You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 

228 lines
9.2 KiB

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2016 Scott Shawcroft
*
* 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.
*/
// This file contains all of the Python API definitions for the
// bitbangio.SPI class.
#include <string.h>
#include "shared-bindings/bitbangio/SPI.h"
#include "shared-bindings/microcontroller/Pin.h"
#include "lib/utils/context_manager_helpers.h"
#include "py/runtime.h"
//| .. currentmodule:: bitbangio
//|
//| :class:`SPI` -- a 3-4 wire serial protocol
//| -----------------------------------------------
//|
//| SPI is a serial protocol that has exclusive pins for data in and out of the
//| master. It is typically faster than :py:class:`~bitbangio.I2C` because a
//| separate pin is used to control the active slave rather than a transmitted
//| address. This class only manages three of the four SPI lines: `!clock`,
//| `!MOSI`, `!MISO`. Its up to the client to manage the appropriate slave
//| select line. (This is common because multiple slaves can share the `!clock`,
//| `!MOSI` and `!MISO` lines and therefore the hardware.)
//|
//| .. class:: SPI(clock, MOSI, MISO)
//|
//| Construct an SPI object on the given pins.
//|
//| :param ~microcontroller.Pin clock: the pin to use for the clock.
//| :param ~microcontroller.Pin MOSI: the Master Out Slave In pin.
//| :param ~microcontroller.Pin MISO: the Master In Slave Out pin.
//|
// TODO(tannewt): Support LSB SPI.
STATIC mp_obj_t bitbangio_spi_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *pos_args) {
mp_arg_check_num(n_args, n_kw, 0, MP_OBJ_FUN_ARGS_MAX, true);
bitbangio_spi_obj_t *self = m_new_obj(bitbangio_spi_obj_t);
self->base.type = &bitbangio_spi_type;
mp_map_t kw_args;
mp_map_init_fixed_table(&kw_args, n_kw, pos_args + n_args);
enum { ARG_clock, ARG_MOSI, ARG_MISO, ARG_baudrate, ARG_polarity, ARG_phase, ARG_bits, ARG_firstbit };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_clock, MP_ARG_REQUIRED | MP_ARG_OBJ },
{ MP_QSTR_MOSI, MP_ARG_OBJ, {.u_obj = mp_const_none} },
{ MP_QSTR_MISO, MP_ARG_OBJ, {.u_obj = mp_const_none} },
};
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args, pos_args, &kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
assert_pin(args[ARG_clock].u_obj, false);
assert_pin(args[ARG_MOSI].u_obj, true);
assert_pin(args[ARG_MISO].u_obj, true);
const mcu_pin_obj_t* clock = MP_OBJ_TO_PTR(args[ARG_clock].u_obj);
const mcu_pin_obj_t* mosi = MP_OBJ_TO_PTR(args[ARG_MOSI].u_obj);
const mcu_pin_obj_t* miso = MP_OBJ_TO_PTR(args[ARG_MISO].u_obj);
shared_module_bitbangio_spi_construct(self, clock, mosi, miso);
return (mp_obj_t)self;
}
//| .. method:: SPI.deinit()
//|
//| Turn off the SPI bus.
//|
STATIC mp_obj_t bitbangio_spi_obj_deinit(mp_obj_t self_in) {
bitbangio_spi_obj_t *self = MP_OBJ_TO_PTR(self_in);
shared_module_bitbangio_spi_deinit(self);
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_1(bitbangio_spi_deinit_obj, bitbangio_spi_obj_deinit);
//| .. method:: SPI.__enter__()
//|
//| No-op used by Context Managers.
//|
// Provided by context manager helper.
//| .. method:: SPI.__exit__()
//|
//| Automatically deinitializes the hardware when exiting a context.
//|
STATIC mp_obj_t bitbangio_spi_obj___exit__(size_t n_args, const mp_obj_t *args) {
(void)n_args;
shared_module_bitbangio_spi_deinit(args[0]);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(bitbangio_spi_obj___exit___obj, 4, 4, bitbangio_spi_obj___exit__);
static void check_lock(bitbangio_spi_obj_t *self) {
if (!shared_module_bitbangio_spi_has_lock(self)) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, "Function requires SPI lock."));
}
}
//| .. method:: SPI.configure(baudrate=100000)
//|
//| Configures the SPI bus. Only valid when locked.
//|
STATIC mp_obj_t bitbangio_spi_configure(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_baudrate, ARG_polarity, ARG_phase, ARG_bits };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_baudrate, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 100000} },
{ MP_QSTR_polarity, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_phase, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_bits, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 8} },
};
bitbangio_spi_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
check_lock(self);
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
uint8_t polarity = args[ARG_polarity].u_int;
if (polarity != 0 && polarity != 1) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "Invalid polarity."));
}
uint8_t phase = args[ARG_phase].u_int;
if (phase != 0 && phase != 1) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "Invalid phase."));
}
uint8_t bits = args[ARG_bits].u_int;
if (bits != 8 && bits != 9) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "Invalid number of bits."));
}
shared_module_bitbangio_spi_configure(self, args[ARG_baudrate].u_int, polarity, phase, bits);
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_KW(bitbangio_spi_configure_obj, 1, bitbangio_spi_configure);
//| .. method:: SPI.try_lock()
//|
//| Attempts to grab the SPI lock. Returns True on success.
//|
STATIC mp_obj_t bitbangio_spi_obj_try_lock(mp_obj_t self_in) {
shared_module_bitbangio_spi_try_lock(MP_OBJ_TO_PTR(self_in));
return self_in;
}
MP_DEFINE_CONST_FUN_OBJ_1(bitbangio_spi_try_lock_obj, bitbangio_spi_obj_try_lock);
//| .. method:: SPI.unlock()
//|
//| Releases the SPI lock.
//|
STATIC mp_obj_t bitbangio_spi_obj_unlock(mp_obj_t self_in) {
shared_module_bitbangio_spi_unlock(MP_OBJ_TO_PTR(self_in));
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_1(bitbangio_spi_unlock_obj, bitbangio_spi_obj_unlock);
//| .. method:: SPI.write(buf)
//|
//| Write the data contained in ``buf``. Requires the SPI being locked.
//|
STATIC mp_obj_t bitbangio_spi_write(mp_obj_t self_in, mp_obj_t wr_buf) {
mp_buffer_info_t src;
mp_get_buffer_raise(wr_buf, &src, MP_BUFFER_READ);
bitbangio_spi_obj_t *self = MP_OBJ_TO_PTR(self_in);
check_lock(self);
bool ok = shared_module_bitbangio_spi_write(self, src.buf, src.len);
if (!ok) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, "SPI bus error"));
}
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_2(bitbangio_spi_write_obj, bitbangio_spi_write);
//| .. method:: SPI.readinto(buf)
//|
//| Read into the buffer specified by ``buf`` while writing zeroes. Requires the SPI being locked.
//|
STATIC mp_obj_t bitbangio_spi_readinto(size_t n_args, const mp_obj_t *args) {
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[1], &bufinfo, MP_BUFFER_WRITE);
check_lock(args[0]);
bool ok = shared_module_bitbangio_spi_read(args[0], bufinfo.buf, bufinfo.len);
if (!ok) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, "SPI bus error"));
}
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(bitbangio_spi_readinto_obj, 2, 2, bitbangio_spi_readinto);
STATIC const mp_rom_map_elem_t bitbangio_spi_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&bitbangio_spi_deinit_obj) },
{ MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&default___enter___obj) },
{ MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&bitbangio_spi_obj___exit___obj) },
{ MP_ROM_QSTR(MP_QSTR_configure), MP_ROM_PTR(&bitbangio_spi_configure_obj) },
{ MP_ROM_QSTR(MP_QSTR_try_lock), MP_ROM_PTR(&bitbangio_spi_try_lock_obj) },
{ MP_ROM_QSTR(MP_QSTR_unlock), MP_ROM_PTR(&bitbangio_spi_unlock_obj) },
{ MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&bitbangio_spi_readinto_obj) },
{ MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&bitbangio_spi_write_obj) },
};
STATIC MP_DEFINE_CONST_DICT(bitbangio_spi_locals_dict, bitbangio_spi_locals_dict_table);
const mp_obj_type_t bitbangio_spi_type = {
{ &mp_type_type },
.name = MP_QSTR_SPI,
.make_new = bitbangio_spi_make_new,
.locals_dict = (mp_obj_dict_t*)&bitbangio_spi_locals_dict,
};