324 lines
10 KiB
C
324 lines
10 KiB
C
/*
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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 "ets_sys.h"
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#include "etshal.h"
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#include "osapi.h"
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#include "gpio.h"
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#include "py/runtime.h"
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#include "modpyb.h"
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typedef struct _pyb_i2c_obj_t {
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mp_obj_base_t base;
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pyb_pin_obj_t *scl;
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pyb_pin_obj_t *sda;
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} pyb_i2c_obj_t;
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// these set the frequency of SCL
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#define mphal_i2c_wait_a() os_delay_us(2)
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#define mphal_i2c_wait_b() os_delay_us(1)
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STATIC void mphal_i2c_set_sda(pyb_i2c_obj_t *self, uint8_t sda) {
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uint32_t port = self->sda->phys_port;
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sda &= 0x01;
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gpio_output_set(sda << port, (1 - sda) << port, 1 << port, 0);
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}
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STATIC void mphal_i2c_set_scl(pyb_i2c_obj_t *self, uint8_t scl) {
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uint32_t port = self->scl->phys_port;
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scl &= 0x01;
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gpio_output_set(scl << port, (1 - scl) << port, 1 << port, 0);
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}
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STATIC int mphal_i2c_get_sda(pyb_i2c_obj_t *self) {
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return GPIO_INPUT_GET(GPIO_ID_PIN(self->sda->phys_port));
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}
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STATIC void mphal_i2c_start(pyb_i2c_obj_t *self) {
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mphal_i2c_set_sda(self, 1);
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mphal_i2c_wait_a();
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mphal_i2c_set_scl(self, 1);
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mphal_i2c_wait_a();
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mphal_i2c_set_sda(self, 0);
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mphal_i2c_wait_a();
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}
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STATIC void mphal_i2c_stop(pyb_i2c_obj_t *self) {
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mphal_i2c_wait_a();
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mphal_i2c_set_sda(self, 0);
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mphal_i2c_wait_a();
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mphal_i2c_set_scl(self, 1);
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mphal_i2c_wait_a();
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mphal_i2c_set_sda(self, 1);
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mphal_i2c_wait_a();
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}
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STATIC void mphal_i2c_init(pyb_i2c_obj_t *self, uint32_t freq) {
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pyb_pin_obj_t *scl = self->scl;
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pyb_pin_obj_t *sda = self->sda;
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ETS_GPIO_INTR_DISABLE();
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//ETS_INTR_LOCK();
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PIN_FUNC_SELECT(sda->periph, sda->func);
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PIN_FUNC_SELECT(scl->periph, scl->func);
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GPIO_REG_WRITE(GPIO_PIN_ADDR(GPIO_ID_PIN(sda->phys_port)),
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GPIO_REG_READ(GPIO_PIN_ADDR(GPIO_ID_PIN(sda->phys_port)))
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| GPIO_PIN_PAD_DRIVER_SET(GPIO_PAD_DRIVER_ENABLE)); // open drain
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GPIO_REG_WRITE(GPIO_ENABLE_ADDRESS,
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GPIO_REG_READ(GPIO_ENABLE_ADDRESS) | (1 << sda->phys_port));
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GPIO_REG_WRITE(GPIO_PIN_ADDR(GPIO_ID_PIN(scl->phys_port)),
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GPIO_REG_READ(GPIO_PIN_ADDR(GPIO_ID_PIN(scl->phys_port)))
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| GPIO_PIN_PAD_DRIVER_SET(GPIO_PAD_DRIVER_ENABLE)); // open drain
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GPIO_REG_WRITE(GPIO_ENABLE_ADDRESS,
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GPIO_REG_READ(GPIO_ENABLE_ADDRESS) | (1 << scl->phys_port));
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mphal_i2c_set_scl(self, 1);
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mphal_i2c_set_sda(self, 1);
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ETS_GPIO_INTR_ENABLE();
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//ETS_INTR_UNLOCK();
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mphal_i2c_set_scl(self, 0);
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mphal_i2c_wait_a();
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// when SCL = 0, toggle SDA to clear up
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mphal_i2c_set_sda(self, 0);
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mphal_i2c_wait_a();
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mphal_i2c_set_sda(self, 1);
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mphal_i2c_wait_a();
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// set data_cnt to max value
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for (uint8_t i = 0; i < 28; i++) {
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mphal_i2c_set_scl(self, 0);
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mphal_i2c_wait_a();
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mphal_i2c_set_scl(self, 1);
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mphal_i2c_wait_a();
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}
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// reset all
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mphal_i2c_stop(self);
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}
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STATIC int mphal_i2c_write_byte(pyb_i2c_obj_t *self, uint8_t val) {
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uint8_t dat;
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sint8 i;
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mphal_i2c_wait_a();
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mphal_i2c_set_scl(self, 0);
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mphal_i2c_wait_a();
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for (i = 7; i >= 0; i--) {
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dat = val >> i;
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mphal_i2c_set_sda(self, dat);
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mphal_i2c_wait_a();
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mphal_i2c_set_scl(self, 1);
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mphal_i2c_wait_a();
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if (i == 0) {
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mphal_i2c_wait_b();
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}
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mphal_i2c_set_scl(self, 0);
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mphal_i2c_wait_a();
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}
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mphal_i2c_set_sda(self, 1);
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mphal_i2c_wait_a();
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mphal_i2c_set_scl(self, 1);
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mphal_i2c_wait_a();
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int ret = mphal_i2c_get_sda(self);
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mphal_i2c_wait_a();
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mphal_i2c_set_scl(self, 0);
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mphal_i2c_wait_a();
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return !ret;
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}
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STATIC void mphal_i2c_write(pyb_i2c_obj_t *self, uint8_t addr, uint8_t *data, size_t len, bool stop) {
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mphal_i2c_start(self);
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if (!mphal_i2c_write_byte(self, addr << 1)) {
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goto er;
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}
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while (len--) {
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if (!mphal_i2c_write_byte(self, *data++)) {
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goto er;
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}
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}
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if (stop) {
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mphal_i2c_stop(self);
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}
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return;
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er:
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mphal_i2c_stop(self);
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nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, "I2C bus error"));
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}
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STATIC int mphal_i2c_read_byte(pyb_i2c_obj_t *self, uint8_t *val) {
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mphal_i2c_wait_a();
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mphal_i2c_set_scl(self, 0);
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mphal_i2c_wait_a();
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uint8_t dat = 0;
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for (int i = 7; i >= 0; i--) {
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mphal_i2c_set_scl(self, 1);
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mphal_i2c_wait_a();
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dat = (dat << 1) | mphal_i2c_get_sda(self);
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mphal_i2c_wait_a();
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mphal_i2c_set_scl(self, 0);
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mphal_i2c_wait_a();
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}
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*val = dat;
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mphal_i2c_wait_a();
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mphal_i2c_set_scl(self, 1);
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mphal_i2c_wait_a();
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mphal_i2c_wait_b();
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mphal_i2c_set_scl(self, 0);
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mphal_i2c_wait_a();
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return 1; // success
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}
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STATIC void mphal_i2c_read(pyb_i2c_obj_t *self, uint8_t addr, uint8_t *data, size_t len, bool stop) {
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mphal_i2c_start(self);
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if (!mphal_i2c_write_byte(self, (addr << 1) | 1)) {
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goto er;
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}
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while (len--) {
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if (!mphal_i2c_read_byte(self, data++)) {
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goto er;
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}
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}
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if (stop) {
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mphal_i2c_stop(self);
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}
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return;
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er:
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mphal_i2c_stop(self);
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nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, "I2C bus error"));
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}
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/******************************************************************************/
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// MicroPython bindings for I2C
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STATIC void pyb_i2c_obj_init_helper(pyb_i2c_obj_t *self, mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
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enum { ARG_scl, ARG_sda, ARG_freq };
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static const mp_arg_t allowed_args[] = {
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{ MP_QSTR_scl, MP_ARG_REQUIRED | MP_ARG_OBJ },
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{ MP_QSTR_sda, MP_ARG_REQUIRED | MP_ARG_OBJ },
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{ MP_QSTR_freq, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 400000} },
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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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self->scl = mp_obj_get_pin_obj(args[ARG_scl].u_obj);
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self->sda = mp_obj_get_pin_obj(args[ARG_sda].u_obj);
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mphal_i2c_init(self, args[ARG_freq].u_int);
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}
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STATIC mp_obj_t pyb_i2c_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_i2c_obj_t *self = m_new_obj(pyb_i2c_obj_t);
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self->base.type = &pyb_i2c_type;
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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_i2c_obj_init_helper(self, n_args, args, &kw_args);
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return (mp_obj_t)self;
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}
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STATIC mp_obj_t pyb_i2c_obj_init(mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
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pyb_i2c_obj_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_i2c_init_obj, 1, pyb_i2c_obj_init);
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STATIC mp_obj_t pyb_i2c_readfrom(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
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enum { ARG_addr, ARG_n, ARG_stop };
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static const mp_arg_t allowed_args[] = {
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{ MP_QSTR_addr, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
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{ MP_QSTR_n, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
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{ MP_QSTR_stop, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = true} },
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};
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pyb_i2c_obj_t *self = pos_args[0];
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mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
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mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
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// do the I2C transfer
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vstr_t vstr;
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vstr_init_len(&vstr, args[ARG_n].u_int);
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mphal_i2c_read(self, args[ARG_addr].u_int, (uint8_t*)vstr.buf, vstr.len, args[ARG_stop].u_bool);
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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_KW(pyb_i2c_readfrom_obj, 1, pyb_i2c_readfrom);
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STATIC mp_obj_t pyb_i2c_writeto(mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
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enum { ARG_addr, ARG_buf, ARG_stop };
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static const mp_arg_t allowed_args[] = {
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{ MP_QSTR_addr, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
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{ MP_QSTR_buf, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
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{ MP_QSTR_stop, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = true} },
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};
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pyb_i2c_obj_t *self = pos_args[0];
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mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
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mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
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// get the buffer to write from
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mp_buffer_info_t bufinfo;
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mp_get_buffer_raise(args[ARG_buf].u_obj, &bufinfo, MP_BUFFER_READ);
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// do the I2C transfer
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mphal_i2c_write(self, args[ARG_addr].u_int, bufinfo.buf, bufinfo.len, args[ARG_stop].u_bool);
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return mp_const_none;
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}
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STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_writeto_obj, 1, pyb_i2c_writeto);
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STATIC const mp_rom_map_elem_t pyb_i2c_locals_dict_table[] = {
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{ MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&pyb_i2c_init_obj) },
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{ MP_ROM_QSTR(MP_QSTR_readfrom), MP_ROM_PTR(&pyb_i2c_readfrom_obj) },
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{ MP_ROM_QSTR(MP_QSTR_writeto), MP_ROM_PTR(&pyb_i2c_writeto_obj) },
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};
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STATIC MP_DEFINE_CONST_DICT(pyb_i2c_locals_dict, pyb_i2c_locals_dict_table);
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const mp_obj_type_t pyb_i2c_type = {
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{ &mp_type_type },
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.name = MP_QSTR_I2C,
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.make_new = pyb_i2c_make_new,
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.locals_dict = (mp_obj_dict_t*)&pyb_i2c_locals_dict,
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};
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