258 lines
8.1 KiB
C
258 lines
8.1 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) 2018 Noralf Trønnes
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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/i2ctarget/I2CTarget.h"
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#include "shared-bindings/microcontroller/Pin.h"
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#include "common-hal/busio/I2C.h"
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#include "shared/runtime/interrupt_char.h"
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#include "py/mperrno.h"
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#include "py/mphal.h"
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#include "py/runtime.h"
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#include "hal/include/hal_gpio.h"
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#include "peripherals/samd/sercom.h"
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void common_hal_i2ctarget_i2c_target_construct(i2ctarget_i2c_target_obj_t *self,
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const mcu_pin_obj_t *scl, const mcu_pin_obj_t *sda,
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uint8_t *addresses, unsigned int num_addresses, bool smbus) {
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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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raise_ValueError_invalid_pins();
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}
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self->sercom = sercom;
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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_function(sda->number, sda_pinmux);
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gpio_set_pin_function(scl->number, scl_pinmux);
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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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samd_peripherals_sercom_clock_init(sercom, sercom_index);
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#ifdef SAM_D5X_E5X
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sercom->I2CS.CTRLC.bit.SDASETUP = 0x08;
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#endif
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sercom->I2CS.CTRLA.bit.SWRST = 1;
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while (sercom->I2CS.CTRLA.bit.SWRST || sercom->I2CS.SYNCBUSY.bit.SWRST) {
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}
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sercom->I2CS.CTRLB.bit.AACKEN = 0; // Automatic acknowledge is disabled.
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if (num_addresses == 1) {
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sercom->I2CS.CTRLB.bit.AMODE = 0x0; // MASK
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sercom->I2CS.ADDR.bit.ADDR = addresses[0];
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sercom->I2CS.ADDR.bit.ADDRMASK = 0x00; // Match exact address
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} else if (num_addresses == 2) {
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sercom->I2CS.CTRLB.bit.AMODE = 0x1; // 2_ADDRS
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sercom->I2CS.ADDR.bit.ADDR = addresses[0];
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sercom->I2CS.ADDR.bit.ADDRMASK = addresses[1];
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} else {
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uint32_t combined = 0; // all addresses OR'ed
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uint32_t differ = 0; // bits that differ between addresses
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for (unsigned int i = 0; i < num_addresses; i++) {
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combined |= addresses[i];
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differ |= addresses[0] ^ addresses[i];
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}
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sercom->I2CS.CTRLB.bit.AMODE = 0x0; // MASK
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sercom->I2CS.ADDR.bit.ADDR = combined;
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sercom->I2CS.ADDR.bit.ADDRMASK = differ;
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}
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self->addresses = addresses;
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self->num_addresses = num_addresses;
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if (smbus) {
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sercom->I2CS.CTRLA.bit.LOWTOUTEN = 1; // Errata 12003
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sercom->I2CS.CTRLA.bit.SEXTTOEN = 1; // SCL Low Extend/Cumulative Time-Out 25ms
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}
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sercom->I2CS.CTRLA.bit.SCLSM = 0; // Clock stretch before ack
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sercom->I2CS.CTRLA.bit.MODE = 0x04; // Device mode
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sercom->I2CS.CTRLA.bit.ENABLE = 1;
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}
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bool common_hal_i2ctarget_i2c_target_deinited(i2ctarget_i2c_target_obj_t *self) {
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return self->sda_pin == NO_PIN;
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}
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void common_hal_i2ctarget_i2c_target_deinit(i2ctarget_i2c_target_obj_t *self) {
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if (common_hal_i2ctarget_i2c_target_deinited(self)) {
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return;
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}
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self->sercom->I2CS.CTRLA.bit.ENABLE = 0;
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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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static int i2c_target_check_error(i2ctarget_i2c_target_obj_t *self, bool raise) {
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if (!self->sercom->I2CS.INTFLAG.bit.ERROR) {
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return 0;
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}
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int err = MP_EIO;
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if (self->sercom->I2CS.STATUS.bit.LOWTOUT || self->sercom->I2CS.STATUS.bit.SEXTTOUT) {
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err = MP_ETIMEDOUT;
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}
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self->sercom->I2CS.INTFLAG.reg = SERCOM_I2CS_INTFLAG_ERROR; // Clear flag
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if (raise) {
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mp_raise_OSError(err);
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}
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return -err;
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}
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int common_hal_i2ctarget_i2c_target_is_addressed(i2ctarget_i2c_target_obj_t *self, uint8_t *address, bool *is_read, bool *is_restart) {
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int err = i2c_target_check_error(self, false);
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if (err) {
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return err;
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}
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if (!self->sercom->I2CS.INTFLAG.bit.AMATCH) {
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return 0;
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}
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self->writing = false;
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*address = self->sercom->I2CS.DATA.reg >> 1;
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*is_read = self->sercom->I2CS.STATUS.bit.DIR;
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*is_restart = self->sercom->I2CS.STATUS.bit.SR;
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for (unsigned int i = 0; i < self->num_addresses; i++) {
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if (*address == self->addresses[i]) {
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common_hal_i2ctarget_i2c_target_ack(self, true);
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return 1;
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}
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}
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// This should clear AMATCH, but it doesn't...
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common_hal_i2ctarget_i2c_target_ack(self, false);
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return 0;
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}
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int common_hal_i2ctarget_i2c_target_read_byte(i2ctarget_i2c_target_obj_t *self, uint8_t *data) {
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for (int t = 0; t < 100 && !self->sercom->I2CS.INTFLAG.reg; t++) {
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mp_hal_delay_us(10);
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}
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i2c_target_check_error(self, true);
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if (!self->sercom->I2CS.INTFLAG.bit.DRDY ||
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self->sercom->I2CS.INTFLAG.bit.PREC ||
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self->sercom->I2CS.INTFLAG.bit.AMATCH) {
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return 0;
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}
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*data = self->sercom->I2CS.DATA.reg;
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return 1;
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}
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int common_hal_i2ctarget_i2c_target_write_byte(i2ctarget_i2c_target_obj_t *self, uint8_t data) {
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for (int t = 0; !self->sercom->I2CS.INTFLAG.reg && t < 100; t++) {
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mp_hal_delay_us(10);
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}
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i2c_target_check_error(self, true);
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if (self->sercom->I2CS.INTFLAG.bit.PREC) {
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return 0;
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}
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// RXNACK can carry over from the previous transfer
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if (self->writing && self->sercom->I2CS.STATUS.bit.RXNACK) {
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return 0;
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}
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self->writing = true;
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if (!self->sercom->I2CS.INTFLAG.bit.DRDY) {
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return 0;
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}
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self->sercom->I2CS.DATA.bit.DATA = data; // Send data
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return 1;
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}
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void common_hal_i2ctarget_i2c_target_ack(i2ctarget_i2c_target_obj_t *self, bool ack) {
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self->sercom->I2CS.CTRLB.bit.ACKACT = !ack;
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self->sercom->I2CS.CTRLB.bit.CMD = 0x03;
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}
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void common_hal_i2ctarget_i2c_target_close(i2ctarget_i2c_target_obj_t *self) {
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for (int t = 0; !self->sercom->I2CS.INTFLAG.reg && t < 100; t++) {
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mp_hal_delay_us(10);
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}
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if (self->sercom->I2CS.INTFLAG.bit.AMATCH || !self->sercom->I2CS.STATUS.bit.CLKHOLD) {
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return;
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}
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if (!self->sercom->I2CS.STATUS.bit.DIR) {
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common_hal_i2ctarget_i2c_target_ack(self, false);
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} else {
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int i = 0;
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while (self->sercom->I2CS.INTFLAG.reg == SERCOM_I2CS_INTFLAG_DRDY) {
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if (mp_hal_is_interrupted()) {
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return;
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}
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self->sercom->I2CS.DATA.bit.DATA = 0xff; // Send dummy byte
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// Wait for a result (if any).
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// test_byte_word.py::TestWord::test_write_seq leaves us with no INTFLAGs set in some of the tests
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for (int t = 0; !self->sercom->I2CS.INTFLAG.reg && t < 100; t++) {
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mp_hal_delay_us(10);
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}
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if (++i > 1000) { // Avoid getting stuck "forever"
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mp_raise_OSError(MP_EIO);
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}
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}
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}
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if (self->sercom->I2CS.INTFLAG.bit.AMATCH) {
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return;
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}
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if (self->sercom->I2CS.STATUS.bit.CLKHOLD) {
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// Unable to release the clock.
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// The device might have to be re-initialized to get unstuck.
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mp_raise_OSError(MP_EIO);
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}
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}
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