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authorLinus Torvalds <torvalds@linux-foundation.org>2020-12-15 16:39:06 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-12-15 16:39:06 -0800
commitaab7ce2b099bd9df82573cd3170acf6518fdebeb (patch)
tree88caa27e82f334f1f949dacc874e7af1b276af7e /Documentation
parentb4ec805464a4a0299216a003278351d0b4806450 (diff)
parent38a0925c5fc89689433f2a2ad415982397cf626e (diff)
Merge tag 'acpi-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI updates from Rafael Wysocki: "These update the ACPICA code in the kernel to upstream revision 20201113, fix and clean up some resources manipulation code, extend the enumeration and gpio-line-names property documentation, clean up the handling of _DEP during device enumeration, add a new backlight DMI quirk, clean up transaction handling in the EC driver and make some assorted janitorial changes. Specifics: - Update ACPICA code in the kernel to upstream revision 20201113 with changes as follows: * Add 5 new UUIDs to the known UUID table (Bob Moore) * Remove extreaneous "the" in comments (Colin Ian King) * Add function trace macros to improve debugging (Erik Kaneda) * Fix interpreter memory leak (Erik Kaneda) * Handle "orphan" _REG for GPIO OpRegions (Hans de Goede) - Introduce resource_union() and resource_intersection() helpers and clean up some resource-manipulation code with the help of them (Andy Shevchenko) - Revert problematic commit related to the handling of resources in the ACPI core (Daniel Scally) - Extend the ACPI device enumeration documentation and the gpio-line-names _DSD property documentation, clean up the latter (Flavio Suligoi) - Clean up _DEP handling during device enumeration, modify the list of _DEP exceptions and the handling of it and fix up terminology related to _DEP (Hans de Goede, Rafael Wysocki) - Eliminate in_interrupt() usage from the ACPI EC driver (Sebastian Andrzej Siewior) - Clean up the advance_transaction() routine and related code in the ACPI EC driver (Rafael Wysocki) - Add new backlight quirk for GIGABYTE GB-BXBT-2807 (Jasper St Pierre) - Make assorted janitorial changes in several ACPI-related pieces of code (Hanjun Guo, Jason Yan, Punit Agrawal)" * tag 'acpi-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (40 commits) ACPI: scan: Fix up _DEP-related terminology with supplier/consumer ACPI: scan: Drop INT3396 from acpi_ignore_dep_ids[] ACPI: video: Add DMI quirk for GIGABYTE GB-BXBT-2807 Revert "ACPI / resources: Use AE_CTRL_TERMINATE to terminate resources walks" ACPI: scan: Add PNP0D80 to the _DEP exceptions list ACPI: scan: Call acpi_get_object_info() from acpi_add_single_object() ACPI: scan: Add acpi_info_matches_hids() helper ACPICA: Update version to 20201113 ACPICA: Interpreter: fix memory leak by using existing buffer ACPICA: Add function trace macros to improve debugging ACPICA: Also handle "orphan" _REG methods for GPIO OpRegions ACPICA: Remove extreaneous "the" in comments ACPICA: Add 5 new UUIDs to the known UUID table resource: provide meaningful MODULE_LICENSE() in test suite ASoC: Intel: catpt: Replace open coded variant of resource_intersection() ACPI: processor: Drop duplicate setting of shared_cpu_map ACPI: EC: Clean up status flags checks in advance_transaction() ACPI: EC: Untangle error handling in advance_transaction() ACPI: EC: Simplify error handling in advance_transaction() ACPI: EC: Rename acpi_ec_is_gpe_raised() ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/firmware-guide/acpi/dsd/leds.rst8
-rw-r--r--Documentation/firmware-guide/acpi/enumeration.rst154
-rw-r--r--Documentation/firmware-guide/acpi/gpio-properties.rst56
3 files changed, 213 insertions, 5 deletions
diff --git a/Documentation/firmware-guide/acpi/dsd/leds.rst b/Documentation/firmware-guide/acpi/dsd/leds.rst
index aba1e9abfeeb..b99fff8e06f2 100644
--- a/Documentation/firmware-guide/acpi/dsd/leds.rst
+++ b/Documentation/firmware-guide/acpi/dsd/leds.rst
@@ -90,10 +90,10 @@ where
References
==========
-[1] Device tree. <URL:https://www.devicetree.org>, referenced 2019-02-21.
+[1] Device tree. https://www.devicetree.org, referenced 2019-02-21.
[2] Advanced Configuration and Power Interface Specification.
- <URL:https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf>,
+ https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf,
referenced 2019-02-21.
[3] Documentation/devicetree/bindings/leds/common.txt
@@ -101,11 +101,11 @@ References
[4] Documentation/devicetree/bindings/media/video-interfaces.txt
[5] Device Properties UUID For _DSD.
- <URL:https://www.uefi.org/sites/default/files/resources/_DSD-device-properties-UUID.pdf>,
+ https://www.uefi.org/sites/default/files/resources/_DSD-device-properties-UUID.pdf,
referenced 2019-02-21.
[6] Hierarchical Data Extension UUID For _DSD.
- <URL:https://www.uefi.org/sites/default/files/resources/_DSD-hierarchical-data-extension-UUID-v1.1.pdf>,
+ https://www.uefi.org/sites/default/files/resources/_DSD-hierarchical-data-extension-UUID-v1.1.pdf,
referenced 2019-02-21.
[7] Documentation/firmware-guide/acpi/dsd/data-node-references.rst
diff --git a/Documentation/firmware-guide/acpi/enumeration.rst b/Documentation/firmware-guide/acpi/enumeration.rst
index c13fee8b02ba..9f0d5c854fa4 100644
--- a/Documentation/firmware-guide/acpi/enumeration.rst
+++ b/Documentation/firmware-guide/acpi/enumeration.rst
@@ -461,3 +461,157 @@ Otherwise, the _DSD itself is regarded as invalid and therefore the "compatible"
property returned by it is meaningless.
Refer to :doc:`DSD-properties-rules` for more information.
+
+PCI hierarchy representation
+============================
+
+Sometimes could be useful to enumerate a PCI device, knowing its position on the
+PCI bus.
+
+For example, some systems use PCI devices soldered directly on the mother board,
+in a fixed position (ethernet, Wi-Fi, serial ports, etc.). In this conditions it
+is possible to refer to these PCI devices knowing their position on the PCI bus
+topology.
+
+To identify a PCI device, a complete hierarchical description is required, from
+the chipset root port to the final device, through all the intermediate
+bridges/switches of the board.
+
+For example, let us assume to have a system with a PCIe serial port, an
+Exar XR17V3521, soldered on the main board. This UART chip also includes
+16 GPIOs and we want to add the property ``gpio-line-names`` [1] to these pins.
+In this case, the ``lspci`` output for this component is::
+
+ 07:00.0 Serial controller: Exar Corp. XR17V3521 Dual PCIe UART (rev 03)
+
+The complete ``lspci`` output (manually reduced in length) is::
+
+ 00:00.0 Host bridge: Intel Corp... Host Bridge (rev 0d)
+ ...
+ 00:13.0 PCI bridge: Intel Corp... PCI Express Port A #1 (rev fd)
+ 00:13.1 PCI bridge: Intel Corp... PCI Express Port A #2 (rev fd)
+ 00:13.2 PCI bridge: Intel Corp... PCI Express Port A #3 (rev fd)
+ 00:14.0 PCI bridge: Intel Corp... PCI Express Port B #1 (rev fd)
+ 00:14.1 PCI bridge: Intel Corp... PCI Express Port B #2 (rev fd)
+ ...
+ 05:00.0 PCI bridge: Pericom Semiconductor Device 2404 (rev 05)
+ 06:01.0 PCI bridge: Pericom Semiconductor Device 2404 (rev 05)
+ 06:02.0 PCI bridge: Pericom Semiconductor Device 2404 (rev 05)
+ 06:03.0 PCI bridge: Pericom Semiconductor Device 2404 (rev 05)
+ 07:00.0 Serial controller: Exar Corp. XR17V3521 Dual PCIe UART (rev 03) <-- Exar
+ ...
+
+The bus topology is::
+
+ -[0000:00]-+-00.0
+ ...
+ +-13.0-[01]----00.0
+ +-13.1-[02]----00.0
+ +-13.2-[03]--
+ +-14.0-[04]----00.0
+ +-14.1-[05-09]----00.0-[06-09]--+-01.0-[07]----00.0 <-- Exar
+ | +-02.0-[08]----00.0
+ | \-03.0-[09]--
+ ...
+ \-1f.1
+
+To describe this Exar device on the PCI bus, we must start from the ACPI name
+of the chipset bridge (also called "root port") with address::
+
+ Bus: 0 - Device: 14 - Function: 1
+
+To find this information is necessary disassemble the BIOS ACPI tables, in
+particular the DSDT (see also [2])::
+
+ mkdir ~/tables/
+ cd ~/tables/
+ acpidump > acpidump
+ acpixtract -a acpidump
+ iasl -e ssdt?.* -d dsdt.dat
+
+Now, in the dsdt.dsl, we have to search the device whose address is related to
+0x14 (device) and 0x01 (function). In this case we can find the following
+device::
+
+ Scope (_SB.PCI0)
+ {
+ ... other definitions follow ...
+ Device (RP02)
+ {
+ Method (_ADR, 0, NotSerialized) // _ADR: Address
+ {
+ If ((RPA2 != Zero))
+ {
+ Return (RPA2) /* \RPA2 */
+ }
+ Else
+ {
+ Return (0x00140001)
+ }
+ }
+ ... other definitions follow ...
+
+and the _ADR method [3] returns exactly the device/function couple that
+we are looking for. With this information and analyzing the above ``lspci``
+output (both the devices list and the devices tree), we can write the following
+ACPI description for the Exar PCIe UART, also adding the list of its GPIO line
+names::
+
+ Scope (_SB.PCI0.RP02)
+ {
+ Device (BRG1) //Bridge
+ {
+ Name (_ADR, 0x0000)
+
+ Device (BRG2) //Bridge
+ {
+ Name (_ADR, 0x00010000)
+
+ Device (EXAR)
+ {
+ Name (_ADR, 0x0000)
+
+ Name (_DSD, Package ()
+ {
+ ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ Package ()
+ {
+ Package ()
+ {
+ "gpio-line-names",
+ Package ()
+ {
+ "mode_232",
+ "mode_422",
+ "mode_485",
+ "misc_1",
+ "misc_2",
+ "misc_3",
+ "",
+ "",
+ "aux_1",
+ "aux_2",
+ "aux_3",
+ }
+ }
+ }
+ })
+ }
+ }
+ }
+ }
+
+The location "_SB.PCI0.RP02" is obtained by the above investigation in the
+dsdt.dsl table, whereas the device names "BRG1", "BRG2" and "EXAR" are
+created analyzing the position of the Exar UART in the PCI bus topology.
+
+References
+==========
+
+[1] Documentation/firmware-guide/acpi/gpio-properties.rst
+
+[2] Documentation/admin-guide/acpi/initrd_table_override.rst
+
+[3] ACPI Specifications, Version 6.3 - Paragraph 6.1.1 _ADR Address)
+ https://uefi.org/sites/default/files/resources/ACPI_6_3_May16.pdf,
+ referenced 2020-11-18
diff --git a/Documentation/firmware-guide/acpi/gpio-properties.rst b/Documentation/firmware-guide/acpi/gpio-properties.rst
index 59aad6138b6e..b36aa3e743d8 100644
--- a/Documentation/firmware-guide/acpi/gpio-properties.rst
+++ b/Documentation/firmware-guide/acpi/gpio-properties.rst
@@ -133,7 +133,61 @@ Example::
- gpio-line-names
-Example::
+The ``gpio-line-names`` declaration is a list of strings ("names"), which
+describes each line/pin of a GPIO controller/expander. This list, contained in
+a package, must be inserted inside the GPIO controller declaration of an ACPI
+table (typically inside the DSDT). The ``gpio-line-names`` list must respect the
+following rules (see also the examples):
+
+ - the first name in the list corresponds with the first line/pin of the GPIO
+ controller/expander
+ - the names inside the list must be consecutive (no "holes" are permitted)
+ - the list can be incomplete and can end before the last GPIO line: in
+ other words, it is not mandatory to fill all the GPIO lines
+ - empty names are allowed (two quotation marks ``""`` correspond to an empty
+ name)
+
+Example of a GPIO controller of 16 lines, with an incomplete list with two
+empty names::
+
+ Package () {
+ "gpio-line-names",
+ Package () {
+ "pin_0",
+ "pin_1",
+ "",
+ "",
+ "pin_3",
+ "pin_4_push_button",
+ }
+ }
+
+At runtime, the above declaration produces the following result (using the
+"libgpiod" tools)::
+
+ root@debian:~# gpioinfo gpiochip4
+ gpiochip4 - 16 lines:
+ line 0: "pin_0" unused input active-high
+ line 1: "pin_1" unused input active-high
+ line 2: unnamed unused input active-high
+ line 3: unnamed unused input active-high
+ line 4: "pin_3" unused input active-high
+ line 5: "pin_4_push_button" unused input active-high
+ line 6: unnamed unused input active-high
+ line 7 unnamed unused input active-high
+ line 8: unnamed unused input active-high
+ line 9: unnamed unused input active-high
+ line 10: unnamed unused input active-high
+ line 11: unnamed unused input active-high
+ line 12: unnamed unused input active-high
+ line 13: unnamed unused input active-high
+ line 14: unnamed unused input active-high
+ line 15: unnamed unused input active-high
+ root@debian:~# gpiofind pin_4_push_button
+ gpiochip4 5
+ root@debian:~#
+
+Another example::
Package () {
"gpio-line-names",