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