circuitpython/extmod/machine_i2c.h
Damien George 4a1ae99ac3 extmod/machine_i2c: Add optional support for write-then-read transfers.
This option is useful for ports where it's more efficient to do a full I2C
transfer in one go.

Signed-off-by: Damien George <damien@micropython.org>
2022-06-01 13:20:27 +10:00

88 lines
3.7 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2016 Damien P. George
*
* 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.
*/
#ifndef MICROPY_INCLUDED_EXTMOD_MACHINE_I2C_H
#define MICROPY_INCLUDED_EXTMOD_MACHINE_I2C_H
#include "py/obj.h"
#include "py/mphal.h"
// Temporary support for legacy construction of SoftI2C via I2C type.
#define MP_MACHINE_I2C_CHECK_FOR_LEGACY_SOFTI2C_CONSTRUCTION(n_args, n_kw, all_args) \
do { \
if (n_args == 0 || all_args[0] == MP_OBJ_NEW_SMALL_INT(-1)) { \
mp_print_str(MICROPY_ERROR_PRINTER, "Warning: I2C(-1, ...) is deprecated, use SoftI2C(...) instead\n"); \
if (n_args != 0) { \
--n_args; \
++all_args; \
} \
return mp_machine_soft_i2c_type.make_new(&mp_machine_soft_i2c_type, n_args, n_kw, all_args); \
} \
} while (0)
#define MP_MACHINE_I2C_FLAG_READ (0x01) // if not set then it's a write
#define MP_MACHINE_I2C_FLAG_STOP (0x02)
#if MICROPY_PY_MACHINE_I2C_TRANSFER_WRITE1
// If set, the first mp_machine_i2c_buf_t in a transfer is a write.
#define MP_MACHINE_I2C_FLAG_WRITE1 (0x04)
#endif
typedef struct _mp_machine_i2c_buf_t {
size_t len;
uint8_t *buf;
} mp_machine_i2c_buf_t;
// I2C protocol
// - init must be non-NULL
// - start/stop/read/write can be NULL, meaning operation is not supported
// - transfer must be non-NULL
// - transfer_single only needs to be set if transfer=mp_machine_i2c_transfer_adaptor
typedef struct _mp_machine_i2c_p_t {
void (*init)(mp_obj_base_t *obj, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args);
int (*start)(mp_obj_base_t *obj);
int (*stop)(mp_obj_base_t *obj);
int (*read)(mp_obj_base_t *obj, uint8_t *dest, size_t len, bool nack);
int (*write)(mp_obj_base_t *obj, const uint8_t *src, size_t len);
int (*transfer)(mp_obj_base_t *obj, uint16_t addr, size_t n, mp_machine_i2c_buf_t *bufs, unsigned int flags);
int (*transfer_single)(mp_obj_base_t *obj, uint16_t addr, size_t len, uint8_t *buf, unsigned int flags);
} mp_machine_i2c_p_t;
typedef struct _mp_machine_soft_i2c_obj_t {
mp_obj_base_t base;
uint32_t us_delay;
uint32_t us_timeout;
mp_hal_pin_obj_t scl;
mp_hal_pin_obj_t sda;
} mp_machine_soft_i2c_obj_t;
extern const mp_obj_type_t mp_machine_soft_i2c_type;
extern const mp_obj_dict_t mp_machine_i2c_locals_dict;
int mp_machine_i2c_transfer_adaptor(mp_obj_base_t *self, uint16_t addr, size_t n, mp_machine_i2c_buf_t *bufs, unsigned int flags);
int mp_machine_soft_i2c_transfer(mp_obj_base_t *self, uint16_t addr, size_t n, mp_machine_i2c_buf_t *bufs, unsigned int flags);
#endif // MICROPY_INCLUDED_EXTMOD_MACHINE_I2C_H