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I2C.c
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I2C.c
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/*
* 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"
typedef enum {
STATUS_FREE = 0,
STATUS_IN_USE,
STATUS_NEVER_RESET
} i2c_status_t;
static i2c_status_t i2c_status[I2C_NUM_MAX];
void never_reset_i2c(i2c_port_t num) {
i2c_status[num] = STATUS_NEVER_RESET;
}
void i2c_reset(void) {
for (i2c_port_t num = 0; num < I2C_NUM_MAX; num++) {
if (i2c_status[num] == STATUS_IN_USE) {
i2c_status[num] = STATUS_FREE;
}
}
}
static bool i2c_inited[I2C_NUM_MAX];
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_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);
// We must pull up within 3us to achieve 400khz.
common_hal_mcu_delay_us(3);
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("SDA or SCL needs a pull up"));
}
#endif
if (xSemaphoreCreateBinaryStatic(&self->semaphore) != &self->semaphore) {
mp_raise_RuntimeError(translate("Unable to create lock"));
}
xSemaphoreGive(&self->semaphore);
self->sda_pin = sda;
self->scl_pin = scl;
self->i2c_num = I2C_NUM_MAX;
for (i2c_port_t num = 0; num < I2C_NUM_MAX; num++) {
if (i2c_status[num] == STATUS_FREE) {
self->i2c_num = num;
}
}
if (self->i2c_num == I2C_NUM_MAX) {
mp_raise_ValueError(translate("All I2C peripherals are in use"));
}
i2c_status[self->i2c_num] = STATUS_IN_USE;
i2c_config_t i2c_conf = {
.mode = I2C_MODE_MASTER,
.sda_io_num = self->sda_pin->number,
.scl_io_num = self->scl_pin->number,
.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*/
.master = {
.clk_speed = frequency,
}
};
esp_err_t result = i2c_param_config(self->i2c_num, &i2c_conf);
if (result != ESP_OK) {
mp_raise_ValueError(translate("Invalid pins"));
}
if (!i2c_inited[self->i2c_num]) {
result = i2c_driver_install(self->i2c_num,
I2C_MODE_MASTER,
0,
0,
0);
if (result != ESP_OK) {
mp_raise_OSError(MP_EIO);
}
i2c_inited[self->i2c_num] = true;
}
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;
}
i2c_status[self->i2c_num] = STATUS_FREE;
common_hal_reset_pin(self->sda_pin);
common_hal_reset_pin(self->scl_pin);
self->sda_pin = NULL;
self->scl_pin = NULL;
}
bool common_hal_busio_i2c_probe(busio_i2c_obj_t *self, uint8_t addr) {
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, 10);
i2c_cmd_link_delete(cmd);
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->semaphore, 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->semaphore);
self->has_lock = false;
}
uint8_t common_hal_busio_i2c_write(busio_i2c_obj_t *self, uint16_t addr,
const uint8_t *data, size_t len, bool transmit_stop_bit) {
i2c_cmd_handle_t cmd = i2c_cmd_link_create();
i2c_master_start(cmd);
i2c_master_write_byte(cmd, addr << 1, true);
i2c_master_write(cmd, (uint8_t*) data, len, true);
if (transmit_stop_bit) {
i2c_master_stop(cmd);
}
esp_err_t result = i2c_master_cmd_begin(self->i2c_num, cmd, 100 /* wait in ticks */);
i2c_cmd_link_delete(cmd);
if (result == ESP_OK) {
return 0;
} else if (result == ESP_FAIL) {
return MP_ENODEV;
}
return MP_EIO;
}
uint8_t common_hal_busio_i2c_read(busio_i2c_obj_t *self, uint16_t addr,
uint8_t *data, size_t len) {
i2c_cmd_handle_t cmd = i2c_cmd_link_create();
i2c_master_start(cmd);
i2c_master_write_byte(cmd, addr << 1 | 1, true); // | 1 to indicate read
if (len > 1) {
i2c_master_read(cmd, data, len - 1, 0);
}
i2c_master_read_byte(cmd, data + len - 1, 1);
i2c_master_stop(cmd);
esp_err_t result = i2c_master_cmd_begin(self->i2c_num, cmd, 100 /* wait in ticks */);
i2c_cmd_link_delete(cmd);
if (result == ESP_OK) {
return 0;
} else if (result == ESP_FAIL) {
return MP_ENODEV;
}
return MP_EIO;
}
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);
}