add CAN support to Nucleo L432KC (Nucleo 32)

[donsez]

Description

The Nucleo L432KC board is a Nucleo 32 board supported by RIOT OS.

This board supports CAN interface. However, CAN periph is not enabled into Makefile.features and the definition of the CAN pins is not correct for the STM32L432KC : PA11/PA12 instead of PB8/PB9 into cpu/stm32/include/can_params.h

Steps to reproduce the issue

The following patch is enough for using the CAN bus with Nucleo L432KC

diff --git a/boards/nucleo-l432kc/Makefile.features b/boards/nucleo-l432kc/Makefile.features
index 1bf6b33cbc..a0c1c07920 100644
--- a/boards/nucleo-l432kc/Makefile.features
+++ b/boards/nucleo-l432kc/Makefile.features
@@ -2,6 +2,7 @@ CPU = stm32
 CPU_MODEL = stm32l432kc

 # Put defined MCU peripherals here (in alphabetical order)
+FEATURES_PROVIDED += periph_can
 FEATURES_PROVIDED += periph_i2c
 FEATURES_PROVIDED += periph_pwm
 FEATURES_PROVIDED += periph_rtc
diff --git a/cpu/stm32/include/can_params.h b/cpu/stm32/include/can_params.h
index d1c0e26912..8a6a58c7be 100644
--- a/cpu/stm32/include/can_params.h
+++ b/cpu/stm32/include/can_params.h
@@ -54,9 +54,15 @@ static const can_conf_t candev_conf[] = {
        .rx_pin = GPIO_PIN(PORT_A, 11),
        .tx_pin = GPIO_PIN(PORT_A, 12),
 #elif defined(CPU_FAM_STM32L4) || defined(CPU_FAM_STM32F4)
+#if  defined(BOARD_NUCLEO_L432KC)
+       .rx_pin = GPIO_PIN(PORT_A, 11),
+       .tx_pin = GPIO_PIN(PORT_A, 12),
+       .af = GPIO_AF9,
+#else
        .rx_pin = GPIO_PIN(PORT_B, 8),
        .tx_pin = GPIO_PIN(PORT_B, 9),
        .af = GPIO_AF9,
+#endif
 #else
        .rx_pin = GPIO_PIN(PORT_D, 0),
        .tx_pin = GPIO_PIN(PORT_D, 1),

Expected results

Actual results

Versions

Operating System Environment
----------------------------
         Operating System: macOS 14.6.1
                   Kernel: Darwin 23.6.0 x86_64 i386
             System shell: GNU bash, version 3.2.57(1)-release (x86_64-apple-darwin23)
             make's shell: GNU bash, version 3.2.57(1)-release (x86_64-apple-darwin23)

Installed compiler toolchains
-----------------------------
               native gcc: Apple clang version 15.0.0 (clang-1500.3.9.4)
        arm-none-eabi-gcc: arm-none-eabi-gcc (GNU Arm Embedded Toolchain 10.3-2021.10) 10.3.1 20210824 (release)
                  avr-gcc: missing
           msp430-elf-gcc: missing
       riscv-none-elf-gcc: missing
  riscv64-unknown-elf-gcc: missing
     riscv-none-embed-gcc: missing
      riscv32-esp-elf-gcc: missing
     xtensa-esp32-elf-gcc: missing
   xtensa-esp32s2-elf-gcc: missing
   xtensa-esp32s3-elf-gcc: missing
   xtensa-esp8266-elf-gcc: missing
                    clang: Apple clang version 15.0.0 (clang-1500.3.9.4)

Installed compiler libs
-----------------------
     arm-none-eabi-newlib: "4.1.0"
        msp430-elf-newlib: missing
    riscv-none-elf-newlib: missing
riscv64-unknown-elf-newlib: missing
  riscv-none-embed-newlib: missing
   riscv32-esp-elf-newlib: missing
  xtensa-esp32-elf-newlib: missing
xtensa-esp32s2-elf-newlib: missing
xtensa-esp32s3-elf-newlib: missing
xtensa-esp8266-elf-newlib: missing
                 avr-libc: missing (missing)

Installed development tools
---------------------------
                   ccache: ccache version 4.9.1
                    cmake: cmake version 3.29.3
                 cppcheck: Cppcheck 2.14.0
                  doxygen: 1.10.0 (GIT-NOTFOUND)
                      git: git version 2.45.0
                     make: GNU Make 3.81
                  openocd: Open On-Chip Debugger 0.12.0
                   python: Python 3.10.6
                  python2: missing
                  python3: Python 3.10.6
                   flake8: error: /Users/donsez/miniforge3/bin/python3: No module named flake8
               coccinelle: missing

Misc

This LoRa gateway board for cubesat uses CAN bus for communication with other boards into the INISAT cubesat.

[donsez]

Note: the Nucleo32 boards nucleo-f303k8 and nucleo-f042k6 have also a CAN bus interface.

[krzysztof-cabaj]

Hi! I looked at STM32L432KC datasheet and presented config (PA11/12 and AF9) seams reasonable.

I currently don't have nucleo-l432kc but if you would like, I could prepare PR with your changes. Or I could help you with submitting PR.

[donsez]

Note Bene: I've tried to add FEATURES_PROVIDED += periph_can to the Makefile.features of the Nucleo32 boards nucleo-f303k8 and nucleo-f042k6 but the build of tests/sys/conn_can failed.

[krzysztof-cabaj]

Hi! I try compile this code and errors are associated with various names of CMSIS defines in the candev_conf struct from cpu/stm32/include/can_param.h. For example for f303 .can should be CAN not CAN1, .rcc_mask should be RCC_APB1ENR_CANEN not RCC_APB1ENR_CAN1EN etc.. . To fix this some additional defines should be added - but this could lead to very hard to read/maintence code.