path: root/Documentation/acpi
diff options
authorLinus Torvalds <>2015-04-14 20:21:54 -0700
committerLinus Torvalds <>2015-04-14 20:21:54 -0700
commit2481bc75283ea10e75d5fb1a8b42af363fc4b45c (patch)
tree42dd659a23041a08955aceebab859b616164c2f6 /Documentation/acpi
parent8691c130fae136bb2b7d0554422a2dff4c6ac169 (diff)
parent518b4e272d99dcb13699b229ea480bc845c141f6 (diff)
Merge tag 'pm+acpi-4.1-rc1' of git://
Pull power management and ACPI updates from Rafael Wysocki: "These are mostly fixes and cleanups all over, although there are a few items that sort of fall into the new feature category. First off, we have new callbacks for PM domains that should help us to handle some issues related to device initialization in a better way. There also is some consolidation in the unified device properties API area allowing us to use that inferface for accessing data coming from platform initialization code in addition to firmware-provided data. We have some new device/CPU IDs in a few drivers, support for new chips and a new cpufreq driver too. Specifics: - Generic PM domains support update including new PM domain callbacks to handle device initialization better (Russell King, Rafael J Wysocki, Kevin Hilman) - Unified device properties API update including a new mechanism for accessing data provided by platform initialization code (Rafael J Wysocki, Adrian Hunter) - ARM cpuidle update including ARM32/ARM64 handling consolidation (Daniel Lezcano) - intel_idle update including support for the Silvermont Core in the Baytrail SOC and for the Airmont Core in the Cherrytrail and Braswell SOCs (Len Brown, Mathias Krause) - New cpufreq driver for Hisilicon ACPU (Leo Yan) - intel_pstate update including support for the Knights Landing chip (Dasaratharaman Chandramouli, Kristen Carlson Accardi) - QorIQ cpufreq driver update (Tang Yuantian, Arnd Bergmann) - powernv cpufreq driver update (Shilpasri G Bhat) - devfreq update including Tegra support changes (Tomeu Vizoso, MyungJoo Ham, Chanwoo Choi) - powercap RAPL (Running-Average Power Limit) driver update including support for Intel Broadwell server chips (Jacob Pan, Mathias Krause) - ACPI device enumeration update related to the handling of the special PRP0001 device ID allowing DT-style 'compatible' property to be used for ACPI device identification (Rafael J Wysocki) - ACPI EC driver update including limited _DEP support (Lan Tianyu, Lv Zheng) - ACPI backlight driver update including a new mechanism to allow native backlight handling to be forced on non-Windows 8 systems and a new quirk for Lenovo Ideapad Z570 (Aaron Lu, Hans de Goede) - New Windows Vista compatibility quirk for Sony VGN-SR19XN (Chen Yu) - Assorted ACPI fixes and cleanups (Aaron Lu, Martin Kepplinger, Masanari Iida, Mika Westerberg, Nan Li, Rafael J Wysocki) - Fixes related to suspend-to-idle for the iTCO watchdog driver and the ACPI core system suspend/resume code (Rafael J Wysocki, Chen Yu) - PM tracing support for the suspend phase of system suspend/resume transitions (Zhonghui Fu) - Configurable delay for the system suspend/resume testing facility (Brian Norris) - PNP subsystem cleanups (Peter Huewe, Rafael J Wysocki)" * tag 'pm+acpi-4.1-rc1' of git:// (74 commits) ACPI / scan: Fix NULL pointer dereference in acpi_companion_match() ACPI / scan: Rework modalias creation when "compatible" is present intel_idle: mark cpu id array as __initconst powercap / RAPL: mark rapl_ids array as __initconst powercap / RAPL: add ID for Broadwell server intel_pstate: Knights Landing support intel_pstate: remove MSR test cpufreq: fix qoriq uniprocessor build ACPI / scan: Take the PRP0001 position in the list of IDs into account ACPI / scan: Simplify acpi_match_device() ACPI / scan: Generalize of_compatible matching device property: Introduce firmware node type for platform data device property: Make it possible to use secondary firmware nodes PM / watchdog: iTCO: stop watchdog during system suspend cpufreq: hisilicon: add acpu driver ACPI / EC: Call acpi_walk_dep_device_list() after installing EC opregion handler cpufreq: powernv: Report cpu frequency throttling intel_idle: Add support for the Airmont Core in the Cherrytrail and Braswell SOCs intel_idle: Update support for Silvermont Core in Baytrail SOC PM / devfreq: tegra: Register governor on module init ...
Diffstat (limited to 'Documentation/acpi')
1 files changed, 23 insertions, 3 deletions
diff --git a/Documentation/acpi/enumeration.txt b/Documentation/acpi/enumeration.txt
index 9b121a569ab4..750401f91341 100644
--- a/Documentation/acpi/enumeration.txt
+++ b/Documentation/acpi/enumeration.txt
@@ -254,8 +254,13 @@ GPIO support
ACPI 5 introduced two new resources to describe GPIO connections: GpioIo
and GpioInt. These resources are used be used to pass GPIO numbers used by
-the device to the driver. For example:
+the device to the driver. ACPI 5.1 extended this with _DSD (Device
+Specific Data) which made it possible to name the GPIOs among other things.
+For example:
+Device (DEV)
Method (_CRS, 0, NotSerialized)
Name (SBUF, ResourceTemplate()
@@ -285,6 +290,18 @@ the device to the driver. For example:
Return (SBUF)
+ // ACPI 5.1 _DSD used for naming the GPIOs
+ Name (_DSD, Package ()
+ {
+ ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ Package ()
+ {
+ Package () {"power-gpios", Package() {^DEV, 0, 0, 0 }},
+ Package () {"irq-gpios", Package() {^DEV, 1, 0, 0 }},
+ }
+ })
+ ...
These GPIO numbers are controller relative and path "\\_SB.PCI0.GPI0"
specifies the path to the controller. In order to use these GPIOs in Linux
we need to translate them to the corresponding Linux GPIO descriptors.
@@ -300,11 +317,11 @@ a code like this:
struct gpio_desc *irq_desc, *power_desc;
- irq_desc = gpiod_get_index(dev, NULL, 1);
+ irq_desc = gpiod_get(dev, "irq");
if (IS_ERR(irq_desc))
/* handle error */
- power_desc = gpiod_get_index(dev, NULL, 0);
+ power_desc = gpiod_get(dev, "power");
if (IS_ERR(power_desc))
/* handle error */
@@ -313,6 +330,9 @@ a code like this:
There are also devm_* versions of these functions which release the
descriptors once the device is released.
+See Documentation/acpi/gpio-properties.txt for more information about the
+_DSD binding related to GPIOs.
MFD devices
The MFD devices register their children as platform devices. For the child