# 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