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Add Full-duplex serial driver for ARM boards (#9842)

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Stefan Kerkmann 2021-05-27 05:37:54 +02:00 • committed by GitHub
parent a78964c918
commit d9610120de
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4 changed files with 506 additions and 56 deletions
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261
drivers/chibios/serial_usart_duplex.c Normal file
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/* 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;
}