arch/xtensa/esp32[-s3]: Add ULP RISCV coprocessor wakeup

[eren-terzioglu]

Note: Please merge #17235 first

Summary

• arch/xtensa/esp32[-s3]: Add ULP RISCV coprocessor wakeup board support

Add ULP RISC-V coprocessor wakeup board support for esp32s3

• arch/xtensa/esp32[-s3]: Add ULP RISCV coprocessor wakeup

Add ULP RISCV coprocessor wakeup support for esp32s3

Impact

Impact on user: Yes, ULP RISC-V coprocessor can wake up HP core

Impact on build: No

Impact on hardware: No

Impact on documentation: No

Impact on security: No

Impact on compatibility: No

Testing

esp32s3-devkit:pm used as a base with these options added:

CONFIG_ESP32S3_ULP_COPROC_ENABLED=y
CONFIG_ESP32S3_ULP_COPROC_RESERVE_MEM=8000
CONFIG_ESP32S2_ULP_COPROC_RESERVE_MEM=8000
CONFIG_PM_ULP_WAKEUP=y
CONFIG_PM_SLEEP_WAKEUP_SEC=25

To test this feature an example created, here are the snippets:

// HP core application
#include <nuttx/config.h>
#include <nuttx/power/pm.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <inttypes.h>
#include "ulp/ulp/ulp_main.h"
#include "ulp/ulp/ulp_code.h"
#include "esp32s3_pm.h"

void load_ulp_wakeup_binary(void)
{
  int fd;
  fd = open("/dev/ulp", O_WRONLY);
  if (fd < 0)
    {
      printf("Failed to open ULP: %d\n", errno);
      return;
    }
  write(fd, ulp_wakeup_bin, ulp_wakeup_bin_len);
}

int main(int argc, char *argv[])
{
  int ulp_fd;

  ulp_fd = open("/dev/ulp", O_WRONLY);
  if (ulp_fd < 0)
    {
      printf("Failed to open ULP: %d\n", errno);
      return ERROR;
    }

  load_ulp_wakeup_binary();

  // esp32s3_pmsleep can be used for deep sleep as well
  esp32s3_pmstandby(CONFIG_PM_ALARM_SEC * 1000000 +
                    CONFIG_PM_ALARM_NSEC / 1000);

  return OK;
}

// LP core application
#include <stdint.h>
#include <stdio.h>
#include <stdbool.h>
#include "ulp_riscv.h"
#include "ulp_riscv_utils.h"
#include "ulp_riscv_print.h"
#include "sdkconfig.h"

#define nop()   __asm__ __volatile__ ("nop")

int main(void)
{
    while (1)
        {
            /* Delay */

            for (int i = 0; i < 1000000; i++)
                {
                    nop();
                }
            ulp_riscv_wakeup_main_processor();
        }

    /* ulp_lp_core_halt() is called automatically when main exits */

    return 0;
}

Building

NuttX build process applied to related config. Assuming we updated pm config with related options

make -j distclean && ./tools/configure.sh esp32s3-devkit:pm && make -j && make download ESPTOOL_PORT=/dev/ttyUSB0 ESPTOOL_BAUD=921600 ESPTOOL_BINDIR=./

Running

Example run

Results

Device should got into sleep and nsh would be unresponsive for a few seconds but it needs to return back less than 25 seconds (or whatever assigned to CONFIG_PM_SLEEP_WAKEUP_SEC)

[acassis]

@eren-terzioglu suggestion: please include the test example in to Documentation/ and explain the steps to test it. This way people could use this feature easily

[eren-terzioglu]

@eren-terzioglu suggestion: please include the test example in to Documentation/ and explain the steps to test it. This way people could use this feature easily

ULP example has only one line difference than documentation which is mentioned on Kconfig option and defconfig doc. Also PM defconfig doc should include tricks to let device sleep. Should we add it? I thought it will be unnecessary repeating.

[acassis]

@eren-terzioglu suggestion: please include the test example in to Documentation/ and explain the steps to test it. This way people could use this feature easily

ULP example has only one line difference than documentation which is mentioned on Kconfig option and defconfig doc. Also PM defconfig doc should include tricks to let device sleep. Should we add it? I thought it will be unnecessary repeating.

Is this only one line necessary to get ULP working correctly on NuttX? If so I think it is important to document it, even if you decide not to include this sample source code.

[eren-terzioglu]

@eren-terzioglu suggestion: please include the test example in to Documentation/ and explain the steps to test it. This way people could use this feature easily

ULP example has only one line difference than documentation which is mentioned on Kconfig option and defconfig doc. Also PM defconfig doc should include tricks to let device sleep. Should we add it? I thought it will be unnecessary repeating.

Is this only one line necessary to get ULP working correctly on NuttX? If so I think it is important to document it, even if you decide not to include this sample source code.

Only different line is ulp_riscv_wakeup_main_processor and it is waking up the HP core but I can add it into ULP example with a comment, it will be efficient and informational.

[eren-terzioglu]

Thanks @acassis, updated