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Fix for #8093

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This adds a check to make sure that SDA and SCL are in a sane condition
before starting any I2C operation. If they are not it tries to rectify it,
and then returns an error code if unable to do so.
This commit is contained in:
Phil Underwood 2023-06-19 22:20:46 +01:00
parent 1f20328068
commit fae14cc55b
2 changed files with 50 additions and 7 deletions
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1
ports/nrf/Makefile
View File

@ -114,6 +114,7 @@ SRC_NRFX = $(addprefix nrfx/,\
drivers/src/nrfx_spim.c \
drivers/src/nrfx_timer.c \
drivers/src/nrfx_twim.c \
drivers/src/nrfx_twi_twim.c \
drivers/src/nrfx_uarte.c \
drivers/src/nrfx_gpiote.c \
drivers/src/nrfx_rtc.c \

56
ports/nrf/common-hal/busio/I2C.c
View File

@ -79,20 +79,54 @@ void common_hal_busio_i2c_never_reset(busio_i2c_obj_t *self) {
}
}
#define TWI_TWIM_PIN_CONFIGURE(_pin) nrf_gpio_cfg((_pin), \
NRF_GPIO_PIN_DIR_OUTPUT, \
NRF_GPIO_PIN_INPUT_CONNECT, \
NRF_GPIO_PIN_PULLUP, \
NRF_GPIO_PIN_S0D1, \
NRF_GPIO_PIN_NOSENSE)
static nrfx_err_t _safe_twim_enable(busio_i2c_obj_t *self) {
// check to see if bus is in sensible state before enabling twim
nrfx_err_t recover_result;
nrf_gpio_cfg_input(self->scl_pin_number, NRF_GPIO_PIN_PULLDOWN);
nrf_gpio_cfg_input(self->sda_pin_number, NRF_GPIO_PIN_PULLDOWN);
common_hal_mcu_delay_us(10);
nrf_gpio_cfg_input(self->scl_pin_number, NRF_GPIO_PIN_NOPULL);
nrf_gpio_cfg_input(self->sda_pin_number, NRF_GPIO_PIN_NOPULL);
// We must pull up within 3us to achieve 400khz.
common_hal_mcu_delay_us(3);
if (!nrf_gpio_pin_read(self->sda_pin_number) || !nrf_gpio_pin_read(self->scl_pin_number)) {
// bus not in a sane state - try to recover
recover_result = nrfx_twim_bus_recover(self->scl_pin_number, self->sda_pin_number);
if (NRFX_SUCCESS != recover_result) {
// return error message if unable to recover the bus
return recover_result;
}
}
nrfx_twim_enable(&self->twim_peripheral->twim);
return NRFX_SUCCESS;
}
static uint8_t twi_error_to_mp(const nrfx_err_t err) {
switch (err) {
case NRFX_ERROR_DRV_TWI_ERR_ANACK:
return MP_ENODEV;
case NRFX_ERROR_BUSY:
return MP_EBUSY;
case NRFX_SUCCESS:
return 0;
case NRFX_ERROR_DRV_TWI_ERR_DNACK:
case NRFX_ERROR_INVALID_ADDR:
return MP_EIO;
case NRFX_ERROR_INTERNAL:
default:
break;
return MP_EIO;
}
return 0;
}
void common_hal_busio_i2c_construct(busio_i2c_obj_t *self, const mcu_pin_obj_t *scl, const mcu_pin_obj_t *sda, uint32_t frequency, uint32_t timeout) {
@ -188,7 +222,9 @@ bool common_hal_busio_i2c_probe(busio_i2c_obj_t *self, uint8_t addr) {
NRF_TWIM_Type *reg = self->twim_peripheral->twim.p_twim;
bool found = true;
nrfx_twim_enable(&self->twim_peripheral->twim);
if (NRFX_SUCCESS != _safe_twim_enable(self)) {
return false;
}
nrf_twim_address_set(reg, addr);
nrf_twim_tx_buffer_set(reg, NULL, 0);
@ -246,7 +282,10 @@ STATIC uint8_t _common_hal_busio_i2c_write(busio_i2c_obj_t *self, uint16_t addr,
nrfx_err_t err = NRFX_SUCCESS;
nrfx_twim_enable(&self->twim_peripheral->twim);
err = _safe_twim_enable(self);
if (NRFX_SUCCESS != err) {
return twi_error_to_mp(err);
}
// break into MAX_XFER_LEN transaction
while (len) {
@ -278,7 +317,10 @@ uint8_t common_hal_busio_i2c_read(busio_i2c_obj_t *self, uint16_t addr, uint8_t
nrfx_err_t err = NRFX_SUCCESS;
nrfx_twim_enable(&self->twim_peripheral->twim);
err = _safe_twim_enable(self);
if (NRFX_SUCCESS != err) {
return twi_error_to_mp(err);
}
// break into MAX_XFER_LEN transaction
while (len) {