xref: /kernel/linux/linux-5.10/drivers/mtd/chips/Kconfig (revision 8c2ecf20)

# SPDX-License-Identifier: GPL-2.0-only
menu "RAM/ROM/Flash chip drivers"
	depends on MTD!=n

config MTD_CFI
	tristate "Detect flash chips by Common Flash Interface (CFI) probe"
	select MTD_GEN_PROBE
	select MTD_CFI_UTIL
	help
	  The Common Flash Interface specification was developed by Intel,
	  AMD and other flash manufactures that provides a universal method
	  for probing the capabilities of flash devices. If you wish to
	  support any device that is CFI-compliant, you need to enable this
	  option. Visit <https://www.amd.com/products/nvd/overview/cfi.html>
	  for more information on CFI.

config MTD_JEDECPROBE
	tristate "Detect non-CFI AMD/JEDEC-compatible flash chips"
	select MTD_GEN_PROBE
	select MTD_CFI_UTIL
	help
	  This option enables JEDEC-style probing of flash chips which are not
	  compatible with the Common Flash Interface, but will use the common
	  CFI-targeted flash drivers for any chips which are identified which
	  are in fact compatible in all but the probe method. This actually
	  covers most AMD/Fujitsu-compatible chips and also non-CFI
	  Intel chips.

config MTD_GEN_PROBE
	tristate

config MTD_CFI_ADV_OPTIONS
	bool "Flash chip driver advanced configuration options"
	depends on MTD_GEN_PROBE
	help
	  If you need to specify a specific endianness for access to flash
	  chips, or if you wish to reduce the size of the kernel by including
	  support for only specific arrangements of flash chips, say 'Y'. This
	  option does not directly affect the code, but will enable other
	  configuration options which allow you to do so.

	  If unsure, say 'N'.

choice
	prompt "Flash cmd/query data swapping"
	depends on MTD_CFI_ADV_OPTIONS
	default MTD_CFI_NOSWAP
	help
	  This option defines the way in which the CPU attempts to arrange
	  data bits when writing the 'magic' commands to the chips. Saying
	  'NO', which is the default when CONFIG_MTD_CFI_ADV_OPTIONS isn't
	  enabled, means that the CPU will not do any swapping; the chips
	  are expected to be wired to the CPU in 'host-endian' form.
	  Specific arrangements are possible with the BIG_ENDIAN_BYTE and
	  LITTLE_ENDIAN_BYTE, if the bytes are reversed.

config MTD_CFI_NOSWAP
	depends on !ARCH_IXP4XX || CPU_BIG_ENDIAN
	bool "NO"

config MTD_CFI_BE_BYTE_SWAP
	bool "BIG_ENDIAN_BYTE"

config MTD_CFI_LE_BYTE_SWAP
	depends on !ARCH_IXP4XX
	bool "LITTLE_ENDIAN_BYTE"

endchoice

config MTD_CFI_GEOMETRY
	bool "Specific CFI Flash geometry selection"
	depends on MTD_CFI_ADV_OPTIONS
	select MTD_MAP_BANK_WIDTH_1 if  !(MTD_MAP_BANK_WIDTH_2 || \
		 MTD_MAP_BANK_WIDTH_4  || MTD_MAP_BANK_WIDTH_8 || \
		 MTD_MAP_BANK_WIDTH_16 || MTD_MAP_BANK_WIDTH_32)
	select MTD_CFI_I1 if !(MTD_CFI_I2 || MTD_CFI_I4 || MTD_CFI_I8)
	help
	  This option does not affect the code directly, but will enable
	  some other configuration options which would allow you to reduce
	  the size of the kernel by including support for only certain
	  arrangements of CFI chips. If unsure, say 'N' and all options
	  which are supported by the current code will be enabled.

config MTD_MAP_BANK_WIDTH_1
	bool "Support  8-bit buswidth" if MTD_CFI_GEOMETRY
	default y
	help
	  If you wish to support CFI devices on a physical bus which is
	  8 bits wide, say 'Y'.

config MTD_MAP_BANK_WIDTH_2
	bool "Support 16-bit buswidth" if MTD_CFI_GEOMETRY
	default y
	help
	  If you wish to support CFI devices on a physical bus which is
	  16 bits wide, say 'Y'.

config MTD_MAP_BANK_WIDTH_4
	bool "Support 32-bit buswidth" if MTD_CFI_GEOMETRY
	default y
	help
	  If you wish to support CFI devices on a physical bus which is
	  32 bits wide, say 'Y'.

config MTD_MAP_BANK_WIDTH_8
	bool "Support 64-bit buswidth" if MTD_CFI_GEOMETRY
	default n
	help
	  If you wish to support CFI devices on a physical bus which is
	  64 bits wide, say 'Y'.

config MTD_MAP_BANK_WIDTH_16
	bool "Support 128-bit buswidth" if MTD_CFI_GEOMETRY
	default n
	help
	  If you wish to support CFI devices on a physical bus which is
	  128 bits wide, say 'Y'.

config MTD_MAP_BANK_WIDTH_32
	bool "Support 256-bit buswidth" if MTD_CFI_GEOMETRY
	select MTD_COMPLEX_MAPPINGS if HAS_IOMEM
	default n
	help
	  If you wish to support CFI devices on a physical bus which is
	  256 bits wide, say 'Y'.

config MTD_CFI_I1
	bool "Support 1-chip flash interleave" if MTD_CFI_GEOMETRY
	default y
	help
	  If your flash chips are not interleaved - i.e. you only have one
	  flash chip addressed by each bus cycle, then say 'Y'.

config MTD_CFI_I2
	bool "Support 2-chip flash interleave" if MTD_CFI_GEOMETRY
	default y
	help
	  If your flash chips are interleaved in pairs - i.e. you have two
	  flash chips addressed by each bus cycle, then say 'Y'.

config MTD_CFI_I4
	bool "Support 4-chip flash interleave" if MTD_CFI_GEOMETRY
	default n
	help
	  If your flash chips are interleaved in fours - i.e. you have four
	  flash chips addressed by each bus cycle, then say 'Y'.

config MTD_CFI_I8
	bool "Support 8-chip flash interleave" if MTD_CFI_GEOMETRY
	default n
	help
	  If your flash chips are interleaved in eights - i.e. you have eight
	  flash chips addressed by each bus cycle, then say 'Y'.

config MTD_OTP
	bool "Protection Registers aka one-time programmable (OTP) bits"
	depends on MTD_CFI_ADV_OPTIONS
	default n
	help
	  This enables support for reading, writing and locking so called
	  "Protection Registers" present on some flash chips.
	  A subset of them are pre-programmed at the factory with a
	  unique set of values. The rest is user-programmable.

	  The user-programmable Protection Registers contain one-time
	  programmable (OTP) bits; when programmed, register bits cannot be
	  erased. Each Protection Register can be accessed multiple times to
	  program individual bits, as long as the register remains unlocked.

	  Each Protection Register has an associated Lock Register bit. When a
	  Lock Register bit is programmed, the associated Protection Register
	  can only be read; it can no longer be programmed. Additionally,
	  because the Lock Register bits themselves are OTP, when programmed,
	  Lock Register bits cannot be erased. Therefore, when a Protection
	  Register is locked, it cannot be unlocked.

	  This feature should therefore be used with extreme care. Any mistake
	  in the programming of OTP bits will waste them.

config MTD_CFI_INTELEXT
	tristate "Support for CFI command set 0001 (Intel/Sharp chips)"
	depends on MTD_GEN_PROBE
	select MTD_CFI_UTIL
	help
	  The Common Flash Interface defines a number of different command
	  sets which a CFI-compliant chip may claim to implement. This code
	  provides support for command set 0001, used on Intel StrataFlash
	  and other parts.

config MTD_CFI_AMDSTD
	tristate "Support for CFI command set 0002 (AMD/Fujitsu/Spansion chips)"
	depends on MTD_GEN_PROBE
	select MTD_CFI_UTIL
	help
	  The Common Flash Interface defines a number of different command
	  sets which a CFI-compliant chip may claim to implement. This code
	  provides support for command set 0002, used on chips including
	  the AMD Am29LV320.

config MTD_CFI_STAA
	tristate "Support for CFI command set 0020 (ST (Advanced Architecture) chips)"
	depends on MTD_GEN_PROBE
	select MTD_CFI_UTIL
	help
	  The Common Flash Interface defines a number of different command
	  sets which a CFI-compliant chip may claim to implement. This code
	  provides support for command set 0020.

config MTD_CFI_UTIL
	tristate

config MTD_RAM
	tristate "Support for RAM chips in bus mapping"
	help
	  This option enables basic support for RAM chips accessed through
	  a bus mapping driver.

config MTD_ROM
	tristate "Support for ROM chips in bus mapping"
	help
	  This option enables basic support for ROM chips accessed through
	  a bus mapping driver.

config MTD_ABSENT
	tristate "Support for absent chips in bus mapping"
	help
	  This option enables support for a dummy probing driver used to
	  allocated placeholder MTD devices on systems that have socketed
	  or removable media.  Use of this driver as a fallback chip probe
	  preserves the expected registration order of MTD device nodes on
	  the system regardless of media presence.  Device nodes created
	  with this driver will return -ENODEV upon access.

config MTD_XIP
	bool "XIP aware MTD support"
	depends on !SMP && (MTD_CFI_INTELEXT || MTD_CFI_AMDSTD) && ARCH_MTD_XIP
	default y if XIP_KERNEL
	help
	  This allows MTD support to work with flash memory which is also
	  used for XIP purposes.  If you're not sure what this is all about
	  then say N.

endmenu