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author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-07-15 17:53:24 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-07-15 17:53:24 -0700 |
commit | b3c0eccb485404d3ea5eaae483b1a2e9e2134d21 (patch) | |
tree | 758c02cabc8614ae879704bd7df68f9f59295ad2 | |
parent | 3f32ab146c557f0fd9060b03003d0d4b2815968a (diff) | |
parent | dfda97e37de4c2fa4a079ae77737c6b9ed021f79 (diff) | |
download | linux-b3c0eccb485404d3ea5eaae483b1a2e9e2134d21.tar.gz linux-b3c0eccb485404d3ea5eaae483b1a2e9e2134d21.tar.bz2 linux-b3c0eccb485404d3ea5eaae483b1a2e9e2134d21.zip |
Merge tag 'gpio-updates-for-v6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
Pull gpio updates from Bartosz Golaszewski:
"The majority of added lines are two new modules: the GPIO virtual
consumer module that improves our ability to add automated tests for
the kernel API and the "sloppy" logic analyzer module that uses the
GPIO API to implement a coarse-grained debugging tool for useful for
remote development.
Other than that we have the usual assortment of various driver
extensions, improvements to the core GPIO code, DT-bindings and other
documentation updates as well as an extension to the interrupt
simulator:
GPIOLIB core:
- rework kfifo handling rework in the character device code
- improve the labeling of GPIOs requested as interrupts and show more
info on interrupt-only GPIOs in debugfs
- remove unused APIs
- unexport interfaces that are only used from the core GPIO code
- drop the return value from gpiochip_set_desc_names() as it cannot
fail
- move a string array definition out of a header and into a specific
compilation unit
- convert the last user of gpiochip_get_desc() other than GPIO core
to using a safer alternative
- use array_index_nospec() where applicable
New drivers:
- add a "virtual GPIO consumer" module that allows requesting GPIOs
from actual hardware and driving tests of the in-kernel GPIO API
from user-space over debugfs
- add a GPIO-based "sloppy" logic analyzer module useful for "first
glance" debugging on remote boards
Driver improvements:
- add support for a new model to gpio-pca953x
- lock GPIOs as interrupts in gpio-sim when the lines are requested
as irqs via the simulator domain + some other minor improvements
- improve error reporting in gpio-syscon
- convert gpio-ath79 to using dynamic GPIO base and range
- use pcibios_err_to_errno() for converting PCIBIOS error codes to
errno vaues in gpio-amd8111 and gpio-rdc321x
- allow building gpio-brcmstb for the BCM2835 architecture
DT bindings:
- convert DT bindings for lsi,zevio, mpc8xxx, and atmel to DT schema
- document new properties for aspeed,gpio, fsl,qoriq-gpio and
gpio-vf610
- document new compatibles for pca953x and fsl,qoriq-gpio
Documentation:
- document stricter behavior of the GPIO character device uAPI with
regards to reconfiguring requested line without direction set
- clarify the effect of the active-low flag on line values and edges
- remove documentation for the legacy GPIO API in order to stop
tempting people to use it
- document the preference for using pread() for reading edge events
in the sysfs API
Other:
- add an extended initializer to the interrupt simulator allowing to
specify a number of callbacks callers can use to be notified about
irqs being requested and released"
* tag 'gpio-updates-for-v6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (41 commits)
gpio: mc33880: Convert comma to semicolon
gpio: virtuser: actually use the "trimmed" local variable
dt-bindings: gpio: convert Atmel GPIO to json-schema
gpio: virtuser: new virtual testing driver for the GPIO API
dt-bindings: gpio: vf610: Allow gpio-line-names to be set
gpio: sim: lock GPIOs as interrupts when they are requested
genirq/irq_sim: add an extended irq_sim initializer
dt-bindings: gpio: fsl,qoriq-gpio: Add compatible string fsl,ls1046a-gpio
gpiolib: unexport gpiochip_get_desc()
gpio: add sloppy logic analyzer using polling
Documentation: gpio: Reconfiguration with unset direction (uAPI v2)
Documentation: gpio: Reconfiguration with unset direction (uAPI v1)
dt-bindings: gpio: fsl,qoriq-gpio: add common property gpio-line-names
gpio: ath79: convert to dynamic GPIO base allocation
pinctrl: da9062: replace gpiochip_get_desc() with gpio_device_get_desc()
gpiolib: put gpio_suffixes in a single compilation unit
Documentation: gpio: Clarify effect of active low flag on line edges
Documentation: gpio: Clarify effect of active low flag on line values
gpiolib: Remove data-less gpiochip_add() function
gpio: sim: use devm_mutex_init()
...
54 files changed, 3187 insertions, 2123 deletions
diff --git a/Documentation/admin-guide/gpio/gpio-virtuser.rst b/Documentation/admin-guide/gpio/gpio-virtuser.rst new file mode 100644 index 000000000000..2aca70db9f3b --- /dev/null +++ b/Documentation/admin-guide/gpio/gpio-virtuser.rst @@ -0,0 +1,177 @@ +.. SPDX-License-Identifier: GPL-2.0-only + +Virtual GPIO Consumer +===================== + +The virtual GPIO Consumer module allows users to instantiate virtual devices +that request GPIOs and then control their behavior over debugfs. Virtual +consumer devices can be instantiated from device-tree or over configfs. + +A virtual consumer uses the driver-facing GPIO APIs and allows to cover it with +automated tests driven by user-space. The GPIOs are requested using +``gpiod_get_array()`` and so we support multiple GPIOs per connector ID. + +Creating GPIO consumers +----------------------- + +The gpio-consumer module registers a configfs subsystem called +``'gpio-virtuser'``. For details of the configfs filesystem, please refer to +the configfs documentation. + +The user can create a hierarchy of configfs groups and items as well as modify +values of exposed attributes. Once the consumer is instantiated, this hierarchy +will be translated to appropriate device properties. The general structure is: + +**Group:** ``/config/gpio-virtuser`` + +This is the top directory of the gpio-consumer configfs tree. + +**Group:** ``/config/gpio-consumer/example-name`` + +**Attribute:** ``/config/gpio-consumer/example-name/live`` + +**Attribute:** ``/config/gpio-consumer/example-name/dev_name`` + +This is a directory representing a GPIO consumer device. + +The read-only ``dev_name`` attribute exposes the name of the device as it will +appear in the system on the platform bus. This is useful for locating the +associated debugfs directory under +``/sys/kernel/debug/gpio-virtuser/$dev_name``. + +The ``'live'`` attribute allows to trigger the actual creation of the device +once it's fully configured. The accepted values are: ``'1'`` to enable the +virtual device and ``'0'`` to disable and tear it down. + +Creating GPIO lookup tables +--------------------------- + +Users can create a number of configfs groups under the device group: + +**Group:** ``/config/gpio-consumer/example-name/con_id`` + +The ``'con_id'`` directory represents a single GPIO lookup and its value maps +to the ``'con_id'`` argument of the ``gpiod_get()`` function. For example: +``con_id`` == ``'reset'`` maps to the ``reset-gpios`` device property. + +Users can assign a number of GPIOs to each lookup. Each GPIO is a sub-directory +with a user-defined name under the ``'con_id'`` group. + +**Attribute:** ``/config/gpio-consumer/example-name/con_id/0/key`` + +**Attribute:** ``/config/gpio-consumer/example-name/con_id/0/offset`` + +**Attribute:** ``/config/gpio-consumer/example-name/con_id/0/drive`` + +**Attribute:** ``/config/gpio-consumer/example-name/con_id/0/pull`` + +**Attribute:** ``/config/gpio-consumer/example-name/con_id/0/active_low`` + +**Attribute:** ``/config/gpio-consumer/example-name/con_id/0/transitory`` + +This is a group describing a single GPIO in the ``con_id-gpios`` property. + +For virtual consumers created using configfs we use machine lookup tables so +this group can be considered as a mapping between the filesystem and the fields +of a single entry in ``'struct gpiod_lookup'``. + +The ``'key'`` attribute represents either the name of the chip this GPIO +belongs to or the GPIO line name. This depends on the value of the ``'offset'`` +attribute: if its value is >= 0, then ``'key'`` represents the label of the +chip to lookup while ``'offset'`` represents the offset of the line in that +chip. If ``'offset'`` is < 0, then ``'key'`` represents the name of the line. + +The remaining attributes map to the ``'flags'`` field of the GPIO lookup +struct. The first two take string values as arguments: + +**``'drive'``:** ``'push-pull'``, ``'open-drain'``, ``'open-source'`` +**``'pull'``:** ``'pull-up'``, ``'pull-down'``, ``'pull-disabled'``, ``'as-is'`` + +``'active_low'`` and ``'transitory'`` are boolean attributes. + +Activating GPIO consumers +------------------------- + +Once the confiuration is complete, the ``'live'`` attribute must be set to 1 in +order to instantiate the consumer. It can be set back to 0 to destroy the +virtual device. The module will synchronously wait for the new simulated device +to be successfully probed and if this doesn't happen, writing to ``'live'`` will +result in an error. + +Device-tree +----------- + +Virtual GPIO consumers can also be defined in device-tree. The compatible string +must be: ``"gpio-virtuser"`` with at least one property following the +standardized GPIO pattern. + +An example device-tree code defining a virtual GPIO consumer: + +.. code-block :: none + + gpio-virt-consumer { + compatible = "gpio-virtuser"; + + foo-gpios = <&gpio0 5 GPIO_ACTIVE_LOW>, <&gpio1 2 0>; + bar-gpios = <&gpio0 6 0>; + }; + +Controlling virtual GPIO consumers +---------------------------------- + +Once active, the device will export debugfs attributes for controlling GPIO +arrays as well as each requested GPIO line separately. Let's consider the +following device property: ``foo-gpios = <&gpio0 0 0>, <&gpio0 4 0>;``. + +The following debugfs attribute groups will be created: + +**Group:** ``/sys/kernel/debug/gpio-virtuser/$dev_name/gpiod:foo/`` + +This is the group that will contain the attributes for the entire GPIO array. + +**Attribute:** ``/sys/kernel/debug/gpio-virtuser/$dev_name/gpiod:foo/values`` + +**Attribute:** ``/sys/kernel/debug/gpio-virtuser/$dev_name/gpiod:foo/values_atomic`` + +Both attributes allow to read and set arrays of GPIO values. User must pass +exactly the number of values that the array contains in the form of a string +containing zeroes and ones representing inactive and active GPIO states +respectively. In this example: ``echo 11 > values``. + +The ``values_atomic`` attribute works the same as ``values`` but the kernel +will execute the GPIO driver callbacks in interrupt context. + +**Group:** ``/sys/kernel/debug/gpio-virtuser/$dev_name/gpiod:foo:$index/`` + +This is a group that represents a single GPIO with ``$index`` being its offset +in the array. + +**Attribute:** ``/sys/kernel/debug/gpio-virtuser/$dev_name/gpiod:foo:$index/consumer`` + +Allows to set and read the consumer label of the GPIO line. + +**Attribute:** ``/sys/kernel/debug/gpio-virtuser/$dev_name/gpiod:foo:$index/debounce`` + +Allows to set and read the debounce period of the GPIO line. + +**Attribute:** ``/sys/kernel/debug/gpio-virtuser/$dev_name/gpiod:foo:$index/direction`` + +**Attribute:** ``/sys/kernel/debug/gpio-virtuser/$dev_name/gpiod:foo:$index/direction_atomic`` + +These two attributes allow to set the direction of the GPIO line. They accept +"input" and "output" as values. The atomic variant executes the driver callback +in interrupt context. + +**Attribute:** ``/sys/kernel/debug/gpio-virtuser/$dev_name/gpiod:foo:$index/interrupts`` + +If the line is requested in input mode, writing ``1`` to this attribute will +make the module listen for edge interrupts on the GPIO. Writing ``0`` disables +the monitoring. Reading this attribute returns the current number of registered +interrupts (both edges). + +**Attribute:** ``/sys/kernel/debug/gpio-virtuser/$dev_name/gpiod:foo:$index/value`` + +**Attribute:** ``/sys/kernel/debug/gpio-virtuser/$dev_name/gpiod:foo:$index/value_atomic`` + +Both attributes allow to read and set values of individual requested GPIO lines. +They accept the following values: ``1`` and ``0``. diff --git a/Documentation/admin-guide/gpio/index.rst b/Documentation/admin-guide/gpio/index.rst index 460afd29617e..712f379731cb 100644 --- a/Documentation/admin-guide/gpio/index.rst +++ b/Documentation/admin-guide/gpio/index.rst @@ -10,6 +10,7 @@ GPIO Character Device Userspace API <../../userspace-api/gpio/chardev> gpio-aggregator gpio-sim + gpio-virtuser Obsolete APIs <obsolete> .. only:: subproject and html diff --git a/Documentation/dev-tools/gpio-sloppy-logic-analyzer.rst b/Documentation/dev-tools/gpio-sloppy-logic-analyzer.rst new file mode 100644 index 000000000000..d69f24c0d9e1 --- /dev/null +++ b/Documentation/dev-tools/gpio-sloppy-logic-analyzer.rst @@ -0,0 +1,93 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============================================= +Linux Kernel GPIO based sloppy logic analyzer +============================================= + +:Author: Wolfram Sang + +Introduction +============ + +This document briefly describes how to run the GPIO based in-kernel sloppy +logic analyzer running on an isolated CPU. + +The sloppy logic analyzer will utilize a few GPIO lines in input mode on a +system to rapidly sample these digital lines, which will, if the Nyquist +criteria is met, result in a time series log with approximate waveforms as they +appeared on these lines. One way to use it is to analyze external traffic +connected to these GPIO lines with wires (i.e. digital probes), acting as a +common logic analyzer. + +Another feature is to snoop on on-chip peripherals if the I/O cells of these +peripherals can be used in GPIO input mode at the same time as they are being +used as inputs or outputs for the peripheral. That means you could e.g. snoop +I2C traffic without any wiring (if your hardware supports it). In the pin +control subsystem such pin controllers are called "non-strict": a certain pin +can be used with a certain peripheral and as a GPIO input line at the same +time. + +Note that this is a last resort analyzer which can be affected by latencies, +non-deterministic code paths and non-maskable interrupts. It is called 'sloppy' +for a reason. However, for e.g. remote development, it may be useful to get a +first view and aid further debugging. + +Setup +===== + +Your kernel must have CONFIG_DEBUG_FS and CONFIG_CPUSETS enabled. Ideally, your +runtime environment does not utilize cpusets otherwise, then isolation of a CPU +core is easiest. If you do need cpusets, check that helper script for the +sloppy logic analyzer does not interfere with your other settings. + +Tell the kernel which GPIOs are used as probes. For a Device Tree based system, +you need to use the following bindings. Because these bindings are only for +debugging, there is no official schema:: + + i2c-analyzer { + compatible = "gpio-sloppy-logic-analyzer"; + probe-gpios = <&gpio6 21 GPIO_OPEN_DRAIN>, <&gpio6 4 GPIO_OPEN_DRAIN>; + probe-names = "SCL", "SDA"; + }; + +Note that you must provide a name for every GPIO specified. Currently a +maximum of 8 probes are supported. 32 are likely possible but are not +implemented yet. + +Usage +===== + +The logic analyzer is configurable via files in debugfs. However, it is +strongly recommended to not use them directly, but to use the script +``tools/gpio/gpio-sloppy-logic-analyzer``. Besides checking parameters more +extensively, it will isolate the CPU core so you will have the least +disturbance while measuring. + +The script has a help option explaining the parameters. For the above DT +snippet which analyzes an I2C bus at 400kHz on a Renesas Salvator-XS board, the +following settings are used: The isolated CPU shall be CPU1 because it is a big +core in a big.LITTLE setup. Because CPU1 is the default, we don't need a +parameter. The bus speed is 400kHz. So, the sampling theorem says we need to +sample at least at 800kHz. However, falling edges of both signals in an I2C +start condition happen faster, so we need a higher sampling frequency, e.g. +``-s 1500000`` for 1.5MHz. Also, we don't want to sample right away but wait +for a start condition on an idle bus. So, we need to set a trigger to a falling +edge on SDA while SCL stays high, i.e. ``-t 1H+2F``. Last is the duration, let +us assume 15ms here which results in the parameter ``-d 15000``. So, +altogether:: + + gpio-sloppy-logic-analyzer -s 1500000 -t 1H+2F -d 15000 + +Note that the process will return you back to the prompt but a sub-process is +still sampling in the background. Unless this has finished, you will not find a +result file in the current or specified directory. For the above example, we +will then need to trigger I2C communication:: + + i2cdetect -y -r <your bus number> + +Result is a .sr file to be consumed with PulseView or sigrok-cli from the free +`sigrok`_ project. It is a zip file which also contains the binary sample data +which may be consumed by other software. The filename is the logic analyzer +instance name plus a since-epoch timestamp. + +.. _sigrok: https://sigrok.org/ diff --git a/Documentation/dev-tools/index.rst b/Documentation/dev-tools/index.rst index efa49cdc8e2e..6971ed581c08 100644 --- a/Documentation/dev-tools/index.rst +++ b/Documentation/dev-tools/index.rst @@ -32,6 +32,7 @@ Documentation/dev-tools/testing-overview.rst kunit/index ktap checkuapi + gpio-sloppy-logic-analyzer .. only:: subproject and html diff --git a/Documentation/devicetree/bindings/gpio/aspeed,sgpio.yaml b/Documentation/devicetree/bindings/gpio/aspeed,sgpio.yaml index 46bb121360dc..1046f0331c09 100644 --- a/Documentation/devicetree/bindings/gpio/aspeed,sgpio.yaml +++ b/Documentation/devicetree/bindings/gpio/aspeed,sgpio.yaml @@ -33,6 +33,11 @@ properties: gpio-controller: true + # Each SGPIO is represented as a pair of input and output GPIOs + gpio-line-names: + minItems: 160 + maxItems: 256 + '#gpio-cells': const: 2 @@ -41,6 +46,9 @@ properties: interrupt-controller: true + '#interrupt-cells': + const: 2 + clocks: maxItems: 1 @@ -55,6 +63,7 @@ required: - '#gpio-cells' - interrupts - interrupt-controller + - '#interrupt-cells' - ngpios - clocks - bus-frequency @@ -72,6 +81,7 @@ examples: reg = <0x1e780200 0x0100>; clocks = <&syscon ASPEED_CLK_APB>; interrupt-controller; + #interrupt-cells = <2>; ngpios = <80>; bus-frequency = <12000000>; }; diff --git a/Documentation/devicetree/bindings/gpio/atmel,at91rm9200-gpio.yaml b/Documentation/devicetree/bindings/gpio/atmel,at91rm9200-gpio.yaml new file mode 100644 index 000000000000..3dd70933ed8e --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/atmel,at91rm9200-gpio.yaml @@ -0,0 +1,81 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/gpio/atmel,at91rm9200-gpio.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Microchip GPIO controller (PIO) + +maintainers: + - Manikandan Muralidharan <manikandan.m@microchip.com> + +properties: + compatible: + oneOf: + - items: + - enum: + - atmel,at91sam9x5-gpio + - microchip,sam9x60-gpio + - const: atmel,at91rm9200-gpio + - items: + - enum: + - microchip,sam9x7-gpio + - const: microchip,sam9x60-gpio + - const: atmel,at91rm9200-gpio + - items: + - const: atmel,at91rm9200-gpio + + reg: + maxItems: 1 + + interrupts: + maxItems: 1 + + interrupt-controller: true + + "#interrupt-cells": + const: 2 + + gpio-controller: true + gpio-line-names: true + + "#gpio-cells": + const: 2 + + clocks: + maxItems: 1 + + "#gpio-lines": + description: + Number of gpio, 32 by default if absent + maxItems: 1 + default: 32 + +required: + - compatible + - reg + - interrupts + - interrupt-controller + - "#interrupt-cells" + - gpio-controller + - "#gpio-cells" + - clocks + +additionalProperties: false + +examples: + - | + #include <dt-bindings/clock/at91.h> + #include <dt-bindings/interrupt-controller/irq.h> + + gpio@fffff400 { + compatible = "atmel,at91rm9200-gpio"; + reg = <0xfffff400 0x200>; + interrupts = <2 IRQ_TYPE_LEVEL_HIGH 1>; + #gpio-cells = <2>; + gpio-controller; + interrupt-controller; + #interrupt-cells = <2>; + clocks = <&pmc PMC_TYPE_PERIPHERAL 2>; + }; +... diff --git a/Documentation/devicetree/bindings/gpio/fsl,qoriq-gpio.yaml b/Documentation/devicetree/bindings/gpio/fsl,qoriq-gpio.yaml new file mode 100644 index 000000000000..84fd82291ee4 --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/fsl,qoriq-gpio.yaml @@ -0,0 +1,87 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/gpio/fsl,qoriq-gpio.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Freescale MPC512x/MPC8xxx/QorIQ/Layerscape GPIO controller + +maintainers: + - Frank Li <Frank.Li@nxp.com> + +properties: + compatible: + oneOf: + - enum: + - fsl,mpc5121-gpio + - fsl,mpc5125-gpio + - fsl,mpc8349-gpio + - fsl,mpc8572-gpio + - fsl,mpc8610-gpio + - fsl,pq3-gpio + - items: + - enum: + - fsl,ls1021a-gpio + - fsl,ls1028a-gpio + - fsl,ls1043a-gpio + - fsl,ls1046a-gpio + - fsl,ls1088a-gpio + - fsl,ls2080a-gpio + - const: fsl,qoriq-gpio + + reg: + maxItems: 1 + + interrupts: + maxItems: 1 + + "#gpio-cells": + const: 2 + + gpio-controller: true + + interrupt-controller: true + + "#interrupt-cells": + const: 2 + + gpio-line-names: + minItems: 1 + maxItems: 32 + + little-endian: + $ref: /schemas/types.yaml#/definitions/flag + description: + GPIO registers are used as little endian. If not + present registers are used as big endian by default. + +required: + - compatible + - reg + - interrupts + - "#gpio-cells" + +additionalProperties: false + +examples: + - | + gpio@1100 { + compatible = "fsl,mpc5125-gpio"; + reg = <0x1100 0x080>; + interrupts = <78 0x8>; + gpio-controller; + #gpio-cells = <2> |