//=============================================================================
//
//      ser_asb.c
//
//      Simple driver for the serial controllers on the AM33 ASB305 board
//
//=============================================================================
// ####ECOSGPLCOPYRIGHTBEGIN####                                            
// -------------------------------------------                              
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// version.                                                                 
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// for more details.                                                        
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//
// As a special exception, if other files instantiate templates or use      
// macros or inline functions from this file, or you compile this file      
// and link it with other works to produce a work based on this file,       
// this file does not by itself cause the resulting work to be covered by   
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// General Public License v2.                                               
//
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// on this file might be covered by the GNU General Public License.         
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// ####ECOSGPLCOPYRIGHTEND####                                              
//=============================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):   dhowells
// Contributors:dmoseley, nickg, gthomas
// Date:        2001-05-18
// Description: Simple driver for the ASB2305 debug serial port
//
//####DESCRIPTIONEND####
//
//=============================================================================

#include <pkgconf/hal.h>

#include <cyg/hal/hal_arch.h>           // SAVE/RESTORE GP macros
#include <cyg/hal/hal_io.h>             // IO macros
#include <cyg/hal/hal_if.h>             // interface API
#include <cyg/hal/hal_intr.h>           // HAL_ENABLE/MASK/UNMASK_INTERRUPTS
#include <cyg/hal/hal_misc.h>           // Helper functions
#include <cyg/hal/drv_api.h>            // CYG_ISR_HANDLED

#if defined(CYGNUM_HAL_AM33_PLF_SERIAL_CHANNELS) && CYGNUM_HAL_AM33_PLF_SERIAL_CHANNELS > 0

/*---------------------------------------------------------------------------*/
/* From serial_16550.h */
#if CYGNUM_HAL_VIRTUAL_VECTOR_CONSOLE_CHANNEL_BAUD==9600
#define CYG_DEVICE_SERIAL_BAUD_MSB        0x00
#define CYG_DEVICE_SERIAL_BAUD_LSB        0x78
#endif
#if CYGNUM_HAL_VIRTUAL_VECTOR_CONSOLE_CHANNEL_BAUD==19200
#define CYG_DEVICE_SERIAL_BAUD_MSB        0x00
#define CYG_DEVICE_SERIAL_BAUD_LSB        0x3C
#endif
#if CYGNUM_HAL_VIRTUAL_VECTOR_CONSOLE_CHANNEL_BAUD==38400
#define CYG_DEVICE_SERIAL_BAUD_MSB        0x00
#define CYG_DEVICE_SERIAL_BAUD_LSB        0x1E
#endif
#if CYGNUM_HAL_VIRTUAL_VECTOR_CONSOLE_CHANNEL_BAUD==57600
#define CYG_DEVICE_SERIAL_BAUD_MSB        0x00
#define CYG_DEVICE_SERIAL_BAUD_LSB        0x14
#endif
#if CYGNUM_HAL_VIRTUAL_VECTOR_CONSOLE_CHANNEL_BAUD==115200
#define CYG_DEVICE_SERIAL_BAUD_MSB        0x00
#define CYG_DEVICE_SERIAL_BAUD_LSB        0x0A
#endif

#ifndef CYG_DEVICE_SERIAL_BAUD_MSB
#error Missing/incorrect serial baud rate defined - CDL error?
#endif

/*---------------------------------------------------------------------------*/
// Define the serial registers.
#define CYG_DEV_RBR 0x00   // receiver buffer register, read, dlab = 0
#define CYG_DEV_THR 0x00   // transmitter holding register, write, dlab = 0
#define CYG_DEV_DLL 0x00   // divisor latch (LS), read/write, dlab = 1
#define CYG_DEV_IER 0x04   // interrupt enable register, read/write, dlab = 0
#define CYG_DEV_DLM 0x04   // divisor latch (MS), read/write, dlab = 1
#define CYG_DEV_IIR 0x08   // interrupt identification register, read, dlab = 0
#define CYG_DEV_FCR 0x08   // fifo control register, write, dlab = 0
#define CYG_DEV_LCR 0x0C   // line control register, read/write
#define CYG_DEV_MCR 0x10   // modem control register, read/write
#define CYG_DEV_LSR 0x14   // line status register, read
#define CYG_DEV_MSR 0x18   // modem status register, read

// Interrupt Enable Register
#define SIO_IER_RCV 0x01
#define SIO_IER_XMT 0x02
#define SIO_IER_LS  0x04
#define SIO_IER_MS  0x08

// The line status register bits.
#define SIO_LSR_DR      0x01            // data ready
#define SIO_LSR_OE      0x02            // overrun error
#define SIO_LSR_PE      0x04            // parity error
#define SIO_LSR_FE      0x08            // framing error
#define SIO_LSR_BI      0x10            // break interrupt
#define SIO_LSR_THRE    0x20            // transmitter holding register empty
#define SIO_LSR_TEMT    0x40            // transmitter register empty
#define SIO_LSR_ERR     0x80            // any error condition

// The modem status register bits.
#define SIO_MSR_DCTS  0x01              // delta clear to send
#define SIO_MSR_DDSR  0x02              // delta data set ready
#define SIO_MSR_TERI  0x04              // trailing edge ring indicator
#define SIO_MSR_DDCD  0x08              // delta data carrier detect
#define SIO_MSR_CTS   0x10              // clear to send
#define SIO_MSR_DSR   0x20              // data set ready
#define SIO_MSR_RI    0x40              // ring indicator
#define SIO_MSR_DCD   0x80              // data carrier detect

// The line control register bits.
#define SIO_LCR_WLS0   0x01             // word length select bit 0
#define SIO_LCR_WLS1   0x02             // word length select bit 1
#define SIO_LCR_STB    0x04             // number of stop bits
#define SIO_LCR_PEN    0x08             // parity enable
#define SIO_LCR_EPS    0x10             // even parity select
#define SIO_LCR_SP     0x20             // stick parity
#define SIO_LCR_SB     0x40             // set break
#define SIO_LCR_DLAB   0x80             // divisor latch access bit

// Modem Control Register
#define SIO_MCR_DTR 0x01
#define SIO_MCR_RTS 0x02
#define SIO_MCR_INT 0x08   // Enable interrupts

#define LSR_WAIT_FOR(STATE) do { cyg_uint8 lsr; do { HAL_READ_UINT8(base+CYG_DEV_LSR, lsr); } while (!(lsr&SIO_LSR_##STATE)); } while(0)
#define LSR_QUERY(STATE) ({ cyg_uint8 lsr; HAL_READ_UINT8(base+CYG_DEV_LSR, lsr); (lsr&SIO_LSR_##STATE); })

#ifdef CYGSEM_HAL_VIRTUAL_VECTOR_CONSOLE_CHANNEL_RTSCTS
#define FLOWCTL_QUERY(LINE) ({ cyg_uint8 msr; HAL_READ_UINT8(base+CYG_DEV_MSR, msr); (msr&SIO_MSR_##LINE); })
#define FLOWCTL_WAIT_FOR(LINE) do { cyg_uint8 msr; do { HAL_READ_UINT8(base+CYG_DEV_MSR, msr); } while (!(msr&SIO_MSR_##LINE)); } while(0)
#define FLOWCTL_CLEAR(LINE) do { cyg_uint8 mcr; HAL_READ_UINT8(base+CYG_DEV_MCR,mcr); mcr &= ~SIO_MCR_##LINE; HAL_WRITE_UINT8(base+CYG_DEV_MCR, mcr); } while (0);
#define FLOWCTL_SET(LINE) do { cyg_uint8 mcr; HAL_READ_UINT8(base+CYG_DEV_MCR,mcr); mcr |= SIO_MCR_##LINE; HAL_WRITE_UINT8(base+CYG_DEV_MCR, mcr); } while (0);

#else
#define FLOWCTL_QUERY(LINE) 1
#define FLOWCTL_WAIT_FOR(LINE) do { ; } while(0)
#define FLOWCTL_CLEAR(LINE) do { ; } while(0)
#define FLOWCTL_SET(LINE) do { ; } while(0)

#endif

//-----------------------------------------------------------------------------
typedef struct {
    cyg_uint8* base;
    cyg_int32 msec_timeout;
    int isr_vector;
} channel_data_t;

static channel_data_t asb2305_serial_channels[] = {
    { (cyg_uint8*)0xA6FB0000, 1000, CYGNUM_HAL_INTERRUPT_SERIAL_0_RX }
};

//-----------------------------------------------------------------------------

static void
cyg_hal_plf_serial_init_channel(const void* __ch_data)
{
    cyg_uint8* base = ((channel_data_t*)__ch_data)->base;
    cyg_uint8 lcr;

    // 8-1-no parity.
    HAL_WRITE_UINT8(base+CYG_DEV_LCR, SIO_LCR_WLS0 | SIO_LCR_WLS1);

    HAL_READ_UINT8(base+CYG_DEV_LCR, lcr);
    lcr |= SIO_LCR_DLAB;
    HAL_WRITE_UINT8(base+CYG_DEV_LCR, lcr);
    HAL_WRITE_UINT8(base+CYG_DEV_DLL, CYG_DEVICE_SERIAL_BAUD_LSB);
    HAL_WRITE_UINT8(base+CYG_DEV_DLM, CYG_DEVICE_SERIAL_BAUD_MSB);
    lcr &= ~SIO_LCR_DLAB;
    HAL_WRITE_UINT8(base+CYG_DEV_LCR, lcr);
    HAL_WRITE_UINT8(base+CYG_DEV_FCR, 0x07);  // Enable & clear FIFO

    FLOWCTL_CLEAR(DTR);
    FLOWCTL_CLEAR(RTS);
}

static void
cyg_hal_plf_serial_putc_aux(cyg_uint8* base, char c)
{
    LSR_WAIT_FOR(THRE);

    FLOWCTL_WAIT_FOR(CTS);

    HAL_WRITE_UINT8(base+CYG_DEV_THR, c);
}

void
cyg_hal_plf_serial_putc(void *__ch_data, char c)
{
    cyg_uint8* base = ((channel_data_t*)__ch_data)->base;
    CYGARC_HAL_SAVE_GP();

    FLOWCTL_SET(DTR);

    cyg_hal_plf_serial_putc_aux(base,c);

    FLOWCTL_CLEAR(DTR);

    CYGARC_HAL_RESTORE_GP();
}

static cyg_bool
cyg_hal_plf_serial_getc_nonblock(void* __ch_data, cyg_uint8* ch)
{
    cyg_uint8* base = ((channel_data_t*)__ch_data)->base;

    if (!LSR_QUERY(DR))
        return false;

    HAL_READ_UINT8(base+CYG_DEV_RBR, *ch);

    return true;
}

cyg_uint8
cyg_hal_plf_serial_getc(void* __ch_data)
{
    cyg_uint8* base = ((channel_data_t*)__ch_data)->base;
    cyg_uint8 ch;
    CYGARC_HAL_SAVE_GP();

    /* see if there's some cached data in the FIFO */
    if (!cyg_hal_plf_serial_getc_nonblock(__ch_data, &ch)) {
	/* there isn't - open the flood gates */
	FLOWCTL_WAIT_FOR(DSR);
	FLOWCTL_SET(RTS);

	while (!cyg_hal_plf_serial_getc_nonblock(__ch_data, &ch));

	FLOWCTL_CLEAR(RTS);
    }

    CYGARC_HAL_RESTORE_GP();
    return ch;
}

static void
cyg_hal_plf_serial_write(void* __ch_data, const cyg_uint8* __buf,
                         cyg_uint32 __len)
{
    cyg_uint8* base = ((channel_data_t*)__ch_data)->base;
    CYGARC_HAL_SAVE_GP();

    FLOWCTL_SET(DTR);

    while(__len-- > 0)
        cyg_hal_plf_serial_putc_aux(__ch_data, *__buf++);

    FLOWCTL_CLEAR(DTR);

    CYGARC_HAL_RESTORE_GP();
}

static void
cyg_hal_plf_serial_read(void* __ch_data, cyg_uint8* __buf, cyg_uint32 __len)
{
    CYGARC_HAL_SAVE_GP();

    while(__len-- > 0)
        *__buf++ = cyg_hal_plf_serial_getc(__ch_data);

    CYGARC_HAL_RESTORE_GP();
}

#define TM0MD 0xD4003000
#define TM0BR 0xD4003010
#define TM0BC 0xD4003020

cyg_bool
cyg_hal_plf_serial_getc_timeout(void* __ch_data, cyg_uint8* ch)
{
#if 1
    int delay_count;
    channel_data_t* chan = (channel_data_t*)__ch_data;
    cyg_uint8* base = chan->base;
    cyg_uint8 last, val;
    cyg_bool res;
    CYGARC_HAL_SAVE_GP();

    /* see if there's any cached data in the FIFO */
    res = cyg_hal_plf_serial_getc_nonblock(__ch_data,ch);
    if (!res) {
	/* there isn't - open the flood gates */
	delay_count = chan->msec_timeout * 125; // want delay in 8uS steps

	HAL_WRITE_UINT8(TM0BR,200); // IOCLK is 25MHz, we want 125KHz
	HAL_WRITE_UINT8(TM0MD,0x40); // stop and load
	HAL_WRITE_UINT8(TM0MD,0x80); // set source to be IOCLK and go
	HAL_READ_UINT8(TM0BC,last);

	while (delay_count>0 && !FLOWCTL_QUERY(DSR)) {
		HAL_READ_UINT8(TM0BC,val);
		if (val==last) continue;
		if (val>last)
			delay_count--; // count the underflows
		last = val;
	}
	if (delay_count==0)
	    goto timeout;

	FLOWCTL_SET(RTS);

	while (delay_count>0 && !LSR_QUERY(DR)) {
		HAL_READ_UINT8(TM0BC,val);
		if (val==last) continue;
		if (val>last)
			delay_count--; // count the underflows
		last = val;
	}

	FLOWCTL_CLEAR(RTS);

	if (LSR_QUERY(DR)) {
	    HAL_READ_UINT8(base+CYG_DEV_RBR, *ch);
	    res = true;
	}

    timeout:
	HAL_WRITE_UINT8(TM0MD,0x00); // stop h/w timer
    }

    CYGARC_HAL_RESTORE_GP();
    return res;

#else
    int delay_count;
    channel_data_t* chan = (channel_data_t*)__ch_data;
    cyg_uint8* base = chan->base;
    cyg_bool res;
    CYGARC_HAL_SAVE_GP();

    /* see if there's some cached data in the FIFO */
    res = cyg_hal_plf_serial_getc_nonblock(__ch_data,ch);
    if (!res) {
	/* there isn't - open the flood gates */
	delay_count = chan->msec_timeout * 1000; // want delay in uS steps

	for (; delay_count>0 && !FLOWCTL_QUERY(DSR); delay_count--)
	    CYGACC_CALL_IF_DELAY_US(1);
	if (delay_count==0)
	    goto timeout;

	FLOWCTL_SET(RTS);

	for (; delay_count>0 && !LSR_QUERY(DR); delay_count--)
	    CYGACC_CALL_IF_DELAY_US(1);

	FLOWCTL_CLEAR(RTS);

	if (LSR_QUERY(DR)) {
	    HAL_READ_UINT8(base+CYG_DEV_RBR, *ch);
	    res = true;
	}

    }

timeout:
    CYGARC_HAL_RESTORE_GP();
    return res;
#endif
}

static int
cyg_hal_plf_serial_control(void *__ch_data, __comm_control_cmd_t __func, ...)
{
    static int irq_state = 0;
    channel_data_t* chan = (channel_data_t*)__ch_data;
    int ret = 0;
    CYGARC_HAL_SAVE_GP();

    switch (__func) {
    case __COMMCTL_IRQ_ENABLE:
        irq_state = 1;

        HAL_WRITE_UINT8(chan->base+CYG_DEV_IER, SIO_IER_RCV);
        HAL_WRITE_UINT8(chan->base+CYG_DEV_MCR, SIO_MCR_INT|SIO_MCR_DTR|SIO_MCR_RTS);

        HAL_INTERRUPT_UNMASK(chan->isr_vector);
        break;
    case __COMMCTL_IRQ_DISABLE:
        ret = irq_state;
        irq_state = 0;

        HAL_WRITE_UINT8(chan->base+CYG_DEV_IER, 0);

        HAL_INTERRUPT_MASK(chan->isr_vector);
        break;
    case __COMMCTL_DBG_ISR_VECTOR:
        ret = chan->isr_vector;
        break;
    case __COMMCTL_SET_TIMEOUT:
    {
        va_list ap;

        va_start(ap, __func);

        ret = chan->msec_timeout;
        chan->msec_timeout = va_arg(ap, cyg_uint32);

        va_end(ap);
    }
    default:
        break;
    }
    CYGARC_HAL_RESTORE_GP();
    return ret;
}

static int
cyg_hal_plf_serial_isr(void *__ch_data, int* __ctrlc,
                       CYG_ADDRWORD __vector, CYG_ADDRWORD __data)
{
    int res = 0;
    channel_data_t* chan = (channel_data_t*)__ch_data;
    char c;
    cyg_uint8 lsr;
    CYGARC_HAL_SAVE_GP();

    cyg_drv_interrupt_acknowledge(chan->isr_vector);

    *__ctrlc = 0;
    HAL_READ_UINT8(chan->base+CYG_DEV_LSR, lsr);
    if ( (lsr & SIO_LSR_DR) != 0 ) {

        HAL_READ_UINT8(chan->base+CYG_DEV_RBR, c);
        if( cyg_hal_is_break( &c , 1 ) )
            *__ctrlc = 1;

        res = CYG_ISR_HANDLED;
    }

    CYGARC_HAL_RESTORE_GP();
    return res;
}

static void
cyg_hal_plf_serial_init(void)
{
    hal_virtual_comm_table_t* comm;
    int cur = CYGACC_CALL_IF_SET_CONSOLE_COMM(CYGNUM_CALL_IF_SET_COMM_ID_QUERY_CURRENT);

    // Disable interrupts.
    HAL_INTERRUPT_MASK(asb2305_serial_channels[0].isr_vector);

    // Init channels
    cyg_hal_plf_serial_init_channel(&asb2305_serial_channels[0]);

    // Setup procs in the vector table

    // Set channel 0
    CYGACC_CALL_IF_SET_CONSOLE_COMM(0);
    comm = CYGACC_CALL_IF_CONSOLE_PROCS();
    CYGACC_COMM_IF_CH_DATA_SET(*comm, &asb2305_serial_channels[0]);
    CYGACC_COMM_IF_WRITE_SET(*comm, cyg_hal_plf_serial_write);
    CYGACC_COMM_IF_READ_SET(*comm, cyg_hal_plf_serial_read);
    CYGACC_COMM_IF_PUTC_SET(*comm, cyg_hal_plf_serial_putc);
    CYGACC_COMM_IF_GETC_SET(*comm, cyg_hal_plf_serial_getc);
    CYGACC_COMM_IF_CONTROL_SET(*comm, cyg_hal_plf_serial_control);
    CYGACC_COMM_IF_DBG_ISR_SET(*comm, cyg_hal_plf_serial_isr);
    CYGACC_COMM_IF_GETC_TIMEOUT_SET(*comm, cyg_hal_plf_serial_getc_timeout);

    // Restore original console
    CYGACC_CALL_IF_SET_CONSOLE_COMM(cur);
}

void
cyg_hal_plf_comms_init(void)
{
    static int initialized = 0;

    if (initialized)
        return;

    initialized = 1;

    cyg_hal_plf_serial_init();

#if defined(CYGNUM_HAL_AM33_SERIAL_CHANNELS) && CYGNUM_HAL_AM33_SERIAL_CHANNELS > 0
    cyg_hal_am33_serial_init(1);
#endif
}

#endif // defined(CYGNUM_HAL_AM33_PLF_SERIAL_CHANNELS) && CYGNUM_HAL_AM33_PLF_SERIAL_CHANNELS > 0

/*---------------------------------------------------------------------------*/
/* End of ser_asb.c */