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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2016 Scott Shawcroft
*
* 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 "hal/include/hal_gpio.h"
#include "hal/include/hal_i2c_m_sync.h"
#include "hal/include/hpl_i2c_m_sync.h"
#include "peripherals.h"
#include "pins.h"
#include "shared-bindings/microcontroller/__init__.h"
// Number of times to try to send packet if failed.
#define ATTEMPTS 2
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) {
Sercom* sercom = NULL;
uint8_t sercom_index;
uint32_t sda_pinmux = 0;
uint32_t scl_pinmux = 0;
for (int i = 0; i < NUM_SERCOMS_PER_PIN; i++) {
sercom_index = sda->sercom[i].index;
if (sercom_index >= SERCOM_INST_NUM) {
continue;
}
Sercom* potential_sercom = sercom_insts[sercom_index];
if (potential_sercom->I2CM.CTRLA.bit.ENABLE != 0 ||
sda->sercom[i].pad != 0) {
continue;
}
sda_pinmux = PINMUX(sda->pin, (i == 0) ? MUX_C : MUX_D);
for (int j = 0; j < NUM_SERCOMS_PER_PIN; j++) {
if (sercom_index == scl->sercom[j].index &&
scl->sercom[j].pad == 1) {
scl_pinmux = PINMUX(scl->pin, (j == 0) ? MUX_C : MUX_D);
sercom = potential_sercom;
break;
}
}
if (sercom != NULL) {
break;
}
}
if (sercom == NULL) {
mp_raise_ValueError("Invalid pins");
}
// Test that the pins are in a high state. (Hopefully indicating they are pulled up.)
gpio_set_pin_function(sda->pin, GPIO_PIN_FUNCTION_OFF);
gpio_set_pin_function(scl->pin, GPIO_PIN_FUNCTION_OFF);
gpio_set_pin_direction(sda->pin, GPIO_DIRECTION_IN);
gpio_set_pin_direction(scl->pin, GPIO_DIRECTION_IN);
gpio_set_pin_pull_mode(sda->pin, GPIO_PULL_DOWN);
gpio_set_pin_pull_mode(scl->pin, GPIO_PULL_DOWN);
common_hal_mcu_delay_us(10);
gpio_set_pin_pull_mode(sda->pin, GPIO_PULL_OFF);
gpio_set_pin_pull_mode(scl->pin, GPIO_PULL_OFF);
// We must pull up within 3us to achieve 400khz.
common_hal_mcu_delay_us(3);
if (!gpio_get_pin_level(sda->pin) || !gpio_get_pin_level(scl->pin)) {
reset_pin(sda->pin);
reset_pin(scl->pin);
mp_raise_RuntimeError("SDA or SCL needs a pull up");
}
gpio_set_pin_function(sda->pin, sda_pinmux);
gpio_set_pin_function(scl->pin, scl_pinmux);
// Set up I2C clocks on sercom.
samd_peripherals_sercom_clock_init(sercom, sercom_index);
if (i2c_m_sync_init(&self->i2c_desc, sercom) != ERR_NONE) {
reset_pin(sda->pin);
reset_pin(scl->pin);
mp_raise_OSError(MP_EIO);
}
// clkrate is always 0. baud_rate is in kHz.
// Frequency must be set before the I2C device is enabled.
if (i2c_m_sync_set_baudrate(&self->i2c_desc, 0, frequency / 1000) != ERR_NONE) {
reset_pin(sda->pin);
reset_pin(scl->pin);
mp_raise_ValueError("Unsupported baudrate");
}
self->sda_pin = sda->pin;
self->scl_pin = scl->pin;
claim_pin(sda);
claim_pin(scl);
if (i2c_m_sync_enable(&self->i2c_desc) != ERR_NONE) {
common_hal_busio_i2c_deinit(self);
mp_raise_OSError(MP_EIO);
}
}
bool common_hal_busio_i2c_deinited(busio_i2c_obj_t *self) {
return self->sda_pin == NO_PIN;
}
void common_hal_busio_i2c_deinit(busio_i2c_obj_t *self) {
if (common_hal_busio_i2c_deinited(self)) {
return;
}
i2c_m_sync_disable(&self->i2c_desc);
i2c_m_sync_deinit(&self->i2c_desc);
reset_pin(self->sda_pin);
reset_pin(self->scl_pin);
self->sda_pin = NO_PIN;
self->scl_pin = NO_PIN;
}
bool common_hal_busio_i2c_probe(busio_i2c_obj_t *self, uint8_t addr) {
struct io_descriptor *i2c_io;
i2c_m_sync_get_io_descriptor(&self->i2c_desc, &i2c_io);
i2c_m_sync_set_slaveaddr(&self->i2c_desc, addr, I2C_M_SEVEN);
// Write no data when just probing
return io_write(i2c_io, NULL, 0) == ERR_NONE;
}
bool common_hal_busio_i2c_try_lock(busio_i2c_obj_t *self) {
bool grabbed_lock = false;
CRITICAL_SECTION_ENTER()
if (!self->has_lock) {
grabbed_lock = true;
self->has_lock = true;
}
CRITICAL_SECTION_LEAVE();
return grabbed_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) {
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) {
uint16_t attempts = ATTEMPTS;
int32_t status;
do {
struct _i2c_m_msg msg;
msg.addr = addr;
msg.len = len;
msg.flags = transmit_stop_bit ? I2C_M_STOP : 0;
msg.buffer = (uint8_t *) data;
status = _i2c_m_sync_transfer(&self->i2c_desc.device, &msg);
// Give up after ATTEMPTS tries.
if (--attempts == 0) {
break;
}
} while (status != I2C_OK);
if (status == I2C_OK) {
return 0;
} else if (status == I2C_ERR_BAD_ADDRESS) {
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) {
uint16_t attempts = ATTEMPTS;
int32_t status;
do {
struct _i2c_m_msg msg;
msg.addr = addr;
msg.len = len;
msg.flags = I2C_M_STOP | I2C_M_RD;
msg.buffer = data;
status = _i2c_m_sync_transfer(&self->i2c_desc.device, &msg);
// Give up after ATTEMPTS tries.
if (--attempts == 0) {
break;
}
} while (status != I2C_OK);
if (status == ERR_NONE) {
return 0;
} else if (status == I2C_ERR_BAD_ADDRESS) {
return MP_ENODEV;
}
return MP_EIO;
}