nRF5340 unable to write with I2C_1 in Zephyr

[Marciano-PL]

I am attempting to write a basic I2C program using Zephyr, but I am currently unable to sent a single byte over I2C. Am I doing something wrong? I'd prefer not to use the nrfxlib. 

Here is a list of the presently known TWIM errata:
(https://infocenter.nordicsemi.com/topic/errata_nRF5340_EngA/ERR/nRF5340/EngineeringA/latest/err_340_new.html)

[21] TWIM: 1000 kbps baud rate is not functional
[37] TWIM: First clock pulse after clock stretching may be too long or too short
[47] TWIM: I2C timing spec is violated at 400 kHz
[82] TWIM: TWIM2 and TWIM3 are not functional

Platform: nRF5340 PDK
SDA: P0.30
SCL: P0.31

Project Configuration: 

CONFIG_NEWLIB_LIBC=y
CONFIG_PRINTK=y
CONFIG_HAS_SEGGER_RTT=y
CONFIG_USE_SEGGER_RTT=y
CONFIG_RTT_CONSOLE=y
CONFIG_UART_CONSOLE=n

# nRF5340 board config
CONFIG_TRUSTED_EXECUTION_SECURE=y

CONFIG_BT=n
CONFIG_TIMESLICING=n
CONFIG_DEVICE_POWER_MANAGEMENT=y
CONFIG_SYS_POWER_MANAGEMENT=y
CONFIG_SYS_POWER_DEEP_SLEEP_STATES=y
CONFIG_DEVICE_POWER_MANAGEMENT=y

CONFIG_I2C=y
CONFIG_I2C_1=y

main.c

#include <zephyr.h>
#include <device.h>
#include <sys/printk.h>
#include <drivers/i2c.h>

/* Application main Thread */
int main(void)
{
  struct device *p_i2c = device_get_binding("I2C_1");
  u32_t dev_config = I2C_SPEED_SET(I2C_SPEED_STANDARD) | I2C_MODE_MASTER;
  int res = i2c_configure(p_i2c, dev_config);
  if (res)
  {
    return res;
  }
  u8_t buf[2] = {0x0, 0xFF};
  i2c_burst_write(p_i2c, 0x77, 0x14, buf, 2);
  return 0;
}

Waveform:

[ljking]

First the HW related questions, do you have pull-ups turned on on the GPIOs? or do you have external pull up resistors? and what i2c device do you have connected to the bus? 

Is i2c_burst_write() supported by the nrf5340? read https://docs.zephyrproject.org/apidoc/latest/group__i2c__interface_gae57ea5a1b4059e0d03d3bc068288de1f.html 

I have been using this for simple transfers on the nrf52840 (previous generation nrf chip)

int i;
struct i2c_msg msgs[2];
u8_t data[2][2];

printf("pca9536_init().\n");
i2c_dev = device_get_binding("I2C_1");
if (!i2c_dev) {
printf("pca9536_init(): I2C Device driver not found.\n");
return;
}
// set the pins to outputs, and drive high
data[0][0] = 3; // config register
data[0][1] = 0xFF^((1<<PCA9536_RED_LED_PIN)|(1<<PCA9536_GREEN_LED_PIN)|(1<<PCA9536_BLUE_LED_PIN)); // 3 outputs
msgs[0].buf = data[0];
msgs[0].len = 2U;
msgs[0].flags = I2C_MSG_WRITE | I2C_MSG_STOP;

data[1][0] = 1; // output register
data[1][1] = pca9536_state;
msgs[1].buf = data[1];
msgs[1].len = 2U;
msgs[1].flags = I2C_MSG_WRITE | I2C_MSG_STOP;
i = i2c_transfer(i2c_dev, &msgs[0], 2, (u8_t)PCA9536_I2C_ADDR);
if (i!=0) {
printf("pca9536_init(): transfer failed.\n");
return;
}

[Marciano-PL]

Thank you for the quick reply. 

Hardware
I have been using external pull-ups and a BME680. I removed the BME680 and kept the pull-ups and observed the same behavior on the bus.

Software
I switched over to using the `i2c_transfer()` function. The bus looks the same as with the previous implementation. The function only returns if I step through each call with the debugger. And only some times. Otherwise the program ends up hanging in nrf_regulators_system_off(...)

Has there been much testing of the nRF5340 by way of i2c on zephyr?