diff options
Diffstat (limited to 'Documentation/acpi')
| -rw-r--r-- | Documentation/acpi/gpio.md | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/Documentation/acpi/gpio.md b/Documentation/acpi/gpio.md index 344e2ee3f4..a3685b8cbb 100644 --- a/Documentation/acpi/gpio.md +++ b/Documentation/acpi/gpio.md @@ -1,13 +1,13 @@ -# GPIO toggling in ACPI AML for coreboot # +# GPIO toggling in ACPI AML for coreboot -# Table of contents # +## Table of contents - Introduction - Platform Interface - Helper routines - Implementation details - Arguments and Local Variables Management -# Introduction # +## Introduction ACPI provides platform-independent interfaces enabling the operating system to perform power management for devices as well as the entire @@ -25,7 +25,7 @@ depend upon platform to do the required work. This document presents a simple interface that can be used by any coreboot driver to generate ACPI AML code for reading or toggling platform GPIOs. -# Platform Interface # +## Platform Interface All platforms that use drivers requiring ACPI AML code for GPIO interactions need to be implement the following functions: @@ -56,7 +56,7 @@ adding them as AML code callbacks for the following reasons: 3. Allows GPIO AML methods to be present under any device scope and gives SoC the flexibility to call them without any restrictions. -# Helper routines # +## Helper routines In order to relieve drivers of the task of implementing the same code for enabling/disabling Tx GPIOs based on the GPIO polarity, helper @@ -73,7 +73,7 @@ calling the platform specific acpigen_soc_{set,clear}_tx_gpio functions internally. Thus, all the ACPI AML calling conventions for the platform functions apply to these helper functions as well. -# Implementation Details # +## Implementation Details ACPI library in coreboot will provide weak definitions for all the above functions with error messages indicating that these functions @@ -163,7 +163,7 @@ get/set/clear any GPIO. In order to decide whether GPIO operations are required, driver code can rely either on some config option or read device-tree to use any user-provided GPIOs. -# Arguments and Local Variables Management # +## Arguments and Local Variables Management Platform-defined functions can call methods using the same calling conventions provided by AML code. However, use of Local Variables is |