stm32: Fix I2S peripheral is not working on H7

[mocleiri]

First you need to use specific SPI pins when connecting the microphone. Also there is a switch needed to be enabled in the mpconfigboard.h file.

// turn on I2S
#define MICROPY_HW_I2S1         (1)

There is also a MICROPY_HW_I2S2 switch. I'm not sure if the nucleo h743 supports more i2s channels or not.

../../lib/stm32lib/STM32H7xx_HAL_Driver/Inc/stm32h7xx_hal_i2s.h:229:42: error: overflow in conversion from 'long unsigned int' to 'int8_t' {aka 'signed char'} changes value from '512' to '0' [-Werror=overflow]
  229 | #define I2S_DATAFORMAT_32B               (SPI_I2SCFGR_DATLEN_1)
      |                                          ^
machine_i2s.c:282:16: note: in expansion of macro 'I2S_DATAFORMAT_32B'
  282 |         return I2S_DATAFORMAT_32B;
      |                ^~~~~~~~~~~~~~~~~~
machine_i2s.c: In function 'i2s_init':
machine_i2s.c:583:9: warning: implicit declaration of function '__HAL_RCC_PLLI2S_ENABLE' [-Wimplicit-function-declaration]
  583 |         __HAL_RCC_PLLI2S_ENABLE();  // start I2S clock
      |         ^~~~~~~~~~~~~~~~~~~~~~~
machine_i2s.c: In function 'machine_i2s_init_helper':
machine_i2s.c:793:9: error: 'I2S_InitTypeDef' has no member named 'ClockSource'
  793 |     init->ClockSource = I2S_CLOCK_PLL;
      |         ^~
machine_i2s.c:793:25: error: 'I2S_CLOCK_PLL' undeclared (first use in this function); did you mean 'IS_RCC_PLL'?
  793 |     init->ClockSource = I2S_CLOCK_PLL;
      |                         ^~~~~~~~~~~~~
      |                         IS_RCC_PLL
machine_i2s.c:793:25: note: each undeclared identifier is reported only once for each function it appears in
cc1: all warnings being treated as errors

[mocleiri]

I was able to build after updating the H7 HAL files.

The stm32lib repo is a submodule at micropython/lib/stm32lib

I cloned the upstream STM32CubeH7 repo:

 git clone https://github.com/STMicroelectronics/STM32CubeH7.git

Then ran the update script:

$ cd micropython/lib/stm32lib
$ ./fetch_from_upstream.sh STM32H7 ~/git/STM32CubeH7/

Then the stm32 build worked to build the firmware.

I'm going to have to file a pull request to update these files and in the interim change the micropython submodule back to my fork which can use the forked and fixed stm32lib repo.

[mocleiri]

I also have to remove the defines to constants defined in the new HAL in micropython-modules/microlite/micropython.mk:

-CXXFLAGS_USERMOD += -D__FPU_PRESENT=1
+# CXXFLAGS_USERMOD += -D__FPU_PRESENT=1 

-CXXFLAGS_USERMOD += -D__ARM_FEATURE_DSP=1
+# CXXFLAGS_USERMOD += -D__ARM_FEATURE_DSP=1 

[mocleiri]

I did something wrong and the build didn't actually work. On closer inspection there are differences in the name of the HAL functions that are used in machine_i2s.c from the STM32F4 and the HAL available on the STM32H7.

I need to bring in some board awareness to machine_i2s.c and then see if I can figure out which methods to use on the H7 HAL.