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

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 Damien P. George
* Copyright (c) 2016 - 2018 Glenn Ruben Bakke
* Copyright (c) 2018 Ayke van Laethem
*
* 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/runtime.h"
#if MICROPY_PY_MACHINE_HW_SPI
#include "py/nlr.h"
#include "py/mphal.h"
#include "extmod/machine_spi.h"
#include "pin.h"
#include "genhdr/pins.h"
#include "spi.h"
#if NRFX_SPI_ENABLED
#include "nrfx_spi.h"
#else
#include "nrfx_spim.h"
#endif
/// \moduleref machine
/// \class 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 machine 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
#if NRFX_SPIM_ENABLED
#define nrfx_spi_t nrfx_spim_t
#define nrfx_spi_config_t nrfx_spim_config_t
#define nrfx_spi_xfer_desc_t nrfx_spim_xfer_desc_t
#define NRFX_SPI_PIN_NOT_USED NRFX_SPIM_PIN_NOT_USED
#define NRFX_SPI_INSTANCE NRFX_SPIM_INSTANCE
#define NRF_SPI_BIT_ORDER_LSB_FIRST NRF_SPIM_BIT_ORDER_LSB_FIRST
#define NRF_SPI_BIT_ORDER_MSB_FIRST NRF_SPIM_BIT_ORDER_MSB_FIRST
#define NRF_SPI_MODE_0 NRF_SPIM_MODE_0
#define NRF_SPI_MODE_1 NRF_SPIM_MODE_1
#define NRF_SPI_MODE_2 NRF_SPIM_MODE_2
#define NRF_SPI_MODE_3 NRF_SPIM_MODE_3
#define NRF_SPI_FREQ_125K NRF_SPIM_FREQ_125K
#define NRF_SPI_FREQ_250K NRF_SPIM_FREQ_250K
#define NRF_SPI_FREQ_500K NRF_SPIM_FREQ_500K
#define NRF_SPI_FREQ_1M NRF_SPIM_FREQ_1M
#define NRF_SPI_FREQ_2M NRF_SPIM_FREQ_2M
#define NRF_SPI_FREQ_4M NRF_SPIM_FREQ_4M
#define NRF_SPI_FREQ_8M NRF_SPIM_FREQ_8M
#define nrfx_spi_init nrfx_spim_init
#define nrfx_spi_uninit nrfx_spim_uninit
#define nrfx_spi_xfer nrfx_spim_xfer
#endif // NRFX_SPIM_ENABLED
typedef struct _machine_hard_spi_obj_t {
mp_obj_base_t base;
const nrfx_spi_t * p_spi; // Driver instance
nrfx_spi_config_t * p_config; // pointer to volatile part
} machine_hard_spi_obj_t;
STATIC const nrfx_spi_t machine_spi_instances[] = {
NRFX_SPI_INSTANCE(0),
NRFX_SPI_INSTANCE(1),
#if defined(NRF52_SERIES)
NRFX_SPI_INSTANCE(2),
#if defined(NRF52840_XXAA) && NRFX_SPIM_ENABLED
NRFX_SPI_INSTANCE(3),
#endif // NRF52840_XXAA && NRFX_SPIM_ENABLED
#endif // NRF52_SERIES
};
STATIC nrfx_spi_config_t configs[MP_ARRAY_SIZE(machine_spi_instances)];
STATIC const machine_hard_spi_obj_t machine_hard_spi_obj[] = {
{{&machine_hard_spi_type}, .p_spi = &machine_spi_instances[0], .p_config = &configs[0]},
{{&machine_hard_spi_type}, .p_spi = &machine_spi_instances[1], .p_config = &configs[1]},
#if defined(NRF52_SERIES)
{{&machine_hard_spi_type}, .p_spi = &machine_spi_instances[2], .p_config = &configs[2]},
#if defined(NRF52840_XXAA) && NRFX_SPIM_ENABLED
{{&machine_hard_spi_type}, .p_spi = &machine_spi_instances[3], .p_config = &configs[3]},
#endif // NRF52840_XXAA && NRFX_SPIM_ENABLED
#endif // NRF52_SERIES
};
void spi_init0(void) {
}
STATIC int spi_find(mp_obj_t id) {
if (mp_obj_is_str(id)) {
// given a string id
const char *port = mp_obj_str_get_str(id);
if (0) {
#ifdef MICROPY_HW_SPI0_NAME
} else if (strcmp(port, MICROPY_HW_SPI0_NAME) == 0) {
return 1;
#endif
}
mp_raise_ValueError(MP_ERROR_TEXT("SPI doesn't exist"));
} else {
// given an integer id
int spi_id = mp_obj_get_int(id);
if (spi_id >= 0 && spi_id < MP_ARRAY_SIZE(machine_hard_spi_obj)) {
return spi_id;
}
mp_raise_ValueError(MP_ERROR_TEXT("SPI doesn't exist"));
}
}
void spi_transfer(const machine_hard_spi_obj_t * self, size_t len, const void * src, void * dest) {
nrfx_spi_xfer_desc_t xfer_desc = {
.p_tx_buffer = src,
.tx_length = len,
.p_rx_buffer = dest,
.rx_length = len
};
nrfx_spi_xfer(self->p_spi, &xfer_desc, 0);
}
/******************************************************************************/
/* MicroPython bindings for machine API */
// for make_new
enum {
ARG_NEW_id,
ARG_NEW_baudrate,
ARG_NEW_polarity,
ARG_NEW_phase,
ARG_NEW_bits,
ARG_NEW_firstbit,
ARG_NEW_sck,
ARG_NEW_mosi,
ARG_NEW_miso
};
// for init
enum {
ARG_INIT_baudrate,
ARG_INIT_polarity,
ARG_INIT_phase,
ARG_INIT_bits,
ARG_INIT_firstbit
};
STATIC mp_obj_t machine_hard_spi_make_new(mp_arg_val_t *args);
STATIC void machine_hard_spi_init(mp_obj_t self, mp_arg_val_t *args);
STATIC void machine_hard_spi_deinit(mp_obj_t self);
/* common code for both soft and hard implementations *************************/
STATIC mp_obj_t machine_spi_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_id, MP_ARG_OBJ, {.u_obj = MP_OBJ_NEW_SMALL_INT(-1)} },
{ MP_QSTR_baudrate, MP_ARG_INT, {.u_int = 1000000} },
{ MP_QSTR_polarity, MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_phase, MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_bits, MP_ARG_INT, {.u_int = 8} },
{ MP_QSTR_firstbit, MP_ARG_INT, {.u_int = 0 /* SPI_FIRSTBIT_MSB */} },
{ MP_QSTR_sck, MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_mosi, MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_miso, MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
};
// 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);
if (args[ARG_NEW_id].u_obj == MP_OBJ_NEW_SMALL_INT(-1)) {
// TODO: implement soft SPI
// return machine_soft_spi_make_new(args);
return mp_const_none;
} else {
// hardware peripheral id given
return machine_hard_spi_make_new(args);
}
}
STATIC mp_obj_t machine_spi_init(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_baudrate, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 1000000} },
{ 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} },
{ MP_QSTR_firstbit, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
};
// parse args
mp_obj_t self = 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);
// dispatch to specific implementation
if (mp_obj_get_type(self) == &machine_hard_spi_type) {
machine_hard_spi_init(self, args);
}
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(machine_spi_init_obj, 1, machine_spi_init);
STATIC mp_obj_t machine_spi_deinit(mp_obj_t self) {
// dispatch to specific implementation
if (mp_obj_get_type(self) == &machine_hard_spi_type) {
machine_hard_spi_deinit(self);
}
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(machine_spi_deinit_obj, machine_spi_deinit);
STATIC const mp_rom_map_elem_t machine_spi_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&machine_spi_init_obj) },
{ MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&machine_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) },
{ MP_ROM_QSTR(MP_QSTR_MSB), MP_ROM_INT(NRF_SPI_BIT_ORDER_MSB_FIRST) },
{ MP_ROM_QSTR(MP_QSTR_LSB), MP_ROM_INT(NRF_SPI_BIT_ORDER_LSB_FIRST) },
};
STATIC MP_DEFINE_CONST_DICT(machine_spi_locals_dict, machine_spi_locals_dict_table);
/* code for hard implementation ***********************************************/
STATIC void machine_hard_spi_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
machine_hard_spi_obj_t *self = self_in;
mp_printf(print, "SPI(%u)", self->p_spi->drv_inst_idx);
}
STATIC mp_obj_t machine_hard_spi_make_new(mp_arg_val_t *args) {
// get static peripheral object
int spi_id = spi_find(args[ARG_NEW_id].u_obj);
const machine_hard_spi_obj_t *self = &machine_hard_spi_obj[spi_id];
// here we would check the sck/mosi/miso pins and configure them
if (args[ARG_NEW_sck].u_obj != MP_OBJ_NULL
&& args[ARG_NEW_mosi].u_obj != MP_OBJ_NULL
&& args[ARG_NEW_miso].u_obj != MP_OBJ_NULL) {
self->p_config->sck_pin = mp_hal_get_pin_obj(args[ARG_NEW_sck].u_obj)->pin;
self->p_config->mosi_pin = mp_hal_get_pin_obj(args[ARG_NEW_mosi].u_obj)->pin;
self->p_config->miso_pin = mp_hal_get_pin_obj(args[ARG_NEW_miso].u_obj)->pin;
} else {
self->p_config->sck_pin = MICROPY_HW_SPI0_SCK;
self->p_config->mosi_pin = MICROPY_HW_SPI0_MOSI;
self->p_config->miso_pin = MICROPY_HW_SPI0_MISO;
}
// Manually trigger slave select from upper layer.
self->p_config->ss_pin = NRFX_SPI_PIN_NOT_USED;
#ifdef NRF51
self->p_config->irq_priority = 3;
#else
self->p_config->irq_priority = 6;
#endif
mp_obj_t self_obj = MP_OBJ_FROM_PTR(self);
machine_hard_spi_init(self_obj, &args[1]); // Skip instance id param.
return self_obj;
}
STATIC void machine_hard_spi_init(mp_obj_t self_in, mp_arg_val_t *args) {
const machine_hard_spi_obj_t *self = MP_OBJ_TO_PTR(self_in);
int baudrate = args[ARG_INIT_baudrate].u_int;
if (baudrate <= 125000) {
self->p_config->frequency = NRF_SPI_FREQ_125K;
} else if (baudrate <= 250000) {
self->p_config->frequency = NRF_SPI_FREQ_250K;
} else if (baudrate <= 500000) {
self->p_config->frequency = NRF_SPI_FREQ_500K;
} else if (baudrate <= 1000000) {
self->p_config->frequency = NRF_SPI_FREQ_1M;
} else if (baudrate <= 2000000) {
self->p_config->frequency = NRF_SPI_FREQ_2M;
} else if (baudrate <= 4000000) {
self->p_config->frequency = NRF_SPI_FREQ_4M;
} else if (baudrate <= 8000000) {
self->p_config->frequency = NRF_SPI_FREQ_8M;
#if defined(NRF52840_XXAA) && NRFX_SPIM_ENABLED
} else if (baudrate <= 16000000) {
self->p_config->frequency = NRF_SPIM_FREQ_16M;
} else if (baudrate <= 32000000) {
self->p_config->frequency = NRF_SPIM_FREQ_32M;
#endif // NRF52840_XXAA && NRFX_SPIM_ENABLED
} else { // Default
self->p_config->frequency = NRF_SPI_FREQ_1M;
}
// Active high
if (args[ARG_INIT_polarity].u_int == 0) {
if (args[ARG_INIT_phase].u_int == 0) {
// First clock edge
self->p_config->mode = NRF_SPI_MODE_0;
} else {
// Second clock edge
self->p_config->mode = NRF_SPI_MODE_1;
}
// Active low
} else {
if (args[ARG_INIT_phase].u_int == 0) {
// First clock edge
self->p_config->mode = NRF_SPI_MODE_2;
} else {
// Second clock edge
self->p_config->mode = NRF_SPI_MODE_3;
}
}
self->p_config->orc = 0xFF; // Overrun character
self->p_config->bit_order = (args[ARG_INIT_firstbit].u_int == 0) ? NRF_SPI_BIT_ORDER_MSB_FIRST : NRF_SPI_BIT_ORDER_LSB_FIRST;
// Set context to this instance of SPI
nrfx_err_t err_code = nrfx_spi_init(self->p_spi, self->p_config, NULL, (void *)self);
if (err_code == NRFX_ERROR_INVALID_STATE) {
// Instance already initialized, deinitialize first.
nrfx_spi_uninit(self->p_spi);
// Initialize again.
nrfx_spi_init(self->p_spi, self->p_config, NULL, (void *)self);
}
}
STATIC void machine_hard_spi_deinit(mp_obj_t self_in) {
const machine_hard_spi_obj_t *self = MP_OBJ_TO_PTR(self_in);
nrfx_spi_uninit(self->p_spi);
}
STATIC void machine_hard_spi_transfer(mp_obj_base_t *self_in, size_t len, const uint8_t *src, uint8_t *dest) {
const machine_hard_spi_obj_t *self = (machine_hard_spi_obj_t*)self_in;
spi_transfer(self, len, src, dest);
}
STATIC mp_obj_t mp_machine_spi_read(size_t n_args, const mp_obj_t *args) {
vstr_t vstr;
vstr_init_len(&vstr, mp_obj_get_int(args[1]));
memset(vstr.buf, n_args == 3 ? mp_obj_get_int(args[2]) : 0, vstr.len);
spi_transfer(args[0], vstr.len, vstr.buf, vstr.buf);
return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr);
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_machine_spi_read_obj, 2, 3, mp_machine_spi_read);
STATIC mp_obj_t mp_machine_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);
memset(bufinfo.buf, n_args == 3 ? mp_obj_get_int(args[2]) : 0, bufinfo.len);
spi_transfer(args[0], bufinfo.len, bufinfo.buf, bufinfo.buf);
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_machine_spi_readinto_obj, 2, 3, mp_machine_spi_readinto);
STATIC mp_obj_t mp_machine_spi_write(mp_obj_t self, mp_obj_t wr_buf) {
mp_buffer_info_t src;
mp_get_buffer_raise(wr_buf, &src, MP_BUFFER_READ);
spi_transfer(self, src.len, (const uint8_t*)src.buf, NULL);
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_2(mp_machine_spi_write_obj, mp_machine_spi_write);
STATIC mp_obj_t mp_machine_spi_write_readinto(mp_obj_t self, mp_obj_t wr_buf, mp_obj_t rd_buf) {
mp_buffer_info_t src;
mp_get_buffer_raise(wr_buf, &src, MP_BUFFER_READ);
mp_buffer_info_t dest;
mp_get_buffer_raise(rd_buf, &dest, MP_BUFFER_WRITE);
if (src.len != dest.len) {
mp_raise_ValueError(MP_ERROR_TEXT("buffers must be the same length"));
}
spi_transfer(self, src.len, src.buf, dest.buf);
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_3(mp_machine_spi_write_readinto_obj, mp_machine_spi_write_readinto);
STATIC const mp_machine_spi_p_t machine_hard_spi_p = {
.transfer = machine_hard_spi_transfer,
};
const mp_obj_type_t machine_hard_spi_type = {
{ &mp_type_type },
.name = MP_QSTR_SPI,
.print = machine_hard_spi_print,
.make_new = machine_spi_make_new,
.protocol = &machine_hard_spi_p,
.locals_dict = (mp_obj_dict_t*)&machine_spi_locals_dict,
};
#endif // MICROPY_PY_MACHINE_HW_SPI
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