SerialBase.cpp

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2013 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 #include "drivers/SerialBase.h"
00017 #include "platform/mbed_wait_api.h"
00018 #include "platform/mbed_critical.h"
00019 #include "platform/mbed_power_mgmt.h"
00020 
00021 #if DEVICE_SERIAL
00022 
00023 namespace mbed {
00024 
00025 SerialBase::SerialBase(PinName tx, PinName rx, int baud) :
00026 #if DEVICE_SERIAL_ASYNCH
00027     _thunk_irq(this), _tx_usage(DMA_USAGE_NEVER),
00028     _rx_usage(DMA_USAGE_NEVER), _tx_callback(NULL),
00029     _rx_callback(NULL),
00030 #endif
00031     _serial(), _baud(baud)
00032 {
00033     // No lock needed in the constructor
00034 
00035     for (size_t i = 0; i < sizeof _irq / sizeof _irq[0]; i++) {
00036         _irq[i] = NULL;
00037     }
00038 
00039     serial_init(&_serial, tx, rx);
00040     serial_baud(&_serial, _baud);
00041     serial_irq_handler(&_serial, SerialBase::_irq_handler, (uint32_t)this);
00042 }
00043 
00044 void SerialBase::baud(int baudrate)
00045 {
00046     lock();
00047     serial_baud(&_serial, baudrate);
00048     _baud = baudrate;
00049     unlock();
00050 }
00051 
00052 void SerialBase::format(int bits, Parity parity, int stop_bits)
00053 {
00054     lock();
00055     serial_format(&_serial, bits, (SerialParity)parity, stop_bits);
00056     unlock();
00057 }
00058 
00059 int SerialBase::readable()
00060 {
00061     lock();
00062     int ret = serial_readable(&_serial);
00063     unlock();
00064     return ret;
00065 }
00066 
00067 
00068 int SerialBase::writeable()
00069 {
00070     lock();
00071     int ret = serial_writable(&_serial);
00072     unlock();
00073     return ret;
00074 }
00075 
00076 void SerialBase::attach(Callback<void()> func, IrqType type)
00077 {
00078     lock();
00079     // Disable interrupts when attaching interrupt handler
00080     core_util_critical_section_enter();
00081     if (func) {
00082         // lock deep sleep only the first time
00083         if (!_irq[type]) {
00084             sleep_manager_lock_deep_sleep();
00085         }
00086         _irq[type] = func;
00087         serial_irq_set(&_serial, (SerialIrq)type, 1);
00088     } else {
00089         // unlock deep sleep only the first time
00090         if (_irq[type]) {
00091             sleep_manager_unlock_deep_sleep();
00092         }
00093         _irq[type] = NULL;
00094         serial_irq_set(&_serial, (SerialIrq)type, 0);
00095     }
00096     core_util_critical_section_exit();
00097     unlock();
00098 }
00099 
00100 void SerialBase::_irq_handler(uint32_t id, SerialIrq irq_type)
00101 {
00102     SerialBase *handler = (SerialBase *)id;
00103     if (handler->_irq[irq_type]) {
00104         handler->_irq[irq_type]();
00105     }
00106 }
00107 
00108 int SerialBase::_base_getc()
00109 {
00110     // Mutex is already held
00111     return serial_getc(&_serial);
00112 }
00113 
00114 int SerialBase::_base_putc(int c)
00115 {
00116     // Mutex is already held
00117     serial_putc(&_serial, c);
00118     return c;
00119 }
00120 
00121 void SerialBase::send_break()
00122 {
00123     lock();
00124     // Wait for 1.5 frames before clearing the break condition
00125     // This will have different effects on our platforms, but should
00126     // ensure that we keep the break active for at least one frame.
00127     // We consider a full frame (1 start bit + 8 data bits bits +
00128     // 1 parity bit + 2 stop bits = 12 bits) for computation.
00129     // One bit time (in us) = 1000000/_baud
00130     // Twelve bits: 12000000/baud delay
00131     // 1.5 frames: 18000000/baud delay
00132     serial_break_set(&_serial);
00133     wait_us(18000000 / _baud);
00134     serial_break_clear(&_serial);
00135     unlock();
00136 }
00137 
00138 void SerialBase::lock()
00139 {
00140     // Stub
00141 }
00142 
00143 void SerialBase:: unlock()
00144 {
00145     // Stub
00146 }
00147 
00148 SerialBase::~SerialBase()
00149 {
00150     // No lock needed in destructor
00151 
00152     // Detaching interrupts releases the sleep lock if it was locked
00153     for (int irq = 0; irq < IrqCnt; irq++) {
00154         attach(NULL, (IrqType)irq);
00155     }
00156 }
00157 
00158 #if DEVICE_SERIAL_FC
00159 void SerialBase::set_flow_control(Flow type, PinName flow1, PinName flow2)
00160 {
00161     lock();
00162     FlowControl flow_type = (FlowControl)type;
00163     switch (type) {
00164         case RTS:
00165             serial_set_flow_control(&_serial, flow_type, flow1, NC);
00166             break;
00167 
00168         case CTS:
00169             serial_set_flow_control(&_serial, flow_type, NC, flow1);
00170             break;
00171 
00172         case RTSCTS:
00173         case Disabled:
00174             serial_set_flow_control(&_serial, flow_type, flow1, flow2);
00175             break;
00176 
00177         default:
00178             break;
00179     }
00180     unlock();
00181 }
00182 #endif
00183 
00184 #if DEVICE_SERIAL_ASYNCH
00185 
00186 int SerialBase::write(const uint8_t *buffer, int length, const event_callback_t &callback, int event)
00187 {
00188     if (serial_tx_active(&_serial)) {
00189         return -1; // transaction ongoing
00190     }
00191     start_write((void *)buffer, length, 8, callback, event);
00192     return 0;
00193 }
00194 
00195 int SerialBase::write(const uint16_t *buffer, int length, const event_callback_t &callback, int event)
00196 {
00197     if (serial_tx_active(&_serial)) {
00198         return -1; // transaction ongoing
00199     }
00200     start_write((void *)buffer, length, 16, callback, event);
00201     return 0;
00202 }
00203 
00204 void SerialBase::start_write(const void *buffer, int buffer_size, char buffer_width, const event_callback_t &callback, int event)
00205 {
00206     _tx_callback = callback;
00207 
00208     _thunk_irq.callback(&SerialBase::interrupt_handler_asynch);
00209     sleep_manager_lock_deep_sleep();
00210     serial_tx_asynch(&_serial, buffer, buffer_size, buffer_width, _thunk_irq.entry(), event, _tx_usage);
00211 }
00212 
00213 void SerialBase::abort_write(void)
00214 {
00215     // rx might still be active
00216     if (_rx_callback) {
00217         sleep_manager_unlock_deep_sleep();
00218     }
00219     _tx_callback = NULL;
00220     serial_tx_abort_asynch(&_serial);
00221 }
00222 
00223 void SerialBase::abort_read(void)
00224 {
00225     // tx might still be active
00226     if (_tx_callback) {
00227         sleep_manager_unlock_deep_sleep();
00228     }
00229     _rx_callback = NULL;
00230     serial_rx_abort_asynch(&_serial);
00231 }
00232 
00233 int SerialBase::set_dma_usage_tx(DMAUsage usage)
00234 {
00235     if (serial_tx_active(&_serial)) {
00236         return -1;
00237     }
00238     _tx_usage = usage;
00239     return 0;
00240 }
00241 
00242 int SerialBase::set_dma_usage_rx(DMAUsage usage)
00243 {
00244     if (serial_tx_active(&_serial)) {
00245         return -1;
00246     }
00247     _rx_usage = usage;
00248     return 0;
00249 }
00250 
00251 int SerialBase::read(uint8_t *buffer, int length, const event_callback_t &callback, int event, unsigned char char_match)
00252 {
00253     if (serial_rx_active(&_serial)) {
00254         return -1; // transaction ongoing
00255     }
00256     start_read((void *)buffer, length, 8, callback, event, char_match);
00257     return 0;
00258 }
00259 
00260 
00261 int SerialBase::read(uint16_t *buffer, int length, const event_callback_t &callback, int event, unsigned char char_match)
00262 {
00263     if (serial_rx_active(&_serial)) {
00264         return -1; // transaction ongoing
00265     }
00266     start_read((void *)buffer, length, 16, callback, event, char_match);
00267     return 0;
00268 }
00269 
00270 
00271 void SerialBase::start_read(void *buffer, int buffer_size, char buffer_width, const event_callback_t &callback, int event, unsigned char char_match)
00272 {
00273     _rx_callback = callback;
00274     _thunk_irq.callback(&SerialBase::interrupt_handler_asynch);
00275     sleep_manager_lock_deep_sleep();
00276     serial_rx_asynch(&_serial, buffer, buffer_size, buffer_width, _thunk_irq.entry(), event, char_match, _rx_usage);
00277 }
00278 
00279 void SerialBase::interrupt_handler_asynch(void)
00280 {
00281     int event = serial_irq_handler_asynch(&_serial);
00282     int rx_event = event & SERIAL_EVENT_RX_MASK;
00283     bool unlock_deepsleep = false;
00284 
00285     if (_rx_callback && rx_event) {
00286         unlock_deepsleep = true;
00287         _rx_callback.call(rx_event);
00288     }
00289 
00290     int tx_event = event & SERIAL_EVENT_TX_MASK;
00291     if (_tx_callback && tx_event) {
00292         unlock_deepsleep = true;
00293         _tx_callback.call(tx_event);
00294     }
00295     // unlock if tx or rx events are generated
00296     if (unlock_deepsleep) {
00297         sleep_manager_unlock_deep_sleep();
00298     }
00299 }
00300 
00301 #endif
00302 
00303 } // namespace mbed
00304 
00305 #endif