From 1e70d57e7285996bcf0a226eac8c5ba43a89f85d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= Date: Tue, 26 Apr 2022 15:24:42 +0300 Subject: ACPI / property: Document RS485 _DSD properties MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Document RS485 related properties returned from ACPI _DSD as device properties. Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220426122448.38997-5-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- Documentation/firmware-guide/acpi/enumeration.rst | 25 +++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'Documentation/firmware-guide') 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 =========== -- cgit v1.2.3