Why should move the spi-nor commands to a header?
The reason is caused by the Freescale's Quadspi controller.
(0) What is the Quadspi controller?
The Quadspi(Quad Serial Peripheral Interface) acts as an interface to
one single or two external serial flash devices, each with up to 4
bidirectional data lines.
(1) The Quadspi controller is driven by the LUT(Look-up Table) registers.
The LUT registers are a look-up-table for sequences of instructions.
A valid sequence consists of four LUT registers.
(2) The definition of the LUT register shows below:
---------------------------------------------------
| INSTR1 | PAD1 | OPRND1 | INSTR0 | PAD0 | OPRND0 |
---------------------------------------------------
There are several types of INSTRx, such as:
CMD : the SPI NOR command.
ADDR : the address for the SPI NOR command.
DUMMY : the dummy cycles needed by the SPI NOR command.
....
(3) We should pre-populate the LUT table before the Quadspi controller
starts to work. Take the SPI Write Enable command for example, we
should set the LUT table like this:
INSTR0 = CMD; PAD0 = 0; OPRND0 = 0x06 (SPI Write Enable command)
(4) Conclusion:
We need to move the SPI NOR commands to a separate header which can be
used the m25p80.c and the drivers, such Quadspi controller.
(It seems the spear-smi.c driver also needs this header.)
Signed-off-by: Huang Shijie <b32955@xxxxxxxxxxxxx>
---
drivers/mtd/devices/m25p80.c | 42 +--------------------------------
include/linux/mtd/spi-nor.h | 53 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 54 insertions(+), 41 deletions(-)
create mode 100644 include/linux/mtd/spi-nor.h
diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index 26b14f9..299cc69 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -30,52 +30,12 @@
#include <linux/mtd/cfi.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
+#include <linux/mtd/spi-nor.h>
#include <linux/of_platform.h>
#include <linux/spi/spi.h>
#include <linux/spi/flash.h>
-/* Flash opcodes. */
-#define OPCODE_WREN 0x06 /* Write enable */
-#define OPCODE_RDSR 0x05 /* Read status register */
-#define OPCODE_WRSR 0x01 /* Write status register 1 byte */
-#define OPCODE_NORM_READ 0x03 /* Read data bytes (low frequency) */
-#define OPCODE_FAST_READ 0x0b /* Read data bytes (high frequency) */
-#define OPCODE_PP 0x02 /* Page program (up to 256 bytes) */
-#define OPCODE_BE_4K 0x20 /* Erase 4KiB block */
-#define OPCODE_BE_4K_PMC 0xd7 /* Erase 4KiB block on PMC chips */
-#define OPCODE_BE_32K 0x52 /* Erase 32KiB block */
-#define OPCODE_CHIP_ERASE 0xc7 /* Erase whole flash chip */
-#define OPCODE_SE 0xd8 /* Sector erase (usually 64KiB) */
-#define OPCODE_RDID 0x9f /* Read JEDEC ID */
-
-/* 4-byte address opcodes - used on Spansion and some Macronix flashes. */
-#define OPCODE_NORM_READ_4B 0x13 /* Read data bytes (low frequency) */
-#define OPCODE_FAST_READ_4B 0x0c /* Read data bytes (high frequency) */
-#define OPCODE_PP_4B 0x12 /* Page program (up to 256 bytes) */
-#define OPCODE_SE_4B 0xdc /* Sector erase (usually 64KiB) */
-
-/* Used for SST flashes only. */
-#define OPCODE_BP 0x02 /* Byte program */
-#define OPCODE_WRDI 0x04 /* Write disable */
-#define OPCODE_AAI_WP 0xad /* Auto address increment word program */
-
-/* Used for Macronix and Winbond flashes. */
-#define OPCODE_EN4B 0xb7 /* Enter 4-byte mode */
-#define OPCODE_EX4B 0xe9 /* Exit 4-byte mode */
-
-/* Used for Spansion flashes only. */
-#define OPCODE_BRWR 0x17 /* Bank register write */
-
-/* Status Register bits. */
-#define SR_WIP 1 /* Write in progress */
-#define SR_WEL 2 /* Write enable latch */
-/* meaning of other SR_* bits may differ between vendors */
-#define SR_BP0 4 /* Block protect 0 */
-#define SR_BP1 8 /* Block protect 1 */
-#define SR_BP2 0x10 /* Block protect 2 */
-#define SR_SRWD 0x80 /* SR write protect */
-
/* Define max times to check status register before we give up. */
#define MAX_READY_WAIT_JIFFIES (40 * HZ) /* M25P16 specs 40s max chip erase */
#define MAX_CMD_SIZE 5
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
new file mode 100644
index 0000000..f2637b9
--- /dev/null
+++ b/include/linux/mtd/spi-nor.h
@@ -0,0 +1,53 @@
+/*
+ * This header contains the SPI-NOR commands and the relative macros
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+#ifndef __LINUX_MTD_SPI_NOR_H
+#define __LINUX_MTD_SPI_NOR_H
+
+/* Flash opcodes. */
+#define OPCODE_WREN 0x06 /* Write enable */
+#define OPCODE_RDSR 0x05 /* Read status register */
+#define OPCODE_WRSR 0x01 /* Write status register 1 byte */
+#define OPCODE_NORM_READ 0x03 /* Read data bytes (low frequency) */
+#define OPCODE_FAST_READ 0x0b /* Read data bytes (high frequency) */
+#define OPCODE_PP 0x02 /* Page program (up to 256 bytes) */
+#define OPCODE_BE_4K 0x20 /* Erase 4KiB block */
+#define OPCODE_BE_4K_PMC 0xd7 /* Erase 4KiB block on PMC chips */
+#define OPCODE_BE_32K 0x52 /* Erase 32KiB block */
+#define OPCODE_CHIP_ERASE 0xc7 /* Erase whole flash chip */
+#define OPCODE_SE 0xd8 /* Sector erase (usually 64KiB) */
+#define OPCODE_RDID 0x9f /* Read JEDEC ID */
+
+/* 4-byte address opcodes - used on Spansion and some Macronix flashes. */
+#define OPCODE_NORM_READ_4B 0x13 /* Read data bytes (low frequency) */
+#define OPCODE_FAST_READ_4B 0x0c /* Read data bytes (high frequency) */
+#define OPCODE_PP_4B 0x12 /* Page program (up to 256 bytes) */
+#define OPCODE_SE_4B 0xdc /* Sector erase (usually 64KiB) */
+
+/* Used for SST flashes only. */
+#define OPCODE_BP 0x02 /* Byte program */
+#define OPCODE_WRDI 0x04 /* Write disable */
+#define OPCODE_AAI_WP 0xad /* Auto address increment word program */
+
+/* Used for Macronix and Winbond flashes. */
+#define OPCODE_EN4B 0xb7 /* Enter 4-byte mode */
+#define OPCODE_EX4B 0xe9 /* Exit 4-byte mode */
+
+/* Used for Spansion flashes only. */
+#define OPCODE_BRWR 0x17 /* Bank register write */
+
+/* Status Register bits. */
+#define SR_WIP 1 /* Write in progress */
+#define SR_WEL 2 /* Write enable latch */
+/* meaning of other SR_* bits may differ between vendors */
+#define SR_BP0 4 /* Block protect 0 */
+#define SR_BP1 8 /* Block protect 1 */
+#define SR_BP2 0x10 /* Block protect 2 */
+#define SR_SRWD 0x80 /* SR write protect */
+
+#endif /* __LINUX_MTD_SPI_NOR_H */
--
1.7.1
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