Hi Simon, On Thu, Aug 31, 2023 at 09:04:43AM -0600, Simon Glass wrote: > Hi, > > On Wed, 30 Aug 2023 at 23:28, AKASHI Takahiro > <takahiro.aka...@linaro.org> wrote: > > > > Hi Simon, > > > > On Wed, Aug 30, 2023 at 08:49:05PM -0600, Simon Glass wrote: > > > Hi, > > > > > > On Wed, 30 Aug 2023 at 18:38, AKASHI Takahiro > > > <takahiro.aka...@linaro.org> wrote: > > > > > > > > Hi, > > > > > > > > I'm working on implementing SCMI-based pinctrl/gpio driver, > > > > and want to re-use sandbox UT to test the code. However, > > > > It is somehow sandbox-specific (with additional DT nodes). > > > > How can/should we make it more generic for other targets/drivers > > > > rather than just by copying the test code? > > > > (I have already created a test for pinmux since there is only > > > > one existing scenario, but gpio test has many.) > > > > > > > > Even if I say 'generic', my case may be special since real > > > > hardware (device drivers) cannot always run all the test cases, > > > > while SCMI-based drivers potentially can with a dummy SCMI server > > > > for sandbox. > > > > See: > > > > drivers/firmware/scmi/sandbox-scmi_agent.c > > > > > > We don't have a good way to test drivers that talk to hardware, in > > > general. > > > > > > For I2C, SPI and some PCI devices you can sometimes write an emulator > > > for the chip and then your driver can talk to the emulator as if it > > > were talking to the hardware. Sandbox does actually support that with > > > memory-mapped I/O too, although it is fairly rarely used. > > > > Well, I don't want or need to emulate some *real* hardware. > > Instead, I would like to emulate what the current sandbox drivers > > (pinctrl-sandbox.c and gpio/sandbox.c) emulate so that we can re-use > > (some portion of) test cases for sandbox (test/dm/pinmux.c and gpio.c). > > > > As you might know, SCMI protocol with associated drivers on U-Boot is > > so generic that it would be able to talk to any of real pinctrl/gpio > > drivers/firmware (say, run on OPTEE or SCP). > > By implementing/mimicking protocol messages in sandbox-scmi_agent.c, > > SCMI drivers are expected to provide *virtual* pinctrl/gpio devices > > similar to what sandbox does. > > I actually know almost nothing about SCMI. > > > > > I have already implemented pinmux test with some tweaks by copying > > test/dm/pinmux.c and duplicating almost the same DT nodes as "pinctrl-gpio" > > in test.dts. > > But I'm looking for any other means without test code duplication. > > > > Did I clarify my question a bit? > > Well you should be able to factor out the test code into a function, > then call it from two places with the two different devices (or other > params) that are needed. > > For the DT, copying a few nodes is not the end of the world, IMO. > > BTW have you seen this talk? [2] It seems that you are moving pieces > into firmware which should be OS drivers? > > Anyway, if you place a sandbox pinmux device under the SCMI node in > the DT, then you should end up with a pinmux device you can use likely > normal. Then if that device uses the sandbox emulator, you can run the > existing tests on it with little modification, I suspect. > > But if I am still missing the point, a diagram or patch might help me > understand!
I just posted my RFC for supporting SCMI pinctrl protocol[1], hoping it will help you understand what I'm planning to do regarding test methodology, in particular by looking at patch#5 and #6. [1] https://lists.denx.de/pipermail/u-boot/2023-September/529765.html Thanks, -Takahiro Akashi > Regards, > Simon > > > > > > -Takahiro Akashi > > > > > > > We have done this a lot with Zephyr, as well[1] and achieved 90% code > > > coverage on some boards. > > > > > > But I'm not quite sure I am answering the right question, so I will stop > > > here. > > > > > > Regards, > > > Simon > > > > > > [1] https://www.youtube.com/watch?v=usXCAXR2G_c > > [2] https://www.usenix.org/conference/osdi21/presentation/fri-keynote
