Messages in this thread Patch in this message | | | From | Miquel Raynal <> | Subject | [PATCH v5 3/4] mtd: Add get_mtd_device_by_node() helper | Date | Wed, 27 Nov 2019 11:55:21 +0100 |
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From: Bernhard Frauendienst <kernel@nospam.obeliks.de>
Add an helper to retrieve a MTD device by its OF node. Since drivers can assign arbitrary names to MTD devices in the absence of a 'label' DT property, there is no other reliable way to retrieve a MTD device for a given OF node.
Signed-off-by: Bernhard Frauendienst <kernel@nospam.obeliks.de> Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> [<miquel.raynal@bootlin.com>: light internals rework] Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> --- drivers/mtd/mtdcore.c | 38 ++++++++++++++++++++++++++++++++++++++ include/linux/mtd/mtd.h | 2 ++ 2 files changed, 40 insertions(+)
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c index 76b4264936ff..5a94a2c0a6de 100644 --- a/drivers/mtd/mtdcore.c +++ b/drivers/mtd/mtdcore.c @@ -985,6 +985,44 @@ struct mtd_info *get_mtd_device_nm(const char *name) } EXPORT_SYMBOL_GPL(get_mtd_device_nm); +/** + * get_mtd_device_by_node - obtain a validated handle for an MTD device + * by of_node + * @of_node: OF node of MTD device to open + * + * This function returns an MTD device structure in case of success, + * an error code otherwise. + */ +struct mtd_info *get_mtd_device_by_node(const struct device_node *of_node) +{ + struct mtd_info *mtd; + bool found = false; + int ret; + + mutex_lock(&mtd_table_mutex); + + mtd_for_each_device(mtd) { + if (of_node == mtd->dev.of_node) { + found = true; + break; + } + } + + if (found) + ret = __get_mtd_device(mtd); + + mutex_unlock(&mtd_table_mutex); + + if (!found) + return ERR_PTR(-ENODEV); + + if (ret) + return ERR_PTR(ret); + + return mtd; +} +EXPORT_SYMBOL_GPL(get_mtd_device_by_node); + void put_mtd_device(struct mtd_info *mtd) { mutex_lock(&mtd_table_mutex); diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h index 677768b21a1d..0f25c476a1a3 100644 --- a/include/linux/mtd/mtd.h +++ b/include/linux/mtd/mtd.h @@ -573,6 +573,8 @@ 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 *get_mtd_device_nm(const char *name); +extern struct mtd_info *get_mtd_device_by_node( + const struct device_node *of_node); extern void put_mtd_device(struct mtd_info *mtd); -- 2.20.1
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