/*
   *  Copyright (C) 1996  Linus Torvalds & author (see below)
   */
  
  /*
   * ALI M14xx chipset EIDE controller
   *
   * Works for ALI M1439/1443/1445/1487/1489 chipsets.
   *
   * Adapted from code developed by derekn@vw.ece.cmu.edu.  -ml
   * Derek's notes follow:
   *
   * I think the code should be pretty understandable,
   * but I'll be happy to (try to) answer questions.
   *
   * The critical part is in the setupDrive function.  The initRegisters
   * function doesn't seem to be necessary, but the DOS driver does it, so
   * I threw it in.
   *
   * I've only tested this on my system, which only has one disk.  I posted
   * it to comp.sys.linux.hardware, so maybe some other people will try it
   * out.
   *
   * Derek Noonburg  (derekn@ece.cmu.edu)
   * 95-sep-26
   *
   * Update 96-jul-13:
   *
   * I've since upgraded to two disks and a CD-ROM, with no trouble, and
   * I've also heard from several others who have used it successfully.
   * This driver appears to work with both the 1443/1445 and the 1487/1489
   * chipsets.  I've added support for PIO mode 4 for the 1487.  This
   * seems to work just fine on the 1443 also, although I'm not sure it's
   * advertised as supporting mode 4.  (I've been running a WDC AC21200 in
   * mode 4 for a while now with no trouble.)  -Derek
   */
  
  #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 DRV_NAME "ali14xx"
  
  /* port addresses for auto-detection */
  #define ALI_NUM_PORTS 4
  static const int ports[ALI_NUM_PORTS] __initconst =
  	{ 0x074, 0x0f4, 0x034, 0x0e4 };
  
  /* register initialization data */
  typedef struct { u8 reg, data; } RegInitializer;
  
  static const RegInitializer initData[] __initconst = {
  	{0x01, 0x0f}, {0x02, 0x00}, {0x03, 0x00}, {0x04, 0x00},
  	{0x05, 0x00}, {0x06, 0x00}, {0x07, 0x2b}, {0x0a, 0x0f},
  	{0x25, 0x00}, {0x26, 0x00}, {0x27, 0x00}, {0x28, 0x00},
  	{0x29, 0x00}, {0x2a, 0x00}, {0x2f, 0x00}, {0x2b, 0x00},
  	{0x2c, 0x00}, {0x2d, 0x00}, {0x2e, 0x00}, {0x30, 0x00},
  	{0x31, 0x00}, {0x32, 0x00}, {0x33, 0x00}, {0x34, 0xff},
  	{0x35, 0x03}, {0x00, 0x00}
  };
  
  /* timing parameter registers for each drive */
  static struct { u8 reg1, reg2, reg3, reg4; } regTab[4] = {
  	{0x03, 0x26, 0x04, 0x27},     /* drive 0 */
  	{0x05, 0x28, 0x06, 0x29},     /* drive 1 */
  	{0x2b, 0x30, 0x2c, 0x31},     /* drive 2 */
  	{0x2d, 0x32, 0x2e, 0x33},     /* drive 3 */
  };
  
  static int basePort;	/* base port address */
  static int regPort;	/* port for register number */
  static int dataPort;	/* port for register data */
  static u8 regOn;	/* output to base port to access registers */
  static u8 regOff;	/* output to base port to close registers */
  
  /*------------------------------------------------------------------------*/
  
  /*
   * Read a controller register.
   */
  static inline u8 inReg(u8 reg)
  {
  	outb_p(reg, regPort);
  	return inb(dataPort);
  }
  
  /*
   * Write a controller register.
   */
  static void outReg(u8 data, u8 reg)
  {
  	outb_p(reg, regPort);
  	outb_p(data, dataPort);
  }
  
  static DEFINE_SPINLOCK(ali14xx_lock);
  
  /*
   * Set PIO mode for the specified drive.
   * This function computes timing parameters
   * and sets controller registers accordingly.
   */
  static void ali14xx_set_pio_mode(ide_hwif_t *hwif, ide_drive_t *drive)
  {
  	int driveNum;
  	int time1, time2;
  	u8 param1, param2, param3, param4;
  	unsigned long flags;
  	int bus_speed = ide_vlb_clk ? ide_vlb_clk : 50;
  	const u8 pio = drive->pio_mode - XFER_PIO_0;
  	struct ide_timing *t = ide_timing_find_mode(XFER_PIO_0 + pio);
  
  	/* calculate timing, according to PIO mode */
  	time1 = ide_pio_cycle_time(drive, pio);
  	time2 = t->active;
  	param3 = param1 = (time2 * bus_speed + 999) / 1000;
  	param4 = param2 = (time1 * bus_speed + 999) / 1000 - param1;
  	if (pio < 3) {
  		param3 += 8;
  		param4 += 8;
  	}
  	printk(KERN_DEBUG "%s: PIO mode%d, t1=%dns, t2=%dns, cycles = %d+%d, %d+%d
  ",
  		drive->name, pio, time1, time2, param1, param2, param3, param4);
  
  	/* stuff timing parameters into controller registers */
  	driveNum = (drive->hwif->index << 1) + (drive->dn & 1);
  	spin_lock_irqsave(&ali14xx_lock, flags);
  	outb_p(regOn, basePort);
  	outReg(param1, regTab[driveNum].reg1);
  	outReg(param2, regTab[driveNum].reg2);
  	outReg(param3, regTab[driveNum].reg3);
  	outReg(param4, regTab[driveNum].reg4);
  	outb_p(regOff, basePort);
  	spin_unlock_irqrestore(&ali14xx_lock, flags);
  }
  
  /*
   * Auto-detect the IDE controller port.
   */
  static int __init findPort(void)
  {
  	int i;
  	u8 t;
  	unsigned long flags;
  
  	local_irq_save(flags);
  	for (i = 0; i < ALI_NUM_PORTS; ++i) {
  		basePort = ports[i];
  		regOff = inb(basePort);
  		for (regOn = 0x30; regOn <= 0x33; ++regOn) {
  			outb_p(regOn, basePort);
  			if (inb(basePort) == regOn) {
  				regPort = basePort + 4;
  				dataPort = basePort + 8;
  				t = inReg(0) & 0xf0;
  				outb_p(regOff, basePort);
  				local_irq_restore(flags);
  				if (t != 0x50)
  					return 0;
  				return 1;  /* success */
  			}
  		}
  		outb_p(regOff, basePort);
  	}
  	local_irq_restore(flags);
  	return 0;
  }
  
  /*
   * Initialize controller registers with default values.
   */
  static int __init initRegisters(void)
  {
  	const RegInitializer *p;
  	u8 t;
  	unsigned long flags;
  
  	local_irq_save(flags);
  	outb_p(regOn, basePort);
  	for (p = initData; p->reg != 0; ++p)
  		outReg(p->data, p->reg);
  	outb_p(0x01, regPort);
  	t = inb(regPort) & 0x01;
  	outb_p(regOff, basePort);
  	local_irq_restore(flags);
  	return t;
  }
  
  static const struct ide_port_ops ali14xx_port_ops = {
  	.set_pio_mode		= ali14xx_set_pio_mode,
  };
  
  static const struct ide_port_info ali14xx_port_info = {
  	.name			= DRV_NAME,
  	.chipset		= ide_ali14xx,
  	.port_ops		= &ali14xx_port_ops,
  	.host_flags		= IDE_HFLAG_NO_DMA,
  	.pio_mask		= ATA_PIO4,
  };
  
  static int __init ali14xx_probe(void)
  {
  	printk(KERN_DEBUG "ali14xx: base=0x%03x, regOn=0x%02x.
  ",
  			  basePort, regOn);
  
  	/* initialize controller registers */
  	if (!initRegisters()) {
  		printk(KERN_ERR "ali14xx: Chip initialization failed.
  ");
  		return 1;
  	}
  
  	return ide_legacy_device_add(&ali14xx_port_info, 0);
  }
  
  static bool probe_ali14xx;
  
  module_param_named(probe, probe_ali14xx, bool, 0);
  MODULE_PARM_DESC(probe, "probe for ALI M14xx chipsets");
  
  static int __init ali14xx_init(void)
  {
  	if (probe_ali14xx == 0)
  		goto out;
  
  	/* auto-detect IDE controller port */
  	if (findPort()) {
  		if (ali14xx_probe())
  			return -ENODEV;
  		return 0;
  	}
  	printk(KERN_ERR "ali14xx: not found.
  ");
  out:
  	return -ENODEV;
  }
  
  module_init(ali14xx_init);
  
  MODULE_AUTHOR("see local file");
  MODULE_DESCRIPTION("support of ALI 14XX IDE chipsets");
  MODULE_LICENSE("GPL");