u-boot/drivers/mtd/spi/Kconfig
Siarhei Siamashka 19e99fb4ff sunxi: Support booting from SPI flash
Allwinner devices support SPI flash as one of the possible
bootable media type. The SPI flash chip needs to be connected
to SPI0 pins (port C) to make this work. More information is
available at:

    https://linux-sunxi.org/Bootable_SPI_flash

This patch adds the initial support for booting from SPI flash.
The existing SPI frameworks are not used in order to reduce the
SPL code size. Right now the SPL size grows by ~370 bytes when
CONFIG_SPL_SPI_SUNXI option is enabled.

While there are no popular Allwinner devices with SPI flash at
the moment, testing can be done using a SPI flash module (it
can be bought for ~2$ on ebay) and jumper wires with the boards,
which expose relevant pins on the expansion header. The SPI flash
chips themselves are very cheap (some prices are even listed as
low as 4 cents) and should not cost much if somebody decides to
design a development board with an SPI flash chip soldered on
the PCB.

Another nice feature of the SPI flash is that it can be safely
accessed in a device-independent way (since we know that the
boot ROM is already probing these pins during the boot time).
And if, for example, Olimex boards opted to use SPI flash instead
of EEPROM, then they would have been able to have U-Boot installed
in the SPI flash now and boot the rest of the system from the SATA
hard drive. Hopefully we may see new interesting Allwinner based
development boards in the future, now that the software support
for the SPI flash is in a better shape :-)

Testing can be done by enabling the CONFIG_SPL_SPI_SUNXI option
in a board defconfig, then building U-Boot and finally flashing
the resulting u-boot-sunxi-with-spl.bin binary over USB OTG with
a help of the sunxi-fel tool:

   sunxi-fel spiflash-write 0 u-boot-sunxi-with-spl.bin

The device needs to be switched into FEL (USB recovery) mode first.
The most suitable boards for testing are Orange Pi PC and Pine64.
Because these boards are cheap, have no built-in NAND/eMMC and
expose SPI0 pins on the Raspberry Pi compatible expansion header.
The A13-OLinuXino-Micro board also can be used.

Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2016-07-15 08:34:34 +02:00

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menu "SPI Flash Support"
config DM_SPI_FLASH
bool "Enable Driver Model for SPI flash"
depends on DM && DM_SPI
help
Enable driver model for SPI flash. This SPI flash interface
(spi_flash_probe(), spi_flash_write(), etc.) is then
implemented by the SPI flash uclass. There is one standard
SPI flash driver which knows how to probe most chips
supported by U-Boot. The uclass interface is defined in
include/spi_flash.h, but is currently fully compatible
with the old interface to avoid confusion and duplication
during the transition parent. SPI and SPI flash must be
enabled together (it is not possible to use driver model
for one and not the other).
config SPI_FLASH_SANDBOX
bool "Support sandbox SPI flash device"
depends on SANDBOX && DM_SPI_FLASH
help
Since sandbox cannot access real devices, an emulation mechanism is
provided instead. Drivers can be connected up to the sandbox SPI
bus (see CONFIG_SANDBOX_SPI) and SPI traffic will be routed to this
device. Typically the contents of the emulated SPI flash device is
stored in a file on the host filesystem.
config SPI_FLASH
bool "Legacy SPI Flash Interface support"
help
Enable the legacy SPI flash support. This will include basic
standard support for things like probing, read / write, and
erasing through cmd_sf interface.
If unsure, say N
config SPI_FLASH_BAR
bool "SPI flash Bank/Extended address register support"
depends on SPI_FLASH
help
Enable the SPI flash Bank/Extended address register support.
Bank/Extended address registers are used to access the flash
which has size > 16MiB in 3-byte addressing.
if SPI_FLASH
config SPI_FLASH_ATMEL
bool "Atmel SPI flash support"
help
Add support for various Atmel SPI flash chips (AT45xxx and AT25xxx)
config SPI_FLASH_EON
bool "EON SPI flash support"
help
Add support for various EON SPI flash chips (EN25xxx)
config SPI_FLASH_GIGADEVICE
bool "GigaDevice SPI flash support"
help
Add support for various GigaDevice SPI flash chips (GD25xxx)
config SPI_FLASH_MACRONIX
bool "Macronix SPI flash support"
help
Add support for various Macronix SPI flash chips (MX25Lxxx)
config SPI_FLASH_SPANSION
bool "Spansion SPI flash support"
help
Add support for various Spansion SPI flash chips (S25FLxxx)
config SPI_FLASH_STMICRO
bool "STMicro SPI flash support"
help
Add support for various STMicro SPI flash chips (M25Pxxx and N25Qxxx)
config SPI_FLASH_SST
bool "SST SPI flash support"
help
Add support for various SST SPI flash chips (SST25xxx)
config SPI_FLASH_WINBOND
bool "Winbond SPI flash support"
help
Add support for various Winbond SPI flash chips (W25xxx)
endif
config SPI_FLASH_USE_4K_SECTORS
bool "Use small 4096 B erase sectors"
depends on SPI_FLASH
default y
help
Many flash memories support erasing small (4096 B) sectors. Depending
on the usage this feature may provide performance gain in comparison
to erasing whole blocks (32/64 KiB).
Changing a small part of the flash's contents is usually faster with
small sectors. On the other hand erasing should be faster when using
64 KiB block instead of 16 × 4 KiB sectors.
Please note that some tools/drivers/filesystems may not work with
4096 B erase size (e.g. UBIFS requires 15 KiB as a minimum).
config SPI_FLASH_DATAFLASH
bool "AT45xxx DataFlash support"
depends on SPI_FLASH && DM_SPI_FLASH
help
Enable the access for SPI-flash-based AT45xxx DataFlash chips.
DataFlash is a kind of SPI flash. Most AT45 chips have two buffers
in each chip, which may be used for double buffered I/O; but this
driver doesn't (yet) use these for any kind of i/o overlap or prefetching.
Sometimes DataFlash is packaged in MMC-format cards, although the
MMC stack can't (yet?) distinguish between MMC and DataFlash
protocols during enumeration.
If unsure, say N
config SPI_FLASH_MTD
bool "SPI Flash MTD support"
depends on SPI_FLASH
help
Enable the MTD support for spi flash layer, this adapter is for
translating mtd_read/mtd_write commands into spi_flash_read/write
commands. It is not intended to use it within sf_cmd or the SPI
flash subsystem. Such an adapter is needed for subsystems like
UBI which can only operate on top of the MTD layer.
If unsure, say N
if SPL
config SPL_SPI_SUNXI
bool "Support for SPI Flash on Allwinner SoCs in SPL"
depends on MACH_SUN4I || MACH_SUN5I || MACH_SUN7I || MACH_SUN8I_H3 || MACH_SUN50I
---help---
Enable support for SPI Flash. This option allows SPL to read from
sunxi SPI Flash. It uses the same method as the boot ROM, so does
not need any extra configuration.
endif
endmenu # menu "SPI Flash Support"