mtd: rawnand: Add destructive operation

Erase and program operations need the write protect (wp) pin to be
de-asserted to take effect. Add the concept of destructive
operation and pass the information to exec_op() so controllers know
when they should de-assert this pin without having to decode
the command opcode.
Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: David Regan <dregan@broadcom.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20231125012438.15191-1-dregan@broadcom.com

drivers/mtd/nand/raw/nand_base.c

@@ -1493,7 +1493,8 @@ static int nand_exec_prog_page_op(struct nand_chip *chip, unsigned int page,
 			    NAND_COMMON_TIMING_NS(conf, tWB_max)),
 		NAND_OP_WAIT_RDY(NAND_COMMON_TIMING_MS(conf, tPROG_max), 0),
 	};
-	struct nand_operation op = NAND_OPERATION(chip->cur_cs, instrs);
+	struct nand_operation op = NAND_DESTRUCTIVE_OPERATION(chip->cur_cs,
+							      instrs);
 	int naddrs = nand_fill_column_cycles(chip, addrs, offset_in_page);
 
 	if (naddrs < 0)
@@ -1916,7 +1917,8 @@ int nand_erase_op(struct nand_chip *chip, unsigned int eraseblock)
 			NAND_OP_WAIT_RDY(NAND_COMMON_TIMING_MS(conf, tBERS_max),
 					 0),
 		};
-		struct nand_operation op = NAND_OPERATION(chip->cur_cs, instrs);
+		struct nand_operation op = NAND_DESTRUCTIVE_OPERATION(chip->cur_cs,
+								      instrs);
 
 		if (chip->options & NAND_ROW_ADDR_3)
 			instrs[1].ctx.addr.naddrs++;

include/linux/mtd/rawnand.h

@@ -1003,6 +1003,8 @@ struct nand_op_parser {
 /**
  * struct nand_operation - NAND operation descriptor
  * @cs: the CS line to select for this NAND operation
+ * @deassert_wp: set to true when the operation requires the WP pin to be
+ *		 de-asserted (ERASE, PROG, ...)
  * @instrs: array of instructions to execute
  * @ninstrs: length of the @instrs array
  *
@@ -1010,6 +1012,7 @@ struct nand_op_parser {
  */
 struct nand_operation {
 	unsigned int cs;
+	bool deassert_wp;
 	const struct nand_op_instr *instrs;
 	unsigned int ninstrs;
 };
@@ -1021,6 +1024,14 @@ struct nand_operation {
 		.ninstrs = ARRAY_SIZE(_instrs),			\
 	}
 
+#define NAND_DESTRUCTIVE_OPERATION(_cs, _instrs)		\
+	{							\
+		.cs = _cs,					\
+		.deassert_wp = true,				\
+		.instrs = _instrs,				\
+		.ninstrs = ARRAY_SIZE(_instrs),			\
+	}
+
 int nand_op_parser_exec_op(struct nand_chip *chip,
 			   const struct nand_op_parser *parser,
 			   const struct nand_operation *op, bool check_only);