ser_asb.c

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//=============================================================================
//
//      ser_asb.c
//
//      Simple driver for the serial controllers on the AM33 ASB305 board
//
//=============================================================================
//####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
// the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 2 or (at your option) any later version.
//
// eCos is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
// for more details.
//
// You should have received a copy of the GNU General Public License along
// with eCos; if not, write to the Free Software Foundation, Inc.,
// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
//
// 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 the GNU General Public
// License. However the source code for this file must still be made available
// in accordance with section (3) of the GNU General Public License.
//
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// this file might be covered by the GNU General Public License.
//
// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
// at http://sources.redhat.com/ecos/ecos-license/
// -------------------------------------------
//####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;