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//==========================================================================

//

//      io/serial/v85x/v85x_v850_serial.c

//

//      NEC V850 Serial I/O Interface Module (interrupt driven)

//

//==========================================================================

//####ECOSGPLCOPYRIGHTBEGIN####

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

// This file is part of eCos, the Embedded Configurable Operating System.

// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.

//

// eCos is free software; you can redistribute it and/or modify it under

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// You should have received a copy of the GNU General Public License along

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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

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//####ECOSGPLCOPYRIGHTEND####

//==========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):    gthomas

// Contributors: gthomas,jlarmour

// Date:         2001-03-21

// Purpose:      V850 Serial I/O module (interrupt driven version)

// Description: 

//

//####DESCRIPTIONEND####

//

//==========================================================================

#include <pkgconf/system.h>

#include <pkgconf/io_serial.h>

#include <pkgconf/io.h>

#ifdef CYGPKG_KERNEL

#include <pkgconf/kernel.h>

#endif

#include CYGBLD_HAL_TARGET_H

#include <cyg/io/io.h>

#include <cyg/hal/hal_intr.h>

#include <cyg/io/devtab.h>

#include <cyg/io/serial.h>

#include <cyg/infra/diag.h>

#ifdef CYGVAR_KERNEL_COUNTERS_CLOCK

#include <cyg/kernel/kapi.h>

#endif

#ifdef CYGPKG_IO_SERIAL_V85X_V850

#include "v85x_v850_serial.h"

typedef struct v850_serial_info {

    CYG_ADDRWORD   base;

    CYG_WORD       int_num;

    cyg_interrupt  serial_interrupt[3];

    cyg_handle_t   serial_interrupt_handle[3];

    cyg_bool       tx_busy;

#ifdef CYGVAR_KERNEL_COUNTERS_CLOCK

    cyg_alarm      tx_timeout;

    cyg_handle_t   tx_timeout_handle;

#endif

} v850_serial_info;

static bool v850_serial_init(struct cyg_devtab_entry *tab);

static bool v850_serial_putc(serial_channel *chan, unsigned char c);

static Cyg_ErrNo v850_serial_lookup(struct cyg_devtab_entry **tab,

                                    struct cyg_devtab_entry *sub_tab,

                                    const char *name);

static unsigned char v850_serial_getc(serial_channel *chan);

static Cyg_ErrNo v850_serial_set_config(serial_channel *chan, cyg_uint32 key,

                                        const void *xbuf, cyg_uint32 *len);

static void v850_serial_start_xmit(serial_channel *chan);

static void v850_serial_stop_xmit(serial_channel *chan);

static cyg_uint32 v850_serial_ISR(cyg_vector_t vector, cyg_addrword_t data);

static void       v850_serial_DSR(cyg_vector_t vector, cyg_ucount32 count, cyg_addrword_t data);

static SERIAL_FUNS(v850_serial_funs,

                   v850_serial_putc,

                   v850_serial_getc,

                   v850_serial_set_config,

                   v850_serial_start_xmit,

                   v850_serial_stop_xmit

    );

#ifdef CYGPKG_IO_SERIAL_V85X_V850_SERIAL0

static v850_serial_info v850_serial_info0 = {V850_REG_ASIM0,

                                             CYGNUM_HAL_VECTOR_INTSER0};

#if CYGNUM_IO_SERIAL_V85X_V850_SERIAL0_BUFSIZE > 0

static unsigned char v850_serial_out_buf0[CYGNUM_IO_SERIAL_V85X_V850_SERIAL0_BUFSIZE];

static unsigned char v850_serial_in_buf0[CYGNUM_IO_SERIAL_V85X_V850_SERIAL0_BUFSIZE];

static SERIAL_CHANNEL_USING_INTERRUPTS(v850_serial_channel0,

                                       v850_serial_funs,

                                       v850_serial_info0,

                                       CYG_SERIAL_BAUD_RATE(CYGNUM_IO_SERIAL_V85X_V850_SERIAL0_BAUD),

                                       CYG_SERIAL_STOP_DEFAULT,

                                       CYG_SERIAL_PARITY_DEFAULT,

                                       CYG_SERIAL_WORD_LENGTH_DEFAULT,

                                       CYG_SERIAL_FLAGS_DEFAULT,

                                       &v850_serial_out_buf0[0], sizeof(v850_serial_out_buf0),

                                       &v850_serial_in_buf0[0], sizeof(v850_serial_in_buf0)

    );

#else

static SERIAL_CHANNEL(v850_serial_channel0,

                      v850_serial_funs,

                      v850_serial_info0,

                      CYG_SERIAL_BAUD_RATE(CYGNUM_IO_SERIAL_V85X_V850_SERIAL0_BAUD),

                      CYG_SERIAL_STOP_DEFAULT,

                      CYG_SERIAL_PARITY_DEFAULT,

                      CYG_SERIAL_WORD_LENGTH_DEFAULT,

                      CYG_SERIAL_FLAGS_DEFAULT

    );

#endif

DEVTAB_ENTRY(v850_serial_io0,

             CYGDAT_IO_SERIAL_V85X_V850_SERIAL0_NAME,

             0,                     // Does not depend on a lower level interface

             &cyg_io_serial_devio,

             v850_serial_init,

             v850_serial_lookup,     // Serial driver may need initializing

             &v850_serial_channel0

    );

#endif //  CYGPKG_IO_SERIAL_V85X_V850_SERIAL0

// Internal function to actually configure the hardware to desired baud rate, etc.

static bool

v850_serial_config_port(serial_channel *chan, cyg_serial_info_t *new_config, bool init)

{

    v850_serial_info *v850_chan = (v850_serial_info *)chan->dev_priv;

    volatile struct serial_port *port = (volatile struct serial_port *)v850_chan->base;

    unsigned char parity = select_parity[new_config->parity];

    unsigned char word_length = select_word_length[new_config->word_length-CYGNUM_SERIAL_WORD_LENGTH_5];

    unsigned char stop_bits = select_stop_bits[new_config->stop];

    int divisor, count;

    if ((select_baud[new_config->baud].count == 0) ||

        (word_length == 0xFF) ||

        (parity == 0xFF) ||

        (stop_bits == 0xFF)) {

        return false;  // Unsupported configuration

    }

    port->asim = ASIM_TxRx_Tx | ASIM_TxRx_Rx | parity | word_length | stop_bits;

    count = select_baud[new_config->baud].count;

    divisor = select_baud[new_config->baud].divisor;

    while (count > 0xFF) {

        count >>= 1;

        divisor++;

    }

    port->brgc = count;

    port->brgm = divisor & 0x07;

#if CYGINT_HAL_V850_VARIANT_SB1

    port->brgm1 = divisor >> 3;

#endif

    if (new_config != &chan->config) {

        chan->config = *new_config;

    }

    return true;

}

#ifdef CYGVAR_KERNEL_COUNTERS_CLOCK

//

// The serial ports on the V850 are incredibly stupid.  There is no

// interface status register which can tell you if it is possible to

// read or write a character!  The only way to discern this is by using

// interrupts [or at least an interrupt register and polling it].  Thus

// the serial transmit code has a problem in that it will be required by

// upper layers to "send until full".  The only way to decide "not full" is

// that an interrupt has happened.  If the serial driver is being mixed

// with diagnostic I/O, then serial transmit interrupts will possibly be

// lost.  

//

// This code attempts to compenstate by using a kernel alarm to reset the

// "device is busy" flag after some timeout.  The timeout period will be

// sufficiently long so as to not interfere with normal interrupt handling.

//

static void

v850_serial_tx_timeout(cyg_handle_t alarm, cyg_addrword_t p)

{

    v850_serial_info *v850_chan = (v850_serial_info *)p;

    v850_chan->tx_busy = false;

}

#endif

// Function to initialize the device.  Called at bootstrap time.

static bool

v850_serial_init(struct cyg_devtab_entry *tab)

{

    int i;

    serial_channel *chan = (serial_channel *)tab->priv;

    v850_serial_info *v850_chan = (v850_serial_info *)chan->dev_priv;

#ifdef CYGVAR_KERNEL_COUNTERS_CLOCK

    cyg_handle_t h;

#endif

#ifdef CYGDBG_IO_INIT

    diag_printf("V850 SERIAL init - dev: %x.%d\n", v850_chan->base, v850_chan->int_num);

#endif

    (chan->callbacks->serial_init)(chan);  // Really only required for interrupt driven devices

    if (chan->out_cbuf.len != 0) {

        for (i = 0;  i < 3;  i++) {

            cyg_drv_interrupt_create(v850_chan->int_num+i,

                                     99,                     // Priority - unused

                                     (cyg_addrword_t)chan,   // Data item passed to interrupt handler

                                     v850_serial_ISR,

                                     v850_serial_DSR,

                                     &v850_chan->serial_interrupt_handle[i],

                                     &v850_chan->serial_interrupt[i]);

            cyg_drv_interrupt_attach(v850_chan->serial_interrupt_handle[i]);

            cyg_drv_interrupt_unmask(v850_chan->int_num+i);

#ifdef CYGVAR_KERNEL_COUNTERS_CLOCK

            cyg_clock_to_counter(cyg_real_time_clock(), &h);

            cyg_alarm_create(h, v850_serial_tx_timeout, (cyg_addrword_t)v850_chan,

                             &v850_chan->tx_timeout_handle, &v850_chan->tx_timeout);

#endif

        }

    }

    v850_chan->tx_busy = false;

    return v850_serial_config_port(chan, &chan->config, true);

}

// This routine is called when the device is "looked" up (i.e. attached)

static Cyg_ErrNo

v850_serial_lookup(struct cyg_devtab_entry **tab,

                  struct cyg_devtab_entry *sub_tab,

                  const char *name)

{

    serial_channel *chan = (serial_channel *)(*tab)->priv;

    (chan->callbacks->serial_init)(chan);  // Really only required for interrupt driven devices

    return ENOERR;

}

// Send a character to the device output buffer.

// Return 'true' if character is sent to device

static bool

v850_serial_putc(serial_channel *chan, unsigned char c)

{

    v850_serial_info *v850_chan = (v850_serial_info *)chan->dev_priv;

    volatile struct serial_port *port = (volatile struct serial_port *)v850_chan->base;

    if (!v850_chan->tx_busy) {

        v850_chan->tx_busy = true;

        port->txs = c;

#ifdef CYGVAR_KERNEL_COUNTERS_CLOCK

        cyg_alarm_initialize(v850_chan->tx_timeout_handle, cyg_current_time()+10, 0);

#endif

        return true;

    } else {

        return false;  // Couldn't send, tx was busy

    }

}

// Fetch a character from the device input buffer, waiting if necessary

static unsigned char

v850_serial_getc(serial_channel *chan)

{

    v850_serial_info *v850_chan = (v850_serial_info *)chan->dev_priv;

    volatile struct serial_port *port = (volatile struct serial_port *)v850_chan->base;

    return port->rxs;

}

// Set up the device characteristics; baud rate, etc.

static Cyg_ErrNo

v850_serial_set_config(serial_channel *chan, cyg_uint32 key,

                       const void *xbuf, cyg_uint32 *len)

{

    switch (key) {

    case CYG_IO_SET_CONFIG_SERIAL_INFO:

      {

        cyg_serial_info_t *config = (cyg_serial_info_t *)xbuf;

        if ( *len < sizeof(cyg_serial_info_t) ) {

            return -EINVAL;

        }

        *len = sizeof(cyg_serial_info_t);

        if ( true != v850_serial_config_port(chan, config, false) )

            return -EINVAL;

      }

      break;

    default:

        return -EINVAL;

    }

    return ENOERR;

}

// Enable the transmitter on the device

static void

v850_serial_start_xmit(serial_channel *chan)

{

    v850_serial_info *v850_chan = (v850_serial_info *)chan->dev_priv;

    (chan->callbacks->xmt_char)(chan);  // Kick transmitter (if necessary)

    cyg_drv_interrupt_unmask(v850_chan->int_num+INT_Tx);  // Enable Tx interrupt

}

// Disable the transmitter on the device

static void

v850_serial_stop_xmit(serial_channel *chan)

{

    v850_serial_info *v850_chan = (v850_serial_info *)chan->dev_priv;

    cyg_drv_interrupt_mask(v850_chan->int_num+INT_Tx);  // Disable Tx interrupt

}

// Serial I/O - low level interrupt handler (ISR)

static cyg_uint32

v850_serial_ISR(cyg_vector_t vector, cyg_addrword_t data)

{

    cyg_drv_interrupt_mask(vector);

    cyg_drv_interrupt_acknowledge(vector);

    return CYG_ISR_CALL_DSR;  // Cause DSR to be run

}

// Serial I/O - high level interrupt handler (DSR)

static void

v850_serial_DSR(cyg_vector_t vector, cyg_ucount32 count, cyg_addrword_t data)

{

    serial_channel *chan = (serial_channel *)data;

    v850_serial_info *v850_chan = (v850_serial_info *)chan->dev_priv;

    volatile struct serial_port *port = (volatile struct serial_port *)v850_chan->base;

    switch (vector-(v850_chan->int_num)) {

    case INT_ERR:

    case INT_Rx:

        (chan->callbacks->rcv_char)(chan, port->rxs);

        break;

    case INT_Tx:

        v850_chan->tx_busy = false;

#ifdef CYGVAR_KERNEL_COUNTERS_CLOCK

        cyg_alarm_initialize(v850_chan->tx_timeout_handle, 0, 0);

#endif

        (chan->callbacks->xmt_char)(chan);

        break;

    }

    cyg_drv_interrupt_unmask(vector);

}

#endif

// EOF v85x_v850_serial.c