mtd: spinand: add OTP support

The MTD subsystem already supports accessing two OTP areas: user and
factory. User areas can be written by the user.

This patch provides the SPINAND_FACT_OTP_INFO and SPINAND_USER_OTP_INFO
macros to add parameters to spinand_info.
To implement OTP operations, the client (flash driver) is provided with
callbacks for user area:
    .read(), .write(), .info(), .lock(), .erase();
and for factory area:
    .read(), .info();

Signed-off-by: Martin Kurbanov <mmkurbanov@salutedevices.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

1 files changed, 93 insertions, 0 deletions

diff --git a/include/linux/mtd/spinand.h b/include/linux/mtd/spinand.h
index 34ddd2441fc9..f4c965ae2f65 100644
--- a/include/linux/mtd/spinand.h
+++ b/include/linux/mtd/spinand.h
@@ -375,6 +375,67 @@ struct spinand_ondie_ecc_conf {
 };
 
 /**
+ * struct spinand_otp_layout - structure to describe the SPI NAND OTP area
+ * @npages: number of pages in the OTP
+ * @start_page: start page of the user/factory OTP area.
+ */
+struct spinand_otp_layout {
+	unsigned int npages;
+	unsigned int start_page;
+};
+
+/**
+ * struct spinand_fact_otp_ops - SPI NAND OTP methods for factory area
+ * @info: get the OTP area information
+ * @read: read from the SPI NAND OTP area
+ */
+struct spinand_fact_otp_ops {
+	int (*info)(struct spinand_device *spinand, size_t len,
+		    struct otp_info *buf, size_t *retlen);
+	int (*read)(struct spinand_device *spinand, loff_t from, size_t len,
+		    size_t *retlen, u8 *buf);
+};
+
+/**
+ * struct spinand_user_otp_ops - SPI NAND OTP methods for user area
+ * @info: get the OTP area information
+ * @lock: lock an OTP region
+ * @erase: erase an OTP region
+ * @read: read from the SPI NAND OTP area
+ * @write: write to the SPI NAND OTP area
+ */
+struct spinand_user_otp_ops {
+	int (*info)(struct spinand_device *spinand, size_t len,
+		    struct otp_info *buf, size_t *retlen);
+	int (*lock)(struct spinand_device *spinand, loff_t from, size_t len);
+	int (*erase)(struct spinand_device *spinand, loff_t from, size_t len);
+	int (*read)(struct spinand_device *spinand, loff_t from, size_t len,
+		    size_t *retlen, u8 *buf);
+	int (*write)(struct spinand_device *spinand, loff_t from, size_t len,
+		     size_t *retlen, const u8 *buf);
+};
+
+/**
+ * struct spinand_fact_otp - SPI NAND OTP grouping structure for factory area
+ * @layout: OTP region layout
+ * @ops: OTP access ops
+ */
+struct spinand_fact_otp {
+	const struct spinand_otp_layout layout;
+	const struct spinand_fact_otp_ops *ops;
+};
+
+/**
+ * struct spinand_user_otp - SPI NAND OTP grouping structure for user area
+ * @layout: OTP region layout
+ * @ops: OTP access ops
+ */
+struct spinand_user_otp {
+	const struct spinand_otp_layout layout;
+	const struct spinand_user_otp_ops *ops;
+};
+
+/**
  * struct spinand_info - Structure used to describe SPI NAND chips
  * @model: model name
  * @devid: device ID
@@ -389,6 +450,8 @@ struct spinand_ondie_ecc_conf {
  * @select_target: function used to select a target/die. Required only for
  *		   multi-die chips
  * @set_cont_read: enable/disable continuous cached reads
+ * @fact_otp: SPI NAND factory OTP info.
+ * @user_otp: SPI NAND user OTP info.
  *
  * Each SPI NAND manufacturer driver should have a spinand_info table
  * describing all the chips supported by the driver.
@@ -409,6 +472,8 @@ struct spinand_info {
 			     unsigned int target);
 	int (*set_cont_read)(struct spinand_device *spinand,
 			     bool enable);
+	struct spinand_fact_otp fact_otp;
+	struct spinand_user_otp user_otp;
 };
 
 #define SPINAND_ID(__method, ...)					\
@@ -437,6 +502,24 @@ struct spinand_info {
 #define SPINAND_CONT_READ(__set_cont_read)				\
 	.set_cont_read = __set_cont_read,
 
+#define SPINAND_FACT_OTP_INFO(__npages, __start_page, __ops)		\
+	.fact_otp = {							\
+		.layout = {						\
+			.npages = __npages,				\
+			.start_page = __start_page,			\
+		},							\
+		.ops = __ops,						\
+	}
+
+#define SPINAND_USER_OTP_INFO(__npages, __start_page, __ops)		\
+	.user_otp = {							\
+		.layout = {						\
+			.npages = __npages,				\
+			.start_page = __start_page,			\
+		},							\
+		.ops = __ops,						\
+	}
+
 #define SPINAND_INFO(__model, __id, __memorg, __eccreq, __op_variants,	\
 		     __flags, ...)					\
 	{								\
@@ -487,6 +570,8 @@ struct spinand_dirmap {
  *		actually relevant to enable this feature.
  * @set_cont_read: Enable/disable the continuous read feature
  * @priv: manufacturer private data
+ * @fact_otp: SPI NAND factory OTP info.
+ * @user_otp: SPI NAND user OTP info.
  */
 struct spinand_device {
 	struct nand_device base;
@@ -519,6 +604,9 @@ struct spinand_device {
 	bool cont_read_possible;
 	int (*set_cont_read)(struct spinand_device *spinand,
 			     bool enable);
+
+	const struct spinand_fact_otp *fact_otp;
+	const struct spinand_user_otp *user_otp;
 };
 
 /**
@@ -594,4 +682,9 @@ int spinand_read_page(struct spinand_device *spinand,
 int spinand_write_page(struct spinand_device *spinand,
 		       const struct nand_page_io_req *req);
 
+size_t spinand_fact_otp_size(struct spinand_device *spinand);
+size_t spinand_user_otp_size(struct spinand_device *spinand);
+
+int spinand_set_mtd_otp_ops(struct spinand_device *spinand);
+
 #endif /* __LINUX_MTD_SPINAND_H */