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Refactor out test for bus sanity state

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This commit is contained in:
Phil Underwood 2023-06-20 23:32:00 +01:00
parent 028a81922b
commit a753490899
1 changed files with 22 additions and 23 deletions
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45
ports/nrf/common-hal/busio/I2C.c
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@ -79,21 +79,33 @@ void common_hal_busio_i2c_never_reset(busio_i2c_obj_t *self) {
}
}
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);
static bool _bus_is_sane(uint32_t scl_pin, uint32_t sda_pin) {
#if CIRCUITPY_REQUIRE_I2C_PULLUPS
nrf_gpio_cfg_input(scl_pin, NRF_GPIO_PIN_PULLDOWN);
nrf_gpio_cfg_input(sda_pin, 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);
nrf_gpio_cfg_input(scl_pin, NRF_GPIO_PIN_NOPULL);
nrf_gpio_cfg_input(sda_pin, NRF_GPIO_PIN_NOPULL);
// We must pull up within 3us to achieve 400khz.
common_hal_mcu_delay_us(3);
if (!nrf_gpio_pin_read(sda_pin) || !nrf_gpio_pin_read(scl_pin)) {
return false;
} else {
return true;
}
#else
return true;
#endif
}
if (!nrf_gpio_pin_read(self->sda_pin_number) || !nrf_gpio_pin_read(self->scl_pin_number)) {
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;
if (!_bus_is_sane(self->scl_pin_number, self->sda_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) {
@ -141,25 +153,12 @@ void common_hal_busio_i2c_construct(busio_i2c_obj_t *self, const mcu_pin_obj_t *
mp_raise_ValueError(translate("All I2C peripherals are in use"));
}
#if CIRCUITPY_REQUIRE_I2C_PULLUPS
// Test that the pins are in a high state. (Hopefully indicating they are pulled up.)
nrf_gpio_cfg_input(scl->number, NRF_GPIO_PIN_PULLDOWN);
nrf_gpio_cfg_input(sda->number, NRF_GPIO_PIN_PULLDOWN);
common_hal_mcu_delay_us(10);
nrf_gpio_cfg_input(scl->number, NRF_GPIO_PIN_NOPULL);
nrf_gpio_cfg_input(sda->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(sda->number) || !nrf_gpio_pin_read(scl->number)) {
// check bus is in a sane state
if (!_bus_is_sane(scl->number,sda->number)) {
reset_pin_number(sda->number);
reset_pin_number(scl->number);
mp_raise_RuntimeError(translate("No pull up found on SDA or SCL; check your wiring"));
}
#endif
nrfx_twim_config_t config = NRFX_TWIM_DEFAULT_CONFIG(scl->number, sda->number);