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From:   dregan@broadcom.com
To:     dregan@broadcom.com, bcm-kernel-feedback-list@broadcom.com,
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        JaimeLiao <jaimeliao.tw@gmail.com>,
        Arseniy Krasnov <AVKrasnov@sberdevices.ru>,
        Adam Borowski <kilobyte@angband.pl>
Subject: [PATCH v3 2/4] mtd: rawnand: NAND controller write protect
Date:   Tue, 17 Oct 2023 13:14:15 -0700
Message-Id: <20231017201417.129872-2-dregan@broadcom.com>
In-Reply-To: <20231017201417.129872-1-dregan@broadcom.com>
References: <20231017201417.129872-1-dregan@broadcom.com>
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From: David Regan <dregan@broadcom.com>

Allow NAND controller to be responsible for write protect pin
handling during fast path and exec_op destructive operation
when controller_wp flag is set.

Signed-off-by: David Regan <dregan@broadcom.com>
---
Changes in v3: update comments

Changes in v2: none
---
 drivers/mtd/nand/raw/nand_base.c | 4 ++++
 include/linux/mtd/rawnand.h      | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index 47cc2c35153b..38ed0ced5b8e 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -367,6 +367,10 @@ static int nand_check_wp(struct nand_chip *chip)
 	if (chip->options & NAND_BROKEN_XD)
 		return 0;
 
+	/* controller responsible for NAND write protect */
+	if (chip->controller->controller_wp)
+		return 0;
+
 	/* Check the WP bit */
 	ret = nand_status_op(chip, &status);
 	if (ret)
diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h
index 31aceda8616c..fcad94aa0515 100644
--- a/include/linux/mtd/rawnand.h
+++ b/include/linux/mtd/rawnand.h
@@ -1111,6 +1111,7 @@ struct nand_controller_ops {
  *			the bus without restarting an entire read operation nor
  *			changing the column.
  * @supported_op.cont_read: The controller supports sequential cache reads.
+ * @controller_wp:	the controller is in charge of handling the WP pin.
  */
 struct nand_controller {
 	struct mutex lock;
@@ -1119,6 +1120,7 @@ struct nand_controller {
 		unsigned int data_only_read: 1;
 		unsigned int cont_read: 1;
 	} supported_op;
+	bool controller_wp;
 };
 
 static inline void nand_controller_init(struct nand_controller *nfc)
-- 
2.37.3