michaelh/zephyr
1
0
Fork 0
Code Releases Activity

test: Add i2c emulation for targets

Browse source 
Update i2c_emul.c to support i2c_target_register and i2c_target_unregister
function calls as well as support address forwarding in emulation.
Address forwarding helps us test IPCs in native sim. Instead of having to
emulate 2 separate cores, we can forward read/write requests from one bus
to another bus (effectively creating a loop). This way the same image can
simulate both the controller and the target.

Signed-off-by: Yuval Peress <peress@google.com>
This commit is contained in:
Yuval Peress 2024-06-17 12:00:11 -06:00 • committed by Anas Nashif
commit c394b2e6f8
11 changed files with 617 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

34
doc/hardware/emulator/bus_emulators.rst
View file

@ -144,6 +144,38 @@ Zephyr includes the following emulators:
* MSPI emulator driver, allowing drivers to be connected to an emulator so that
tests can be performed without access to the real hardware.
I2C Emulation features
----------------------
In the binding of the I2C emulated bus, there's a custom property for address
based forwarding. Given the following devicetree node:
.. code-block::
i2c0: i2c@100 {
status = "okay";
compatible = "zephyr,i2c-emul-controller";
clock-frequency = <I2C_BITRATE_STANDARD>;
#address-cells = <1>;
#size-cells = <0>;
#forward-cells = <1>;
reg = <0x100 4>;
forwards = <&i2c1 0x20>;
};
The final property, ``forwards`` indicates that any read/write requests sent to
address ``0x20`` should be sent to ``i2c1`` with the same address. This allows
us to test both the controller and the target end of the communication on the
same image.
.. note::
The ``#forward-cells`` attribute should always be 1. Each entry in the
``fowards`` attribute consists of the phandle followed by the address. In
the example above, ``<&i2c1 0x20>`` will forward all read/write operations
made to ``i2c0`` at port ``0x20`` to ``i2c1`` on the same port. Since no
additional cells are used by the emulated controller, the number of cells
should remain 1.
Samples
=======
@ -166,6 +198,6 @@ Here are some examples present in Zephyr:
:gen-args: -DDTC_OVERLAY_FILE=at2x_emul.overlay -DOVERLAY_CONFIG=at2x_emul.conf
API Reference
*************
=============
.. doxygengroup:: io_emulators