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micropython/ports/stm32/pyb_spi.c

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013-2018 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.
*/
#include "py/runtime.h"
#include "extmod/machine_spi.h"
#include "bufhelper.h"
#include "spi.h"
/******************************************************************************/
// MicroPython bindings for legacy pyb API
// class pyb.SPI - a master-driven serial protocol
//
// SPI is a serial protocol that is driven by a master. At the physical level
// there are 3 lines: SCK, MOSI, MISO.
//
// See usage model of I2C; SPI is very similar. Main difference is
// parameters to init the SPI bus:
//
// from pyb import SPI
// spi = SPI(1, SPI.MASTER, baudrate=600000, polarity=1, phase=0, crc=0x7)
//
// Only required parameter is mode, SPI.MASTER or SPI.SLAVE. Polarity can be
// 0 or 1, and is the level the idle clock line sits at. Phase can be 0 or 1
// to sample data on the first or second clock edge respectively. Crc can be
// None for no CRC, or a polynomial specifier.
//
// Additional method for SPI:
//
// data = spi.send_recv(b'1234') # send 4 bytes and receive 4 bytes
// buf = bytearray(4)
// spi.send_recv(b'1234', buf) # send 4 bytes and receive 4 into buf
// spi.send_recv(buf, buf) # send/recv 4 bytes from/to buf
STATIC const pyb_spi_obj_t pyb_spi_obj[] = {
{{&pyb_spi_type}, &spi_obj[0]},
{{&pyb_spi_type}, &spi_obj[1]},
{{&pyb_spi_type}, &spi_obj[2]},
{{&pyb_spi_type}, &spi_obj[3]},
{{&pyb_spi_type}, &spi_obj[4]},
{{&pyb_spi_type}, &spi_obj[5]},
};
STATIC void pyb_spi_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
pyb_spi_obj_t *self = MP_OBJ_TO_PTR(self_in);
spi_print(print, self->spi, true);
}
// init(mode, baudrate=328125, *, polarity=1, phase=0, bits=8, firstbit=SPI.MSB, ti=False, crc=None)
//
// Initialise the SPI bus with the given parameters:
// - `mode` must be either `SPI.MASTER` or `SPI.SLAVE`.
// - `baudrate` is the SCK clock rate (only sensible for a master).
STATIC mp_obj_t pyb_spi_init_helper(const pyb_spi_obj_t *self, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_mode, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_baudrate, MP_ARG_INT, {.u_int = 328125} },
{ MP_QSTR_prescaler, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0xffffffff} },
{ MP_QSTR_polarity, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 1} },
{ MP_QSTR_phase, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_dir, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = SPI_DIRECTION_2LINES} },
{ MP_QSTR_bits, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 8} },
{ MP_QSTR_nss, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = SPI_NSS_SOFT} },
{ MP_QSTR_firstbit, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = SPI_FIRSTBIT_MSB} },
{ MP_QSTR_ti, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = false} },
{ MP_QSTR_crc, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_NONE} },
};
// parse args
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);
// set the SPI configuration values
SPI_InitTypeDef *init = &self->spi->spi->Init;
init->Mode = args[0].u_int;
spi_set_params(self->spi, args[2].u_int, args[1].u_int, args[3].u_int, args[4].u_int,
args[6].u_int, args[8].u_int);
init->Direction = args[5].u_int;
init->NSS = args[7].u_int;
init->TIMode = args[9].u_bool ? SPI_TIMODE_ENABLE : SPI_TIMODE_DISABLE;
if (args[10].u_obj == mp_const_none) {
init->CRCCalculation = SPI_CRCCALCULATION_DISABLE;
init->CRCPolynomial = 0;
} else {
init->CRCCalculation = SPI_CRCCALCULATION_ENABLE;
init->CRCPolynomial = mp_obj_get_int(args[10].u_obj);
}
// init the SPI bus
spi_init(self->spi, init->NSS != SPI_NSS_SOFT);
return mp_const_none;
}
// constructor(bus, ...)
//
// Construct an SPI object on the given bus. `bus` can be 1 or 2.
// With no additional parameters, the SPI object is created but not
// initialised (it has the settings from the last initialisation of
// the bus, if any). If extra arguments are given, the bus is initialised.
// See `init` for parameters of initialisation.
//
// The physical pins of the SPI busses are:
// - `SPI(1)` is on the X position: `(NSS, SCK, MISO, MOSI) = (X5, X6, X7, X8) = (PA4, PA5, PA6, PA7)`
// - `SPI(2)` is on the Y position: `(NSS, SCK, MISO, MOSI) = (Y5, Y6, Y7, Y8) = (PB12, PB13, PB14, PB15)`
//
// At the moment, the NSS pin is not used by the SPI driver and is free
// for other use.
STATIC mp_obj_t pyb_spi_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
// check arguments
mp_arg_check_num(n_args, n_kw, 1, MP_OBJ_FUN_ARGS_MAX, true);
// work out SPI bus
int spi_id = spi_find_index(args[0]);
// get SPI object
const pyb_spi_obj_t *spi_obj = &pyb_spi_obj[spi_id - 1];
if (n_args > 1 || n_kw > 0) {
// start the peripheral
mp_map_t kw_args;
mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);
pyb_spi_init_helper(spi_obj, n_args - 1, args + 1, &kw_args);
}
return MP_OBJ_FROM_PTR(spi_obj);
}
STATIC mp_obj_t pyb_spi_init(size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
return pyb_spi_init_helper(MP_OBJ_TO_PTR(args[0]), n_args - 1, args + 1, kw_args);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_spi_init_obj, 1, pyb_spi_init);
// deinit()
// Turn off the SPI bus.
STATIC mp_obj_t pyb_spi_deinit(mp_obj_t self_in) {
pyb_spi_obj_t *self = MP_OBJ_TO_PTR(self_in);
spi_deinit(self->spi);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_spi_deinit_obj, pyb_spi_deinit);
// send(send, *, timeout=5000)
// Send data on the bus:
// - `send` is the data to send (an integer to send, or a buffer object).
// - `timeout` is the timeout in milliseconds to wait for the send.
//
// Return value: `None`.
STATIC mp_obj_t pyb_spi_send(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
// TODO assumes transmission size is 8-bits wide
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_send, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 5000} },
};
// parse args
pyb_spi_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
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);
// get the buffer to send from
mp_buffer_info_t bufinfo;
uint8_t data[1];
pyb_buf_get_for_send(args[0].u_obj, &bufinfo, data);
// send the data
spi_transfer(self->spi, bufinfo.len, bufinfo.buf, NULL, args[1].u_int);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_spi_send_obj, 1, pyb_spi_send);
// recv(recv, *, timeout=5000)
//
// Receive data on the bus:
// - `recv` can be an integer, which is the number of bytes to receive,
// or a mutable buffer, which will be filled with received bytes.
// - `timeout` is the timeout in milliseconds to wait for the receive.
//
// Return value: if `recv` is an integer then a new buffer of the bytes received,
// otherwise the same buffer that was passed in to `recv`.
STATIC mp_obj_t pyb_spi_recv(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
// TODO assumes transmission size is 8-bits wide
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_recv, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 5000} },
};
// parse args
pyb_spi_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
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);
// get the buffer to receive into
vstr_t vstr;
mp_obj_t o_ret = pyb_buf_get_for_recv(args[0].u_obj, &vstr);
// receive the data
spi_transfer(self->spi, vstr.len, NULL, (uint8_t *)vstr.buf, args[1].u_int);
// return the received data
if (o_ret != MP_OBJ_NULL) {
return o_ret;
} else {
return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr);
}
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_spi_recv_obj, 1, pyb_spi_recv);
// send_recv(send, recv=None, *, timeout=5000)
//
// Send and receive data on the bus at the same time:
// - `send` is the data to send (an integer to send, or a buffer object).
// - `recv` is a mutable buffer which will be filled with received bytes.
// It can be the same as `send`, or omitted. If omitted, a new buffer will
// be created.
// - `timeout` is the timeout in milliseconds to wait for the receive.
//
// Return value: the buffer with the received bytes.
STATIC mp_obj_t pyb_spi_send_recv(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
// TODO assumes transmission size is 8-bits wide
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_send, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_recv, MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 5000} },
};
// parse args
pyb_spi_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
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);
// get buffers to send from/receive to
mp_buffer_info_t bufinfo_send;
uint8_t data_send[1];
mp_buffer_info_t bufinfo_recv;
vstr_t vstr_recv;
mp_obj_t o_ret;
if (args[0].u_obj == args[1].u_obj) {
// same object for send and receive, it must be a r/w buffer
mp_get_buffer_raise(args[0].u_obj, &bufinfo_send, MP_BUFFER_RW);
bufinfo_recv = bufinfo_send;
o_ret = args[0].u_obj;
} else {
// get the buffer to send from
pyb_buf_get_for_send(args[0].u_obj, &bufinfo_send, data_send);
// get the buffer to receive into
if (args[1].u_obj == MP_OBJ_NULL) {
// only send argument given, so create a fresh buffer of the send length
vstr_init_len(&vstr_recv, bufinfo_send.len);
bufinfo_recv.len = vstr_recv.len;
bufinfo_recv.buf = vstr_recv.buf;
o_ret = MP_OBJ_NULL;
} else {
// recv argument given
mp_get_buffer_raise(args[1].u_obj, &bufinfo_recv, MP_BUFFER_WRITE);
if (bufinfo_recv.len != bufinfo_send.len) {
mp_raise_ValueError("recv must be same length as send");
}
o_ret = args[1].u_obj;
}
}
// do the transfer
spi_transfer(self->spi, bufinfo_send.len, bufinfo_send.buf, bufinfo_recv.buf, args[2].u_int);
// return the received data
if (o_ret != MP_OBJ_NULL) {
return o_ret;
} else {
return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr_recv);
}
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_spi_send_recv_obj, 1, pyb_spi_send_recv);
STATIC const mp_rom_map_elem_t pyb_spi_locals_dict_table[] = {
// instance methods
{ MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&pyb_spi_init_obj) },
{ MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&pyb_spi_deinit_obj) },
{ MP_ROM_QSTR(MP_QSTR_read), MP_ROM_PTR(&mp_machine_spi_read_obj) },
{ MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&mp_machine_spi_readinto_obj) },
{ MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&mp_machine_spi_write_obj) },
{ MP_ROM_QSTR(MP_QSTR_write_readinto), MP_ROM_PTR(&mp_machine_spi_write_readinto_obj) },
// legacy methods
{ MP_ROM_QSTR(MP_QSTR_send), MP_ROM_PTR(&pyb_spi_send_obj) },
{ MP_ROM_QSTR(MP_QSTR_recv), MP_ROM_PTR(&pyb_spi_recv_obj) },
{ MP_ROM_QSTR(MP_QSTR_send_recv), MP_ROM_PTR(&pyb_spi_send_recv_obj) },
// class constants
/// \constant MASTER - for initialising the bus to master mode
/// \constant SLAVE - for initialising the bus to slave mode
/// \constant MSB - set the first bit to MSB
/// \constant LSB - set the first bit to LSB
{ MP_ROM_QSTR(MP_QSTR_MASTER), MP_ROM_INT(SPI_MODE_MASTER) },
{ MP_ROM_QSTR(MP_QSTR_SLAVE), MP_ROM_INT(SPI_MODE_SLAVE) },
{ MP_ROM_QSTR(MP_QSTR_MSB), MP_ROM_INT(SPI_FIRSTBIT_MSB) },
{ MP_ROM_QSTR(MP_QSTR_LSB), MP_ROM_INT(SPI_FIRSTBIT_LSB) },
/* TODO
{ MP_ROM_QSTR(MP_QSTR_DIRECTION_2LINES ((uint32_t)0x00000000)
{ MP_ROM_QSTR(MP_QSTR_DIRECTION_2LINES_RXONLY SPI_CR1_RXONLY
{ MP_ROM_QSTR(MP_QSTR_DIRECTION_1LINE SPI_CR1_BIDIMODE
{ MP_ROM_QSTR(MP_QSTR_NSS_SOFT SPI_CR1_SSM
{ MP_ROM_QSTR(MP_QSTR_NSS_HARD_INPUT ((uint32_t)0x00000000)
{ MP_ROM_QSTR(MP_QSTR_NSS_HARD_OUTPUT ((uint32_t)0x00040000)
*/
};
STATIC MP_DEFINE_CONST_DICT(pyb_spi_locals_dict, pyb_spi_locals_dict_table);
STATIC void spi_transfer_machine(mp_obj_base_t *self_in, size_t len, const uint8_t *src, uint8_t *dest) {
pyb_spi_obj_t *self = (pyb_spi_obj_t *)self_in;
spi_transfer(self->spi, len, src, dest, SPI_TRANSFER_TIMEOUT(len));
}
STATIC const mp_machine_spi_p_t pyb_spi_p = {
.transfer = spi_transfer_machine,
};
const mp_obj_type_t pyb_spi_type = {
{ &mp_type_type },
.name = MP_QSTR_SPI,
.print = pyb_spi_print,
.make_new = pyb_spi_make_new,
.protocol = &pyb_spi_p,
.locals_dict = (mp_obj_dict_t *)&pyb_spi_locals_dict,
};
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