/*
 * linux/arch/m68k/atari/debug.c
 *
 * Atari debugging and serial console stuff
 *
 * Assembled of parts of former atari/config.c 97-12-18 by Roman Hodek
 *  
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 */

#include <linux/config.h>
#include <linux/types.h>
#include <linux/tty.h>
#include <linux/console.h>
#include <linux/init.h>
#include <linux/delay.h>

#include <asm/atarihw.h>
#include <asm/atariints.h>

extern char m68k_debug_device[];

/* Flag that Modem1 port is already initialized and used */
int atari_MFP_init_done = 0;
/* Flag that Modem1 port is already initialized and used */
int atari_SCC_init_done = 0;
/* Can be set somewhere, if a SCC master reset has already be done and should
 * not be repeated; used by kgdb */
int atari_SCC_reset_done = 0;

static struct console atari_console_driver = {
	"debug",
	NULL,			/* write */
	NULL,			/* read */
	NULL,			/* device */
	NULL,			/* wait_key */
	NULL,			/* unblank */
	NULL,			/* setup */
	CON_PRINTBUFFER,
	-1,
	0,
	NULL
};


static inline void ata_mfp_out (char c)
{
    while (!(mfp.trn_stat & 0x80)) /* wait for tx buf empty */
	barrier ();
    mfp.usart_dta = c;
}

void atari_mfp_console_write (struct console *co, const char *str,
			      unsigned int count)
{
    while (count--) {
	if (*str == '\n')
	    ata_mfp_out( '\r' );
	ata_mfp_out( *str++ );
    }
}

static inline void ata_scc_out (char c)
{
    do {
	MFPDELAY();
    } while (!(scc.cha_b_ctrl & 0x04)); /* wait for tx buf empty */
    MFPDELAY();
    scc.cha_b_data = c;
}

void atari_scc_console_write (struct console *co, const char *str,
			      unsigned int count)
{
    while (count--) {
	if (*str == '\n')
	    ata_scc_out( '\r' );
	ata_scc_out( *str++ );
    }
}

static inline void ata_midi_out (char c)
{
    while (!(acia.mid_ctrl & ACIA_TDRE)) /* wait for tx buf empty */
	barrier ();
    acia.mid_data = c;
}

void atari_midi_console_write (struct console *co, const char *str,
			       unsigned int count)
{
    while (count--) {
	if (*str == '\n')
	    ata_midi_out( '\r' );
	ata_midi_out( *str++ );
    }
}

static int ata_par_out (char c)
{
    unsigned char tmp;
    /* This a some-seconds timeout in case no printer is connected */
    unsigned long i = loops_per_sec > 1 ? loops_per_sec : 10000000;

    while( (mfp.par_dt_reg & 1) && --i ) /* wait for BUSY == L */
	;
    if (!i) return( 0 );
    
    sound_ym.rd_data_reg_sel = 15;  /* select port B */
    sound_ym.wd_data = c;           /* put char onto port */
    sound_ym.rd_data_reg_sel = 14;  /* select port A */
    tmp = sound_ym.rd_data_reg_sel;
    sound_ym.wd_data = tmp & ~0x20; /* set strobe L */
    MFPDELAY();                     /* wait a bit */
    sound_ym.wd_data = tmp | 0x20;  /* set strobe H */
    return( 1 );
}

static void atari_par_console_write (struct console *co, const char *str,
				     unsigned int count)
{
    static int printer_present = 1;

    if (!printer_present)
	return;

    while (count--) {
	if (*str == '\n')
	    if (!ata_par_out( '\r' )) {
		printer_present = 0;
		return;
	    }
	if (!ata_par_out( *str++ )) {
	    printer_present = 0;
	    return;
	}
    }
}

#ifdef CONFIG_SERIAL_CONSOLE
int atari_mfp_console_wait_key(struct console *co)
{
    while( !(mfp.rcv_stat & 0x80) ) /* wait for rx buf filled */
	barrier();
    return( mfp.usart_dta );
}

int atari_scc_console_wait_key(struct console *co)
{
    do {
	MFPDELAY();
    } while( !(scc.cha_b_ctrl & 0x01) ); /* wait for rx buf filled */
    MFPDELAY();
    return( scc.cha_b_data );
}

int atari_midi_console_wait_key(struct console *co)
{
    while( !(acia.mid_ctrl & ACIA_RDRF) ) /* wait for rx buf filled */
	barrier();
    return( acia.mid_data );
}
#endif

/* The following two functions do a quick'n'dirty initialization of the MFP or
 * SCC serial ports. They're used by the debugging interface, kgdb, and the
 * serial console code. */
#ifndef CONFIG_SERIAL_CONSOLE
__initfunc(static void atari_init_mfp_port( int cflag ))
#else
void atari_init_mfp_port( int cflag )
#endif
{
    /* timer values for 1200...115200 bps; > 38400 select 110, 134, or 150
     * bps, resp., and work only correct if there's a RSVE or RSSPEED */
    static int baud_table[9] = { 16, 11, 8, 4, 2, 1, 175, 143, 128 };
    int baud = cflag & CBAUD;
    int parity = (cflag & PARENB) ? ((cflag & PARODD) ? 0x04 : 0x06) : 0;
    int csize = ((cflag & CSIZE) == CS7) ? 0x20 : 0x00;

    if (cflag & CBAUDEX)
	baud += B38400;
    if (baud < B1200 || baud > B38400+2)
	baud = B9600; /* use default 9600bps for non-implemented rates */
    baud -= B1200; /* baud_table[] starts at 1200bps */
	
    mfp.trn_stat &= ~0x01; /* disable TX */
    mfp.usart_ctr = parity | csize | 0x88; /* 1:16 clk mode, 1 stop bit */
    mfp.tim_ct_cd &= 0x70;  /* stop timer D */
    mfp.tim_dt_d = baud_table[baud];
    mfp.tim_ct_cd |= 0x01;  /* start timer D, 1:4 */
    mfp.trn_stat |= 0x01;  /* enable TX */

    atari_MFP_init_done = 1;
}

#define SCC_WRITE(reg,val)				\
    do {						\
	scc.cha_b_ctrl = (reg);				\
	MFPDELAY();					\
	scc.cha_b_ctrl = (val);				\
	MFPDELAY();					\
    } while(0)

/* loops_per_sec isn't initialized yet, so we can't use udelay(). This does a
 * delay of ~ 60us. */
#define LONG_DELAY()				\
    do {					\
	int i;					\
	for( i = 100; i > 0; --i )		\
	    MFPDELAY();				\
    } while(0)
    
#ifndef CONFIG_SERIAL_CONSOLE
__initfunc(static void atari_init_scc_port( int cflag ))
#else
void atari_init_scc_port( int cflag )
#endif
{
    extern int atari_SCC_reset_done;
    static int clksrc_table[9] =
	/* reg 11: 0x50 = BRG, 0x00 = RTxC, 0x28 = TRxC */
    	{ 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x00, 0x00 };
    static int brgsrc_table[9] =
	/* reg 14: 0 = RTxC, 2 = PCLK */
    	{ 2, 2, 2, 2, 2, 2, 0, 2, 2 };
    static int clkmode_table[9] =
	/* reg 4: 0x40 = x16, 0x80 = x32, 0xc0 = x64 */
    	{ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0xc0, 0x80 };
    static int div_table[9] =
	/* reg12 (BRG low) */
    	{ 208, 138, 103, 50, 24, 11, 1, 0, 0 };

    int baud = cflag & CBAUD;
    int clksrc, clkmode, div, reg3, reg5;
    
    if (cflag & CBAUDEX)
	baud += B38400;
    if (baud < B1200 || baud > B38400+2)
	baud = B9600; /* use default 9600bps for non-implemented rates */
    baud -= B1200; /* tables starts at 1200bps */

    clksrc  = clksrc_table[baud];
    clkmode = clkmode_table[baud];
    div     = div_table[baud];
    if (ATARIHW_PRESENT(TT_MFP) && baud >= 6) {
	/* special treatment for TT, where rates >= 38400 are done via TRxC */
	clksrc = 0x28; /* TRxC */
	clkmode = baud == 6 ? 0xc0 :
		  baud == 7 ? 0x80 : /* really 76800bps */
			      0x40;  /* really 153600bps */
	div = 0;
    }

    reg3 = (cflag & CSIZE) == CS8 ? 0xc0 : 0x40;
    reg5 = (cflag & CSIZE) == CS8 ? 0x60 : 0x20 | 0x82 /* assert DTR/RTS */;
    
    (void)scc.cha_b_ctrl;	/* reset reg pointer */
    SCC_WRITE( 9, 0xc0 );	/* reset */
    LONG_DELAY();		/* extra delay after WR9 access */
    SCC_WRITE( 4, (cflag & PARENB) ? ((cflag & PARODD) ? 0x01 : 0x03) : 0 |
		  0x04 /* 1 stopbit */ |
		  clkmode );
    SCC_WRITE( 3, reg3 );
    SCC_WRITE( 5, reg5 );
    SCC_WRITE( 9, 0 );		/* no interrupts */
    LONG_DELAY();		/* extra delay after WR9 access */
    SCC_WRITE( 10, 0 );		/* NRZ mode */
    SCC_WRITE( 11, clksrc );	/* main clock source */
    SCC_WRITE( 12, div );	/* BRG value */
    SCC_WRITE( 13, 0 );		/* BRG high byte */
    SCC_WRITE( 14, brgsrc_table[baud] );
    SCC_WRITE( 14, brgsrc_table[baud] | (div ? 1 : 0) );
    SCC_WRITE( 3, reg3 | 1 );
    SCC_WRITE( 5, reg5 | 8 );
    
    atari_SCC_reset_done = 1;
    atari_SCC_init_done = 1;
}

#ifndef CONFIG_SERIAL_CONSOLE 
__initfunc(static void atari_init_midi_port( int cflag ))
#else
void atari_init_midi_port( int cflag )
#endif
{
    int baud = cflag & CBAUD;
    int csize = ((cflag & CSIZE) == CS8) ? 0x10 : 0x00;
    /* warning 7N1 isn't possible! (instead 7O2 is used...) */
    int parity = (cflag & PARENB) ? ((cflag & PARODD) ? 0x0c : 0x08) : 0x04;
    int div;

    /* 4800 selects 7812.5, 115200 selects 500000, all other (incl. 9600 as
     * default) the standard MIDI speed 31250. */
    if (cflag & CBAUDEX)
	baud += B38400;
    if (baud == B4800)
	div = ACIA_DIV64; /* really 7812.5 bps */
    else if (baud == B38400+2 /* 115200 */)
	div = ACIA_DIV1; /* really 500 kbps (does that work??) */
    else
	div = ACIA_DIV16; /* 31250 bps, standard for MIDI */

    /* RTS low, ints disabled */
    acia.mid_ctrl = div | csize | parity |
		    ((atari_switches & ATARI_SWITCH_MIDI) ?
		     ACIA_RHTID : ACIA_RLTID);
}

__initfunc(void atari_debug_init(void))
{
#ifdef CONFIG_KGDB
    /* the m68k_debug_device is used by the GDB stub, do nothing here */
    return;
#endif
    if (!strcmp( m68k_debug_device, "ser" )) {
	/* defaults to ser2 for a Falcon and ser1 otherwise */
	strcpy( m68k_debug_device, MACH_IS_FALCON ? "ser2" : "ser1" );

    }

    if (!strcmp( m68k_debug_device, "ser1" )) {
	/* ST-MFP Modem1 serial port */
	atari_init_mfp_port( B9600|CS8 );
	atari_console_driver.write = atari_mfp_console_write;
    }
    else if (!strcmp( m68k_debug_device, "ser2" )) {
	/* SCC Modem2 serial port */
	atari_init_scc_port( B9600|CS8 );
	atari_console_driver.write = atari_scc_console_write;
    }
    else if (!strcmp( m68k_debug_device, "midi" )) {
	/* MIDI port */
	atari_init_midi_port( B9600|CS8 );
	atari_console_driver.write = atari_midi_console_write;
    }
    else if (!strcmp( m68k_debug_device, "par" )) {
	/* parallel printer */
	atari_turnoff_irq( IRQ_MFP_BUSY ); /* avoid ints */
	sound_ym.rd_data_reg_sel = 7;  /* select mixer control */
	sound_ym.wd_data = 0xff;       /* sound off, ports are output */
	sound_ym.rd_data_reg_sel = 15; /* select port B */
	sound_ym.wd_data = 0;          /* no char */
	sound_ym.rd_data_reg_sel = 14; /* select port A */
	sound_ym.wd_data = sound_ym.rd_data_reg_sel | 0x20; /* strobe H */
	atari_console_driver.write = atari_par_console_write;
    }
    if (atari_console_driver.write)
	register_console(&atari_console_driver);
}

/*
 * Local variables:
 *  c-indent-level: 4
 *  tab-width: 8
 * End:
 */
