mtd: spi-nor: add the basic data structures

The spi_nor{} is cloned from the m25p{}.
The spi_nor{} can be used by both the m25p80 and spi-nor controller.

We also add the spi_nor_xfer_cfg{} which can be used by the two
fundamental primitives: read_xfer/write_xfer.

 1) the hooks for spi_nor{}:
    @prepare/unpreare: used to do some work before or after the
             read/write/erase/lock/unlock.
    @read_xfer/write_xfer: We can use these two hooks to code all
             the following hooks if the driver tries to implement them
             by itself.
    @read_reg: used to read the registers, such as read status register,
             read configure register.
    @write_reg: used to write the registers, such as write enable,
             erase sector.
    @read_id: read out the ID info.
    @wait_till_ready: wait till the NOR becomes ready.
    @read: read out the data from the NOR.
    @write: write data to the NOR.
    @erase: erase a sector of the NOR.

 2) Add a new field sst_write_second for the SST NOR write.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

include/linux/mtd/spi-nor.h

@@ -52,4 +52,114 @@
 /* Configuration Register bits. */
 #define CR_QUAD_EN_SPAN		0x2     /* Spansion Quad I/O */
 
+enum read_mode {
+	SPI_NOR_NORMAL = 0,
+	SPI_NOR_FAST,
+	SPI_NOR_DUAL,
+	SPI_NOR_QUAD,
+};
+
+/**
+ * struct spi_nor_xfer_cfg - Structure for defining a Serial Flash transfer
+ * @wren:		command for "Write Enable", or 0x00 for not required
+ * @cmd:		command for operation
+ * @cmd_pins:		number of pins to send @cmd (1, 2, 4)
+ * @addr:		address for operation
+ * @addr_pins:		number of pins to send @addr (1, 2, 4)
+ * @addr_width:		number of address bytes
+ *			(3,4, or 0 for address not required)
+ * @mode:		mode data
+ * @mode_pins:		number of pins to send @mode (1, 2, 4)
+ * @mode_cycles:	number of mode cycles (0 for mode not required)
+ * @dummy_cycles:	number of dummy cycles (0 for dummy not required)
+ */
+struct spi_nor_xfer_cfg {
+	u8		wren;
+	u8		cmd;
+	u8		cmd_pins;
+	u32		addr;
+	u8		addr_pins;
+	u8		addr_width;
+	u8		mode;
+	u8		mode_pins;
+	u8		mode_cycles;
+	u8		dummy_cycles;
+};
+
+#define	SPI_NOR_MAX_CMD_SIZE	8
+enum spi_nor_ops {
+	SPI_NOR_OPS_READ = 0,
+	SPI_NOR_OPS_WRITE,
+	SPI_NOR_OPS_ERASE,
+	SPI_NOR_OPS_LOCK,
+	SPI_NOR_OPS_UNLOCK,
+};
+
+/**
+ * struct spi_nor - Structure for defining a the SPI NOR layer
+ * @mtd:		point to a mtd_info structure
+ * @lock:		the lock for the read/write/erase/lock/unlock operations
+ * @dev:		point to a spi device, or a spi nor controller device.
+ * @page_size:		the page size of the SPI NOR
+ * @addr_width:		number of address bytes
+ * @erase_opcode:	the opcode for erasing a sector
+ * @read_opcode:	the read opcode
+ * @read_dummy:		the dummy needed by the read operation
+ * @program_opcode:	the program opcode
+ * @flash_read:		the mode of the read
+ * @sst_write_second:	used by the SST write operation
+ * @cfg:		used by the read_xfer/write_xfer
+ * @cmd_buf:		used by the write_reg
+ * @prepare:		[OPTIONAL] do some preparations for the
+ *			read/write/erase/lock/unlock operations
+ * @unprepare:		[OPTIONAL] do some post work after the
+ *			read/write/erase/lock/unlock operations
+ * @read_xfer:		[OPTIONAL] the read fundamental primitive
+ * @write_xfer:		[OPTIONAL] the writefundamental primitive
+ * @read_reg:		[DRIVER-SPECIFIC] read out the register
+ * @write_reg:		[DRIVER-SPECIFIC] write data to the register
+ * @read_id:		[REPLACEABLE] read out the ID data, and find
+ *			the proper spi_device_id
+ * @wait_till_ready:	[REPLACEABLE] wait till the NOR becomes ready
+ * @read:		[DRIVER-SPECIFIC] read data from the SPI NOR
+ * @write:		[DRIVER-SPECIFIC] write data to the SPI NOR
+ * @erase:		[DRIVER-SPECIFIC] erase a sector of the SPI NOR
+ *			at the offset @offs
+ * @priv:		the private data
+ */
+struct spi_nor {
+	struct mtd_info		*mtd;
+	struct mutex		lock;
+	struct device		*dev;
+	u32			page_size;
+	u8			addr_width;
+	u8			erase_opcode;
+	u8			read_opcode;
+	u8			read_dummy;
+	u8			program_opcode;
+	enum read_mode		flash_read;
+	bool			sst_write_second;
+	struct spi_nor_xfer_cfg	cfg;
+	u8			cmd_buf[SPI_NOR_MAX_CMD_SIZE];
+
+	int (*prepare)(struct spi_nor *nor, enum spi_nor_ops ops);
+	void (*unprepare)(struct spi_nor *nor, enum spi_nor_ops ops);
+	int (*read_xfer)(struct spi_nor *nor, struct spi_nor_xfer_cfg *cfg,
+			 u8 *buf, size_t len);
+	int (*write_xfer)(struct spi_nor *nor, struct spi_nor_xfer_cfg *cfg,
+			  u8 *buf, size_t len);
+	int (*read_reg)(struct spi_nor *nor, u8 opcode, u8 *buf, int len);
+	int (*write_reg)(struct spi_nor *nor, u8 opcode, u8 *buf, int len,
+			int write_enable);
+	const struct spi_device_id *(*read_id)(struct spi_nor *nor);
+	int (*wait_till_ready)(struct spi_nor *nor);
+
+	int (*read)(struct spi_nor *nor, loff_t from,
+			size_t len, size_t *retlen, u_char *read_buf);
+	void (*write)(struct spi_nor *nor, loff_t to,
+			size_t len, size_t *retlen, const u_char *write_buf);
+	int (*erase)(struct spi_nor *nor, loff_t offs);
+
+	void *priv;
+};
 #endif