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| author | Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> | 2022-04-26 14:24:42 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-26 14:48:21 +0200 |
| commit | 1e70d57e7285996bcf0a226eac8c5ba43a89f85d (patch) | |
| tree | d102b02791372763da5a11f7c13fbba154641e17 /Documentation/firmware-guide | |
| parent | dt_bindings: rs485: Add receiver enable polarity (diff) | |
| download | linux-1e70d57e7285996bcf0a226eac8c5ba43a89f85d.tar.xz linux-1e70d57e7285996bcf0a226eac8c5ba43a89f85d.zip | |
ACPI / property: Document RS485 _DSD properties
Document RS485 related properties returned from ACPI _DSD as device
properties.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220426122448.38997-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 =========== |