232 lines
7.5 KiB
C
232 lines
7.5 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 Scott Shawcroft
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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 "shared-bindings/busio/I2C.h"
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#include "py/mperrno.h"
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#include "py/runtime.h"
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#include "hal/include/hal_gpio.h"
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#include "hal/include/hal_i2c_m_sync.h"
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#include "hal/include/hpl_i2c_m_sync.h"
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#include "samd/sercom.h"
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#include "shared-bindings/microcontroller/__init__.h"
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#include "supervisor/shared/translate.h"
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// Number of times to try to send packet if failed.
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#define ATTEMPTS 2
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Sercom *samd_i2c_get_sercom(const mcu_pin_obj_t* scl, const mcu_pin_obj_t* sda,
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uint8_t *sercom_index, uint32_t *sda_pinmux, uint32_t *scl_pinmux) {
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*sda_pinmux = 0;
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*scl_pinmux = 0;
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for (int i = 0; i < NUM_SERCOMS_PER_PIN; i++) {
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*sercom_index = sda->sercom[i].index;
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if (*sercom_index >= SERCOM_INST_NUM) {
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continue;
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}
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Sercom* potential_sercom = sercom_insts[*sercom_index];
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if (potential_sercom->I2CM.CTRLA.bit.ENABLE != 0 ||
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sda->sercom[i].pad != 0) {
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continue;
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}
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*sda_pinmux = PINMUX(sda->number, (i == 0) ? MUX_C : MUX_D);
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for (int j = 0; j < NUM_SERCOMS_PER_PIN; j++) {
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if (*sercom_index == scl->sercom[j].index &&
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scl->sercom[j].pad == 1) {
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*scl_pinmux = PINMUX(scl->number, (j == 0) ? MUX_C : MUX_D);
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return potential_sercom;
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}
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}
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}
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return NULL;
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}
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void common_hal_busio_i2c_construct(busio_i2c_obj_t *self,
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const mcu_pin_obj_t* scl, const mcu_pin_obj_t* sda, uint32_t frequency, uint32_t timeout) {
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#ifdef PIRKEY_M0
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mp_raise_NotImplementedError(translate("Not enough pins available"));
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return;
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#endif
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uint8_t sercom_index;
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uint32_t sda_pinmux, scl_pinmux;
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Sercom* sercom = samd_i2c_get_sercom(scl, sda, &sercom_index, &sda_pinmux, &scl_pinmux);
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if (sercom == NULL) {
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mp_raise_ValueError(translate("Invalid pins"));
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}
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// Test that the pins are in a high state. (Hopefully indicating they are pulled up.)
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gpio_set_pin_function(sda->number, GPIO_PIN_FUNCTION_OFF);
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gpio_set_pin_function(scl->number, GPIO_PIN_FUNCTION_OFF);
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gpio_set_pin_direction(sda->number, GPIO_DIRECTION_IN);
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gpio_set_pin_direction(scl->number, GPIO_DIRECTION_IN);
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gpio_set_pin_pull_mode(sda->number, GPIO_PULL_DOWN);
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gpio_set_pin_pull_mode(scl->number, GPIO_PULL_DOWN);
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common_hal_mcu_delay_us(10);
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gpio_set_pin_pull_mode(sda->number, GPIO_PULL_OFF);
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gpio_set_pin_pull_mode(scl->number, GPIO_PULL_OFF);
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// We must pull up within 3us to achieve 400khz.
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common_hal_mcu_delay_us(3);
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if (!gpio_get_pin_level(sda->number) || !gpio_get_pin_level(scl->number)) {
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reset_pin_number(sda->number);
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reset_pin_number(scl->number);
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mp_raise_RuntimeError(translate("SDA or SCL needs a pull up"));
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}
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gpio_set_pin_function(sda->number, sda_pinmux);
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gpio_set_pin_function(scl->number, scl_pinmux);
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// Set up I2C clocks on sercom.
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samd_peripherals_sercom_clock_init(sercom, sercom_index);
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if (i2c_m_sync_init(&self->i2c_desc, sercom) != ERR_NONE) {
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reset_pin_number(sda->number);
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reset_pin_number(scl->number);
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mp_raise_OSError(MP_EIO);
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}
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// clkrate is always 0. baud_rate is in kHz.
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// Frequency must be set before the I2C device is enabled.
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if (i2c_m_sync_set_baudrate(&self->i2c_desc, 0, frequency / 1000) != ERR_NONE) {
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reset_pin_number(sda->number);
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reset_pin_number(scl->number);
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mp_raise_ValueError(translate("Unsupported baudrate"));
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}
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self->sda_pin = sda->number;
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self->scl_pin = scl->number;
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claim_pin(sda);
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claim_pin(scl);
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if (i2c_m_sync_enable(&self->i2c_desc) != ERR_NONE) {
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common_hal_busio_i2c_deinit(self);
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mp_raise_OSError(MP_EIO);
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}
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}
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bool common_hal_busio_i2c_deinited(busio_i2c_obj_t *self) {
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return self->sda_pin == NO_PIN;
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}
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void common_hal_busio_i2c_deinit(busio_i2c_obj_t *self) {
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if (common_hal_busio_i2c_deinited(self)) {
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return;
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}
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i2c_m_sync_disable(&self->i2c_desc);
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i2c_m_sync_deinit(&self->i2c_desc);
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reset_pin_number(self->sda_pin);
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reset_pin_number(self->scl_pin);
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self->sda_pin = NO_PIN;
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self->scl_pin = NO_PIN;
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}
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bool common_hal_busio_i2c_probe(busio_i2c_obj_t *self, uint8_t addr) {
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struct io_descriptor *i2c_io;
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i2c_m_sync_get_io_descriptor(&self->i2c_desc, &i2c_io);
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i2c_m_sync_set_slaveaddr(&self->i2c_desc, addr, I2C_M_SEVEN);
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// Write no data when just probing
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return io_write(i2c_io, NULL, 0) == ERR_NONE;
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}
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bool common_hal_busio_i2c_try_lock(busio_i2c_obj_t *self) {
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bool grabbed_lock = false;
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CRITICAL_SECTION_ENTER()
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if (!self->has_lock) {
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grabbed_lock = true;
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self->has_lock = true;
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}
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CRITICAL_SECTION_LEAVE();
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return grabbed_lock;
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}
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bool common_hal_busio_i2c_has_lock(busio_i2c_obj_t *self) {
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return self->has_lock;
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}
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void common_hal_busio_i2c_unlock(busio_i2c_obj_t *self) {
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self->has_lock = false;
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}
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uint8_t common_hal_busio_i2c_write(busio_i2c_obj_t *self, uint16_t addr,
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const uint8_t *data, size_t len, bool transmit_stop_bit) {
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uint16_t attempts = ATTEMPTS;
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int32_t status;
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do {
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struct _i2c_m_msg msg;
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msg.addr = addr;
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msg.len = len;
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msg.flags = transmit_stop_bit ? I2C_M_STOP : 0;
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msg.buffer = (uint8_t *) data;
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status = _i2c_m_sync_transfer(&self->i2c_desc.device, &msg);
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// Give up after ATTEMPTS tries.
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if (--attempts == 0) {
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break;
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}
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} while (status != I2C_OK);
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if (status == I2C_OK) {
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return 0;
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} else if (status == I2C_ERR_BAD_ADDRESS) {
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return MP_ENODEV;
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}
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return MP_EIO;
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}
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uint8_t common_hal_busio_i2c_read(busio_i2c_obj_t *self, uint16_t addr,
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uint8_t *data, size_t len) {
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uint16_t attempts = ATTEMPTS;
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int32_t status;
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do {
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struct _i2c_m_msg msg;
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msg.addr = addr;
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msg.len = len;
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msg.flags = I2C_M_STOP | I2C_M_RD;
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msg.buffer = data;
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status = _i2c_m_sync_transfer(&self->i2c_desc.device, &msg);
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// Give up after ATTEMPTS tries.
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if (--attempts == 0) {
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break;
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}
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} while (status != I2C_OK);
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if (status == ERR_NONE) {
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return 0;
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} else if (status == I2C_ERR_BAD_ADDRESS) {
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return MP_ENODEV;
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}
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return MP_EIO;
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}
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