circuitpython/ports/nrf/modules/machine/i2c.c

174 lines
5.6 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2017 Glenn Ruben Bakke
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <stdio.h>
#include <string.h>
#include "py/nlr.h"
#include "py/runtime.h"
#include "py/mperrno.h"
#include "py/mphal.h"
#if MICROPY_PY_MACHINE_I2C
#include "extmod/machine_i2c.h"
#include "i2c.h"
#if NRFX_TWI_ENABLED
#include "nrfx_twi.h"
#else
#include "nrfx_twim.h"
#endif
#if NRFX_TWIM_ENABLED
#define nrfx_twi_t nrfx_twim_t
#define nrfx_twi_config_t nrfx_twim_config_t
#define nrfx_twi_init nrfx_twim_init
#define nrfx_twi_enable nrfx_twim_enable
#define nrfx_twi_xfer nrfx_twim_xfer
#define nrfx_twi_disable nrfx_twim_disable
#define nrfx_twi_xfer_desc_t nrfx_twim_xfer_desc_t
#define NRFX_TWI_XFER_DESC_RX NRFX_TWIM_XFER_DESC_RX
#define NRFX_TWI_XFER_DESC_TX NRFX_TWIM_XFER_DESC_TX
#define NRFX_TWI_INSTANCE NRFX_TWIM_INSTANCE
#define NRF_TWI_FREQ_400K NRF_TWIM_FREQ_400K
#endif
typedef struct _machine_hard_i2c_obj_t {
mp_obj_base_t base;
nrfx_twi_t p_twi; // Driver instance
} machine_hard_i2c_obj_t;
STATIC const machine_hard_i2c_obj_t machine_hard_i2c_obj[] = {
{{&machine_hard_i2c_type}, .p_twi = NRFX_TWI_INSTANCE(0)},
{{&machine_hard_i2c_type}, .p_twi = NRFX_TWI_INSTANCE(1)},
};
void i2c_init0(void) {
}
STATIC int i2c_find(mp_obj_t id) {
// given an integer id
int i2c_id = mp_obj_get_int(id);
if (i2c_id >= 0 && i2c_id < MP_ARRAY_SIZE(machine_hard_i2c_obj)) {
return i2c_id;
}
mp_raise_ValueError(MP_ERROR_TEXT("I2C doesn't exist"));
}
STATIC void machine_hard_i2c_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
machine_hard_i2c_obj_t *self = self_in;
mp_printf(print, "I2C(%u)", self->p_twi.drv_inst_idx);
}
/******************************************************************************/
/* MicroPython bindings for machine API */
mp_obj_t machine_hard_i2c_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
MP_MACHINE_I2C_CHECK_FOR_LEGACY_SOFTI2C_CONSTRUCTION(n_args, n_kw, all_args);
enum { ARG_id, ARG_scl, ARG_sda };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_id, MP_ARG_REQUIRED | MP_ARG_OBJ },
{ MP_QSTR_scl, MP_ARG_REQUIRED | MP_ARG_OBJ },
{ MP_QSTR_sda, MP_ARG_REQUIRED | MP_ARG_OBJ },
};
// parse args
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
// get static peripheral object
int i2c_id = i2c_find(args[ARG_id].u_obj);
const machine_hard_i2c_obj_t *self = &machine_hard_i2c_obj[i2c_id];
nrfx_twi_config_t config;
config.scl = mp_hal_get_pin_obj(args[ARG_scl].u_obj)->pin;
config.sda = mp_hal_get_pin_obj(args[ARG_sda].u_obj)->pin;
config.frequency = NRF_TWI_FREQ_400K;
config.hold_bus_uninit = false;
// Set context to this object.
nrfx_twi_init(&self->p_twi, &config, NULL, (void *)self);
return MP_OBJ_FROM_PTR(self);
}
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;
int transfer_ret = 0;
if (flags & MP_MACHINE_I2C_FLAG_READ) {
nrfx_twi_xfer_desc_t desc = NRFX_TWI_XFER_DESC_RX(addr, buf, len);
err_code = nrfx_twi_xfer(&self->p_twi, &desc, 0);
} else {
nrfx_twi_xfer_desc_t desc = NRFX_TWI_XFER_DESC_TX(addr, buf, len);
err_code = nrfx_twi_xfer(&self->p_twi, &desc, (flags & MP_MACHINE_I2C_FLAG_STOP) == 0);
transfer_ret = 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_twi_disable(&self->p_twi);
return transfer_ret;
}
STATIC const mp_machine_i2c_p_t machine_hard_i2c_p = {
.transfer = mp_machine_i2c_transfer_adaptor,
.transfer_single = machine_hard_i2c_transfer_single,
};
const mp_obj_type_t machine_hard_i2c_type = {
{ &mp_type_type },
.name = MP_QSTR_I2C,
.print = machine_hard_i2c_print,
.make_new = machine_hard_i2c_make_new,
.protocol = &machine_hard_i2c_p,
.locals_dict = (mp_obj_dict_t*)&mp_machine_i2c_locals_dict,
};
#endif // MICROPY_PY_MACHINE_I2C