/*
   * 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/types.h>
  #include <linux/tty.h>
  #include <linux/console.h>
  #include <linux/init.h>
  #include <linux/delay.h>
  #include <linux/module.h>
  
  #include <asm/atarihw.h>
  #include <asm/atariints.h>
  
  /* 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;
  EXPORT_SYMBOL(atari_SCC_reset_done);
  
  static struct console atari_console_driver = {
  	.name	= "debug",
  	.flags	= CON_PRINTBUFFER,
  	.index	= -1,
  };
  
  
  static inline void ata_mfp_out(char c)
  {
  	while (!(st_mfp.trn_stat & 0x80))	/* wait for tx buf empty */
  		barrier();
  	st_mfp.usart_dta = c;
  }
  
  static void atari_mfp_console_write(struct console *co, const char *str,
  				    unsigned int count)
  {
  	while (count--) {
  		if (*str == '
  ')
  			ata_mfp_out('\r');
  		ata_mfp_out(*str++);
  	}
  }
  
  static inline void ata_scc_out(char c)
  {
  	do {
  		MFPDELAY();
  	} while (!(atari_scc.cha_b_ctrl & 0x04)); /* wait for tx buf empty */
  	MFPDELAY();
  	atari_scc.cha_b_data = c;
  }
  
  static void atari_scc_console_write(struct console *co, const char *str,
  				    unsigned int count)
  {
  	while (count--) {
  		if (*str == '
  ')
  			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;
  }
  
  static void atari_midi_console_write(struct console *co, const char *str,
  				     unsigned int count)
  {
  	while (count--) {
  		if (*str == '
  ')
  			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_jiffy > 1 ? loops_per_jiffy : 10000000/HZ;
  
  	while ((st_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 == '
  ') {
  			if (!ata_par_out('\r')) {
  				printer_present = 0;
  				return;
  			}
  		}
  		if (!ata_par_out(*str++)) {
  			printer_present = 0;
  			return;
  		}
  	}
  }
  
  #if 0
  int atari_mfp_console_wait_key(struct console *co)
  {
  	while (!(st_mfp.rcv_stat & 0x80))	/* wait for rx buf filled */
  		barrier();
  	return st_mfp.usart_dta;
  }
  
  int atari_scc_console_wait_key(struct console *co)
  {
  	do {
  		MFPDELAY();
  	} while (!(atari_scc.cha_b_ctrl & 0x01)); /* wait for rx buf filled */
  	MFPDELAY();
  	return atari_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.
   */
  static void __init atari_init_mfp_port(int cflag)
  {
  	/*
  	 * 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 */
  
  	st_mfp.trn_stat &= ~0x01;	/* disable TX */
  	st_mfp.usart_ctr = parity | csize | 0x88; /* 1:16 clk mode, 1 stop bit */
  	st_mfp.tim_ct_cd &= 0x70;	/* stop timer D */
  	st_mfp.tim_dt_d = baud_table[baud];
  	st_mfp.tim_ct_cd |= 0x01;	/* start timer D, 1:4 */
  	st_mfp.trn_stat |= 0x01;	/* enable TX */
  }
  
  #define SCC_WRITE(reg, val)				\
  	do {						\
  		atari_scc.cha_b_ctrl = (reg);		\
  		MFPDELAY();				\
  		atari_scc.cha_b_ctrl = (val);		\
  		MFPDELAY();				\
  	} while (0)
  
  /* loops_per_jiffy 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)
  
  static void __init atari_init_scc_port(int cflag)
  {
  	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)atari_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;
  }
  
  static void __init atari_init_midi_port(int cflag)
  {
  	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);
  }
  
  static int __init atari_debug_setup(char *arg)
  {
  	bool registered;
  
  	if (!MACH_IS_ATARI)
  		return 0;
  
  	if (!strcmp(arg, "ser"))
  		/* defaults to ser2 for a Falcon and ser1 otherwise */
  		arg = MACH_IS_FALCON ? "ser2" : "ser1";
  
  	registered = !!atari_console_driver.write;
  	if (!strcmp(arg, "ser1")) {
  		/* ST-MFP Modem1 serial port */
  		atari_init_mfp_port(B9600|CS8);
  		atari_console_driver.write = atari_mfp_console_write;
  	} else if (!strcmp(arg, "ser2")) {
  		/* SCC Modem2 serial port */
  		atari_init_scc_port(B9600|CS8);
  		atari_console_driver.write = atari_scc_console_write;
  	} else if (!strcmp(arg, "midi")) {
  		/* MIDI port */
  		atari_init_midi_port(B9600|CS8);
  		atari_console_driver.write = atari_midi_console_write;
  	} else if (!strcmp(arg, "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 && !registered)
  		register_console(&atari_console_driver);
  
  	return 0;
  }
  
  early_param("debug", atari_debug_setup);