nrf/machine/i2c: Update to support new C-level I2C API.

ports/nrf/modules/machine/i2c.c

@@ -99,35 +99,20 @@ mp_obj_t machine_hard_i2c_make_new(const mp_obj_type_t *type, size_t n_args, siz
     return MP_OBJ_FROM_PTR(self);
 }
 
-int machine_hard_i2c_readfrom(mp_obj_base_t *self_in, uint16_t addr, uint8_t *dest, size_t len, bool stop) {
+int machine_hard_i2c_transfer_single(mp_obj_base_t *self_in, uint16_t addr, size_t len, uint8_t *buf, unsigned int flags) {
     machine_hard_i2c_obj_t *self = (machine_hard_i2c_obj_t *)self_in;
 
     nrfx_twi_enable(&self->p_twi);
 
-    nrfx_err_t err_code = nrfx_twi_rx(&self->p_twi, addr, dest, len);
-
-    if (err_code != NRFX_SUCCESS) {
-        if (err_code == NRFX_ERROR_DRV_TWI_ERR_ANACK) {
-            return -MP_ENODEV;
-        }
-        else if (err_code == NRFX_ERROR_DRV_TWI_ERR_DNACK) {
-            return -MP_EIO;
-        }
-        return -MP_ETIMEDOUT;
+    nrfx_err_t err_code;
+    int transfer_ret = 0;
+    if (flags & MP_MACHINE_I2C_FLAG_READ) {
+        err_code = nrfx_twi_rx(&self->p_twi, addr, buf, len);
+    } else {
+        err_code = nrfx_twi_tx(&self->p_twi, addr, buf, len, (flags & MP_MACHINE_I2C_FLAG_STOP) == 0);
+        transfer_ret = len;
     }
 
-    nrfx_twi_disable(&self->p_twi);
-
-    return 0;
-}
-
-int machine_hard_i2c_writeto(mp_obj_base_t *self_in, uint16_t addr, const uint8_t *src, size_t len, bool stop) {
-    machine_hard_i2c_obj_t *self = (machine_hard_i2c_obj_t *)self_in;
-
-    nrfx_twi_enable(&self->p_twi);
-
-    nrfx_err_t err_code = nrfx_twi_tx(&self->p_twi, addr, src, len, !stop);
-
     if (err_code != NRFX_SUCCESS) {
         if (err_code == NRFX_ERROR_DRV_TWI_ERR_ANACK) {
             return -MP_ENODEV;
@@ -140,12 +125,12 @@ int machine_hard_i2c_writeto(mp_obj_base_t *self_in, uint16_t addr, const uint8_
 
     nrfx_twi_disable(&self->p_twi);
 
-    return len;
+    return transfer_ret;
 }
 
 STATIC const mp_machine_i2c_p_t machine_hard_i2c_p = {
-    .readfrom = machine_hard_i2c_readfrom,
-    .writeto = machine_hard_i2c_writeto,
+    .transfer = mp_machine_i2c_transfer_adaptor,
+    .transfer_single = machine_hard_i2c_transfer_single,
 };
 
 STATIC const mp_obj_type_t machine_hard_i2c_type = {