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; +} | 
