mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-27 05:35:12 +07:00
f8d3bc1004
Certain EEPROMS have a size that is larger than the number of address bytes would allow, and store the MSB of the address in bit 3 of the instruction byte. This can be described in platform data using EE_INSTR_BIT3_IS_ADDR, or in DT using the obsolete legacy "at25,addr-mode" property. But currently there exists no non-deprecated way to describe this in DT. Hence extend the existing "address-width" DT property to allow specifying 9 address bits, and enable support for that in the driver. This has been tested with a Microchip 25LC040A. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
43 lines
1.3 KiB
Plaintext
43 lines
1.3 KiB
Plaintext
EEPROMs (SPI) compatible with Atmel at25.
|
|
|
|
Required properties:
|
|
- compatible : Should be "<vendor>,<type>", and generic value "atmel,at25".
|
|
Example "<vendor>,<type>" values:
|
|
"microchip,25lc040"
|
|
"st,m95m02"
|
|
"st,m95256"
|
|
|
|
- reg : chip select number
|
|
- spi-max-frequency : max spi frequency to use
|
|
- pagesize : size of the eeprom page
|
|
- size : total eeprom size in bytes
|
|
- address-width : number of address bits (one of 8, 9, 16, or 24).
|
|
For 9 bits, the MSB of the address is sent as bit 3 of the instruction
|
|
byte, before the address byte.
|
|
|
|
Optional properties:
|
|
- spi-cpha : SPI shifted clock phase, as per spi-bus bindings.
|
|
- spi-cpol : SPI inverse clock polarity, as per spi-bus bindings.
|
|
- read-only : this parameter-less property disables writes to the eeprom
|
|
|
|
Obsolete legacy properties can be used in place of "size", "pagesize",
|
|
"address-width", and "read-only":
|
|
- at25,byte-len : total eeprom size in bytes
|
|
- at25,addr-mode : addr-mode flags, as defined in include/linux/spi/eeprom.h
|
|
- at25,page-size : size of the eeprom page
|
|
|
|
Additional compatible properties are also allowed.
|
|
|
|
Example:
|
|
eeprom@0 {
|
|
compatible = "st,m95256", "atmel,at25";
|
|
reg = <0>
|
|
spi-max-frequency = <5000000>;
|
|
spi-cpha;
|
|
spi-cpol;
|
|
|
|
pagesize = <64>;
|
|
size = <32768>;
|
|
address-width = <16>;
|
|
};
|