mtd/spinand: rework detect procedure for different READ_ID operation

Currently there are 3 different variants of read_id implementation:
1. opcode only. Found in GD5FxGQ4xF.
2. opcode + 1 addr byte. Found in GD5GxGQ4xA/E
3. opcode + 1 dummy byte. Found in other currently supported chips.

Original implementation was for variant 1 and let detect function
of chips with variant 2 and 3 to ignore the first byte. This isn't
robust:

1. For chips of variant 2, if SPI master doesn't keep MOSI low
during read, chip will get a random id offset, and the entire id
buffer will shift by that offset, causing detect failure.

2. For chips of variant 1, if it happens to get a devid that equals
to manufacture id of variant 2 or 3 chips, it'll get incorrectly
detected.

This patch reworks detect procedure to address problems above. New
logic do detection for all variants separatedly, in 1-2-3 order.
Since all current detect methods do exactly the same id matching
procedure, unify them into core.c and remove detect method from
manufacture_ops.

This is a rework of Chuanhong Guo <gch981213@gmail.com> patch
submitted to linux kernel

Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Link: https://lore.kernel.org/all/20230110115843.391630-1-frieder@fris.de
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>

1 files changed, 44 insertions, 22 deletions

diff --git a/include/linux/mtd/spinand.h b/include/linux/mtd/spinand.h
index 15bcd59f34..1ae4dc6b15 100644
--- a/include/linux/mtd/spinand.h
+++ b/include/linux/mtd/spinand.h
@@ -39,9 +39,9 @@
 		   SPI_MEM_OP_NO_DUMMY,					\
 		   SPI_MEM_OP_NO_DATA)
 
-#define SPINAND_READID_OP(ndummy, buf, len)				\
+#define SPINAND_READID_OP(naddr, ndummy, buf, len)			\
 	SPI_MEM_OP(SPI_MEM_OP_CMD(0x9f, 1),				\
-		   SPI_MEM_OP_NO_ADDR,					\
+		   SPI_MEM_OP_ADDR(naddr, 0, 1),			\
 		   SPI_MEM_OP_DUMMY(ndummy, 1),				\
 		   SPI_MEM_OP_DATA_IN(len, buf, 1))
 
@@ -153,37 +153,46 @@ struct spinand_device;
  * @data: buffer containing the id bytes. Currently 4 bytes large, but can
  *	  be extended if required
  * @len: ID length
- *
- * struct_spinand_id->data contains all bytes returned after a READ_ID command,
- * including dummy bytes if the chip does not emit ID bytes right after the
- * READ_ID command. The responsibility to extract real ID bytes is left to
- * struct_manufacurer_ops->detect().
  */
 struct spinand_id {
 	u8 data[SPINAND_MAX_ID_LEN];
 	int len;
 };
 
+enum spinand_readid_method {
+	SPINAND_READID_METHOD_OPCODE,
+	SPINAND_READID_METHOD_OPCODE_ADDR,
+	SPINAND_READID_METHOD_OPCODE_DUMMY,
+};
+
+/**
+ * struct spinand_devid - SPI NAND device id structure
+ * @id: device id of current chip
+ * @len: number of bytes in device id
+ * @method: method to read chip id
+ *	    There are 3 possible variants:
+ *	    SPINAND_READID_METHOD_OPCODE: chip id is returned immediately
+ *	    after read_id opcode.
+ *	    SPINAND_READID_METHOD_OPCODE_ADDR: chip id is returned after
+ *	    read_id opcode + 1-byte address.
+ *	    SPINAND_READID_METHOD_OPCODE_DUMMY: chip id is returned after
+ *	    read_id opcode + 1 dummy byte.
+ */
+struct spinand_devid {
+	const u8 *id;
+	const u8 len;
+	const enum spinand_readid_method method;
+};
+
 /**
  * struct manufacurer_ops - SPI NAND manufacturer specific operations
- * @detect: detect a SPI NAND device. Every time a SPI NAND device is probed
- *	    the core calls the struct_manufacurer_ops->detect() hook of each
- *	    registered manufacturer until one of them return 1. Note that
- *	    the first thing to check in this hook is that the manufacturer ID
- *	    in struct_spinand_device->id matches the manufacturer whose
- *	    ->detect() hook has been called. Should return 1 if there's a
- *	    match, 0 if the manufacturer ID does not match and a negative
- *	    error code otherwise. When true is returned, the core assumes
- *	    that properties of the NAND chip (spinand->base.memorg and
- *	    spinand->base.eccreq) have been filled
  * @init: initialize a SPI NAND device
  * @cleanup: cleanup a SPI NAND device
  *
  * Each SPI NAND manufacturer driver should implement this interface so that
- * NAND chips coming from this vendor can be detected and initialized properly.
+ * NAND chips coming from this vendor can be initialized properly.
  */
 struct spinand_manufacturer_ops {
-	int (*detect)(struct spinand_device *spinand);
 	int (*init)(struct spinand_device *spinand);
 	void (*cleanup)(struct spinand_device *spinand);
 };
@@ -192,11 +201,16 @@ struct spinand_manufacturer_ops {
  * struct spinand_manufacturer - SPI NAND manufacturer instance
  * @id: manufacturer ID
  * @name: manufacturer name
+ * @devid_len: number of bytes in device ID
+ * @chips: supported SPI NANDs under current manufacturer
+ * @nchips: number of SPI NANDs available in chips array
  * @ops: manufacturer operations
  */
 struct spinand_manufacturer {
 	u8 id;
 	char *name;
+	const struct spinand_info *chips;
+	const size_t nchips;
 	const struct spinand_manufacturer_ops *ops;
 };
 
@@ -268,7 +282,7 @@ struct spinand_ecc_info {
  */
 struct spinand_info {
 	const char *model;
-	u8 devid;
+	struct spinand_devid devid;
 	u32 flags;
 	struct nand_memory_organization memorg;
 	struct nand_ecc_req eccreq;
@@ -282,6 +296,13 @@ struct spinand_info {
 			     unsigned int target);
 };
 
+#define SPINAND_ID(__method, ...)					\
+	{								\
+		.id = (const u8[]){ __VA_ARGS__ },			\
+		.len = sizeof((u8[]){ __VA_ARGS__ }),			\
+		.method = __method,					\
+	}
+
 #define SPINAND_INFO_OP_VARIANTS(__read, __write, __update)		\
 	{								\
 		.read_cache = __read,					\
@@ -440,9 +461,10 @@ static inline void spinand_set_ofnode(struct spinand_device *spinand,
 }
 #endif /* __UBOOT__ */
 
-int spinand_match_and_init(struct spinand_device *dev,
+int spinand_match_and_init(struct spinand_device *spinand,
 			   const struct spinand_info *table,
-			   unsigned int table_size, u8 devid);
+			   unsigned int table_size,
+			   enum spinand_readid_method rdid_method);
 
 int spinand_upd_cfg(struct spinand_device *spinand, u8 mask, u8 val);
 int spinand_select_target(struct spinand_device *spinand, unsigned int target);