File content as of revision 2:2a49171453d5:

/*
    Copyright (c) 2011 Andy Kirkham
 
    Permission is hereby granted, free of charge, to any person obtaining a copy
    of this software and associated documentation files (the "Software"), to deal
    in the Software without restriction, including without limitation the rights
    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    copies of the Software, and to permit persons to whom the Software is
    furnished to do so, subject to the following conditions:
 
    The above copyright notice and this permission notice shall be included in
    all copies or substantial portions of the Software.
 
    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    THE SOFTWARE.
*/

#include "MAX3100.h"

namespace AjK {

void 
MAX3100::init(PinName mosi, PinName miso, PinName sclk, PinName cs, PinName irq, SPI *spi) 
{
    config = 0;
    flushTxBuffer();
    flushRxBuffer();
    
    _parity = 0;
    
    _cs_function = NULL;
    _cs_obj      = NULL;
    _cs_method   = NULL;
    
    _isr_user_function = NULL;
    _isr_user_obj      = NULL;
    _isr_user_method   = NULL;
    
    if (cs != NC) {    
        _cs = new DigitalOut(cs);
        _cs->write( 1 );
    }
    else _cs = (DigitalOut *)NULL;
                
    if (spi) {
        _spi = spi;
    }
    else {                
        _spi = new SPI(mosi, miso, sclk);
        _spi->format(16, 0);
        _spi->frequency(MAX3100_SPI_FREQ);
    }
    
    if (irq != NC) {
        irqMask(irq);
        _irq = new InterruptIn(irq);
        _irq->mode(PullUp);
        topic_1498(irq);       
        _irq->fall(this, &MAX3100::isr);
    }
    else { _irq = (InterruptIn *)NULL; }
        
    baud(10); // 9600baud by default.
}

void 
MAX3100::cs_value(int i)
{
    if (_cs != (DigitalOut *)NULL) _cs->write(i & 1); 
    else {
        if (_cs_function != NULL) (*_cs_function)(_device, i & 1);
        else {
            if (_cs_obj && _cs_method) (_cs_obj->*_cs_method)(_device, i & 1);
        }
    }
}
    
uint16_t 
MAX3100::spiwrite(uint16_t val) 
{
    cs_value(0);
    uint16_t r = _spi->write(val);
    cs_value(1);
    return r;
}

uint16_t 
MAX3100::config_write(uint16_t val) 
{
    return spiwrite(MAX3100_CONF_WR | val); 
}

uint16_t 
MAX3100::config_read(void)          
{ 
    return spiwrite(MAX3100_CONF_RD);     
}


void 
MAX3100::baud(int baudrate) 
{        
    irqDisable();
    config &= ~(0xf);
    config |= (baudrate & 0xf);
    config_write(config);
    irqEnable();
}
    
void 
MAX3100::enableRxIrq(void) 
{ 
    irqDisable();
    config &= ~MAX3100_RM(1);
    config |=  MAX3100_RM(1);
    config_write(config); 
    irqEnable();
}
    
void 
MAX3100::disableRxIrq(void) 
{ 
    irqDisable();
    config &= ~MAX3100_RM(1);
    config_write(config);     
    irqEnable();
}
    
void 
MAX3100::enableTxIrq(void) 
{ 
    irqDisable();
    config &= ~MAX3100_TM(1);
    config |=  MAX3100_TM(1);
    config_write(config); 
    irqEnable();
}
    
void 
MAX3100::disableTxIrq(void) 
{ 
    irqDisable();
    config &= ~MAX3100_TM(1);
    config_write(config);     
    irqEnable();
}
        
int 
MAX3100::putc(int c) 
{ 
    uint16_t data, conf;

    // If no space return -1 as an error code.    
    if (tx_buffer_full) return -1;

    if (_parity) {
        int pBit = parityCal(c & 0xFF);        
        if (_parity == Even && pBit == 0) { c |= (1 << 8); }
        if (_parity == Odd  && pBit == 1) { c |= (1 << 8); }
    }
    else { c &= 0xFF; }
    
    // Function is non-interruptable by the MAX3100 class
    // to avoid SPI bus contention between writing a byte
    // in user context (here) and IRQ context.    
    irqDisable();

    conf = config_read();
        
    if (tx_buffer_in == tx_buffer_out && conf & MAX3100_CONF_T) {
        data = spiwrite(MAX3100_DATA_WR | (c & 0x1FF));              
        // In case we get a byte while writing store it away.
        if (!rx_buffer_full && data & MAX3100_CONF_R) {
            rx_buffer[rx_buffer_in++] = (uint16_t)(data & 0xFF);
            if (rx_buffer_in >= MAX3100_RX_BUFFER_SIZE) rx_buffer_in = 0;
            if (rx_buffer_in == rx_buffer_out) rx_buffer_full = true;
        }
    }
    else {
        tx_buffer[tx_buffer_in++] = (char)(c & 0xFF);
        if (tx_buffer_in >= MAX3100_TX_BUFFER_SIZE) {
            tx_buffer_in = 0;
        }
        if (tx_buffer_in == tx_buffer_out) tx_buffer_full = true;
    }
    
    irqEnable();
        
    return 1;
}

void
MAX3100::puts(char *s) {
    char *q = s;
    while(*(q)) {
        if (putc((int)(*(q))) == -1) return;
        q++;
    }
}

int 
MAX3100::getc(void) { 
    if (!rx_buffer_full && rx_buffer_in == rx_buffer_out) return -1;
    int c = (int)((unsigned char)rx_buffer[rx_buffer_out++]);
    if (rx_buffer_out >= MAX3100_RX_BUFFER_SIZE) rx_buffer_out = 0;
    rx_buffer_full = false;
    return c;
}

char *
MAX3100::gets(char *s, int size)
{
    int i;
    char *q = s;
    while(size) { 
        do { i = getc(); } while (i == -1); // Blocks!
        *(q) = (char)i; size--; 
    }
    return s; 
}

int 
MAX3100::peek(void) { 
    if (!rx_buffer_full && rx_buffer_in == rx_buffer_out) return -1;
    return (int)((unsigned char)rx_buffer[rx_buffer_out]);
}

void 
MAX3100::isr(void) {
    uint16_t data = spiwrite(MAX3100_DATA_RD);
    bool tx_ready = data & MAX3100_CONF_T ? true : false;
        
    // The MAX3100 does have an RX fifo. So attempt to empty it into the RX buffer.
    do {
        if (!rx_buffer_full && data & MAX3100_CONF_R) {
            rx_buffer[rx_buffer_in++] = (char)(data & 0xFF);
            if (rx_buffer_in >= MAX3100_RX_BUFFER_SIZE) rx_buffer_in = 0;
            if (rx_buffer_in == rx_buffer_out) rx_buffer_full = true;
        }
    }
    while ((data = spiwrite(MAX3100_DATA_RD)) & MAX3100_CONF_R);
        
    // The MAX3100 doesn't have a hardware TX fifo, so just test to see if it's TX buffer
    // is empty. If it is and we have bytes in the TX buffer then send one now.
    if (tx_ready && (tx_buffer_full || tx_buffer_in != tx_buffer_out)) {
        data = spiwrite(MAX3100_DATA_WR | (tx_buffer[tx_buffer_out++] & 0x1FF));
        if (tx_buffer_out >= MAX3100_TX_BUFFER_SIZE) tx_buffer_out = 0;
        tx_buffer_full = false;                                        
    }
        
    // In case we get a byte while sending then store it.
    if (!rx_buffer_full && data & MAX3100_CONF_R) {
        rx_buffer[rx_buffer_in++] = (char)(data & 0xFF);
        if (rx_buffer_in >= MAX3100_RX_BUFFER_SIZE) rx_buffer_in = 0;
        if (rx_buffer_in == rx_buffer_out) rx_buffer_full = true;
    }
    
    int isrType = MAX3100::ISR;     
    
    if ( data & MAX3100_CONF_R ) {
        isrType |= MAX3100::ISR_RX;     
    }
    
    if ( tx_ready ) {
        isrType |= MAX3100::ISR_TX;     
    }
    
    
    if (_isr_user_function != NULL) (*_isr_user_function)( isrType );
    else {
       if (_isr_user_obj && _isr_user_method) (_isr_user_obj->*_isr_user_method)( isrType );
    }   
}

void 
MAX3100::setStopBits(int i) 
{
    switch(i) {
        case 1: 
            irqDisable();
            config &= ~(1 << 6);
            config_write(config);     
            irqEnable();
            break;
        case 2: 
            irqDisable();
            config |= (1 << 6);
            config_write(config);     
            irqEnable();
            break;    
    }
}

int 
MAX3100::parityCal(uint8_t c)
{
    int count = 0;
    for (int mask = 1, i = 0; i < 8; i++, mask = mask << 1) {
        if (c & mask) count++;
    }
    return count & 1;
}

void
MAX3100::irqDisable(void)
{
    if (_irqMask0) LPC_GPIOINT->IO0IntEnF &= ~_irqMask0;
    if (_irqMask2) LPC_GPIOINT->IO2IntEnF &= ~_irqMask2;    
}

void
MAX3100::irqEnable(void)
{
    if (_irqMask0) LPC_GPIOINT->IO0IntEnF |= _irqMask0;
    if (_irqMask2) LPC_GPIOINT->IO2IntEnF |= _irqMask2;    
}

void 
MAX3100::irqMask(PinName p)
{
    _irqMask0 = _irqMask2 = 0;
    
    switch( p ) {
        case p5:  _irqMask0 = (1UL << 9); break;
        case p6:  _irqMask0 = (1UL << 8); break;
        case p7:  _irqMask0 = (1UL << 7); break;
        case p8:  _irqMask0 = (1UL << 6); break;
        case p9:  _irqMask0 = (1UL << 0); break;
        case p10: _irqMask0 = (1UL << 1); break;
        case p11: _irqMask0 = (1UL << 18); break;
        case p12: _irqMask0 = (1UL << 17); break;
        case p13: _irqMask0 = (1UL << 15); break;
        case p14: _irqMask0 = (1UL << 16); break;
        case p15: _irqMask0 = (1UL << 23); break;
        case p16: _irqMask0 = (1UL << 24); break;
        case p17: _irqMask0 = (1UL << 25); break;
        case p18: _irqMask0 = (1UL << 26); break;
        case p21: _irqMask2 = (1UL << 5); break;
        case p22: _irqMask2 = (1UL << 4); break;
        case p23: _irqMask2 = (1UL << 3); break;
        case p24: _irqMask2 = (1UL << 2); break;
        case p25: _irqMask2 = (1UL << 1); break;
        case p26: _irqMask2 = (1UL << 0); break;
        case p27: _irqMask0 = (1UL << 11); break;
        case p28: _irqMask0 = (1UL << 10); break;
        case p29: _irqMask0 = (1UL << 5); break;
        case p30: _irqMask0 = (1UL << 4); break;        
    }
}
        
void 
MAX3100::topic_1498(PinName p) {
    // http://mbed.org/forum/bugs-suggestions/topic/1498
    uint32_t clr0 = 0, clr2 = 0;
        
    switch( p ) {
        case p5:  clr0 = (1UL << 9); break;
        case p6:  clr0 = (1UL << 8); break;
        case p7:  clr0 = (1UL << 7); break;
        case p8:  clr0 = (1UL << 6); break;
        case p9:  clr0 = (1UL << 0); break;
        case p10: clr0 = (1UL << 1); break;
        case p11: clr0 = (1UL << 18); break;
        case p12: clr0 = (1UL << 17); break;
        case p13: clr0 = (1UL << 15); break;
        case p14: clr0 = (1UL << 16); break;
        case p15: clr0 = (1UL << 23); break;
        case p16: clr0 = (1UL << 24); break;
        case p17: clr0 = (1UL << 25); break;
        case p18: clr0 = (1UL << 26); break;
        case p21: clr2 = (1UL << 5); break;
        case p22: clr2 = (1UL << 4); break;
        case p23: clr2 = (1UL << 3); break;
        case p24: clr2 = (1UL << 2); break;
        case p25: clr2 = (1UL << 1); break;
        case p26: clr2 = (1UL << 0); break;
        case p27: clr0 = (1UL << 11); break;
        case p28: clr0 = (1UL << 10); break;
        case p29: clr0 = (1UL << 5); break;
        case p30: clr0 = (1UL << 4); break;        
    }
        
    if (clr0) LPC_GPIOINT->IO0IntClr = clr0;
    if (clr2) LPC_GPIOINT->IO2IntClr = clr2;            
}

}; // namespace AjK ends