mtd: spinand: Add support for setting a bus interface

Create a bus interface enumeration, currently only containing the
one we support: SSDR, for single SDR, so any operation whose command is
sent over a single data line in SDR mode, ie. any operation matching
1S-XX-XX.

The main spinand_device structure gets a new parameter to store this
enumeration, for now unused. Of course it is set to SSDR during the SSDR
templates initialization to further clarify the state we are in at the
moment.

This member is subject to be used to know in which bus configuration we
and be updated by the core when we switch to faster mode(s).

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

Author: miquelraynal

drivers/mtd/nand/spi/core.c

@@ -1407,6 +1407,7 @@ static void spinand_init_ssdr_templates(struct spinand_device *spinand)
 	tmpl->page_read = (struct spi_mem_op)SPINAND_PAGE_READ_1S_1S_0_OP(0);
 	tmpl->prog_exec = (struct spi_mem_op)SPINAND_PROG_EXEC_1S_1S_0_OP(0);
 	spinand->op_templates = &spinand->ssdr_op_templates;
+	spinand->bus_iface = SSDR;
 }
 
 static int spinand_support_vendor_ops(struct spinand_device *spinand,

include/linux/mtd/spinand.h

@@ -482,6 +482,14 @@ struct spinand_user_otp {
 	const struct spinand_user_otp_ops *ops;
 };
 
+/**
+ * enum spinand_bus_interface - SPI NAND bus interface types
+ * @SSDR: Bus configuration supporting all 1S-XX-XX operations, including dual and quad
+ */
+enum spinand_bus_interface {
+	SSDR,
+};
+
 /**
  * struct spinand_info - Structure used to describe SPI NAND chips
  * @model: model name
@@ -644,6 +652,7 @@ struct spinand_mem_ops {
  * @flags: NAND flags
  * @ssdr_op_templates: Templates for all single SDR SPI mem operations
  * @op_templates: Templates for all SPI mem operations
+ * @bus_iface: Current bus interface
  * @select_target: select a specific target/die. Usually called before sending
  *		   a command addressing a page or an eraseblock embedded in
  *		   this die. Only required if your chip exposes several dies
@@ -679,6 +688,7 @@ struct spinand_device {
 
 	struct spinand_mem_ops ssdr_op_templates;
 	struct spinand_mem_ops *op_templates;
+	enum spinand_bus_interface bus_iface;
 
 	struct spinand_dirmap *dirmaps;