers handling DT defined MTD partitions in a specific way (e.g. U-Boot (sub)partition with environment variables). Signed-off-by: Rafał Miłecki <rafal@milecki.pl> Acked-by: Miquel Raynal <miquel.raynal@bootlin.com> --- V3: First introduction of of_get_mtd_device_by_node() V4: Use EPROBE_DEFER Srinivas: in V3 Miquel said it's OK to push this patch through NVMEM --- drivers/mtd/mtdcore.c | 28 ++++++++++++++++++++++++++++ include/linux/mtd/mtd.h | 1 + 2 files changed, 29 insertions(+)
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 9eb0680db312..3613cc142f25 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c@@ -1154,6 +1154,34 @@ int __get_mtd_device(struct mtd_info *mtd) } EXPORT_SYMBOL_GPL(__get_mtd_device); +/** + * of_get_mtd_device_by_node - obtain an MTD device associated with a given node + * + * @np: device tree node + */ +struct mtd_info *of_get_mtd_device_by_node(struct device_node *np) +{ + struct mtd_info *mtd = NULL; + struct mtd_info *tmp; + int err; + + mutex_lock(&mtd_table_mutex); + + err = -EPROBE_DEFER; + mtd_for_each_device(tmp) { + if (mtd_get_of_node(tmp) == np) { + mtd = tmp; + err = __get_mtd_device(mtd); + break; + } + } + + mutex_unlock(&mtd_table_mutex); + + return err ? ERR_PTR(err) : mtd; +} +EXPORT_SYMBOL_GPL(of_get_mtd_device_by_node); + /** * get_mtd_device_nm - obtain a validated handle for an MTD device by * device name
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index 955aee14b0f7..6fc841ceef31 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h@@ -677,6 +677,7 @@ 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); extern void __put_mtd_device(struct mtd_info *mtd); +extern struct mtd_info *of_get_mtd_device_by_node(struct device_node *np); extern struct mtd_info *get_mtd_device_nm(const char *name); extern void put_mtd_device(struct mtd_info *mtd);
--
2.34.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel