[PATCH v3 2/7] mtd: spi-nor: add the basic data structures

[Huang Shijie]

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 at freescale.com>
---
 include/linux/mtd/spi-nor.h |  108 +++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 108 insertions(+), 0 deletions(-)

diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index ab2ea1e..83ca63d 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -50,4 +50,112 @@
 /* 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_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 {
+	struct mtd_info		*mtd;
+	struct mutex		lock;
+
+	/* pointer to a spi device */
+	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;
+
+	/* for write_reg */
+	u8			cmd_buf[SPI_NOR_MAX_CMD_SIZE];
+
+	/*
+	 * Do some work before or after we run these operations:
+	 *   read/write/erese/lock/unlock
+	 */
+	int (*prepare)(struct spi_nor *nor, enum spi_nor_ops ops);
+	void (*unprepare)(struct spi_nor *nor, enum spi_nor_ops ops);
+
+	/*
+	 * The two fundamental primitives, you can use them to implement
+	 * all the other hooks, except the prepare/unprepare.
+	 */
+	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);
+
+	/*
+	 * The two hooks are used to read/write SPI NOR register, such as
+	 * read status register, write status register.
+         */
+	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);
+
+	/*
+	 * The hook for reading out the ID, the spi-nor controller drivers
+         * can fill it with its own implementation if the default
+	 * could not meet its requirement.
+	 */
+	const struct spi_device_id *(*read_id)(struct spi_nor *nor);
+
+	/*
+	 * The hook for "Wait till ready", some spi-nor controller drivers
+	 * may fill it with its own implementation.
+	 */
+	int (*wait_till_ready)(struct spi_nor *nor);
+
+	/* write */
+	void (*write)(struct spi_nor *nor, loff_t to,
+			size_t len, size_t *retlen, const u_char *buf);
+	/* read */
+	int (*read)(struct spi_nor *nor, loff_t from,
+			size_t len, size_t *retlen, u_char *buf);
+	/* erase a sector(4K/64K, etc..) */
+	int (*erase)(struct spi_nor *nor, loff_t offs);
+
+	void *priv;
+};
 #endif
-- 
1.7.2.rc3