circuitpython/ports/espressif/common-hal/busio/I2C.c
2022-03-09 07:36:17 +11:00

212 lines
7.3 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2020 Scott Shawcroft for Adafruit Industries LLC
*
* 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 "shared-bindings/busio/I2C.h"
#include "py/mperrno.h"
#include "py/runtime.h"
#include "components/driver/include/driver/i2c.h"
#include "shared-bindings/microcontroller/__init__.h"
#include "shared-bindings/microcontroller/Pin.h"
#include "supervisor/shared/translate.h"
void common_hal_busio_i2c_construct(busio_i2c_obj_t *self,
const mcu_pin_obj_t *scl, const mcu_pin_obj_t *sda, uint32_t frequency, uint32_t timeout) {
// Pins 45 and 46 are "strapping" pins that impact start up behavior. They usually need to
// be pulled-down so pulling them up for I2C is a bad idea. To make this hard, we don't
// support I2C on these pins.
//
// 46 is also input-only so it'll never work.
if (scl->number == 45 || scl->number == 46 || sda->number == 45 || sda->number == 46) {
mp_raise_ValueError(translate("Invalid pins"));
}
#if CIRCUITPY_REQUIRE_I2C_PULLUPS
// Test that the pins are in a high state. (Hopefully indicating they are pulled up.)
gpio_set_direction(sda->number, GPIO_MODE_DEF_INPUT);
gpio_set_direction(scl->number, GPIO_MODE_DEF_INPUT);
gpio_pullup_dis(sda->number);
gpio_pullup_dis(scl->number);
gpio_pulldown_en(sda->number);
gpio_pulldown_en(scl->number);
common_hal_mcu_delay_us(10);
gpio_pulldown_dis(sda->number);
gpio_pulldown_dis(scl->number);
#if CIRCUITPY_I2C_ALLOW_INTERNAL_PULL_UP
gpio_pullup_en(sda->number);
gpio_pullup_en(scl->number);
#endif
// We must pull up within 3us to achieve 400khz.
common_hal_mcu_delay_us((1200000 + frequency - 1) / frequency);
if (gpio_get_level(sda->number) == 0 || gpio_get_level(scl->number) == 0) {
reset_pin_number(sda->number);
reset_pin_number(scl->number);
mp_raise_RuntimeError(translate("No pull up found on SDA or SCL; check your wiring"));
}
#endif
self->xSemaphore = xSemaphoreCreateMutex();
if (self->xSemaphore == NULL) {
mp_raise_RuntimeError(translate("Unable to create lock"));
}
self->sda_pin = sda;
self->scl_pin = scl;
self->i2c_num = peripherals_i2c_get_free_num();
if (self->i2c_num == I2C_NUM_MAX) {
mp_raise_ValueError(translate("All I2C peripherals are in use"));
}
// Delete any previous driver.
i2c_driver_delete(self->i2c_num);
const i2c_config_t i2c_conf = {
.mode = I2C_MODE_MASTER,
.sda_io_num = self->sda_pin->number,
.scl_io_num = self->scl_pin->number,
#if CIRCUITPY_I2C_ALLOW_INTERNAL_PULL_UP
.sda_pullup_en = GPIO_PULLUP_ENABLE, /*!< Internal GPIO pull mode for I2C sda signal*/
.scl_pullup_en = GPIO_PULLUP_ENABLE, /*!< Internal GPIO pull mode for I2C scl signal*/
#else
.sda_pullup_en = GPIO_PULLUP_DISABLE, /*!< Internal GPIO pull mode for I2C sda signal*/
.scl_pullup_en = GPIO_PULLUP_DISABLE, /*!< Internal GPIO pull mode for I2C scl signal*/
#endif
.master = {
.clk_speed = frequency,
}
};
// Initialize I2C.
esp_err_t err = peripherals_i2c_init(self->i2c_num, &i2c_conf);
if (err != ESP_OK) {
if (err == ESP_FAIL) {
mp_raise_OSError(MP_EIO);
} else {
mp_raise_ValueError(translate("Invalid argument"));
}
}
claim_pin(sda);
claim_pin(scl);
}
bool common_hal_busio_i2c_deinited(busio_i2c_obj_t *self) {
return self->sda_pin == NULL;
}
void common_hal_busio_i2c_deinit(busio_i2c_obj_t *self) {
if (common_hal_busio_i2c_deinited(self)) {
return;
}
peripherals_i2c_deinit(self->i2c_num);
common_hal_reset_pin(self->sda_pin);
common_hal_reset_pin(self->scl_pin);
self->sda_pin = NULL;
self->scl_pin = NULL;
}
static esp_err_t i2c_zero_length_write(busio_i2c_obj_t *self, uint8_t addr, TickType_t timeout) {
// i2c_master_write_to_device() won't do zero-length writes, so we do it by hand.
i2c_cmd_handle_t cmd = i2c_cmd_link_create();
i2c_master_start(cmd);
i2c_master_write_byte(cmd, addr << 1, true);
i2c_master_stop(cmd);
esp_err_t result = i2c_master_cmd_begin(self->i2c_num, cmd, timeout);
i2c_cmd_link_delete(cmd);
return result;
}
bool common_hal_busio_i2c_probe(busio_i2c_obj_t *self, uint8_t addr) {
esp_err_t result = i2c_zero_length_write(self, addr, 1);
return result == ESP_OK;
}
bool common_hal_busio_i2c_try_lock(busio_i2c_obj_t *self) {
if (self->has_lock) {
return false;
}
self->has_lock = xSemaphoreTake(self->xSemaphore, 0) == pdTRUE;
return self->has_lock;
}
bool common_hal_busio_i2c_has_lock(busio_i2c_obj_t *self) {
return self->has_lock;
}
void common_hal_busio_i2c_unlock(busio_i2c_obj_t *self) {
xSemaphoreGive(self->xSemaphore);
self->has_lock = false;
}
static uint8_t convert_esp_err(esp_err_t result) {
switch (result) {
case ESP_OK:
return 0;
case ESP_FAIL:
return MP_ENODEV;
case ESP_ERR_TIMEOUT:
return MP_ETIMEDOUT;
default:
return MP_EIO;
}
}
uint8_t common_hal_busio_i2c_write(busio_i2c_obj_t *self, uint16_t addr, const uint8_t *data, size_t len) {
return convert_esp_err(len == 0
? i2c_zero_length_write(self, addr, 100)
: i2c_master_write_to_device(self->i2c_num, (uint8_t)addr, data, len, 100 /* wait in ticks */)
);
}
uint8_t common_hal_busio_i2c_read(busio_i2c_obj_t *self, uint16_t addr, uint8_t *data, size_t len) {
return convert_esp_err(
i2c_master_read_from_device(self->i2c_num, (uint8_t)addr, data, len, 100 /* wait in ticks */));
}
uint8_t common_hal_busio_i2c_write_read(busio_i2c_obj_t *self, uint16_t addr,
uint8_t *out_data, size_t out_len, uint8_t *in_data, size_t in_len) {
return convert_esp_err(
i2c_master_write_read_device(self->i2c_num, (uint8_t)addr,
out_data, out_len, in_data, in_len, 100 /* wait in ticks */));
}
void common_hal_busio_i2c_never_reset(busio_i2c_obj_t *self) {
never_reset_i2c(self->i2c_num);
common_hal_never_reset_pin(self->scl_pin);
common_hal_never_reset_pin(self->sda_pin);
}