kernel: backport U-Boot environment data NVMEM driver

[openwrt/openwrt.git] / target / linux / generic / backport-5.15 / 403-v6.1-mtd-allow-getting-MTD-device-associated-with-a-speci.patch

diff --git a/target/linux/generic/backport-5.15/403-v6.1-mtd-allow-getting-MTD-device-associated-with-a-speci.patch b/target/linux/generic/backport-5.15/403-v6.1-mtd-allow-getting-MTD-device-associated-with-a-speci.patch
new file mode 100644 (file)
index 0000000..be1aa9c
--- /dev/null
+++ b/target/linux/generic/backport-5.15/403-v6.1-mtd-allow-getting-MTD-device-associated-with-a-speci.patch
@@ -0,0 +1,72 @@
+From b0321721be50b80c03a51866a94fde4f94690e18 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Wed, 15 Jun 2022 21:42:59 +0200
+Subject: [PATCH] mtd: allow getting MTD device associated with a specific DT
+ node
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+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>
+Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
+---
+ drivers/mtd/mtdcore.c   | 28 ++++++++++++++++++++++++++++
+ include/linux/mtd/mtd.h |  1 +
+ 2 files changed, 29 insertions(+)
+
+--- a/drivers/mtd/mtdcore.c
++++ b/drivers/mtd/mtdcore.c
+@@ -1227,6 +1227,34 @@ int __get_mtd_device(struct mtd_info *mt
+ 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
+  *    @name: MTD device name to open
+--- a/include/linux/mtd/mtd.h
++++ b/include/linux/mtd/mtd.h
+@@ -682,6 +682,7 @@ extern int mtd_device_unregister(struct
+ 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);
+