[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>
master
Stefan Kerkmann 2021-07-02 00:24:08 +02:00 committed by GitHub
parent 47b12470e7
commit 117bff17ba
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GPG Key ID: 4AEE18F83AFDEB23
7 changed files with 283 additions and 395 deletions

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@ -237,6 +237,7 @@ ifdef MCU_FAMILY
PLATFORM=CHIBIOS
PLATFORM_KEY=chibios
FIRMWARE_FORMAT?=bin
OPT_DEFS += -DMCU_$(MCU_FAMILY)
else ifdef ARM_ATSAM
PLATFORM=ARM_ATSAM
PLATFORM_KEY=arm_atsam

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@ -73,7 +73,7 @@ You must also enable the ChibiOS `SERIAL` feature:
Do note that the configuration required is for the `SERIAL` peripheral, not the `UART` peripheral.
### USART Full-duplex
Targeting STM32 boards where communication is offloaded to a USART hardware device. The advantage over bitbang is that this provides fast and accurate timings. USART Full-Duplex requires two conductors **without** pull-up resistors instead of one conductor with a pull-up resistor unlike the Half-duplex driver, but it is more efficent as it uses DMA transfers, which can result in even faster transmission speeds.
Targeting STM32 boards where communication is offloaded to a USART hardware device. The advantage over bitbang is that this provides fast and accurate timings. USART Full-Duplex requires two conductors **without** pull-up resistors instead of one conductor with a pull-up resistor unlike the Half-duplex driver. Due to its internal design it is more efficent, which can result in even faster transmission speeds.
#### Pin configuration
@ -86,12 +86,13 @@ Please note that `TX` of the master half has to be connected with the `RX` pin o
To use the driver, add this to your rules.mk:
```make
SERIAL_DRIVER = usart_duplex
SERIAL_DRIVER = usart
```
Next configure the hardware via your config.h:
```c
#define SERIAL_USART_FULL_DUPLEX // Enable full duplex operation mode.
#define SERIAL_USART_TX_PIN B6 // USART TX pin
#define SERIAL_USART_RX_PIN B7 // USART RX pin
//#define USART1_REMAP // Remap USART TX and RX pins on STM32F103 MCUs, see table below.
@ -104,17 +105,17 @@ Next configure the hardware via your config.h:
// 3: 57600 baud
// 4: 38400 baud
// 5: 19200 baud
#define SERIAL_USART_DRIVER UARTD1 // USART driver of TX and RX pin. default: UARTD1
#define SERIAL_USART_DRIVER SD1 // USART driver of TX and RX pin. default: SD1
#define SERIAL_USART_TX_PAL_MODE 7 // Pin "alternate function", see the respective datasheet for the appropriate values for your MCU. default: 7
#define SERIAL_USART_RX_PAL_MODE 7 // Pin "alternate function", see the respective datasheet for the appropriate values for your MCU. default: 7
#define SERIAL_USART_TIMEOUT 100 // USART driver timeout. default 100
```
You must also enable the ChibiOS `UART` with blocking api feature:
* In your board's halconf.h: `#define HAL_USE_UART TRUE` and `#define UART_USE_WAIT TRUE`
* In your board's mcuconf.h: `#define STM32_UART_USE_USARTn TRUE` (where 'n' matches the peripheral number of your selected USART on the MCU)
You must also enable the ChibiOS `SERIAL` feature:
* In your board's halconf.h: `#define HAL_USE_SERIAL TRUE`
* In your board's mcuconf.h: `#define STM32_SERIAL_USE_USARTn TRUE` (where 'n' matches the peripheral number of your selected USART on the MCU)
Do note that the configuration required is for the `UART` peripheral, not the `SERIAL` peripheral.
Do note that the configuration required is for the `SERIAL` peripheral, not the `UART` peripheral.
#### Pins for USART Peripherals with Alternate Functions for selected STM32 MCUs

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@ -16,75 +16,93 @@
#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);
// Half duplex requires us to read back the data we just wrote - just throw it away
uint8_t dump[size];
sdRead(driver, dump, size);
return ret;
}
#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);
return ret;
}
#undef sdWriteTimeout
#define sdWriteTimeout sdWriteTimeoutHalfDuplex
static inline void sdClear(SerialDriver* driver) {
while (sdGetTimeout(driver, TIME_IMMEDIATE) != MSG_TIMEOUT) {
// Do nothing with the data
}
}
static SerialConfig sdcfg = {
(SERIAL_USART_SPEED), // speed - mandatory
(SERIAL_USART_CR1), // CR1
(SERIAL_USART_CR2), // CR2
(SERIAL_USART_CR3) // CR3
};
#endif
void handle_soft_serial_slave(void);
static SerialDriver* serial_driver = &SERIAL_USART_DRIVER;
/*
* This thread runs on the slave and responds to transactions initiated
* by the master
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);
/**
* @brief Clear the receive input queue.
*/
static THD_WORKING_AREA(waSlaveThread, 2048);
static THD_FUNCTION(SlaveThread, arg) {
(void)arg;
chRegSetThreadName("slave_transport");
static inline void usart_clear(void) {
osalSysLock();
bool volatile queue_not_empty = !iqIsEmptyI(&serial_driver->iqueue);
osalSysUnlock();
while (true) {
handle_soft_serial_slave();
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_STM32_ALTERNATE_OPENDRAIN);
# else
@ -94,101 +112,204 @@ __attribute__((weak)) void usart_init(void) {
# 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
}
void usart_master_init(void) {
usart_init();
#else
sdcfg.cr3 |= USART_CR3_HDSEL;
sdStart(&SERIAL_USART_DRIVER, &sdcfg);
/**
* @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
}
void usart_slave_init(void) {
#endif
/**
* @brief Overridable master specific initializations.
*/
__attribute__((weak, nonnull)) void usart_master_init(SerialDriver** driver) {
(void)driver;
usart_init();
}
sdcfg.cr3 |= USART_CR3_HDSEL;
sdStart(&SERIAL_USART_DRIVER, &sdcfg);
/**
* @brief Overridable slave specific initializations.
*/
__attribute__((weak, nonnull)) void usart_slave_init(SerialDriver** driver) {
(void)driver;
usart_init();
}
// Start transport thread
/**
* @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);
}
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];
// 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;
}
return true;
}
/////////
// start transaction by initiator
//
// int soft_serial_transaction(int sstd_index)
//
// Returns:
// TRANSACTION_END
// TRANSACTION_NO_RESPONSE
// TRANSACTION_DATA_ERROR
/**
* @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 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);
}
/**
* @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 (sstd_index > NUM_TOTAL_TRANSACTIONS) return TRANSACTION_TYPE_ERROR;
split_transaction_desc_t* trans = &split_transaction_table[sstd_index];
msg_t res = 0;
if (!trans->status) return TRANSACTION_TYPE_ERROR; // not registered
/* Transaction is not registered. Abort. */
if (!trans->status) {
dprintln("USART: Transaction not registered.");
return TRANSACTION_TYPE_ERROR;
}
sdClear(&SERIAL_USART_DRIVER);
// 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;
}
}

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@ -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

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@ -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;
}

View File

@ -412,7 +412,7 @@
* buffers.
*/
#if !defined(SERIAL_BUFFERS_SIZE) || defined(__DOXYGEN__)
#define SERIAL_BUFFERS_SIZE 16
#define SERIAL_BUFFERS_SIZE 128
#endif
/*===========================================================================*/

View File

@ -412,7 +412,7 @@
* buffers.
*/
#if !defined(SERIAL_BUFFERS_SIZE) || defined(__DOXYGEN__)
#define SERIAL_BUFFERS_SIZE 16
#define SERIAL_BUFFERS_SIZE 128
#endif
/*===========================================================================*/