/*

   *  Copyright (C) 1995-2000  Linus Torvalds & author (see below)
   */
  
  /*

   *  HT-6560B EIDE-controller support
   *  To activate controller support use kernel parameter "ide0=ht6560b".
   *  Use hdparm utility to enable PIO mode support.
   *
   *  Author:    Mikko Ala-Fossi            <maf@iki.fi>

   *             Jan Evert van Grootheest   <j.e.van.grootheest@caiway.nl>

   *

   */

  #define DRV_NAME	"ht6560b"

  #define HT6560B_VERSION "v0.08"

  #include <linux/module.h>

  #include <linux/types.h>
  #include <linux/kernel.h>
  #include <linux/delay.h>
  #include <linux/timer.h>
  #include <linux/mm.h>
  #include <linux/ioport.h>
  #include <linux/blkdev.h>

  #include <linux/ide.h>
  #include <linux/init.h>
  
  #include <asm/io.h>
  
  /* #define DEBUG */  /* remove comments for DEBUG messages */
  
  /*
   * The special i/o-port that HT-6560B uses to configuration:
   *    bit0 (0x01): "1" selects secondary interface
   *    bit2 (0x04): "1" enables FIFO function
   *    bit5 (0x20): "1" enables prefetched data read function  (???)
   *
   * The special i/o-port that HT-6560A uses to configuration:
   *    bit0 (0x01): "1" selects secondary interface
   *    bit1 (0x02): "1" enables prefetched data read function
   *    bit2 (0x04): "0" enables multi-master system	      (?)
   *    bit3 (0x08): "1" 3 cycle time, "0" 2 cycle time	      (?)
   */
  #define HT_CONFIG_PORT	  0x3e6

  
  static inline u8 HT_CONFIG(ide_drive_t *drive)
  {
  	return ((unsigned long)ide_get_drivedata(drive) & 0xff00) >> 8;
  }

  /*
   * FIFO + PREFETCH (both a/b-model)
   */
  #define HT_CONFIG_DEFAULT 0x1c /* no prefetch */
  /* #define HT_CONFIG_DEFAULT 0x3c */ /* with prefetch */
  #define HT_SECONDARY_IF	  0x01
  #define HT_PREFETCH_MODE  0x20
  
  /*
   * ht6560b Timing values:
   *
   * I reviewed some assembler source listings of htide drivers and found
   * out how they setup those cycle time interfacing values, as they at Holtek
   * call them. IDESETUP.COM that is supplied with the drivers figures out
   * optimal values and fetches those values to drivers. I found out that

   * they use Select register to fetch timings to the ide board right after

   * interface switching. After that it was quite easy to add code to
   * ht6560b.c.
   *
   * IDESETUP.COM gave me values 0x24, 0x45, 0xaa, 0xff that worked fine
   * for hda and hdc. But hdb needed higher values to work, so I guess
   * that sometimes it is necessary to give higher value than IDESETUP
   * gives.   [see cmd640.c for an extreme example of this. -ml]
   *
   * Perhaps I should explain something about these timing values:
   * The higher nibble of value is the Recovery Time  (rt) and the lower nibble
   * of the value is the Active Time  (at). Minimum value 2 is the fastest and
   * the maximum value 15 is the slowest. Default values should be 15 for both.
   * So 0x24 means 2 for rt and 4 for at. Each of the drives should have
   * both values, and IDESETUP gives automatically rt=15 st=15 for CDROMs or
   * similar. If value is too small there will be all sorts of failures.
   *
   * Timing byte consists of
   *	High nibble:  Recovery Cycle Time  (rt)
   *	     The valid values range from 2 to 15. The default is 15.
   *
   *	Low nibble:   Active Cycle Time	   (at)
   *	     The valid values range from 2 to 15. The default is 15.
   *
   * You can obtain optimized timing values by running Holtek IDESETUP.COM
   * for DOS. DOS drivers get their timing values from command line, where
   * the first value is the Recovery Time and the second value is the
   * Active Time for each drive. Smaller value gives higher speed.
   * In case of failures you should probably fall back to a higher value.
   */

  static inline u8 HT_TIMING(ide_drive_t *drive)
  {
  	return (unsigned long)ide_get_drivedata(drive) & 0x00ff;
  }

  #define HT_TIMING_DEFAULT 0xff
  
  /*
   * This routine handles interface switching for the peculiar hardware design
   * on the F.G.I./Holtek HT-6560B VLB IDE interface.
   * The HT-6560B can only enable one IDE port at a time, and requires a
   * silly sequence (below) whenever we switch between primary and secondary.
   */
  
  /*
   * This routine is invoked from ide.c to prepare for access to a given drive.
   */

  static void ht6560b_dev_select(ide_drive_t *drive)

  {

  	ide_hwif_t *hwif = drive->hwif;

  	unsigned long flags;
  	static u8 current_select = 0;
  	static u8 current_timing = 0;
  	u8 select, timing;
  	
  	local_irq_save(flags);

  	select = HT_CONFIG(drive);
  	timing = HT_TIMING(drive);

  
  	/*
  	 * Need to enforce prefetch sometimes because otherwise
  	 * it'll hang (hard).
  	 */

  	if (drive->media != ide_disk ||
  	    (drive->dev_flags & IDE_DFLAG_PRESENT) == 0)

  		select |= HT_PREFETCH_MODE;

  	if (select != current_select || timing != current_timing) {
  		current_select = select;
  		current_timing = timing;

  		(void)inb(HT_CONFIG_PORT);
  		(void)inb(HT_CONFIG_PORT);
  		(void)inb(HT_CONFIG_PORT);
  		(void)inb(HT_CONFIG_PORT);
  		outb(select, HT_CONFIG_PORT);

  		/*
  		 * Set timing for this drive:
  		 */

  		outb(timing, hwif->io_ports.device_addr);
  		(void)inb(hwif->io_ports.status_addr);

  #ifdef DEBUG
  		printk("ht6560b: %s: select=%#x timing=%#x
  ",
  			drive->name, select, timing);
  #endif
  	}
  	local_irq_restore(flags);

  
  	outb(drive->select | ATA_DEVICE_OBS, hwif->io_ports.device_addr);

  }
  
  /*
   * Autodetection and initialization of ht6560b
   */
  static int __init try_to_init_ht6560b(void)
  {
  	u8 orig_value;
  	int i;
  	
  	/* Autodetect ht6560b */
  	if ((orig_value = inb(HT_CONFIG_PORT)) == 0xff)
  		return 0;
  	
  	for (i=3;i>0;i--) {
  		outb(0x00, HT_CONFIG_PORT);
  		if (!( (~inb(HT_CONFIG_PORT)) & 0x3f )) {
  			outb(orig_value, HT_CONFIG_PORT);
  			return 0;
  		}
  	}
  	outb(0x00, HT_CONFIG_PORT);
  	if ((~inb(HT_CONFIG_PORT))& 0x3f) {
  		outb(orig_value, HT_CONFIG_PORT);
  		return 0;
  	}
  	/*
  	 * Ht6560b autodetected
  	 */
  	outb(HT_CONFIG_DEFAULT, HT_CONFIG_PORT);

  	outb(HT_TIMING_DEFAULT, 0x1f6);	/* Select register */
  	(void)inb(0x1f7);		/* Status register */

  	printk("ht6560b " HT6560B_VERSION

  	       ": chipset detected and initialized"
  #ifdef DEBUG
  	       " with debug enabled"
  #endif

  	       "
  "

  		);
  	return 1;
  }

  static u8 ht_pio2timings(ide_drive_t *drive, const u8 pio)

  {
  	int active_time, recovery_time;
  	int active_cycles, recovery_cycles;

  	int bus_speed = ide_vlb_clk ? ide_vlb_clk : 50;

          if (pio) {

  		unsigned int cycle_time;

  		struct ide_timing *t = ide_timing_find_mode(XFER_PIO_0 + pio);

  		cycle_time = ide_pio_cycle_time(drive, pio);

  		/*
  		 *  Just like opti621.c we try to calculate the
  		 *  actual cycle time for recovery and activity
  		 *  according system bus speed.
  		 */

  		active_time = t->active;
  		recovery_time = cycle_time - active_time - t->setup;

  		/*
  		 *  Cycle times should be Vesa bus cycles
  		 */
  		active_cycles   = (active_time   * bus_speed + 999) / 1000;
  		recovery_cycles = (recovery_time * bus_speed + 999) / 1000;
  		/*
  		 *  Upper and lower limits
  		 */
  		if (active_cycles   < 2)  active_cycles   = 2;
  		if (recovery_cycles < 2)  recovery_cycles = 2;
  		if (active_cycles   > 15) active_cycles   = 15;
  		if (recovery_cycles > 15) recovery_cycles = 0;  /* 0==16 */
  		
  #ifdef DEBUG
  		printk("ht6560b: drive %s setting pio=%d recovery=%d (%dns) active=%d (%dns)
  ", drive->name, pio, recovery_cycles, recovery_time, active_cycles, active_time);
  #endif
  		
  		return (u8)((recovery_cycles << 4) | active_cycles);
  	} else {
  		
  #ifdef DEBUG
  		printk("ht6560b: drive %s setting pio=0
  ", drive->name);
  #endif
  		
  		return HT_TIMING_DEFAULT;    /* default setting */
  	}
  }

  static DEFINE_SPINLOCK(ht6560b_lock);

  /*
   *  Enable/Disable so called prefetch mode
   */
  static void ht_set_prefetch(ide_drive_t *drive, u8 state)
  {

  	unsigned long flags, config;

  	int t = HT_PREFETCH_MODE << 8;

  
  	spin_lock_irqsave(&ht6560b_lock, flags);

  	config = (unsigned long)ide_get_drivedata(drive);

  	/*
  	 *  Prefetch mode and unmask irq seems to conflict
  	 */
  	if (state) {

  		config |= t;   /* enable prefetch mode */

  		drive->dev_flags |= IDE_DFLAG_NO_UNMASK;
  		drive->dev_flags &= ~IDE_DFLAG_UNMASK;

  	} else {

  		config &= ~t;  /* disable prefetch mode */

  		drive->dev_flags &= ~IDE_DFLAG_NO_UNMASK;

  	}

  	ide_set_drivedata(drive, (void *)config);

  	spin_unlock_irqrestore(&ht6560b_lock, flags);

  #ifdef DEBUG
  	printk("ht6560b: drive %s prefetch mode %sabled
  ", drive->name, (state ? "en" : "dis"));
  #endif
  }

  static void ht6560b_set_pio_mode(ide_hwif_t *hwif, ide_drive_t *drive)

  {

  	unsigned long flags, config;

  	const u8 pio = drive->pio_mode - XFER_PIO_0;

  	u8 timing;
  	
  	switch (pio) {
  	case 8:         /* set prefetch off */
  	case 9:         /* set prefetch on */
  		ht_set_prefetch(drive, pio & 1);
  		return;
  	}

  	timing = ht_pio2timings(drive, pio);

  
  	spin_lock_irqsave(&ht6560b_lock, flags);

  	config = (unsigned long)ide_get_drivedata(drive);
  	config &= 0xff00;
  	config |= timing;
  	ide_set_drivedata(drive, (void *)config);

  	spin_unlock_irqrestore(&ht6560b_lock, flags);

  #ifdef DEBUG
  	printk("ht6560b: drive %s tuned to pio mode %#x timing=%#x
  ", drive->name, pio, timing);
  #endif
  }

  static void __init ht6560b_init_dev(ide_drive_t *drive)

  {

  	ide_hwif_t *hwif = drive->hwif;

  	/* Setting default configurations for drives. */
  	int t = (HT_CONFIG_DEFAULT << 8) | HT_TIMING_DEFAULT;
  
  	if (hwif->channel)
  		t |= (HT_SECONDARY_IF << 8);

  	ide_set_drivedata(drive, (void *)t);

  }

  static bool probe_ht6560b;

  
  module_param_named(probe, probe_ht6560b, bool, 0);
  MODULE_PARM_DESC(probe, "probe for HT6560B chipset");

  static const struct ide_tp_ops ht6560b_tp_ops = {
  	.exec_command		= ide_exec_command,
  	.read_status		= ide_read_status,
  	.read_altstatus		= ide_read_altstatus,
  	.write_devctl		= ide_write_devctl,
  
  	.dev_select		= ht6560b_dev_select,
  	.tf_load		= ide_tf_load,
  	.tf_read		= ide_tf_read,
  
  	.input_data		= ide_input_data,
  	.output_data		= ide_output_data,
  };

  static const struct ide_port_ops ht6560b_port_ops = {

  	.init_dev		= ht6560b_init_dev,

  	.set_pio_mode		= ht6560b_set_pio_mode,

  };

  static const struct ide_port_info ht6560b_port_info __initconst = {

  	.name			= DRV_NAME,

  	.chipset		= ide_ht6560b,

  	.tp_ops 		= &ht6560b_tp_ops,

  	.port_ops		= &ht6560b_port_ops,

  	.host_flags		= IDE_HFLAG_SERIALIZE | /* is this needed? */
  				  IDE_HFLAG_NO_DMA |

  				  IDE_HFLAG_ABUSE_PREFETCH,

  	.pio_mask		= ATA_PIO4,

  };

  static int __init ht6560b_init(void)

  {

  	if (probe_ht6560b == 0)
  		return -ENODEV;

  	if (!request_region(HT_CONFIG_PORT, 1, DRV_NAME)) {

  		printk(KERN_NOTICE "%s: HT_CONFIG_PORT not found
  ",

  			__func__);

  		return -ENODEV;
  	}
  
  	if (!try_to_init_ht6560b()) {

  		printk(KERN_NOTICE "%s: HBA not found
  ", __func__);

  		goto release_region;
  	}

  	return ide_legacy_device_add(&ht6560b_port_info, 0);

  
  release_region:
  	release_region(HT_CONFIG_PORT, 1);
  	return -ENODEV;
  }

  module_init(ht6560b_init);

  
  MODULE_AUTHOR("See Local File");
  MODULE_DESCRIPTION("HT-6560B EIDE-controller support");
  MODULE_LICENSE("GPL");