[0/4] Check clock connection between STM32L4x5 RCC and peripherals

Message

Inès Varhol May 7, 2024, 6:55 p.m. UTC

Among implemented STM32L4x5 devices, USART, GPIO and SYSCFG
have a clock source, but none has a corresponding test in QEMU.

This patch makes sure that all 3 devices create a clock,
have a QOM property to access the clock frequency,
and adds QTests checking that clock enable in RCC has the
expected results.

Philippe Mathieu-Daudé suggested the following :
".. We could add the clock properties
directly in qdev_init_clock_in(). Seems useful for the QTest
framework."

However Peter Maydell pointed out the following :
"...Mostly "frequency" properties on devices are for the case
where they *don't* have a Clock input and instead have
ad-hoc legacy handling where the board/SoC that creates the
device sets an integer property to define the input frequency
because it doesn't model the clock tree with Clock objects."

You both agree on the fact that replicating the code in the
different devices is a bad idea, what should be the
alternative?

Thank you for the reviews.

Changes from v1:
- upgrading `VMStateDescription` to version 2 to account for
`VMSTATE_CLOCK()`
- QTests : consolidating `get_clock_freq_hz()` in a header
and making appropriate changes in stm32l4x5q_*-test.c

Signed-off-by: Inès Varhol <[e-mail]>

Inès Varhol (4):
  hw/misc: Create STM32L4x5 SYSCFG clock
  hw/gpio: Handle clock migration in STM32L4x5 gpios
  hw/char: Add QOM property for STM32L4x5 USART clock frequency
  tests/qtest: Check STM32L4x5 clock connections

 include/hw/misc/stm32l4x5_syscfg.h  |  1 +
 tests/qtest/stm32l4x5.h             | 40 +++++++++++++++++++++++++++++
 hw/arm/stm32l4x5_soc.c              |  2 ++
 hw/char/stm32l4x5_usart.c           | 16 ++++++++++--
 hw/gpio/stm32l4x5_gpio.c            |  6 +++--
 hw/misc/stm32l4x5_syscfg.c          | 30 ++++++++++++++++++++--
 tests/qtest/stm32l4x5_gpio-test.c   | 23 +++++++++++++++++
 tests/qtest/stm32l4x5_syscfg-test.c | 19 ++++++++++++--
 tests/qtest/stm32l4x5_usart-test.c  | 26 +++++++++++++++++++
 9 files changed, 155 insertions(+), 8 deletions(-)
 create mode 100644 tests/qtest/stm32l4x5.h

Comments

Peter Maydell May 20, 2024, 2:36 p.m. UTC | #1

On Tue, 7 May 2024 at 19:59, Inès Varhol <[e-mail]> wrote:
>
> Among implemented STM32L4x5 devices, USART, GPIO and SYSCFG
> have a clock source, but none has a corresponding test in QEMU.
>
> This patch makes sure that all 3 devices create a clock,
> have a QOM property to access the clock frequency,
> and adds QTests checking that clock enable in RCC has the
> expected results.
>
> Philippe Mathieu-Daudé suggested the following :
> ".. We could add the clock properties
> directly in qdev_init_clock_in(). Seems useful for the QTest
> framework."
>
> However Peter Maydell pointed out the following :
> "...Mostly "frequency" properties on devices are for the case
> where they *don't* have a Clock input and instead have
> ad-hoc legacy handling where the board/SoC that creates the
> device sets an integer property to define the input frequency
> because it doesn't model the clock tree with Clock objects."
>
> You both agree on the fact that replicating the code in the
> different devices is a bad idea, what should be the
> alternative?

I think we should use the approach discussed in the review
comments on Philippe's patch
https://patchew.org/QEMU/[e-mail]/
where if we're running a qtest then the core clock code creates a
QOM property which is the clock period; the test code can then use
that.

thanks
-- PMM