Add support for GPIO Control using libgpiod (as sysfsgpio is deprecated) #1569

pmelange · 2025-01-19T18:11:03Z

Description

Adds a new protocol ButtonProtocol and the drivers ManualButtonDriver, ExternalButtonDriver, and DigitalOutputButtonDriver to simulate pushing a button (via GPIO lines). This is needed for the tests I will be doing with the logic behind it.
Adds new resources LibGPIO / NetworkLibGPIO / MatchedLibGPIO which uses the libgpiod python library. These new resources also support the active_low attribute
Adds a new field to the existing SysfsGPIO / NetworkSysfsGPIO / MatchedSysfsGPIO resource classes to support the active_low option of a GPIO line, used to invert the logical value of an IO line.
Adds a new LibGPIODigitalOutputDriver which implements the DigitalOutputProtocol, ResetProtocol, PowerProtocol, and the new ButtonProtocol.
Adds support to GPIODigitalOutputDriver to support ResetProtocol, PowerProtocol, and the new ButtonProtocol.
Adds a new LibGPIOExport class
Updates the GPIOSysFSExport to support the active_low attribute
Adds support the labgrid-client to support the new NetworkLibGPIO class and support for the Button actions.
Marks the Sysfs GPIO classes as deprecated
Updates corresponding documentation
Updates the examples for sysfsgpio
Adds examples for libgpio.

As far as new features go...

ButtonProtocol is to be used in my test environment to control pressing the reset button of DUTs. For many of the DUTs, pressing the reset button when powering on provides (via uboot) a TFTP client or server or simply access to a web socket to be able to upload a new firmware image. A logical button is better for the test environment I am creating since it encapsulates the high/low logic levels of IO ports into something logical.

LibGPIO classes are added to get away from the deprecated sysfsgpio subsystem (see https://www.kernel.org/doc/Documentation/gpio/sysfs.txt).

Extending the GPIO based drivers (both libgpio and sysfs) to the Reset, Power, and Button protocols was very straight forward and I did wonder why the Reset and Power protocols had not jet been implemented. They seem like logical extensions to general purpose IO lines.

Adding the active_low attribute was necessary because the IO lines used in the testbed are connected to relays which are active_low.

All development and testing was done on a raspberry pi 4 with opto-coupler relays connected to the GPIO lines to control power and reset buttons.

Checklist

Documentation for the feature
Tests for the feature can be found in the examples/sysfsgpio and examples/libgpio directories
The arguments and description in doc/configuration.rst have been updated
PR has been tested by pulling high and low IO lines using various calls from the DigitalOutput, Reset, Power and Button protocols, both using the exporter/client and as a standalone python script.

A button can be used to simulate pressing a physical button on a device. For example a DigitalOutputButtonDriver can be used when a reset button is connected via a relay to a DigitalOutput. In addition there are the ManualButtonDriver and ExternalButtonDriver drivers analogous to the ManualPowerDriver and ExternalPowerDriver drivers. Operations on a button include "press", "release", "toggle", "toggle_for", and "get". Signed-off-by: Perry Melange <[email protected]>

Add the LibGPIO, NetworkLibGPIO and MatchedLibGPIO resources. These resouces bind to the /dev/gpiochipN and it's associated gpio line. In addition there is an optional active_low attribute which can be used to invert the logical value used on the gpio line. The resources SysfsGPIO, NetworkSysfsGPIO and MatchedSysfsGPIO resources have been modified to have an additional optional active_low attribute which can be used to invert the logical value used on the gpio line. The SysfsGPIO, NetworkSysfsGPIO and MatchedSysfsGPIO resouces are now marked as deprecated. See https://www.kernel.org/doc/Documentation/gpio/sysfs.txt Signed-off-by: Perry Melange <[email protected]>

Add the LibGPIODigitalOutputDriver which implements the DigitalOutputProtocol, ResetProtocol, PowerProtocol, and ButtonProtocol. Update the GPIODigitalOutputDriver to also implement the ResetProtocol, PowerProtocol, and ButtonProtocol. Update the GpioDigitalOutput agent to use the new active_low attribute Mark GPIODigitalOutputDriver and GpioDigitalOutput as deprecated. See https://www.kernel.org/doc/Documentation/gpio/sysfs.txt Signed-off-by: Perry Melange <[email protected]>

Add the LibGPIOExport class to the exporter. Update the GPIOSysFSExport class to use the new active_low attribute Signed-off-by: Perry Melange <[email protected]>

…otocol Add NetworkLibGPIO to the client, including commands for io, power, and button protocols. Update NetworkLibGPIO to support the commands for power and button protocols. Signed-off-by: Perry Melange <[email protected]>

…Drivers Add documentation for LibGPIO, MatchedLibGPIO, ManualButtonDriver, ExternalButtonDriver, DigitalOutputButtonDriver, and LibGPIODigitalOutputDriver. Update the SysfsGPIO, MatchedSysfsGPIO, and GpioDigitalOutputDriver to add the new active_low attribute and the new protocols supported by the GpioDigitalOutputDriver. In addition, add documentation that the SysfsGpio classes are deprecated. Signed-off-by: Perry Melange <[email protected]>

Signed-off-by: Perry Melange <[email protected]>

pmelange · 2025-01-19T18:31:53Z

Rebased so that the commits are no longer behind the main branch :)

Signed-off-by: Perry Melange <[email protected]>

PaulVittorino · 2025-01-19T19:48:47Z

doc/configuration.rst

+ManualButtonDriver
+~~~~~~~~~~~~~~~~~~
+A :any:`ManualButtonDriver` requires the user to control the taget button.
+Theis is required if a stratefy is used with the target, but no automatic


Suggested change

Theis is required if a stratefy is used with the target, but no automatic

This is required if a strategy is used with the target, but no automatic

PaulVittorino · 2025-01-19T20:04:10Z

doc/configuration.rst

+     cmd_toggle_for: 'example_command toggle_for'
+
+Arguments:
+  - cmd_press (str): command to press the button on the board


Suggested change

- cmd_press (str): command to press the button on the board

- cmd_press (str): command to press and hold the button on the board

I suggest clarifying that this means the button must be released.

PaulVittorino · 2025-01-19T20:04:37Z

doc/configuration.rst

+Arguments:
+  - cmd_press (str): command to press the button on the board
+  - cmd_release (str): command to release the button on the board
+  - cmd_toogle (str): command to toggle the button on the board


Suggested change

- cmd_toogle (str): command to toggle the button on the board

- cmd_toogle (str): command to press and release the button on the board

PaulVittorino · 2025-01-19T20:07:46Z

labgrid/driver/buttondriver.py

+    @step()
+    def press(self):
+        self.target.interact(
+            f"Press the button on target {self.target.name} and press enter"


Suggested change

f"Press the button on target {self.target.name} and press enter"

f"Press and hold the button on target {self.target.name} and press enter"

PaulVittorino · 2025-01-19T20:08:27Z

labgrid/driver/buttondriver.py

+    @step()
+    def toggle(self):
+        self.target.interact(
+            f"Toggle the bottuon on the target {self.target.name} and press enter"


Suggested change

f"Toggle the bottuon on the target {self.target.name} and press enter"

f"Toggle the button on the target {self.target.name} and press enter"

PaulVittorino · 2025-01-19T20:13:03Z

doc/configuration.rst

+  - cmd_press (str): command to press the button on the board
+  - cmd_release (str): command to release the button on the board
+  - cmd_toogle (str): command to toggle the button on the board
+  - cmd_toggle_for (str): options command to toggle, pause, and toggle again


The current description reads to me as button down, immediately button up, wait, then button down, immediately button up. Is that correct?

Or did you mean button down, wait, button up? If so, would press_and_hold_for be a better name?

I must admit that it really isn't clear.

Actually, the toggle methods don't really apply to a button. Maybe it would be better to add a new method to DigitialOutputProtocol called "invert". An "invert_for" method is probably not necessary.

About the button methods, I think of press as "press and hold". I can understand how people would think that pressing a button is press then release as one movement. I, on the other hand, think of buttons as being pressed and then released as two movements.. I would like to have it as clear as possible. I am open to suggestions.

Currently my thoughts go more towards "press" for press and hold, "release" to release, and "press_for" as press, wait a delay, and release. I would like to keep the names of the commands short for labgrid-client.

Thanks for catching the spelling errors. :)

I might have time this evening to make the changes, otherwise they will be made tomorrow.

pmelange added 8 commits January 19, 2025 19:30

exporter: add LibGPIOExport and update GPIOSysFSExport

1564cfb

Add the LibGPIOExport class to the exporter. Update the GPIOSysFSExport class to use the new active_low attribute Signed-off-by: Perry Melange <[email protected]>

examples/sysfsgpio: add active_low attribute to examples

d9926c4

Signed-off-by: Perry Melange <[email protected]>

examples/libgpio: add libgpio examples

d114043

Signed-off-by: Perry Melange <[email protected]>

pmelange force-pushed the libgpiod-2.2.3 branch from db29152 to d114043 Compare January 19, 2025 18:30

Emantor requested a review from jluebbe January 19, 2025 18:31

pyproject.toml: add gpiod>=2.2.3 to dependencies

4003d51

Signed-off-by: Perry Melange <[email protected]>

pmelange force-pushed the libgpiod-2.2.3 branch from e6486a4 to 4003d51 Compare January 19, 2025 18:54

PaulVittorino reviewed Jan 19, 2025

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Add support for GPIO Control using libgpiod (as sysfsgpio is deprecated) #1569

Add support for GPIO Control using libgpiod (as sysfsgpio is deprecated) #1569

pmelange commented Jan 19, 2025

pmelange commented Jan 19, 2025

PaulVittorino Jan 19, 2025

PaulVittorino Jan 19, 2025

PaulVittorino Jan 19, 2025

PaulVittorino Jan 19, 2025

PaulVittorino Jan 19, 2025

PaulVittorino Jan 19, 2025

pmelange Jan 20, 2025

	Theis is required if a stratefy is used with the target, but no automatic
	This is required if a strategy is used with the target, but no automatic

	- cmd_press (str): command to press the button on the board
	- cmd_press (str): command to press and hold the button on the board

	- cmd_toogle (str): command to toggle the button on the board
	- cmd_toogle (str): command to press and release the button on the board

	f"Press the button on target {self.target.name} and press enter"
	f"Press and hold the button on target {self.target.name} and press enter"

	f"Toggle the bottuon on the target {self.target.name} and press enter"
	f"Toggle the button on the target {self.target.name} and press enter"

Add support for GPIO Control using libgpiod (as sysfsgpio is deprecated) #1569

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Add support for GPIO Control using libgpiod (as sysfsgpio is deprecated) #1569

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