[PATCH v2 11/15] nand: Add function to unregister NAND devices

[Sean Anderson <seanga2@gmail.com>]

This performs the opposite of nand_register, allowing drivers to unregister
nand devices. This is probably unnecessary for most regular drivers, but we
expect sandbox drivers to get repeatedly bound/unbound, so this will help
avoid dangling pointers.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
---

(no changes since v1)

 drivers/mtd/nand/raw/nand.c | 17 +++++++++++++++++
 include/nand.h              |  1 +
 2 files changed, 18 insertions(+)

diff --git a/drivers/mtd/nand/raw/nand.c b/drivers/mtd/nand/raw/nand.c
index 3abd82068fb..80017b3dddd 100644
--- a/drivers/mtd/nand/raw/nand.c
+++ b/drivers/mtd/nand/raw/nand.c
@@ -74,6 +74,23 @@ int nand_register(int devnum, struct mtd_info *mtd)
 	return 0;
 }
 
+void nand_unregister(struct mtd_info *mtd)
+{
+	int devnum = nand_mtd_to_devnum(mtd);
+
+	if (devnum < 0)
+		return;
+
+	if (nand_curr_device == devnum)
+		nand_curr_device = -1;
+
+	total_nand_size -= mtd->size / 1024;
+
+	del_mtd_device(nand_info[devnum]);
+
+	nand_info[devnum] = NULL;
+}
+
 #if !CONFIG_IS_ENABLED(SYS_NAND_SELF_INIT)
 static void nand_init_chip(int i)
 {
diff --git a/include/nand.h b/include/nand.h
index c1d7533aaac..fc584f5ef7a 100644
--- a/include/nand.h
+++ b/include/nand.h
@@ -22,6 +22,7 @@ int nand_mtd_to_devnum(struct mtd_info *mtd);
 #if CONFIG_IS_ENABLED(SYS_NAND_SELF_INIT)
 void board_nand_init(void);
 int nand_register(int devnum, struct mtd_info *mtd);
+void nand_unregister(struct mtd_info *mtd);
 #else
 struct nand_chip;
 
-- 
2.37.1