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authorLinus Torvalds <torvalds@linux-foundation.org>2022-06-03 11:08:40 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-06-03 11:08:40 -0700
commit932c2989b59008e530ffcc7c7e6ef507a28b28ca (patch)
tree5d51787f2ace2b9a2fd2393662818fd14aa219be /Documentation/firmware-guide
parent4ad680f083ec360e0991c453e18a38ed9ae500d7 (diff)
parent25e02ba60f0fbe65ba07553b5b2b8867726273c4 (diff)
downloadlwn-932c2989b59008e530ffcc7c7e6ef507a28b28ca.tar.gz
lwn-932c2989b59008e530ffcc7c7e6ef507a28b28ca.zip
Merge tag 'tty-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty and serial driver updates from Greg KH: "Here is the big set of tty and serial driver updates for 5.19-rc1. Lots of tiny cleanups in here, the major stuff is: - termbit cleanups and unification by Ilpo. A much needed change that goes a long way to making things simpler for all of the different arches - tty documentation cleanups and movements to their own place in the documentation tree - old tty driver cleanups and fixes from Jiri to bring some existing drivers into the modern world - RS485 cleanups and unifications to make it easier for individual drivers to support this mode instead of having to duplicate logic in each driver - Lots of 8250 driver updates and additions - new device id additions - n_gsm continued fixes and cleanups - other minor serial driver updates and cleanups All of these have been in linux-next for weeks with no reported issues" * tag 'tty-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (166 commits) tty: Rework receive flow control char logic pcmcia: synclink_cs: Don't allow CS5-6 serial: stm32-usart: Correct CSIZE, bits, and parity serial: st-asc: Sanitize CSIZE and correct PARENB for CS7 serial: sifive: Sanitize CSIZE and c_iflag serial: sh-sci: Don't allow CS5-6 serial: txx9: Don't allow CS5-6 serial: rda-uart: Don't allow CS5-6 serial: digicolor-usart: Don't allow CS5-6 serial: uartlite: Fix BRKINT clearing serial: cpm_uart: Fix build error without CONFIG_SERIAL_CPM_CONSOLE serial: core: Do stop_rx in suspend path for console if console_suspend is disabled tty: serial: qcom-geni-serial: Remove uart frequency table. Instead, find suitable frequency with call to clk_round_rate. dt-bindings: serial: renesas,em-uart: Add RZ/V2M clock to access the registers serial: 8250_fintek: Check SER_RS485_RTS_* only with RS485 Revert "serial: 8250_mtk: Make sure to select the right FEATURE_SEL" serial: msm_serial: disable interrupts in __msm_console_write() serial: meson: acquire port->lock in startup() serial: 8250_dw: Use dev_err_probe() serial: 8250_dw: Use devm_add_action_or_reset() ...
Diffstat (limited to 'Documentation/firmware-guide')
-rw-r--r--Documentation/firmware-guide/acpi/enumeration.rst25
1 files changed, 25 insertions, 0 deletions
diff --git a/Documentation/firmware-guide/acpi/enumeration.rst b/Documentation/firmware-guide/acpi/enumeration.rst
index 6b62425ef9cd..dbb03022b127 100644
--- a/Documentation/firmware-guide/acpi/enumeration.rst
+++ b/Documentation/firmware-guide/acpi/enumeration.rst
@@ -389,6 +389,31 @@ 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
===========