Ejemplo n.º 1
0
//===========================================================================
// Initialize CAN driver
//===========================================================================
static void can_init(can_channel *chan)
{
    can_cbuf_t *cbuf;
    
    if (chan->init) 
    {
        return;
    }
    
    cbuf = &chan->in_cbuf;
    cbuf->waiting  = false;
    cbuf->abort    = false;
#ifdef CYGOPT_IO_CAN_SUPPORT_NONBLOCKING
    cbuf->blocking = true;
#endif
    cyg_drv_mutex_init(&cbuf->lock);
    cyg_drv_cond_init(&cbuf->wait, &cbuf->lock);
    
    cbuf = &chan->out_cbuf;
    cbuf->waiting  = false;
    cbuf->abort    = false;
#ifdef CYGOPT_IO_CAN_SUPPORT_NONBLOCKING
    cbuf->blocking = true;
#endif
    cyg_drv_mutex_init(&cbuf->lock);
    cyg_drv_cond_init(&cbuf->wait, &cbuf->lock);
    
    chan->init = true;
}
Ejemplo n.º 2
0
static cyg_bool 
disk_init(struct cyg_devtab_entry *tab)
{
    disk_channel    *chan = (disk_channel *) tab->priv;
    cyg_disk_info_t *info = chan->info;
    int i;
    //diag_printf("file test:disk_init\n");
    if (!chan->init)
    {
        disk_controller *controller = chan->controller;
        
        if( !controller->init )
        {
            cyg_drv_mutex_init( &controller->lock );
            cyg_drv_cond_init( &controller->queue, &controller->lock );
            cyg_drv_cond_init( &controller->async, &controller->lock );
            
            controller->init = true;
        }
        
        info->connected = false;
        
        // clear partition data
        for (i = 0; i < info->partitions_num; i++)
            info->partitions[i].type = 0x00;
            //info->partitions.type = 0x00;

        chan->init = true;
    }
    //diag_printf("file test:disk_init end\n");
    return true;
}
Ejemplo n.º 3
0
//==========================================================================
// Initialize driver & hardware state
//==========================================================================
void cyg_lpc2xxx_i2c_init(struct cyg_i2c_bus *bus)
{
    cyg_lpc2xxx_i2c_extra* extra = (cyg_lpc2xxx_i2c_extra*)bus->i2c_extra;
    cyg_uint16             duty_cycle;
  
    cyg_drv_mutex_init(&extra->i2c_lock);
    cyg_drv_cond_init(&extra->i2c_wait, &extra->i2c_lock);
    cyg_drv_interrupt_create(I2C_ISRVEC(extra),
                             I2C_ISRPRI(extra),
                             (cyg_addrword_t) extra,
                             &lpc2xxx_i2c_isr,
                             &lpc2xxx_i2c_dsr,
                             &(extra->i2c_interrupt_handle),
                             &(extra->i2c_interrupt_data));
    cyg_drv_interrupt_attach(extra->i2c_interrupt_handle);
  
   
    CLR_CON(extra, CON_EN | CON_STA | CON_SI | CON_AA);
    HAL_WRITE_UINT8(I2C_ADR(extra), 0);
    
    //
    // Setup I2C bus frequency
    //
    duty_cycle = (I2C_CLK(extra) / I2C_BUS_FREQ(extra)) / 2;
    HAL_WRITE_UINT16(I2C_SCLL(extra), duty_cycle);
    HAL_WRITE_UINT16(I2C_SCLH(extra), duty_cycle);
    
    SET_CON(extra, CON_EN);
}
Ejemplo n.º 4
0
void
hasp_mpc5xxx_i2c_init()
{
    initReset();										// initialise the reset pin
    resetHigh();

    cyg_drv_mutex_init(&i2c_lock);
    cyg_drv_cond_init(&i2c_wait, &i2c_lock);
    cyg_drv_interrupt_create(i2c_intr_vector,
                             0,
                             (cyg_addrword_t) 0,
                             &mpc5xxx_i2c_isr,
                             &mpc5xxx_i2c_dsr,
                             &(i2c_interrupt_handle),
                             &(i2c_interrupt_data));
    cyg_drv_interrupt_attach(i2c_interrupt_handle);

    HAL_WRITE_UINT32(I2C_0_FDR_REG, 0x89000000);		// Set clock to 100MHz / 352

    HAL_WRITE_UINT32(I2C_0_ADDRESS_REG, 0x00000000);	// Set MPC5xxx slave address, not useful to us

    HAL_WRITE_UINT32(I2C_0_CONTROL_REG, I2C_ENABLE);	// Enable the I2C device but do not start any transfers and leave interrupts disabled.

    HAL_WRITE_UINT32(I2C_0_STATUS_REG, 0x00000000);		// Clear any pending conditions including interrupts.

    HAL_INTERRUPT_UNMASK(i2c_intr_vector);				// Interrupts can now be safely unmasked

    i2c_flag = 0;

    resetLow();

}
Ejemplo n.º 5
0
void
cyg_spi_at91_bus_init(void)
{
    // Create and attach SPI interrupt object
    cyg_drv_interrupt_create(CYGNUM_HAL_INTERRUPT_SPI,
                             4,                   
                             (cyg_addrword_t)&cyg_spi_at91_bus,   
                             spi_at91_ISR,
                             spi_at91_DSR,
                             &cyg_spi_at91_bus.spi_interrupt_handle,
                             &cyg_spi_at91_bus.spi_interrupt);

    cyg_drv_interrupt_attach(cyg_spi_at91_bus.spi_interrupt_handle);

    // Init transfer mutex and condition
    cyg_drv_mutex_init(&cyg_spi_at91_bus.transfer_mx);
    cyg_drv_cond_init(&cyg_spi_at91_bus.transfer_cond, 
                      &cyg_spi_at91_bus.transfer_mx);
   
    // Init flags
    cyg_spi_at91_bus.transfer_end = true;
    cyg_spi_at91_bus.cs_up        = false;
    
    // Soft reset the SPI controller
    HAL_WRITE_UINT32(AT91_SPI+AT91_SPI_CR, AT91_SPI_CR_SWRST);

    // Configure SPI pins
      
    // NOTE: here we let the SPI controller control 
    //       the data in, out and clock signals, but 
    //       we need to handle the chip selects manually 
    //       in order to achieve better chip select control 
    //       inbetween transactions.
    
    // Put SPI MISO, MOIS and SPCK pins into peripheral mode
    HAL_WRITE_UINT32(AT91_SPI_PIO+AT91_PIO_PDR, AT91_PIO_PSR_SPCK |
                                                AT91_PIO_PSR_MISO |
                                                AT91_PIO_PSR_MOIS); 
 
    // Put SPI chip select pins in IO output mode
    HAL_WRITE_UINT32(AT91_SPI_PIO+AT91_PIO_SODR, AT91_SPI_PIO_NPCS(0x0F));
    HAL_WRITE_UINT32(AT91_SPI_PIO+AT91_PIO_PER,  AT91_SPI_PIO_NPCS(0x0F));
    HAL_WRITE_UINT32(AT91_SPI_PIO+AT91_PIO_OER,  AT91_SPI_PIO_NPCS(0x0F));

    // Call upper layer bus init
    CYG_SPI_BUS_COMMON_INIT(&cyg_spi_at91_bus.spi_bus);
}
Ejemplo n.º 6
0
Cyg_ErrNo
usbs_devtab_cwrite(cyg_io_handle_t handle, const void* buf, cyg_uint32* size)
{
    usbs_callback_data  wait;
    cyg_devtab_entry_t* devtab_entry;
    usbs_tx_endpoint*   endpoint;
    int                 result = ENOERR;
    
    CYG_REPORT_FUNCTION();
    
    wait.completed      = 0;
    cyg_drv_mutex_init(&wait.lock);
    cyg_drv_cond_init(&wait.signal, &wait.lock);

    devtab_entry      = (cyg_devtab_entry_t*) handle;
    CYG_CHECK_DATA_PTR( devtab_entry, "A valid endpoint must be supplied");
    endpoint          = (usbs_tx_endpoint*) devtab_entry->priv;
    
    CYG_CHECK_DATA_PTR( endpoint, "The handle must correspond to a USB endpoint");
    CYG_CHECK_FUNC_PTR( endpoint->start_tx_fn, "The endpoint must have a start_tx function");

    endpoint->buffer            = (unsigned char*) buf;
    endpoint->buffer_size       = (int) *size;
    endpoint->complete_fn       = &usbs_devtab_callback;
    endpoint->complete_data     = (void*) &wait;
    (*endpoint->start_tx_fn)(endpoint);
    
    cyg_drv_mutex_lock(&wait.lock);
    cyg_drv_dsr_lock();
    while (!wait.completed) {
        cyg_drv_cond_wait(&wait.signal);
    }
    cyg_drv_dsr_unlock();
    cyg_drv_mutex_unlock(&wait.lock);
    if (wait.result < 0) {
        result = wait.result;
    } else {
        *size = wait.result;
    }
    
    cyg_drv_cond_destroy(&wait.signal);
    cyg_drv_mutex_destroy(&wait.lock);

    CYG_REPORT_RETURN();
    return result;
}
Ejemplo n.º 7
0
static void spi_at91_init_bus(cyg_spi_at91_bus_t * spi_bus)
{
    cyg_uint32 ctr;
    // Create and attach SPI interrupt object
    cyg_drv_interrupt_create(spi_bus->interrupt_number,
                             4,                   
                             (cyg_addrword_t)spi_bus,   
                             spi_at91_ISR,
                             spi_at91_DSR,
                             &spi_bus->spi_interrupt_handle,
                             &spi_bus->spi_interrupt);

    cyg_drv_interrupt_attach(spi_bus->spi_interrupt_handle);

    // Init transfer mutex and condition
    cyg_drv_mutex_init(&spi_bus->transfer_mx);
    cyg_drv_cond_init(&spi_bus->transfer_cond, 
                      &spi_bus->transfer_mx);
   
    // Init flags
    spi_bus->transfer_end = true;
    spi_bus->cs_up        = false;
    
    // Soft reset the SPI controller
    HAL_WRITE_UINT32(spi_bus->base+AT91_SPI_CR, AT91_SPI_CR_SWRST);

    // Configure SPI pins
      

    // Put SPI chip select pins in IO output mode
    for(ctr = 0;ctr<4;ctr++)
    {
       if(spi_bus->cs_en[ctr])
       {
          HAL_ARM_AT91_GPIO_CFG_DIRECTION(spi_bus->cs_gpio[ctr],AT91_PIN_OUT);
          HAL_ARM_AT91_GPIO_SET(spi_bus->cs_gpio[ctr]);
       }
    }
    // Call upper layer bus init
    CYG_SPI_BUS_COMMON_INIT(&spi_bus->spi_bus);
}
Ejemplo n.º 8
0
static void
serial_init(serial_channel *chan)
{
    if (chan->init) return;
    if (chan->out_cbuf.len != 0) {
#ifdef CYGDBG_IO_INIT
        diag_printf("Set output buffer - buf: %x len: %d\n", chan->out_cbuf.data, chan->out_cbuf.len);
#endif
        chan->out_cbuf.waiting = false;
        chan->out_cbuf.abort = false;
#ifdef CYGOPT_IO_SERIAL_SUPPORT_NONBLOCKING
        chan->out_cbuf.blocking = true;
#endif
        chan->out_cbuf.pending = 0;
        cyg_drv_mutex_init(&chan->out_cbuf.lock);
        cyg_drv_cond_init(&chan->out_cbuf.wait, &chan->out_cbuf.lock);
        chan->out_cbuf.low_water = chan->out_cbuf.len / 4;
#ifdef CYGPKG_IO_SERIAL_SELECT_SUPPORT
        cyg_selinit( &chan->out_cbuf.selinfo );
#endif        
    }
    if (chan->in_cbuf.len != 0) {
        cbuf_t *cbuf = &chan->in_cbuf;

#ifdef CYGDBG_IO_INIT
        diag_printf("Set input buffer - buf: %x len: %d\n", cbuf->data, cbuf->len);
#endif
        cbuf->waiting = false;
        cbuf->abort = false;
#ifdef CYGOPT_IO_SERIAL_SUPPORT_NONBLOCKING
        cbuf->blocking = true;
#endif
#ifdef CYGPKG_IO_SERIAL_SELECT_SUPPORT
        cyg_selinit( &cbuf->selinfo );
#endif
#ifdef CYGPKG_IO_SERIAL_FLOW_CONTROL
        cbuf->low_water =
            (CYGNUM_IO_SERIAL_FLOW_CONTROL_LOW_WATER_PERCENT * cbuf->len) / 100;
        cbuf->high_water =
            (CYGNUM_IO_SERIAL_FLOW_CONTROL_HIGH_WATER_PERCENT * cbuf->len) / 100;
# ifdef CYGOPT_IO_SERIAL_FLOW_CONTROL_SOFTWARE
        // But make sure it is at least 35 below buffer size, to allow
        // for 16 byte fifos, twice, plus some latency before s/w flow
        // control can kick in. This doesn't apply to h/w flow control
        // as it is near-instaneous
        if ( (cbuf->len - cbuf->high_water) < 35 )
            cbuf->high_water = cbuf->len - 35;
        // and just in case...
        if ( cbuf->high_water <= 0 )
            cbuf->high_water = 1;
        if ( cbuf->low_water > cbuf->high_water )
            cbuf->low_water = cbuf->high_water;
# endif
#endif
        cyg_drv_mutex_init(&cbuf->lock);
        cyg_drv_cond_init(&cbuf->wait, &cbuf->lock);
    }
#ifdef CYGOPT_IO_SERIAL_SUPPORT_LINE_STATUS
    chan->status_callback = NULL;
#endif

#ifdef CYGDBG_USE_ASSERTS
#if CYGINT_IO_SERIAL_BLOCK_TRANSFER
    chan->in_cbuf.block_mode_xfer_running = false;
    chan->out_cbuf.block_mode_xfer_running = false;
#endif // CYGINT_IO_SERIAL_BLOCK_TRANSFER
#endif // CYGDBG_USE_ASSERTS

#ifdef CYGPKG_NET_BLUEZ_STACK
	//diag_printf("sizeof(serial_channel) = %d cbuf_t %d\n", sizeof(serial_channel), sizeof(cbuf_t));
	//diag_printf("chan->in_cbuf.data=%x,in_cbuf.len=%x,chan->out_cbuf.data=%x\n",chan->in_cbuf.data,chan->in_cbuf.len,chan->out_cbuf.data);
    chan->receive = 0;//clyu
    chan->tty_ldisc = NULL;
#endif
    chan->init = true;
}
Ejemplo n.º 9
0
/**
*
* QSPI bus initialization function
*
* @param    qspi_bus     - Driver handle
*
* @return   none
*
*****************************************************************************/
static void qspi_xc7z_init_bus(cyg_qspi_xc7z_bus_t * qspi_bus)
{
    entry_debug();
    volatile cyg_uint32 reg;
    
    // Create and attach SPI interrupt object
    cyg_drv_interrupt_create(qspi_bus->interrupt_number,
                             4,
                             (cyg_addrword_t)qspi_bus,
                             qspi_xc7z_ISR,
                             qspi_xc7z_DSR,
                             &qspi_bus->qspi_interrupt_handle,
                             &qspi_bus->qspi_interrupt);

    cyg_drv_interrupt_attach(qspi_bus->qspi_interrupt_handle);
    cyg_drv_interrupt_mask(qspi_bus->interrupt_number);  

    // Init transfer mutex and condition
    cyg_drv_mutex_init(&qspi_bus->transfer_mx);
    cyg_drv_cond_init(&qspi_bus->transfer_cond,
                      &qspi_bus->transfer_mx);

    // Init flags
    qspi_bus->transfer_end = true;
    qspi_bus->cs_up        = false;
    
    // Unlock SLCR regs
    HAL_WRITE_UINT32(XC7Z_SYS_CTRL_BASEADDR + XSLCR_UNLOCK_OFFSET, XSLCR_UNLOCK_KEY);
    
    // Enable clock to QSPI module
    HAL_READ_UINT32( XC7Z_SYS_CTRL_BASEADDR + XSLCRAPER_CLK_CTRL_OFFSET, reg);
    reg |= XSLCRAPER_CLK_CTRL_QSPI_EN;
    HAL_WRITE_UINT32(XC7Z_SYS_CTRL_BASEADDR + XSLCRAPER_CLK_CTRL_OFFSET, reg);
    
    // Lock SLCR regs
    HAL_WRITE_UINT32(XC7Z_SYS_CTRL_BASEADDR + XSLCR_LOCK_OFFSET, XSLCR_LOCK_KEY);
    
    // Soft reset the SPI controller
    HAL_WRITE_UINT32(qspi_bus->base + XQSPIPS_ER_OFFSET,        0x00);
   
    //TODO changed, originally was just setting a value without reading
    HAL_READ_UINT32(qspi_bus->base + XQSPIPS_CR_OFFSET, reg);
    reg &= (1 << 17); // preserve the reserved bit which is described as "do not modify"
    reg |= (1 << 31); 
    HAL_WRITE_UINT32(qspi_bus->base + XQSPIPS_CR_OFFSET, reg);
    
    // Disable linear mode
    HAL_WRITE_UINT32(qspi_bus->base + XQSPIPS_LQSPI_CR_OFFSET,  0x00);
    
    // Clear status
    HAL_WRITE_UINT32(qspi_bus->base + XQSPIPS_SR_OFFSET,        0x7F);
    
    // Clear the RX FIFO
    HAL_READ_UINT32(qspi_bus->base + XQSPIPS_SR_OFFSET, reg);
    while (reg & XQSPIPS_IXR_RXNEMPTY_MASK)
    {
        HAL_READ_UINT32(qspi_bus->base + XQSPIPS_RXD_OFFSET, reg);
        HAL_READ_UINT32(qspi_bus->base + XQSPIPS_SR_OFFSET,  reg);
    }
    
    HAL_READ_UINT32(qspi_bus->base + XQSPIPS_CR_OFFSET,         reg);
    reg &= 0xFBFFFFFF; /* Set little endian mode of TX FIFO */
    reg |= (XQSPIPS_CR_IFMODE_MASK | XQSPIPS_CR_MANSTRTEN_MASK | XQSPIPS_CR_SSFORCE_MASK |
            XQSPIPS_CR_SSCTRL_MASK | XQSPIPS_CR_DATA_SZ_MASK | XQSPIPS_CR_MSTREN_MASK);
    HAL_WRITE_UINT32(qspi_bus->base + XQSPIPS_CR_OFFSET,         reg);
    
    // Configure SPI pins
    // All pins was configured in HAL

    // Call upper layer bus init
    CYG_SPI_BUS_COMMON_INIT(&qspi_bus->qspi_bus);
}
Ejemplo n.º 10
0
static void dspi_bus_setup(cyg_spi_freescale_dspi_bus_t* spi_bus_p)
{
    cyghwr_devs_freescale_dspi_t* dspi_p = spi_bus_p->setup_p->dspi_p;
    cyghwr_hal_freescale_dma_set_t* dma_set_p;
    cyghwr_hal_freescale_edma_t* edma_p;
    cyg_uint32 dma_chan_i;

    // Get the clock frequency from HAL.
    spi_bus_p->clock_freq = CYGHWR_IO_SPI_FREESCALE_DSPI_CLOCK;
    DEBUG1_PRINTF("DSPI BUS %p: SysClk=%d\n", spi_bus_p, spi_bus_p->clock_freq);

    // Set up the pins.
    dspi_pin_setup(spi_bus_p->setup_p->spi_pin_list_p,
                   spi_bus_p->setup_p->cs_pin_list_p,
                   spi_bus_p->setup_p->cs_pin_num);

    // Set up default SPI configuration.
    dspi_p->mcr = spi_bus_p->setup_p->mcr_opt | FREESCALE_DSPI_MCR_MSTR_M |
          FREESCALE_DSPI_MCR_CLR_RXF_M | FREESCALE_DSPI_MCR_CLR_TXF_M |
          FREESCALE_DSPI_MCR_MDIS_M;

    // Enable DSPI controller.
    dspi_enable(dspi_p);

    if((dma_set_p=spi_bus_p->setup_p->dma_set_p)) {
        // Initialize DMA channels
        hal_freescale_edma_init_chanset(dma_set_p);
#if DEBUG_SPI >= 1
        hal_freescale_edma_diag(dma_set_p, 0xffff);
        cyghwr_devs_freescale_dspi_diag(spi_bus_p);
#endif
        // Set up DMA transfer control descriptors
        edma_p = dma_set_p->edma_p;
        dma_chan_i = dma_set_p->chan_p[SPI_DMA_CHAN_TX_I].dma_chan_i;
        hal_freescale_edma_transfer_init(edma_p, dma_chan_i,
                                         spi_bus_p->tx_dma_tcd_ini_p);
#if DEBUG_SPI >= 1
        hal_freescale_edma_transfer_diag(edma_p, dma_chan_i, true);
#endif
        dma_chan_i = dma_set_p->chan_p[SPI_DMA_CHAN_RX_I].dma_chan_i;
        hal_freescale_edma_transfer_init(edma_p, dma_chan_i,
                                         spi_bus_p->rx_dma_tcd_ini_p);
#if DEBUG_SPI >= 1
        hal_freescale_edma_transfer_diag(edma_p, dma_chan_i, true);
#endif
        // Enable SPI DMA requests
        dspi_p->rser = FREESCALE_DSPI_RSER_TFFF_DIRS_M |
                       FREESCALE_DSPI_RSER_RFDF_DIRS_M |
                       FREESCALE_DSPI_RSER_TFFF_RE_M |
                       FREESCALE_DSPI_RSER_RFDF_RE_M;
    }
#if DEBUG_SPI >= 1
    cyghwr_devs_freescale_dspi_diag(spi_bus_p);
#endif
    // Initialise the synchronisation primitivies.
    cyg_drv_mutex_init (&spi_bus_p->transfer_mutex);
    cyg_drv_cond_init (&spi_bus_p->transfer_done, &spi_bus_p->transfer_mutex);

    // Hook up the ISR and DSR.
    cyg_drv_interrupt_create (spi_bus_p->setup_p->intr_num,
                              spi_bus_p->setup_p->intr_prio,
                              (cyg_addrword_t) spi_bus_p,
                              dma_set_p ? dspi_dma_ISR : dspi_nodma_ISR,
                              dspi_DSR, &spi_bus_p->intr_handle,
                              &spi_bus_p->intr_data);
    cyg_drv_interrupt_attach (spi_bus_p->intr_handle);

    dspi_p->ctar[1] = dspi_calc_ctar(&aux_clocking, spi_bus_p->clock_freq);

    // Call upper layer bus init.
    CYG_SPI_BUS_COMMON_INIT(&spi_bus_p->spi_bus);
}
Ejemplo n.º 11
0
/*
 * Initialize driver and hardware
 */
void zynq_i2c_init(struct cyg_i2c_bus* bus)
{
    cyg_zynq_i2c_extra* extra = (cyg_zynq_i2c_extra*)bus->i2c_extra;
    cyg_uint16 div_a, div_b;
    cyg_uint16 temp_div_a, temp_div_b;
    cyg_uint32 error, last_error;
    cyg_uint32 temp;
    cyg_uint16 ctrl_reg;

    extra->i2c_isr_vector = XI2CPS_ISR_VECT;
    extra->i2c_isr_priority = 0;
    extra->i2c_hold_flag = 0;
    
    // register ISR
    cyg_drv_mutex_init(&extra->i2c_lock);
    cyg_drv_cond_init(&extra->i2c_wait, &extra->i2c_lock);
    cyg_drv_interrupt_create(extra->i2c_isr_vector,
                             extra->i2c_isr_priority,
                             (cyg_addrword_t) extra,
                             &zynq_i2c_isr,
                             &zynq_i2c_dsr,
                             &(extra->i2c_int_handle),
                             &(extra->i2c_int_data));
    cyg_drv_interrupt_attach(extra->i2c_int_handle);
    
    // Calculate values of diva and divb based o the PCLK and FSCL
    for(temp_div_a = 0; temp_div_a < 4; temp_div_a++)
    {
        //calculate div_b for assumed div_a
        temp = 22 * extra->i2c_bus_freq * (temp_div_a + 1);
        temp_div_b = (CYGPKG_DEVS_I2C_ARM_XC7Z_PCLK / temp) - 1;
        //error = assumed_fscl - calculated_fscl
        error = extra->i2c_bus_freq - (CYGPKG_DEVS_I2C_ARM_XC7Z_PCLK / (22 * (temp_div_a + 1) * (temp_div_b + 1)));
        //don't compare errors for first loop iteration
        if(temp_div_a == 0)
        {
            last_error = error;
            div_a = temp_div_a;
            div_b = temp_div_b;
        }
        else if(last_error < error) //save the best divisors values
        {
            div_a = temp_div_a;
            div_b = temp_div_b;
        }
    }

#ifdef ZYNQ_I2C_DEBUG
    DPRINTF("divisors calculated: ");
    diag_printf("div_a = %d,  div_b = %d\n", div_a, div_b);
#endif
    // read actual config
    HAL_READ_UINT16(XI2CPS_BASE + XI2CPS_CR_OFFSET, ctrl_reg);
    // clear divisor_a and divisor_b fields
    ctrl_reg &= ~(0x0000C000 | 0x00003F00);
    //set new values of divisor_a and divisor_b
    ctrl_reg |= ((div_a << 14) | (div_b << 8));
    // write config
    HAL_WRITE_UINT16(XI2CPS_BASE + XI2CPS_CR_OFFSET, ctrl_reg);
    // enable interrupts
    HAL_WRITE_UINT16(XI2CPS_BASE + XI2CPS_IER_OFFSET, XI2CPS_ENABLED_INTR);
    // set time-out as long as possible
    HAL_WRITE_UINT8(XI2CPS_BASE + XI2CPS_TIME_OUT_OFFSET, 0xFF);
#ifdef ZYNQ_I2C_DEBUG
    DPRINTF("init OK\n");
#endif
}