/*
   *  linux/drivers/hil/hilkbd.c
   *
   *  Copyright (C) 1998 Philip Blundell <philb@gnu.org>
   *  Copyright (C) 1999 Matthew Wilcox <willy@bofh.ai>
   *  Copyright (C) 1999-2007 Helge Deller <deller@gmx.de>
   *
   *  Very basic HP Human Interface Loop (HIL) driver.
   *  This driver handles the keyboard on HP300 (m68k) and on some
   *  HP700 (parisc) series machines.
   *
   *
   * This file is subject to the terms and conditions of the GNU General Public
   * License version 2.  See the file COPYING in the main directory of this
   * archive for more details.
   */
  
  #include <linux/pci_ids.h>
  #include <linux/ioport.h>
  #include <linux/module.h>
  #include <linux/errno.h>
  #include <linux/input.h>
  #include <linux/init.h>
  #include <linux/interrupt.h>
  #include <linux/hil.h>
  #include <linux/io.h>
  #include <linux/sched.h>
  #include <linux/spinlock.h>
  #include <asm/irq.h>
  #ifdef CONFIG_HP300
  #include <asm/hwtest.h>
  #endif
  
  
  MODULE_AUTHOR("Philip Blundell, Matthew Wilcox, Helge Deller");
  MODULE_DESCRIPTION("HIL keyboard driver (basic functionality)");
  MODULE_LICENSE("GPL v2");
  
  
  #if defined(CONFIG_PARISC)
  
   #include <asm/io.h>
   #include <asm/hardware.h>
   #include <asm/parisc-device.h>
   static unsigned long hil_base;	/* HPA for the HIL device */
   static unsigned int hil_irq;
   #define HILBASE		hil_base /* HPPA (parisc) port address */
   #define HIL_DATA		0x800
   #define HIL_CMD		0x801
   #define HIL_IRQ		hil_irq
   #define hil_readb(p)		gsc_readb(p)
   #define hil_writeb(v,p)	gsc_writeb((v),(p))
  
  #elif defined(CONFIG_HP300)
  
   #define HILBASE		0xf0428000UL /* HP300 (m68k) port address */
   #define HIL_DATA		0x1
   #define HIL_CMD		0x3
   #define HIL_IRQ		2
   #define hil_readb(p)		readb(p)
   #define hil_writeb(v,p)	writeb((v),(p))
  
  #else
  #error "HIL is not supported on this platform"
  #endif
  
  
  
  /* HIL helper functions */
  
  #define hil_busy()              (hil_readb(HILBASE + HIL_CMD) & HIL_BUSY)
  #define hil_data_available()    (hil_readb(HILBASE + HIL_CMD) & HIL_DATA_RDY)
  #define hil_status()            (hil_readb(HILBASE + HIL_CMD))
  #define hil_command(x)          do { hil_writeb((x), HILBASE + HIL_CMD); } while (0)
  #define hil_read_data()         (hil_readb(HILBASE + HIL_DATA))
  #define hil_write_data(x)       do { hil_writeb((x), HILBASE + HIL_DATA); } while (0)
  
  /* HIL constants */
  
  #define	HIL_BUSY		0x02
  #define	HIL_DATA_RDY		0x01
  
  #define	HIL_SETARD		0xA0		/* set auto-repeat delay */
  #define	HIL_SETARR		0xA2		/* set auto-repeat rate */
  #define	HIL_SETTONE		0xA3		/* set tone generator */
  #define	HIL_CNMT		0xB2		/* clear nmi */
  #define	HIL_INTON		0x5C		/* Turn on interrupts. */
  #define	HIL_INTOFF		0x5D		/* Turn off interrupts. */
  
  #define	HIL_READKBDSADR		0xF9
  #define	HIL_WRITEKBDSADR	0xE9
  
  static unsigned int hphilkeyb_keycode[HIL_KEYCODES_SET1_TBLSIZE] __read_mostly =
  	{ HIL_KEYCODES_SET1 };
  
  /* HIL structure */
  static struct {
  	struct input_dev *dev;
  
  	unsigned int curdev;
  
  	unsigned char s;
  	unsigned char c;
  	int valid;
  
  	unsigned char data[16];
  	unsigned int ptr;
  	spinlock_t lock;
  
  	void *dev_id;	/* native bus device */
  } hil_dev;
  
  
  static void poll_finished(void)
  {
  	int down;
  	int key;
  	unsigned char scode;
  
  	switch (hil_dev.data[0]) {
  	case 0x40:
  		down = (hil_dev.data[1] & 1) == 0;
  		scode = hil_dev.data[1] >> 1;
  		key = hphilkeyb_keycode[scode];
  		input_report_key(hil_dev.dev, key, down);
  		break;
  	}
  	hil_dev.curdev = 0;
  }
  
  
  static inline void handle_status(unsigned char s, unsigned char c)
  {
  	if (c & 0x8) {
  		/* End of block */
  		if (c & 0x10)
  			poll_finished();
  	} else {
  		if (c & 0x10) {
  			if (hil_dev.curdev)
  				poll_finished();  /* just in case */
  			hil_dev.curdev = c & 7;
  			hil_dev.ptr = 0;
  		}
  	}
  }
  
  
  static inline void handle_data(unsigned char s, unsigned char c)
  {
  	if (hil_dev.curdev) {
  		hil_dev.data[hil_dev.ptr++] = c;
  		hil_dev.ptr &= 15;
  	}
  }
  
  
  /* handle HIL interrupts */
  static irqreturn_t hil_interrupt(int irq, void *handle)
  {
  	unsigned char s, c;
  
  	s = hil_status();
  	c = hil_read_data();
  
  	switch (s >> 4) {
  	case 0x5:
  		handle_status(s, c);
  		break;
  	case 0x6:
  		handle_data(s, c);
  		break;
  	case 0x4:
  		hil_dev.s = s;
  		hil_dev.c = c;
  		mb();
  		hil_dev.valid = 1;
  		break;
  	}
  	return IRQ_HANDLED;
  }
  
  
  /* send a command to the HIL */
  static void hil_do(unsigned char cmd, unsigned char *data, unsigned int len)
  {
  	unsigned long flags;
  
  	spin_lock_irqsave(&hil_dev.lock, flags);
  	while (hil_busy())
  		/* wait */;
  	hil_command(cmd);
  	while (len--) {
  		while (hil_busy())
  			/* wait */;
  		hil_write_data(*(data++));
  	}
  	spin_unlock_irqrestore(&hil_dev.lock, flags);
  }
  
  
  /* initialize HIL */
  static int hil_keyb_init(void)
  {
  	unsigned char c;
  	unsigned int i, kbid;
  	wait_queue_head_t hil_wait;
  	int err;
  
  	if (hil_dev.dev)
  		return -ENODEV; /* already initialized */
  
  	init_waitqueue_head(&hil_wait);
  	spin_lock_init(&hil_dev.lock);
  
  	hil_dev.dev = input_allocate_device();
  	if (!hil_dev.dev)
  		return -ENOMEM;
  
  	err = request_irq(HIL_IRQ, hil_interrupt, 0, "hil", hil_dev.dev_id);
  	if (err) {
  		printk(KERN_ERR "HIL: Can't get IRQ
  ");
  		goto err1;
  	}
  
  	/* Turn on interrupts */
  	hil_do(HIL_INTON, NULL, 0);
  
  	/* Look for keyboards */
  	hil_dev.valid = 0;	/* clear any pending data */
  	hil_do(HIL_READKBDSADR, NULL, 0);
  
  	wait_event_interruptible_timeout(hil_wait, hil_dev.valid, 3 * HZ);
  	if (!hil_dev.valid)
  		printk(KERN_WARNING "HIL: timed out, assuming no keyboard present
  ");
  
  	c = hil_dev.c;
  	hil_dev.valid = 0;
  	if (c == 0) {
  		kbid = -1;
  		printk(KERN_WARNING "HIL: no keyboard present
  ");
  	} else {
  		kbid = ffz(~c);
  		printk(KERN_INFO "HIL: keyboard found at id %d
  ", kbid);
  	}
  
  	/* set it to raw mode */
  	c = 0;
  	hil_do(HIL_WRITEKBDSADR, &c, 1);
  
  	for (i = 0; i < HIL_KEYCODES_SET1_TBLSIZE; i++)
  		if (hphilkeyb_keycode[i] != KEY_RESERVED)
  			__set_bit(hphilkeyb_keycode[i], hil_dev.dev->keybit);
  
  	hil_dev.dev->evbit[0]	= BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
  	hil_dev.dev->ledbit[0]	= BIT_MASK(LED_NUML) | BIT_MASK(LED_CAPSL) |
  		BIT_MASK(LED_SCROLLL);
  	hil_dev.dev->keycodemax	= HIL_KEYCODES_SET1_TBLSIZE;
  	hil_dev.dev->keycodesize= sizeof(hphilkeyb_keycode[0]);
  	hil_dev.dev->keycode	= hphilkeyb_keycode;
  	hil_dev.dev->name	= "HIL keyboard";
  	hil_dev.dev->phys	= "hpkbd/input0";
  
  	hil_dev.dev->id.bustype	= BUS_HIL;
  	hil_dev.dev->id.vendor	= PCI_VENDOR_ID_HP;
  	hil_dev.dev->id.product	= 0x0001;
  	hil_dev.dev->id.version	= 0x0010;
  
  	err = input_register_device(hil_dev.dev);
  	if (err) {
  		printk(KERN_ERR "HIL: Can't register device
  ");
  		goto err2;
  	}
  
  	printk(KERN_INFO "input: %s, ID %d at 0x%08lx (irq %d) found and attached
  ",
  	       hil_dev.dev->name, kbid, HILBASE, HIL_IRQ);
  
  	return 0;
  
  err2:
  	hil_do(HIL_INTOFF, NULL, 0);
  	free_irq(HIL_IRQ, hil_dev.dev_id);
  err1:
  	input_free_device(hil_dev.dev);
  	hil_dev.dev = NULL;
  	return err;
  }
  
  static void hil_keyb_exit(void)
  {
  	if (HIL_IRQ)
  		free_irq(HIL_IRQ, hil_dev.dev_id);
  
  	/* Turn off interrupts */
  	hil_do(HIL_INTOFF, NULL, 0);
  
  	input_unregister_device(hil_dev.dev);
  	hil_dev.dev = NULL;
  }
  
  #if defined(CONFIG_PARISC)
  static int hil_probe_chip(struct parisc_device *dev)
  {
  	/* Only allow one HIL keyboard */
  	if (hil_dev.dev)
  		return -ENODEV;
  
  	if (!dev->irq) {
  		printk(KERN_WARNING "HIL: IRQ not found for HIL bus at 0x%p
  ",
  			(void *)dev->hpa.start);
  		return -ENODEV;
  	}
  
  	hil_base = dev->hpa.start;
  	hil_irq  = dev->irq;
  	hil_dev.dev_id = dev;
  
  	printk(KERN_INFO "Found HIL bus at 0x%08lx, IRQ %d
  ", hil_base, hil_irq);
  
  	return hil_keyb_init();
  }
  
  static int hil_remove_chip(struct parisc_device *dev)
  {
  	hil_keyb_exit();
  
  	return 0;
  }
  
  static struct parisc_device_id hil_tbl[] = {
  	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00073 },
  	{ 0, }
  };
  
  #if 0
  /* Disabled to avoid conflicts with the HP SDC HIL drivers */
  MODULE_DEVICE_TABLE(parisc, hil_tbl);
  #endif
  
  static struct parisc_driver hil_driver = {
  	.name		= "hil",
  	.id_table	= hil_tbl,
  	.probe		= hil_probe_chip,
  	.remove		= hil_remove_chip,
  };
  
  static int __init hil_init(void)
  {
  	return register_parisc_driver(&hil_driver);
  }
  
  static void __exit hil_exit(void)
  {
  	unregister_parisc_driver(&hil_driver);
  }
  
  #else /* !CONFIG_PARISC */
  
  static int __init hil_init(void)
  {
  	int error;
  
  	/* Only allow one HIL keyboard */
  	if (hil_dev.dev)
  		return -EBUSY;
  
  	if (!MACH_IS_HP300)
  		return -ENODEV;
  
  	if (!hwreg_present((void *)(HILBASE + HIL_DATA))) {
  		printk(KERN_ERR "HIL: hardware register was not found
  ");
  		return -ENODEV;
  	}
  
  	if (!request_region(HILBASE + HIL_DATA, 2, "hil")) {
  		printk(KERN_ERR "HIL: IOPORT region already used
  ");
  		return -EIO;
  	}
  
  	error = hil_keyb_init();
  	if (error) {
  		release_region(HILBASE + HIL_DATA, 2);
  		return error;
  	}
  
  	return 0;
  }
  
  static void __exit hil_exit(void)
  {
  	hil_keyb_exit();
  	release_region(HILBASE + HIL_DATA, 2);
  }
  
  #endif /* CONFIG_PARISC */
  
  module_init(hil_init);
  module_exit(hil_exit);