- /* Copyright 2021 QMK
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
- #include "serial_usart.h"
-
- #if defined(SERIAL_USART_CONFIG)
- static SerialConfig serial_config = SERIAL_USART_CONFIG;
- #else
- static SerialConfig serial_config = {
- .speed = (SERIAL_USART_SPEED), /* speed - mandatory */
- .cr1 = (SERIAL_USART_CR1),
- .cr2 = (SERIAL_USART_CR2),
- # if !defined(SERIAL_USART_FULL_DUPLEX)
- .cr3 = ((SERIAL_USART_CR3) | USART_CR3_HDSEL) /* activate half-duplex mode */
- # else
- .cr3 = (SERIAL_USART_CR3)
- # endif
- };
- #endif
-
- static SerialDriver* serial_driver = &SERIAL_USART_DRIVER;
-
- static inline bool react_to_transactions(void);
- static inline bool __attribute__((nonnull)) receive(uint8_t* destination, const size_t size);
- static inline bool __attribute__((nonnull)) send(const uint8_t* source, const size_t size);
- static inline bool initiate_transaction(uint8_t sstd_index);
- static inline void usart_clear(void);
-
- /**
- * @brief Clear the receive input queue.
- */
- static inline void usart_clear(void) {
- osalSysLock();
- bool volatile queue_not_empty = !iqIsEmptyI(&serial_driver->iqueue);
- osalSysUnlock();
-
- while (queue_not_empty) {
- osalSysLock();
- /* Hard reset the input queue. */
- iqResetI(&serial_driver->iqueue);
- osalSysUnlock();
- /* Allow pending interrupts to preempt.
- * Do not merge the lock/unlock blocks into one
- * or the code will not work properly.
- * The empty read adds a tiny amount of delay. */
- (void)queue_not_empty;
- osalSysLock();
- queue_not_empty = !iqIsEmptyI(&serial_driver->iqueue);
- osalSysUnlock();
- }
- }
-
- /**
- * @brief Blocking send of buffer with timeout.
- *
- * @return true Send success.
- * @return false Send failed.
- */
- static inline bool send(const uint8_t* source, const size_t size) {
- bool success = (size_t)sdWriteTimeout(serial_driver, source, size, TIME_MS2I(SERIAL_USART_TIMEOUT)) == size;
-
- #if !defined(SERIAL_USART_FULL_DUPLEX)
- if (success) {
- /* Half duplex fills the input queue with the data we wrote - just throw it away.
- Under the right circumstances (e.g. bad cables paired with high baud rates)
- less bytes can be present in the input queue, therefore a timeout is needed. */
- uint8_t dump[size];
- return receive(dump, size);
- }
- #endif
-
- return success;
- }
-
- /**
- * @brief Blocking receive of size * bytes with timeout.
- *
- * @return true Receive success.
- * @return false Receive failed.
- */
- static inline bool receive(uint8_t* destination, const size_t size) {
- bool success = (size_t)sdReadTimeout(serial_driver, destination, size, TIME_MS2I(SERIAL_USART_TIMEOUT)) == size;
- return success;
- }
-
- #if !defined(SERIAL_USART_FULL_DUPLEX)
-
- /**
- * @brief Initiate pins for USART peripheral. Half-duplex configuration.
- */
- __attribute__((weak)) void usart_init(void) {
- # if defined(MCU_STM32)
- # if defined(USE_GPIOV1)
- palSetLineMode(SERIAL_USART_TX_PIN, PAL_MODE_ALTERNATE_OPENDRAIN);
- # else
- palSetLineMode(SERIAL_USART_TX_PIN, PAL_MODE_ALTERNATE(SERIAL_USART_TX_PAL_MODE) | PAL_OUTPUT_TYPE_OPENDRAIN);
- # endif
-
- # if defined(USART_REMAP)
- USART_REMAP;
- # endif
- # else
- # pragma message "usart_init: MCU Familiy not supported by default, please supply your own init code by implementing usart_init() in your keyboard files."
- # endif
- }
-
- #else
-
- /**
- * @brief Initiate pins for USART peripheral. Full-duplex configuration.
- */
- __attribute__((weak)) void usart_init(void) {
- # if defined(MCU_STM32)
- # if defined(USE_GPIOV1)
- palSetLineMode(SERIAL_USART_TX_PIN, PAL_MODE_ALTERNATE_PUSHPULL);
- palSetLineMode(SERIAL_USART_RX_PIN, PAL_MODE_INPUT);
- # else
- palSetLineMode(SERIAL_USART_TX_PIN, PAL_MODE_ALTERNATE(SERIAL_USART_TX_PAL_MODE) | PAL_OUTPUT_TYPE_PUSHPULL | PAL_OUTPUT_SPEED_HIGHEST);
- palSetLineMode(SERIAL_USART_RX_PIN, PAL_MODE_ALTERNATE(SERIAL_USART_RX_PAL_MODE) | PAL_OUTPUT_TYPE_PUSHPULL | PAL_OUTPUT_SPEED_HIGHEST);
- # endif
-
- # if defined(USART_REMAP)
- USART_REMAP;
- # endif
- # else
- # pragma message "usart_init: MCU Familiy not supported by default, please supply your own init code by implementing usart_init() in your keyboard files."
- # endif
- }
-
- #endif
-
- /**
- * @brief Overridable master specific initializations.
- */
- __attribute__((weak, nonnull)) void usart_master_init(SerialDriver** driver) {
- (void)driver;
- usart_init();
- }
-
- /**
- * @brief Overridable slave specific initializations.
- */
- __attribute__((weak, nonnull)) void usart_slave_init(SerialDriver** driver) {
- (void)driver;
- usart_init();
- }
-
- /**
- * @brief This thread runs on the slave and responds to transactions initiated
- * by the master.
- */
- static THD_WORKING_AREA(waSlaveThread, 1024);
- static THD_FUNCTION(SlaveThread, arg) {
- (void)arg;
- chRegSetThreadName("usart_tx_rx");
-
- while (true) {
- if (!react_to_transactions()) {
- /* Clear the receive queue, to start with a clean slate.
- * Parts of failed transactions or spurious bytes could still be in it. */
- usart_clear();
- }
- }
- }
-
- /**
- * @brief Slave specific initializations.
- */
- void soft_serial_target_init(void) {
- usart_slave_init(&serial_driver);
-
- sdStart(serial_driver, &serial_config);
-
- /* Start transport thread. */
- chThdCreateStatic(waSlaveThread, sizeof(waSlaveThread), HIGHPRIO, SlaveThread, NULL);
- }
-
- /**
- * @brief React to transactions started by the master.
- */
- static inline bool react_to_transactions(void) {
- /* Wait until there is a transaction for us. */
- uint8_t sstd_index = (uint8_t)sdGet(serial_driver);
-
- /* Sanity check that we are actually responding to a valid transaction. */
- if (sstd_index >= NUM_TOTAL_TRANSACTIONS) {
- return false;
- }
-
- split_transaction_desc_t* trans = &split_transaction_table[sstd_index];
-
- /* Send back the handshake which is XORed as a simple checksum,
- to signal that the slave is ready to receive possible transaction buffers */
- sstd_index ^= HANDSHAKE_MAGIC;
- if (!send(&sstd_index, sizeof(sstd_index))) {
- return false;
- }
-
- /* Receive transaction buffer from the master. If this transaction requires it.*/
- if (trans->initiator2target_buffer_size) {
- if (!receive(split_trans_initiator2target_buffer(trans), trans->initiator2target_buffer_size)) {
- return false;
- }
- }
-
- /* Allow any slave processing to occur. */
- if (trans->slave_callback) {
- trans->slave_callback(trans->initiator2target_buffer_size, split_trans_initiator2target_buffer(trans), trans->initiator2target_buffer_size, split_trans_target2initiator_buffer(trans));
- }
-
- /* Send transaction buffer to the master. If this transaction requires it. */
- if (trans->target2initiator_buffer_size) {
- if (!send(split_trans_target2initiator_buffer(trans), trans->target2initiator_buffer_size)) {
- return false;
- }
- }
-
- return true;
- }
-
- /**
- * @brief Master specific initializations.
- */
- void soft_serial_initiator_init(void) {
- usart_master_init(&serial_driver);
-
- #if defined(MCU_STM32) && defined(SERIAL_USART_PIN_SWAP)
- serial_config.cr2 |= USART_CR2_SWAP; // master has swapped TX/RX pins
- #endif
-
- sdStart(serial_driver, &serial_config);
- }
-
- /**
- * @brief Start transaction from the master half to the slave half.
- *
- * @param index Transaction Table index of the transaction to start.
- * @return bool Indicates success of transaction.
- */
- bool soft_serial_transaction(int index) {
- /* Clear the receive queue, to start with a clean slate.
- * Parts of failed transactions or spurious bytes could still be in it. */
- usart_clear();
- return initiate_transaction((uint8_t)index);
- }
-
- /**
- * @brief Initiate transaction to slave half.
- */
- static inline bool initiate_transaction(uint8_t sstd_index) {
- /* Sanity check that we are actually starting a valid transaction. */
- if (sstd_index >= NUM_TOTAL_TRANSACTIONS) {
- dprintln("USART: Illegal transaction Id.");
- return false;
- }
-
- split_transaction_desc_t* trans = &split_transaction_table[sstd_index];
-
- /* Send transaction table index to the slave, which doubles as basic handshake token. */
- if (!send(&sstd_index, sizeof(sstd_index))) {
- dprintln("USART: Send Handshake failed.");
- return false;
- }
-
- uint8_t sstd_index_shake = 0xFF;
-
- /* Which we always read back first so that we can error out correctly.
- * - due to the half duplex limitations on return codes, we always have to read *something*.
- * - without the read, write only transactions *always* succeed, even during the boot process where the slave is not ready.
- */
- if (!receive(&sstd_index_shake, sizeof(sstd_index_shake)) || (sstd_index_shake != (sstd_index ^ HANDSHAKE_MAGIC))) {
- dprintln("USART: Handshake failed.");
- return false;
- }
-
- /* Send transaction buffer to the slave. If this transaction requires it. */
- if (trans->initiator2target_buffer_size) {
- if (!send(split_trans_initiator2target_buffer(trans), trans->initiator2target_buffer_size)) {
- dprintln("USART: Send failed.");
- return false;
- }
- }
-
- /* Receive transaction buffer from the slave. If this transaction requires it. */
- if (trans->target2initiator_buffer_size) {
- if (!receive(split_trans_target2initiator_buffer(trans), trans->target2initiator_buffer_size)) {
- dprintln("USART: Receive failed.");
- return false;
- }
- }
-
- return true;
- }
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