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Supports speeds up to 500k baud, polarity=0/1, phase=0/1, and using any pins. Only supports MSB output at the moment.pull/1936/head
Damien George
9 years ago
committed by
Paul Sokolovsky
Paul Sokolovsky
6 changed files with 235 additions and 0 deletions
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/*
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* This file is part of the MicroPython project, http://micropython.org/
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* |
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* The MIT License (MIT) |
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* |
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* Copyright (c) 2016 Damien P. George |
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* |
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* Permission is hereby granted, free of charge, to any person obtaining a copy |
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* of this software and associated documentation files (the "Software"), to deal |
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* in the Software without restriction, including without limitation the rights |
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
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* copies of the Software, and to permit persons to whom the Software is |
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* furnished to do so, subject to the following conditions: |
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* |
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* The above copyright notice and this permission notice shall be included in |
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* all copies or substantial portions of the Software. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
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* THE SOFTWARE. |
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*/ |
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#include <stdio.h> |
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#include <stdint.h> |
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#include <string.h> |
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#include <errno.h> |
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#include "ets_sys.h" |
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#include "etshal.h" |
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#include "ets_alt_task.h" |
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#include "py/runtime.h" |
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#include "py/stream.h" |
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#include "modpyb.h" |
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typedef struct _pyb_spi_obj_t { |
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mp_obj_base_t base; |
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uint32_t baudrate; |
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uint8_t polarity; |
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uint8_t phase; |
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pyb_pin_obj_t *sck; |
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pyb_pin_obj_t *mosi; |
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pyb_pin_obj_t *miso; |
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} pyb_spi_obj_t; |
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STATIC void mp_hal_spi_transfer(pyb_spi_obj_t *self, size_t src_len, const uint8_t *src_buf, size_t dest_len, uint8_t *dest_buf) { |
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// only MSB transfer is implemented
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uint32_t delay_half = 500000 / self->baudrate + 1; |
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for (size_t i = 0; i < src_len || i < dest_len; ++i) { |
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uint8_t data_out; |
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if (src_len == 1) { |
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data_out = src_buf[0]; |
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} else { |
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data_out = src_buf[i]; |
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} |
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uint8_t data_in = 0; |
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for (int j = 0; j < 8; ++j, data_out <<= 1) { |
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pin_set(self->mosi->phys_port, (data_out >> 7) & 1); |
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if (self->phase == 0) { |
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ets_delay_us(delay_half); |
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pin_set(self->sck->phys_port, 1 - self->polarity); |
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} else { |
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pin_set(self->sck->phys_port, 1 - self->polarity); |
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ets_delay_us(delay_half); |
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} |
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data_in = (data_in << 1) | pin_get(self->miso->phys_port); |
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if (self->phase == 0) { |
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ets_delay_us(delay_half); |
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pin_set(self->sck->phys_port, self->polarity); |
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} else { |
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pin_set(self->sck->phys_port, self->polarity); |
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ets_delay_us(delay_half); |
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} |
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} |
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if (dest_len != 0) { |
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dest_buf[i] = data_in; |
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} |
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// make sure pending tasks have a chance to run
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ets_loop_iter(); |
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} |
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} |
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/******************************************************************************/ |
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// MicroPython bindings for SPI
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STATIC void pyb_spi_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) { |
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pyb_spi_obj_t *self = MP_OBJ_TO_PTR(self_in); |
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mp_printf(print, "SPI(baudrate=%u, polarity=%u, phase=%u, sck=%u, mosi=%u, miso=%u)", |
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self->baudrate, self->polarity, self->phase, self->sck->phys_port, self->mosi->phys_port, self->miso->phys_port); |
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} |
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STATIC void pyb_spi_init_helper(pyb_spi_obj_t *self, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { |
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enum { ARG_baudrate, ARG_polarity, ARG_phase, ARG_sck, ARG_mosi, ARG_miso }; |
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static const mp_arg_t allowed_args[] = { |
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{ MP_QSTR_baudrate, MP_ARG_INT, {.u_int = -1} }, |
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{ MP_QSTR_polarity, MP_ARG_INT, {.u_int = -1} }, |
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{ MP_QSTR_phase, MP_ARG_INT, {.u_int = -1} }, |
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{ MP_QSTR_sck, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} }, |
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{ MP_QSTR_mosi, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} }, |
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{ MP_QSTR_miso, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} }, |
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}; |
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mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)]; |
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mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args); |
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if (args[ARG_baudrate].u_int != -1) { |
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self->baudrate = args[ARG_baudrate].u_int; |
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} |
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if (args[ARG_polarity].u_int != -1) { |
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self->polarity = args[ARG_polarity].u_int; |
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} |
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if (args[ARG_phase].u_int != -1) { |
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self->phase = args[ARG_phase].u_int; |
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} |
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if (args[ARG_sck].u_obj != MP_OBJ_NULL) { |
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self->sck = mp_obj_get_pin_obj(args[ARG_sck].u_obj); |
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} |
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if (args[ARG_mosi].u_obj != MP_OBJ_NULL) { |
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self->mosi = mp_obj_get_pin_obj(args[ARG_mosi].u_obj); |
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} |
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if (args[ARG_miso].u_obj != MP_OBJ_NULL) { |
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self->miso = mp_obj_get_pin_obj(args[ARG_miso].u_obj); |
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} |
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} |
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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) { |
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mp_arg_check_num(n_args, n_kw, 0, MP_OBJ_FUN_ARGS_MAX, true); |
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pyb_spi_obj_t *self = m_new_obj(pyb_spi_obj_t); |
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self->base.type = &pyb_spi_type; |
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// set defaults
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self->baudrate = 500000; |
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self->polarity = 0; |
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self->phase = 0; |
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self->sck = NULL; |
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self->mosi = NULL; |
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self->miso = NULL; |
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mp_map_t kw_args; |
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mp_map_init_fixed_table(&kw_args, n_kw, args + n_args); |
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pyb_spi_init_helper(self, n_args, args, &kw_args); |
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return MP_OBJ_FROM_PTR(self); |
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} |
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STATIC mp_obj_t pyb_spi_init(size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) { |
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pyb_spi_init_helper(args[0], n_args - 1, args + 1, kw_args); |
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return mp_const_none; |
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} |
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MP_DEFINE_CONST_FUN_OBJ_KW(pyb_spi_init_obj, 1, pyb_spi_init); |
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STATIC mp_obj_t pyb_spi_read(size_t n_args, const mp_obj_t *args) { |
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pyb_spi_obj_t *self = MP_OBJ_TO_PTR(args[0]); |
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uint8_t write_byte = 0; |
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if (n_args == 3) { |
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write_byte = mp_obj_get_int(args[2]); |
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} |
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vstr_t vstr; |
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vstr_init_len(&vstr, mp_obj_get_int(args[1])); |
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mp_hal_spi_transfer(self, 1, &write_byte, vstr.len, (uint8_t*)vstr.buf); |
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return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr); |
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} |
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MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_spi_read_obj, 2, 3, pyb_spi_read); |
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STATIC mp_obj_t pyb_spi_readinto(size_t n_args, const mp_obj_t *args) { |
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pyb_spi_obj_t *self = MP_OBJ_TO_PTR(args[0]); |
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mp_buffer_info_t bufinfo; |
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mp_get_buffer_raise(args[1], &bufinfo, MP_BUFFER_WRITE); |
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uint8_t write_byte = 0; |
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if (n_args == 3) { |
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write_byte = mp_obj_get_int(args[2]); |
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} |
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mp_hal_spi_transfer(self, 1, &write_byte, bufinfo.len, (uint8_t*)bufinfo.buf); |
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return mp_const_none; |
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} |
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MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_spi_readinto_obj, 2, 3, pyb_spi_readinto); |
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STATIC mp_obj_t pyb_spi_write(mp_obj_t self_in, mp_obj_t wr_buf_in) { |
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pyb_spi_obj_t *self = MP_OBJ_TO_PTR(self_in); |
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mp_buffer_info_t src_buf; |
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mp_get_buffer_raise(wr_buf_in, &src_buf, MP_BUFFER_READ); |
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mp_hal_spi_transfer(self, src_buf.len, (const uint8_t*)src_buf.buf, 0, NULL); |
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return mp_const_none; |
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} |
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MP_DEFINE_CONST_FUN_OBJ_2(pyb_spi_write_obj, pyb_spi_write); |
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STATIC mp_obj_t pyb_spi_write_readinto(mp_obj_t self_in, mp_obj_t wr_buf_in, mp_obj_t rd_buf_in) { |
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pyb_spi_obj_t *self = MP_OBJ_TO_PTR(self_in); |
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mp_buffer_info_t src_buf; |
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mp_get_buffer_raise(wr_buf_in, &src_buf, MP_BUFFER_READ); |
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mp_buffer_info_t dest_buf; |
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mp_get_buffer_raise(rd_buf_in, &dest_buf, MP_BUFFER_WRITE); |
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if (src_buf.len != dest_buf.len) { |
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nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "buffers must be the same length")); |
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} |
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mp_hal_spi_transfer(self, src_buf.len, (const uint8_t*)src_buf.buf, dest_buf.len, (uint8_t*)dest_buf.buf); |
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return mp_const_none; |
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} |
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MP_DEFINE_CONST_FUN_OBJ_3(pyb_spi_write_readinto_obj, pyb_spi_write_readinto); |
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STATIC const mp_rom_map_elem_t pyb_spi_locals_dict_table[] = { |
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{ MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&pyb_spi_init_obj) }, |
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{ MP_ROM_QSTR(MP_QSTR_read), MP_ROM_PTR(&pyb_spi_read_obj) }, |
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{ MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&pyb_spi_readinto_obj) }, |
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{ MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&pyb_spi_write_obj) }, |
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{ MP_ROM_QSTR(MP_QSTR_write_readinto), MP_ROM_PTR(&pyb_spi_write_readinto_obj) }, |
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}; |
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STATIC MP_DEFINE_CONST_DICT(pyb_spi_locals_dict, pyb_spi_locals_dict_table); |
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const mp_obj_type_t pyb_spi_type = { |
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{ &mp_type_type }, |
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.name = MP_QSTR_SPI, |
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.print = pyb_spi_print, |
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.make_new = pyb_spi_make_new, |
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.locals_dict = (mp_obj_dict_t*)&pyb_spi_locals_dict, |
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}; |
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