mtd: rawnand: Add the concept of destructive operation

Erase and program operations need the WP (Write Protect) pin to be
de-asserted to take effect. Let's 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 guess it from
the command opcode.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>

drivers/mtd/nand/raw/nand_base.c

@@ -1416,7 +1416,8 @@ static int nand_exec_prog_page_op(struct nand_chip *chip, unsigned int page,
 		NAND_OP_CMD(NAND_CMD_PAGEPROG, PSEC_TO_NSEC(sdr->tWB_max)),
 		NAND_OP_WAIT_RDY(PSEC_TO_MSEC(sdr->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);
 	int ret;
 	u8 status;
@@ -1803,7 +1804,8 @@ int nand_erase_op(struct nand_chip *chip, unsigned int eraseblock)
 				    PSEC_TO_MSEC(sdr->tWB_max)),
 			NAND_OP_WAIT_RDY(PSEC_TO_MSEC(sdr->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

@@ -871,13 +871,16 @@ 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
  *
  * The actual operation structure that will be passed to chip->exec_op().
  */
 struct nand_operation {
 	unsigned int cs;
+	bool deassert_wp;
 	const struct nand_op_instr *instrs;
 	unsigned int ninstrs;
 };
@@ -889,6 +892,14 @@ 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);