From d72f06cee0d5cad0056967f0edc2c23b984238ba Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Tue, 1 Mar 2022 00:39:31 +0200 Subject: [PATCH] ACPI: docs: enumeration: Update UART serial bus resource documentation In some cases UART serial bus resource may be represented by struct serdev_device. Fixes: 53c7626356c7 ("serdev: Add ACPI support") Signed-off-by: Andy Shevchenko Signed-off-by: Rafael J. Wysocki --- Documentation/firmware-guide/acpi/enumeration.rst | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/Documentation/firmware-guide/acpi/enumeration.rst b/Documentation/firmware-guide/acpi/enumeration.rst index cda41e4255eb..799ca240e612 100644 --- a/Documentation/firmware-guide/acpi/enumeration.rst +++ b/Documentation/firmware-guide/acpi/enumeration.rst @@ -19,16 +19,17 @@ possible we decided to do following: platform devices. - Devices behind real busses where there is a connector resource - are represented as struct spi_device or struct i2c_device - (standard UARTs are not busses so there is no struct uart_device). + are represented as struct spi_device or struct i2c_device. Note + that standard UARTs are not busses so there is no struct uart_device, + although some of them may be represented by sturct serdev_device. As both ACPI and Device Tree represent a tree of devices (and their resources) this implementation follows the Device Tree way as much as possible. -The ACPI implementation enumerates devices behind busses (platform, SPI and -I2C), creates the physical devices and binds them to their ACPI handle in -the ACPI namespace. +The ACPI implementation enumerates devices behind busses (platform, SPI, +I2C, and in some cases UART), creates the physical devices and binds them +to their ACPI handle in the ACPI namespace. This means that when ACPI_HANDLE(dev) returns non-NULL the device was enumerated from ACPI namespace. This handle can be used to extract other