diff options
Diffstat (limited to 'platforms/chibios/drivers/serial_usart.c')
| -rw-r--r-- | platforms/chibios/drivers/serial_usart.c | 318 |
1 files changed, 318 insertions, 0 deletions
diff --git a/platforms/chibios/drivers/serial_usart.c b/platforms/chibios/drivers/serial_usart.c new file mode 100644 index 0000000000..ea4473791c --- /dev/null +++ b/platforms/chibios/drivers/serial_usart.c @@ -0,0 +1,318 @@ +/* Copyright 2021 QMK + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include "serial_usart.h" + +#if defined(SERIAL_USART_CONFIG) +static SerialConfig serial_config = SERIAL_USART_CONFIG; +#else +static SerialConfig serial_config = { + .speed = (SERIAL_USART_SPEED), /* speed - mandatory */ + .cr1 = (SERIAL_USART_CR1), + .cr2 = (SERIAL_USART_CR2), +# if !defined(SERIAL_USART_FULL_DUPLEX) + .cr3 = ((SERIAL_USART_CR3) | USART_CR3_HDSEL) /* activate half-duplex mode */ +# else + .cr3 = (SERIAL_USART_CR3) +# endif +}; +#endif + +static SerialDriver* serial_driver = &SERIAL_USART_DRIVER; + +static inline bool react_to_transactions(void); +static inline bool __attribute__((nonnull)) receive(uint8_t* destination, const size_t size); +static inline bool __attribute__((nonnull)) send(const uint8_t* source, const size_t size); +static inline int initiate_transaction(uint8_t sstd_index); +static inline void usart_clear(void); + +/** + * @brief Clear the receive input queue. + */ +static inline void usart_clear(void) { + osalSysLock(); + bool volatile queue_not_empty = !iqIsEmptyI(&serial_driver->iqueue); + osalSysUnlock(); + + while (queue_not_empty) { + osalSysLock(); + /* Hard reset the input queue. */ + iqResetI(&serial_driver->iqueue); + osalSysUnlock(); + /* Allow pending interrupts to preempt. + * Do not merge the lock/unlock blocks into one + * or the code will not work properly. + * The empty read adds a tiny amount of delay. */ + (void)queue_not_empty; + osalSysLock(); + queue_not_empty = !iqIsEmptyI(&serial_driver->iqueue); + osalSysUnlock(); + } +} + +/** + * @brief Blocking send of buffer with timeout. + * + * @return true Send success. + * @return false Send failed. + */ +static inline bool send(const uint8_t* source, const size_t size) { + bool success = (size_t)sdWriteTimeout(serial_driver, source, size, TIME_MS2I(SERIAL_USART_TIMEOUT)) == size; + +#if !defined(SERIAL_USART_FULL_DUPLEX) + if (success) { + /* Half duplex fills the input queue with the data we wrote - just throw it away. + Under the right circumstances (e.g. bad cables paired with high baud rates) + less bytes can be present in the input queue, therefore a timeout is needed. */ + uint8_t dump[size]; + return receive(dump, size); + } +#endif + + return success; +} + +/** + * @brief Blocking receive of size * bytes with timeout. + * + * @return true Receive success. + * @return false Receive failed. + */ +static inline bool receive(uint8_t* destination, const size_t size) { + bool success = (size_t)sdReadTimeout(serial_driver, destination, size, TIME_MS2I(SERIAL_USART_TIMEOUT)) == size; + return success; +} + +#if !defined(SERIAL_USART_FULL_DUPLEX) + +/** + * @brief Initiate pins for USART peripheral. Half-duplex configuration. + */ +__attribute__((weak)) void usart_init(void) { +# if defined(MCU_STM32) +# if defined(USE_GPIOV1) + palSetLineMode(SERIAL_USART_TX_PIN, PAL_MODE_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) + USART_REMAP; +# endif +# else +# pragma message "usart_init: MCU Familiy not supported by default, please supply your own init code by implementing usart_init() in your keyboard files." +# endif +} + +#else + +/** + * @brief Initiate pins for USART peripheral. Full-duplex configuration. + */ +__attribute__((weak)) void usart_init(void) { +# if defined(MCU_STM32) +# if defined(USE_GPIOV1) + palSetLineMode(SERIAL_USART_TX_PIN, PAL_MODE_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(); +} + +/** + * @brief Overridable slave specific initializations. + */ +__attribute__((weak, nonnull)) void usart_slave_init(SerialDriver** driver) { + (void)driver; + usart_init(); +} + +/** + * @brief This thread runs on the slave and responds to transactions initiated + * by the master. + */ +static THD_WORKING_AREA(waSlaveThread, 1024); +static THD_FUNCTION(SlaveThread, arg) { + (void)arg; + chRegSetThreadName("usart_tx_rx"); + + while (true) { + if (!react_to_transactions()) { + /* Clear the receive queue, to start with a clean slate. + * Parts of failed transactions or spurious bytes could still be in it. */ + usart_clear(); + } + } +} + +/** + * @brief Slave specific initializations. + */ +void soft_serial_target_init(void) { + usart_slave_init(&serial_driver); + + sdStart(serial_driver, &serial_config); + + /* Start transport thread. */ + chThdCreateStatic(waSlaveThread, sizeof(waSlaveThread), HIGHPRIO, SlaveThread, NULL); +} + +/** + * @brief React to transactions started by the master. + */ +static inline bool react_to_transactions(void) { + /* Wait until there is a transaction for us. */ + uint8_t sstd_index = (uint8_t)sdGet(serial_driver); + + /* Sanity check that we are actually responding to a valid transaction. */ + if (sstd_index >= NUM_TOTAL_TRANSACTIONS) { + return false; + } + + split_transaction_desc_t* trans = &split_transaction_table[sstd_index]; + + /* Send back the handshake which is XORed as a simple checksum, + to signal that the slave is ready to receive possible transaction buffers */ + sstd_index ^= HANDSHAKE_MAGIC; + if (!send(&sstd_index, sizeof(sstd_index))) { + *trans->status = TRANSACTION_DATA_ERROR; + return false; + } + + /* Receive transaction buffer from the master. If this transaction requires it.*/ + if (trans->initiator2target_buffer_size) { + if (!receive(split_trans_initiator2target_buffer(trans), trans->initiator2target_buffer_size)) { + *trans->status = TRANSACTION_DATA_ERROR; + return false; + } + } + + /* Allow any slave processing to occur. */ + if (trans->slave_callback) { + trans->slave_callback(trans->initiator2target_buffer_size, split_trans_initiator2target_buffer(trans), trans->initiator2target_buffer_size, split_trans_target2initiator_buffer(trans)); + } + + /* Send transaction buffer to the master. If this transaction requires it. */ + if (trans->target2initiator_buffer_size) { + if (!send(split_trans_target2initiator_buffer(trans), trans->target2initiator_buffer_size)) { + *trans->status = TRANSACTION_DATA_ERROR; + return false; + } + } + + *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); +} + +/** + * @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) { + /* 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; + } + + split_transaction_desc_t* trans = &split_transaction_table[sstd_index]; + + /* Transaction is not registered. Abort. */ + if (!trans->status) { + dprintln("USART: Transaction not registered."); + return TRANSACTION_TYPE_ERROR; + } + + /* 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. + */ + 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) { + 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) { + if (!receive(split_trans_target2initiator_buffer(trans), trans->target2initiator_buffer_size)) { + dprintln("USART: Receive failed."); + return TRANSACTION_NO_RESPONSE; + } + } + + return TRANSACTION_END; +} |