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

//

//      io/serial/arm/at91/at91_serial.c

//

//      Atmel AT91/EB40 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.

//

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// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

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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

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//####ECOSGPLCOPYRIGHTEND####

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

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

//

// Author(s):     gthomas

// Contributors:  gthomas

// Date:          2001-07-24

// Purpose:       Atmel AT91/EB40 Serial I/O module (interrupt driven version)

// Description: 

//

//####DESCRIPTIONEND####

//

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

#include <pkgconf/system.h>

#include <pkgconf/io_serial.h>

#include <pkgconf/io.h>

#include <pkgconf/kernel.h>

#include <cyg/io/io.h>

#include <cyg/hal/hal_io.h>

#include <cyg/hal/hal_intr.h>

#include <cyg/io/devtab.h>

#include <cyg/io/serial.h>

#include <cyg/infra/diag.h>

#ifdef CYGPKG_IO_SERIAL_ARM_AT91

#include "at91_serial.h"

typedef struct at91_serial_info {

    CYG_ADDRWORD   base;

    CYG_WORD       int_num;

    cyg_interrupt  serial_interrupt;

    cyg_handle_t   serial_interrupt_handle;

} at91_serial_info;

static bool at91_serial_init(struct cyg_devtab_entry *tab);

static bool at91_serial_putc(serial_channel *chan, unsigned char c);

static Cyg_ErrNo at91_serial_lookup(struct cyg_devtab_entry **tab,

                                    struct cyg_devtab_entry *sub_tab,

                                    const char *name);

static unsigned char at91_serial_getc(serial_channel *chan);

static Cyg_ErrNo at91_serial_set_config(serial_channel *chan, cyg_uint32 key,

                                        const void *xbuf, cyg_uint32 *len);

static void at91_serial_start_xmit(serial_channel *chan);

static void at91_serial_stop_xmit(serial_channel *chan);

static cyg_uint32 at91_serial_ISR(cyg_vector_t vector, cyg_addrword_t data);

static void       at91_serial_DSR(cyg_vector_t vector, cyg_ucount32 count, cyg_addrword_t data);

static SERIAL_FUNS(at91_serial_funs,

                   at91_serial_putc,

                   at91_serial_getc,

                   at91_serial_set_config,

                   at91_serial_start_xmit,

                   at91_serial_stop_xmit

    );

#ifdef CYGPKG_IO_SERIAL_ARM_AT91_SERIAL0

static at91_serial_info at91_serial_info0 = {(CYG_ADDRWORD)AT91_USART0,

                                             CYGNUM_HAL_INTERRUPT_USART0};

#if CYGNUM_IO_SERIAL_ARM_AT91_SERIAL0_BUFSIZE > 0

static unsigned char at91_serial_out_buf0[CYGNUM_IO_SERIAL_ARM_AT91_SERIAL0_BUFSIZE];

static unsigned char at91_serial_in_buf0[CYGNUM_IO_SERIAL_ARM_AT91_SERIAL0_BUFSIZE];

static SERIAL_CHANNEL_USING_INTERRUPTS(at91_serial_channel0,

                                       at91_serial_funs,

                                       at91_serial_info0,

                                       CYG_SERIAL_BAUD_RATE(CYGNUM_IO_SERIAL_ARM_AT91_SERIAL0_BAUD),

                                       CYG_SERIAL_STOP_DEFAULT,

                                       CYG_SERIAL_PARITY_DEFAULT,

                                       CYG_SERIAL_WORD_LENGTH_DEFAULT,

                                       CYG_SERIAL_FLAGS_DEFAULT,

                                       &at91_serial_out_buf0[0], sizeof(at91_serial_out_buf0),

                                       &at91_serial_in_buf0[0], sizeof(at91_serial_in_buf0)

    );

#else

static SERIAL_CHANNEL(at91_serial_channel0,

                      at91_serial_funs,

                      at91_serial_info0,

                      CYG_SERIAL_BAUD_RATE(CYGNUM_IO_SERIAL_ARM_AT91_SERIAL0_BAUD),

                      CYG_SERIAL_STOP_DEFAULT,

                      CYG_SERIAL_PARITY_DEFAULT,

                      CYG_SERIAL_WORD_LENGTH_DEFAULT,

                      CYG_SERIAL_FLAGS_DEFAULT

    );

#endif

DEVTAB_ENTRY(at91_serial_io0,

             CYGDAT_IO_SERIAL_ARM_AT91_SERIAL0_NAME,

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

             &cyg_io_serial_devio,

             at91_serial_init,

             at91_serial_lookup,     // Serial driver may need initializing

             &at91_serial_channel0

    );

#endif //  CYGPKG_IO_SERIAL_ARM_AT91_SERIAL1

#ifdef CYGPKG_IO_SERIAL_ARM_AT91_SERIAL1

static at91_serial_info at91_serial_info1 = {(CYG_ADDRWORD)AT91_USART1,

                                              CYGNUM_HAL_INTERRUPT_USART1};

#if CYGNUM_IO_SERIAL_ARM_AT91_SERIAL1_BUFSIZE > 0

static unsigned char at91_serial_out_buf1[CYGNUM_IO_SERIAL_ARM_AT91_SERIAL1_BUFSIZE];

static unsigned char at91_serial_in_buf1[CYGNUM_IO_SERIAL_ARM_AT91_SERIAL1_BUFSIZE];

static SERIAL_CHANNEL_USING_INTERRUPTS(at91_serial_channel1,

                                       at91_serial_funs,

                                       at91_serial_info1,

                                       CYG_SERIAL_BAUD_RATE(CYGNUM_IO_SERIAL_ARM_AT91_SERIAL1_BAUD),

                                       CYG_SERIAL_STOP_DEFAULT,

                                       CYG_SERIAL_PARITY_DEFAULT,

                                       CYG_SERIAL_WORD_LENGTH_DEFAULT,

                                       CYG_SERIAL_FLAGS_DEFAULT,

                                       &at91_serial_out_buf1[0], sizeof(at91_serial_out_buf1),

                                       &at91_serial_in_buf1[0], sizeof(at91_serial_in_buf1)

    );

#else

static SERIAL_CHANNEL(at91_serial_channel1,

                      at91_serial_funs,

                      at91_serial_info1,

                      CYG_SERIAL_BAUD_RATE(CYGNUM_IO_SERIAL_ARM_AT91_SERIAL1_BAUD),

                      CYG_SERIAL_STOP_DEFAULT,

                      CYG_SERIAL_PARITY_DEFAULT,

                      CYG_SERIAL_WORD_LENGTH_DEFAULT,

                      CYG_SERIAL_FLAGS_DEFAULT

    );

#endif

DEVTAB_ENTRY(at91_serial_io1,

             CYGDAT_IO_SERIAL_ARM_AT91_SERIAL1_NAME,

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

             &cyg_io_serial_devio,

             at91_serial_init,

             at91_serial_lookup,     // Serial driver may need initializing

             &at91_serial_channel1

    );

#endif //  CYGPKG_IO_SERIAL_ARM_AT91_SERIAL1

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

static bool

at91_serial_config_port(serial_channel *chan, cyg_serial_info_t *new_config, bool init)

{

    at91_serial_info *at91_chan = (at91_serial_info *)chan->dev_priv;

    CYG_ADDRWORD base = at91_chan->base;

    cyg_uint32 parity = select_parity[new_config->parity];

    cyg_uint32 word_length = select_word_length[new_config->word_length-CYGNUM_SERIAL_WORD_LENGTH_5];

    cyg_uint32 stop_bits = select_stop_bits[new_config->stop];

    if ((word_length == 0xFF) ||

        (parity == 0xFF) ||

        (stop_bits == 0xFF)) {

        return false;  // Unsupported configuration

    }

    // Reset device

    HAL_WRITE_UINT32(base+AT91_US_CR, AT91_US_CR_RxRESET | AT91_US_CR_TxRESET);

    // Configuration

    HAL_WRITE_UINT32(base+AT91_US_MR, parity | word_length | stop_bits);

    // Baud rate

    HAL_WRITE_UINT32(base+AT91_US_BRG, AT91_US_BAUD(select_baud[new_config->baud]));

    // Disable all interrupts

    HAL_WRITE_UINT32(base+AT91_US_IDR, 0xFFFFFFFF);

    // Enable Rx interrupts

    HAL_WRITE_UINT32(base+AT91_US_IER, AT91_US_IER_RxRDY);

    // Enable RX and TX

    HAL_WRITE_UINT32(base+AT91_US_CR, AT91_US_CR_RxENAB | AT91_US_CR_TxENAB);

    return true;

}

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

static bool

at91_serial_init(struct cyg_devtab_entry *tab)

{

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

    at91_serial_info *at91_chan = (at91_serial_info *)chan->dev_priv;

    int res;

#ifdef CYGDBG_IO_INIT

    diag_printf("AT91 SERIAL init - dev: %x.%d\n", at91_chan->base, at91_chan->int_num);

#endif

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

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

        cyg_drv_interrupt_create(at91_chan->int_num,

                                 4,                      // Priority

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

                                 at91_serial_ISR,

                                 at91_serial_DSR,

                                 &at91_chan->serial_interrupt_handle,

                                 &at91_chan->serial_interrupt);

        cyg_drv_interrupt_attach(at91_chan->serial_interrupt_handle);

        cyg_drv_interrupt_unmask(at91_chan->int_num);

    }

    res = at91_serial_config_port(chan, &chan->config, true);

    return res;

}

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

static Cyg_ErrNo

at91_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

at91_serial_putc(serial_channel *chan, unsigned char c)

{

    at91_serial_info *at91_chan = (at91_serial_info *)chan->dev_priv;

    CYG_ADDRWORD base = at91_chan->base;

    cyg_uint32 stat;

    // Check status

    HAL_READ_UINT32(base+AT91_US_CSR, stat);

    // Send character if possible

    if ((stat & AT91_US_CSR_TxRDY) != 0) {

        HAL_WRITE_UINT32(base+AT91_US_THR, c);

        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

at91_serial_getc(serial_channel *chan)

{

    at91_serial_info *at91_chan = (at91_serial_info *)chan->dev_priv;

    CYG_ADDRWORD base = at91_chan->base;

    cyg_uint32 c;

    // Read data

    HAL_READ_UINT32(base+AT91_US_RHR, c);

    return c;

}

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

static Cyg_ErrNo

at91_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 != at91_serial_config_port(chan, config, false) )

            return -EINVAL;

      }

      break;

    default:

        return -EINVAL;

    }

    return ENOERR;

}

// Enable the transmitter on the device

static void

at91_serial_start_xmit(serial_channel *chan)

{

    at91_serial_info *at91_chan = (at91_serial_info *)chan->dev_priv;

    CYG_ADDRWORD base = at91_chan->base;

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

    HAL_WRITE_UINT32(base+AT91_US_IER, AT91_US_IER_TxRDY);

}

// Disable the transmitter on the device

static void

at91_serial_stop_xmit(serial_channel *chan)

{

    at91_serial_info *at91_chan = (at91_serial_info *)chan->dev_priv;

    CYG_ADDRWORD base = at91_chan->base;

    HAL_WRITE_UINT32(base+AT91_US_IDR, AT91_US_IER_TxRDY);

}

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

static cyg_uint32

at91_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|CYG_ISR_HANDLED);  // Cause DSR to be run

}

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

static void

at91_serial_DSR(cyg_vector_t vector, cyg_ucount32 count, cyg_addrword_t data)

{

    serial_channel *chan = (serial_channel *)data;

    at91_serial_info *at91_chan = (at91_serial_info *)chan->dev_priv;

    CYG_ADDRWORD base = at91_chan->base;

    cyg_uint32 stat, c;

    // Check status

    HAL_READ_UINT32(base+AT91_US_IMR, stat);

    if (stat & (AT91_US_IER_TxRDY)) {

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

    }

    if (stat & (AT91_US_IER_RxRDY)) {

        while (true) {

            HAL_READ_UINT32(base+AT91_US_CSR, stat);

            if ((stat & AT91_US_CSR_RxRDY) == 0) {

                break;

            }

            HAL_READ_UINT32(base+AT91_US_RHR, c);

            (chan->callbacks->rcv_char)(chan, c);

        }

    }

    cyg_drv_interrupt_unmask(vector);

}

#endif