From 117bff17ba89a70dd85163b499c262b879f52afd Mon Sep 17 00:00:00 2001
From: Stefan Kerkmann <karlk90@pm.me>
Date: Fri, 2 Jul 2021 00:24:08 +0200
Subject: [Core] Unite half-duplex and full-duplex serial drivers (#13081)
* Unite half-duplex and full-duplex serial driver.
* Add full duplex operation mode to the interrupt based driver
* Delete DMA UART based full duplex driver
* The new driver targets #11930
* Fix freezes with failing transactions in half-duplex
* Increase default serial TX/RX buffer size to 128 bytes
* Correctly use bool instead of size_t
Co-authored-by: Nick Brassel <nick@tzarc.org>
---
drivers/chibios/serial_usart.c | 337 +++++++++++++++++++++++-----------
drivers/chibios/serial_usart.h | 40 +++-
drivers/chibios/serial_usart_duplex.c | 261 --------------------------
3 files changed, 262 insertions(+), 376 deletions(-)
delete mode 100644 drivers/chibios/serial_usart_duplex.c
(limited to 'drivers/chibios')
diff --git a/drivers/chibios/serial_usart.c b/drivers/chibios/serial_usart.c
index 9f180d2d74..ea4473791c 100644
--- a/drivers/chibios/serial_usart.c
+++ b/drivers/chibios/serial_usart.c
@@ -16,179 +16,300 @@
#include "serial_usart.h"
-#ifndef USE_GPIOV1
-// The default PAL alternate modes are used to signal that the pins are used for USART
-# ifndef SERIAL_USART_TX_PAL_MODE
-# define SERIAL_USART_TX_PAL_MODE 7
+#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
-#ifndef SERIAL_USART_DRIVER
-# define SERIAL_USART_DRIVER SD1
-#endif
-
-#ifdef SOFT_SERIAL_PIN
-# define SERIAL_USART_TX_PIN SOFT_SERIAL_PIN
-#endif
-
-static inline msg_t sdWriteHalfDuplex(SerialDriver* driver, uint8_t* data, uint8_t size) {
- msg_t ret = sdWrite(driver, data, size);
+static SerialDriver* serial_driver = &SERIAL_USART_DRIVER;
- // Half duplex requires us to read back the data we just wrote - just throw it away
- uint8_t dump[size];
- sdRead(driver, dump, size);
+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 int initiate_transaction(uint8_t sstd_index);
+static inline void usart_clear(void);
- return ret;
+/**
+ * @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();
+ }
}
-#undef sdWrite
-#define sdWrite sdWriteHalfDuplex
-
-static inline msg_t sdWriteTimeoutHalfDuplex(SerialDriver* driver, uint8_t* data, uint8_t size, uint32_t timeout) {
- msg_t ret = sdWriteTimeout(driver, data, size, timeout);
- // Half duplex requires us to read back the data we just wrote - just throw it away
- uint8_t dump[size];
- sdReadTimeout(driver, dump, size, timeout);
+/**
+ * @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 ret;
+ return success;
}
-#undef sdWriteTimeout
-#define sdWriteTimeout sdWriteTimeoutHalfDuplex
-static inline void sdClear(SerialDriver* driver) {
- while (sdGetTimeout(driver, TIME_IMMEDIATE) != MSG_TIMEOUT) {
- // Do nothing with the data
- }
+/**
+ * @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;
}
-static SerialConfig sdcfg = {
- (SERIAL_USART_SPEED), // speed - mandatory
- (SERIAL_USART_CR1), // CR1
- (SERIAL_USART_CR2), // CR2
- (SERIAL_USART_CR3) // CR3
-};
-
-void handle_soft_serial_slave(void);
+#if !defined(SERIAL_USART_FULL_DUPLEX)
-/*
- * This thread runs on the slave and responds to transactions initiated
- * by the master
+/**
+ * @brief Initiate pins for USART peripheral. Half-duplex configuration.
*/
-static THD_WORKING_AREA(waSlaveThread, 2048);
-static THD_FUNCTION(SlaveThread, arg) {
- (void)arg;
- chRegSetThreadName("slave_transport");
+__attribute__((weak)) void usart_init(void) {
+# if defined(MCU_STM32)
+# if defined(USE_GPIOV1)
+ palSetLineMode(SERIAL_USART_TX_PIN, PAL_MODE_STM32_ALTERNATE_OPENDRAIN);
+# else
+ palSetLineMode(SERIAL_USART_TX_PIN, PAL_MODE_ALTERNATE(SERIAL_USART_TX_PAL_MODE) | PAL_STM32_OTYPE_OPENDRAIN);
+# endif
- while (true) {
- handle_soft_serial_slave();
- }
+# 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
}
-__attribute__((weak)) void usart_init(void) {
-#if defined(USE_GPIOV1)
- palSetLineMode(SERIAL_USART_TX_PIN, PAL_MODE_STM32_ALTERNATE_OPENDRAIN);
#else
- palSetLineMode(SERIAL_USART_TX_PIN, PAL_MODE_ALTERNATE(SERIAL_USART_TX_PAL_MODE) | PAL_STM32_OTYPE_OPENDRAIN);
-#endif
-#if defined(USART_REMAP)
+/**
+ * @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_STM32_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_STM32_OTYPE_PUSHPULL | PAL_STM32_OSPEED_HIGHEST);
+ palSetLineMode(SERIAL_USART_RX_PIN, PAL_MODE_ALTERNATE(SERIAL_USART_RX_PAL_MODE) | PAL_STM32_OTYPE_PUSHPULL | PAL_STM32_OSPEED_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();
}
-void usart_master_init(void) {
+/**
+ * @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");
- sdcfg.cr3 |= USART_CR3_HDSEL;
- sdStart(&SERIAL_USART_DRIVER, &sdcfg);
+ 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();
+ }
+ }
}
-void usart_slave_init(void) {
- usart_init();
+/**
+ * @brief Slave specific initializations.
+ */
+void soft_serial_target_init(void) {
+ usart_slave_init(&serial_driver);
- sdcfg.cr3 |= USART_CR3_HDSEL;
- sdStart(&SERIAL_USART_DRIVER, &sdcfg);
+ sdStart(serial_driver, &serial_config);
- // Start transport thread
+ /* Start transport thread. */
chThdCreateStatic(waSlaveThread, sizeof(waSlaveThread), HIGHPRIO, SlaveThread, NULL);
}
-void soft_serial_initiator_init(void) { usart_master_init(); }
+/**
+ * @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);
-void soft_serial_target_init(void) { usart_slave_init(); }
+ /* Sanity check that we are actually responding to a valid transaction. */
+ if (sstd_index >= NUM_TOTAL_TRANSACTIONS) {
+ return false;
+ }
-void handle_soft_serial_slave(void) {
- uint8_t sstd_index = sdGet(&SERIAL_USART_DRIVER); // first chunk is always transaction id
- split_transaction_desc_t* trans = &split_transaction_table[sstd_index];
+ split_transaction_desc_t* trans = &split_transaction_table[sstd_index];
- // Always write back the sstd_index as part of a basic handshake
+ /* 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;
- sdWrite(&SERIAL_USART_DRIVER, &sstd_index, sizeof(sstd_index));
+ if (!send(&sstd_index, sizeof(sstd_index))) {
+ *trans->status = TRANSACTION_DATA_ERROR;
+ return false;
+ }
+ /* Receive transaction buffer from the master. If this transaction requires it.*/
if (trans->initiator2target_buffer_size) {
- sdRead(&SERIAL_USART_DRIVER, split_trans_initiator2target_buffer(trans), trans->initiator2target_buffer_size);
+ if (!receive(split_trans_initiator2target_buffer(trans), trans->initiator2target_buffer_size)) {
+ *trans->status = TRANSACTION_DATA_ERROR;
+ return false;
+ }
}
- // Allow any slave processing to occur
+ /* Allow any slave processing to occur. */
if (trans->slave_callback) {
- trans->slave_callback(trans->initiator2target_buffer_size, split_trans_initiator2target_buffer(trans), trans->target2initiator_buffer_size, split_trans_target2initiator_buffer(trans));
+ 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) {
- sdWrite(&SERIAL_USART_DRIVER, split_trans_target2initiator_buffer(trans), trans->target2initiator_buffer_size);
+ if (!send(split_trans_target2initiator_buffer(trans), trans->target2initiator_buffer_size)) {
+ *trans->status = TRANSACTION_DATA_ERROR;
+ return false;
+ }
}
- if (trans->status) {
- *trans->status = TRANSACTION_ACCEPTED;
- }
+ *trans->status = TRANSACTION_ACCEPTED;
+ 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);
}
-/////////
-// start transaction by initiator
-//
-// int soft_serial_transaction(int sstd_index)
-//
-// Returns:
-// TRANSACTION_END
-// TRANSACTION_NO_RESPONSE
-// TRANSACTION_DATA_ERROR
+/**
+ * @brief Start transaction from the master half to the slave half.
+ *
+ * @param index Transaction Table index of the transaction to start.
+ * @return int TRANSACTION_NO_RESPONSE in case of Timeout.
+ * TRANSACTION_TYPE_ERROR in case of invalid transaction index.
+ * TRANSACTION_END in case of success.
+ */
int soft_serial_transaction(int index) {
- uint8_t sstd_index = 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);
+}
- if (sstd_index > NUM_TOTAL_TRANSACTIONS) return TRANSACTION_TYPE_ERROR;
- split_transaction_desc_t* trans = &split_transaction_table[sstd_index];
- msg_t res = 0;
+/**
+ * @brief Initiate transaction to slave half.
+ */
+static inline int 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 TRANSACTION_TYPE_ERROR;
+ }
- if (!trans->status) return TRANSACTION_TYPE_ERROR; // not registered
+ split_transaction_desc_t* trans = &split_transaction_table[sstd_index];
- sdClear(&SERIAL_USART_DRIVER);
+ /* Transaction is not registered. Abort. */
+ if (!trans->status) {
+ dprintln("USART: Transaction not registered.");
+ return TRANSACTION_TYPE_ERROR;
+ }
- // First chunk is always transaction id
- sdWriteTimeout(&SERIAL_USART_DRIVER, &sstd_index, sizeof(sstd_index), TIME_MS2I(SERIAL_USART_TIMEOUT));
+ /* 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 TRANSACTION_TYPE_ERROR;
+ }
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
- res = sdReadTimeout(&SERIAL_USART_DRIVER, &sstd_index_shake, sizeof(sstd_index_shake), TIME_MS2I(SERIAL_USART_TIMEOUT));
- if (res < 0 || (sstd_index_shake != (sstd_index ^ HANDSHAKE_MAGIC))) {
- dprintf("serial::usart_shake NO_RESPONSE\n");
+ /* 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 TRANSACTION_NO_RESPONSE;
}
+ /* Send transaction buffer to the slave. If this transaction requires it. */
if (trans->initiator2target_buffer_size) {
- res = sdWriteTimeout(&SERIAL_USART_DRIVER, split_trans_initiator2target_buffer(trans), trans->initiator2target_buffer_size, TIME_MS2I(SERIAL_USART_TIMEOUT));
- if (res < 0) {
- dprintf("serial::usart_transmit NO_RESPONSE\n");
+ if (!send(split_trans_initiator2target_buffer(trans), trans->initiator2target_buffer_size)) {
+ dprintln("USART: Send failed.");
return TRANSACTION_NO_RESPONSE;
}
}
+ /* Receive transaction buffer from the slave. If this transaction requires it. */
if (trans->target2initiator_buffer_size) {
- res = sdReadTimeout(&SERIAL_USART_DRIVER, split_trans_target2initiator_buffer(trans), trans->target2initiator_buffer_size, TIME_MS2I(SERIAL_USART_TIMEOUT));
- if (res < 0) {
- dprintf("serial::usart_receive NO_RESPONSE\n");
+ if (!receive(split_trans_target2initiator_buffer(trans), trans->target2initiator_buffer_size)) {
+ dprintln("USART: Receive failed.");
return TRANSACTION_NO_RESPONSE;
}
}
diff --git a/drivers/chibios/serial_usart.h b/drivers/chibios/serial_usart.h
index fee7b4d159..c64e15566f 100644
--- a/drivers/chibios/serial_usart.h
+++ b/drivers/chibios/serial_usart.h
@@ -23,19 +23,45 @@
#include <ch.h>
#include <hal.h>
-#ifndef USART_CR1_M0
+#if !defined(SERIAL_USART_DRIVER)
+# define SERIAL_USART_DRIVER SD1
+#endif
+
+#if !defined(USE_GPIOV1)
+/* The default PAL alternate modes are used to signal that the pins are used for USART. */
+# if !defined(SERIAL_USART_TX_PAL_MODE)
+# define SERIAL_USART_TX_PAL_MODE 7
+# endif
+# if !defined(SERIAL_USART_RX_PAL_MODE)
+# define SERIAL_USART_RX_PAL_MODE 7
+# endif
+#endif
+
+#if defined(SOFT_SERIAL_PIN)
+# define SERIAL_USART_TX_PIN SOFT_SERIAL_PIN
+#endif
+
+#if !defined(SERIAL_USART_TX_PIN)
+# define SERIAL_USART_TX_PIN A9
+#endif
+
+#if !defined(SERIAL_USART_RX_PIN)
+# define SERIAL_USART_RX_PIN A10
+#endif
+
+#if !defined(USART_CR1_M0)
# define USART_CR1_M0 USART_CR1_M // some platforms (f1xx) dont have this so
#endif
-#ifndef SERIAL_USART_CR1
+#if !defined(SERIAL_USART_CR1)
# define SERIAL_USART_CR1 (USART_CR1_PCE | USART_CR1_PS | USART_CR1_M0) // parity enable, odd parity, 9 bit length
#endif
-#ifndef SERIAL_USART_CR2
+#if !defined(SERIAL_USART_CR2)
# define SERIAL_USART_CR2 (USART_CR2_STOP_1) // 2 stop bits
#endif
-#ifndef SERIAL_USART_CR3
+#if !defined(SERIAL_USART_CR3)
# define SERIAL_USART_CR3 0
#endif
@@ -61,11 +87,11 @@
} while (0)
#endif
-#ifndef SELECT_SOFT_SERIAL_SPEED
+#if !defined(SELECT_SOFT_SERIAL_SPEED)
# define SELECT_SOFT_SERIAL_SPEED 1
#endif
-#ifdef SERIAL_USART_SPEED
+#if defined(SERIAL_USART_SPEED)
// Allow advanced users to directly set SERIAL_USART_SPEED
#elif SELECT_SOFT_SERIAL_SPEED == 0
# define SERIAL_USART_SPEED 460800
@@ -83,7 +109,7 @@
# error invalid SELECT_SOFT_SERIAL_SPEED value
#endif
-#ifndef SERIAL_USART_TIMEOUT
+#if !defined(SERIAL_USART_TIMEOUT)
# define SERIAL_USART_TIMEOUT 100
#endif
diff --git a/drivers/chibios/serial_usart_duplex.c b/drivers/chibios/serial_usart_duplex.c
deleted file mode 100644
index cc9b889ac2..0000000000
--- a/drivers/chibios/serial_usart_duplex.c
+++ /dev/null
@@ -1,261 +0,0 @@
-/* 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"
-
-#include <stdatomic.h>
-
-#if !defined(USE_GPIOV1)
-// The default PAL alternate modes are used to signal that the pins are used for USART
-# if !defined(SERIAL_USART_TX_PAL_MODE)
-# define SERIAL_USART_TX_PAL_MODE 7
-# endif
-# if !defined(SERIAL_USART_RX_PAL_MODE)
-# define SERIAL_USART_RX_PAL_MODE 7
-# endif
-#endif
-
-#if !defined(SERIAL_USART_DRIVER)
-# define SERIAL_USART_DRIVER UARTD1
-#endif
-
-#if !defined(SERIAL_USART_TX_PIN)
-# define SERIAL_USART_TX_PIN A9
-#endif
-
-#if !defined(SERIAL_USART_RX_PIN)
-# define SERIAL_USART_RX_PIN A10
-#endif
-
-#define SIGNAL_HANDSHAKE_RECEIVED 0x1
-
-void handle_transactions_slave(uint8_t sstd_index);
-static void receive_transaction_handshake(UARTDriver* uartp, uint16_t received_handshake);
-
-/*
- * UART driver configuration structure. We use the blocking DMA enabled API and
- * the rxchar callback to receive handshake tokens but only on the slave halve.
- */
-// clang-format off
-static UARTConfig uart_config = {
- .txend1_cb = NULL,
- .txend2_cb = NULL,
- .rxend_cb = NULL,
- .rxchar_cb = NULL,
- .rxerr_cb = NULL,
- .timeout_cb = NULL,
- .speed = (SERIAL_USART_SPEED),
- .cr1 = (SERIAL_USART_CR1),
- .cr2 = (SERIAL_USART_CR2),
- .cr3 = (SERIAL_USART_CR3)
-};
-// clang-format on
-
-static SSTD_t* Transaction_table = NULL;
-static uint8_t Transaction_table_size = 0;
-static atomic_uint_least8_t handshake = 0xFF;
-static thread_reference_t tp_target = NULL;
-
-/*
- * This callback is invoked when a character is received but the application
- * was not ready to receive it, the character is passed as parameter.
- * Receive transaction table index from initiator, which doubles as basic handshake token. */
-static void receive_transaction_handshake(UARTDriver* uartp, uint16_t received_handshake) {
- /* Check if received handshake is not a valid transaction id.
- * Please note that we can still catch a seemingly valid handshake
- * i.e. a byte from a ongoing transfer which is in the allowed range.
- * So this check mainly prevents any obviously wrong handshakes and
- * subsequent wakeups of the receiving thread, which is a costly operation. */
- if (received_handshake > Transaction_table_size) {
- return;
- }
-
- handshake = (uint8_t)received_handshake;
- chSysLockFromISR();
- /* Wakeup receiving thread to start a transaction. */
- chEvtSignalI(tp_target, (eventmask_t)SIGNAL_HANDSHAKE_RECEIVED);
- chSysUnlockFromISR();
-}
-
-__attribute__((weak)) void usart_init(void) {
-#if defined(USE_GPIOV1)
- palSetLineMode(SERIAL_USART_TX_PIN, PAL_MODE_STM32_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_STM32_OTYPE_PUSHPULL | PAL_STM32_OSPEED_HIGHEST);
- palSetLineMode(SERIAL_USART_RX_PIN, PAL_MODE_ALTERNATE(SERIAL_USART_RX_PAL_MODE) | PAL_STM32_OTYPE_PUSHPULL | PAL_STM32_OSPEED_HIGHEST);
-#endif
-}
-
-/*
- * This thread runs on the slave half and reacts to transactions initiated from the master.
- */
-static THD_WORKING_AREA(waSlaveThread, 1024);
-static THD_FUNCTION(SlaveThread, arg) {
- (void)arg;
- chRegSetThreadName("slave_usart_tx_rx");
-
- while (true) {
- /* We sleep as long as there is no handshake waiting for us. */
- chEvtWaitAny((eventmask_t)SIGNAL_HANDSHAKE_RECEIVED);
- handle_transactions_slave(handshake);
- }
-}
-
-void soft_serial_target_init(SSTD_t* const sstd_table, int sstd_table_size) {
- Transaction_table = sstd_table;
- Transaction_table_size = (uint8_t)sstd_table_size;
- usart_init();
-
-#if defined(USART_REMAP)
- USART_REMAP;
-#endif
-
- tp_target = chThdCreateStatic(waSlaveThread, sizeof(waSlaveThread), HIGHPRIO, SlaveThread, NULL);
-
- // Start receiving handshake tokens on slave halve
- uart_config.rxchar_cb = receive_transaction_handshake;
- uartStart(&SERIAL_USART_DRIVER, &uart_config);
-}
-
-/**
- * @brief React to transactions started by the master.
- * This version uses duplex send and receive usart pheriphals and DMA backed transfers.
- */
-void inline handle_transactions_slave(uint8_t sstd_index) {
- size_t buffer_size = 0;
- msg_t msg = 0;
- SSTD_t* trans = &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;
- buffer_size = (size_t)sizeof(sstd_index);
- msg = uartSendTimeout(&SERIAL_USART_DRIVER, &buffer_size, &sstd_index, TIME_MS2I(SERIAL_USART_TIMEOUT));
-
- if (msg != MSG_OK) {
- if (trans->status) {
- *trans->status = TRANSACTION_NO_RESPONSE;
- }
- return;
- }
-
- /* Receive transaction buffer from the master. If this transaction requires it.*/
- buffer_size = (size_t)trans->initiator2target_buffer_size;
- if (buffer_size) {
- msg = uartReceiveTimeout(&SERIAL_USART_DRIVER, &buffer_size, trans->initiator2target_buffer, TIME_MS2I(SERIAL_USART_TIMEOUT));
- if (msg != MSG_OK) {
- if (trans->status) {
- *trans->status = TRANSACTION_NO_RESPONSE;
- }
- return;
- }
- }
-
- /* Send transaction buffer to the master. If this transaction requires it. */
- buffer_size = (size_t)trans->target2initiator_buffer_size;
- if (buffer_size) {
- msg = uartSendFullTimeout(&SERIAL_USART_DRIVER, &buffer_size, trans->target2initiator_buffer, TIME_MS2I(SERIAL_USART_TIMEOUT));
- if (msg != MSG_OK) {
- if (trans->status) {
- *trans->status = TRANSACTION_NO_RESPONSE;
- }
- return;
- }
- }
-
- if (trans->status) {
- *trans->status = TRANSACTION_ACCEPTED;
- }
-}
-
-void soft_serial_initiator_init(SSTD_t* const sstd_table, int sstd_table_size) {
- Transaction_table = sstd_table;
- Transaction_table_size = (uint8_t)sstd_table_size;
- usart_init();
-
-#if defined(SERIAL_USART_PIN_SWAP)
- uart_config.cr2 |= USART_CR2_SWAP; // master has swapped TX/RX pins
-#endif
-
-#if defined(USART_REMAP)
- USART_REMAP;
-#endif
-
- uartStart(&SERIAL_USART_DRIVER, &uart_config);
-}
-
-/**
- * @brief Start transaction from the master to the slave.
- * This version uses duplex send and receive usart pheriphals and DMA backed transfers.
- *
- * @param index Transaction Table index of the transaction to start.
- * @return int TRANSACTION_NO_RESPONSE in case of Timeout.
- * TRANSACTION_TYPE_ERROR in case of invalid transaction index.
- * TRANSACTION_END in case of success.
- */
-#if !defined(SERIAL_USE_MULTI_TRANSACTION)
-int soft_serial_transaction(void) {
- uint8_t sstd_index = 0;
-#else
-int soft_serial_transaction(int index) {
- uint8_t sstd_index = index;
-#endif
-
- if (sstd_index > Transaction_table_size) {
- return TRANSACTION_TYPE_ERROR;
- }
-
- SSTD_t* const trans = &Transaction_table[sstd_index];
- msg_t msg = 0;
- size_t buffer_size = (size_t)sizeof(sstd_index);
-
- /* Send transaction table index to the slave, which doubles as basic handshake token. */
- uartSendFullTimeout(&SERIAL_USART_DRIVER, &buffer_size, &sstd_index, TIME_MS2I(SERIAL_USART_TIMEOUT));
-
- uint8_t sstd_index_shake = 0xFF;
- buffer_size = (size_t)sizeof(sstd_index_shake);
-
- /* Receive the handshake token from the slave. The token was XORed by the slave as a simple checksum.
- If the tokens match, the master will start to send and receive possible transaction buffers. */
- msg = uartReceiveTimeout(&SERIAL_USART_DRIVER, &buffer_size, &sstd_index_shake, TIME_MS2I(SERIAL_USART_TIMEOUT));
- if (msg != MSG_OK || (sstd_index_shake != (sstd_index ^ HANDSHAKE_MAGIC))) {
- dprintln("USART: Handshake Failed");
- return TRANSACTION_NO_RESPONSE;
- }
-
- /* Send transaction buffer to the slave. If this transaction requires it. */
- buffer_size = (size_t)trans->initiator2target_buffer_size;
- if (buffer_size) {
- msg = uartSendFullTimeout(&SERIAL_USART_DRIVER, &buffer_size, trans->initiator2target_buffer, TIME_MS2I(SERIAL_USART_TIMEOUT));
- if (msg != MSG_OK) {
- dprintln("USART: Send Failed");
- return TRANSACTION_NO_RESPONSE;
- }
- }
-
- /* Receive transaction buffer from the slave. If this transaction requires it. */
- buffer_size = (size_t)trans->target2initiator_buffer_size;
- if (buffer_size) {
- msg = uartReceiveTimeout(&SERIAL_USART_DRIVER, &buffer_size, trans->target2initiator_buffer, TIME_MS2I(SERIAL_USART_TIMEOUT));
- if (msg != MSG_OK) {
- dprintln("USART: Receive Failed");
- return TRANSACTION_NO_RESPONSE;
- }
- }
-
- return TRANSACTION_END;
-}
--
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