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Diffstat (limited to 'Documentation/firmware-guide')
| -rw-r--r-- | Documentation/firmware-guide/acpi/enumeration.rst | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/Documentation/firmware-guide/acpi/enumeration.rst b/Documentation/firmware-guide/acpi/enumeration.rst index 47fb4d6d4557..f584a6a0c5e3 100644 --- a/Documentation/firmware-guide/acpi/enumeration.rst +++ b/Documentation/firmware-guide/acpi/enumeration.rst @@ -390,6 +390,31 @@ descriptors once the device is released. See Documentation/firmware-guide/acpi/gpio-properties.rst for more information about the _DSD binding related to GPIOs. +RS-485 support +============== + +ACPI _DSD (Device Specific Data) can be used to describe RS-485 capability +of UART. + +For example:: + + Device (DEV) + { + ... + + // ACPI 5.1 _DSD used for RS-485 capabilities + Name (_DSD, Package () + { + ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), + Package () + { + Package () {"rs485-rts-active-low", Zero}, + Package () {"rs485-rx-active-high", Zero}, + Package () {"rs485-rx-during-tx", Zero}, + } + }) + ... + MFD devices =========== |