text: /*
   * Generic linux-input device driver for axis-bearing devices
   *
   * Copyright (c) 2001 Brian S. Julin
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions, and the following disclaimer,
   *    without modification.
   * 2. The name of the author may not be used to endorse or promote products
   *    derived from this software without specific prior written permission.
   *
   * Alternatively, this software may be distributed under the terms of the
   * GNU General Public License ("GPL").
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
   * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   *
   * References:
   * HP-HIL Technical Reference Manual.  Hewlett Packard Product No. 45918A
   *
   */
  
  #include <linux/hil.h>
  #include <linux/input.h>
  #include <linux/serio.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/slab.h>
  #include <linux/pci_ids.h>
  
  #define PREFIX "HIL PTR: "
  #define HIL_GENERIC_NAME "HIL pointer device"
  
  MODULE_AUTHOR("Brian S. Julin <bri@calyx.com>");
  MODULE_DESCRIPTION(HIL_GENERIC_NAME " driver");
  MODULE_LICENSE("Dual BSD/GPL");
  
  
  #define TABLET_SIMULATES_MOUSE	/* allow tablet to be used as mouse */
  #undef  TABLET_AUTOADJUST	/* auto-adjust valid tablet ranges */
  
  
  #define HIL_PTR_MAX_LENGTH 16
  
  struct hil_ptr {
  	struct input_dev *dev;
  	struct serio *serio;
  
  	/* Input buffer and index for packets from HIL bus. */
  	hil_packet data[HIL_PTR_MAX_LENGTH];
  	int idx4; /* four counts per packet */
  
  	/* Raw device info records from HIL bus, see hil.h for fields. */
  	char	idd[HIL_PTR_MAX_LENGTH];	/* DID byte and IDD record */
  	char	rsc[HIL_PTR_MAX_LENGTH];	/* RSC record */
  	char	exd[HIL_PTR_MAX_LENGTH];	/* EXD record */
  	char	rnm[HIL_PTR_MAX_LENGTH + 1];	/* RNM record + NULL term. */
  
  	/* Extra device details not contained in struct input_dev. */
  	unsigned int nbtn, naxes;
  	unsigned int btnmap[7];
  
  	/* Something to sleep around with. */
  	struct semaphore sem;
  };
  
  /* Process a complete packet after transfer from the HIL */
  static void hil_ptr_process_record(struct hil_ptr *ptr)
  {
  	struct input_dev *dev = ptr->dev;
  	hil_packet *data = ptr->data;
  	hil_packet p;
  	int idx, i, cnt, laxis;
  	int ax16, absdev;
  
  	idx = ptr->idx4/4;
  	p = data[idx - 1];
  
  	if ((p & ~HIL_CMDCT_POL) ==
  	    (HIL_ERR_INT | HIL_PKT_CMD | HIL_CMD_POL))
  		goto report;
  	if ((p & ~HIL_CMDCT_RPL) ==
  	    (HIL_ERR_INT | HIL_PKT_CMD | HIL_CMD_RPL))
  		goto report;
  
  	/* Not a poll response.  See if we are loading config records. */
  	switch (p & HIL_PKT_DATA_MASK) {
  	case HIL_CMD_IDD:
  		for (i = 0; i < idx; i++)
  			ptr->idd[i] = ptr->data[i] & HIL_PKT_DATA_MASK;
  		for (; i < HIL_PTR_MAX_LENGTH; i++)
  			ptr->idd[i] = 0;
  		break;
  
  	case HIL_CMD_RSC:
  		for (i = 0; i < idx; i++)
  			ptr->rsc[i] = ptr->data[i] & HIL_PKT_DATA_MASK;
  		for (; i < HIL_PTR_MAX_LENGTH; i++)
  			ptr->rsc[i] = 0;
  		break;
  
  	case HIL_CMD_EXD:
  		for (i = 0; i < idx; i++)
  			ptr->exd[i] = ptr->data[i] & HIL_PKT_DATA_MASK;
  		for (; i < HIL_PTR_MAX_LENGTH; i++)
  			ptr->exd[i] = 0;
  		break;
  
  	case HIL_CMD_RNM:
  		for (i = 0; i < idx; i++)
  			ptr->rnm[i] = ptr->data[i] & HIL_PKT_DATA_MASK;
  		for (; i < HIL_PTR_MAX_LENGTH + 1; i++)
  			ptr->rnm[i] = 0;
  		break;
  
  	default:
  		/* These occur when device isn't present */
  		if (p == (HIL_ERR_INT | HIL_PKT_CMD))
  			break;
  		/* Anything else we'd like to know about. */
  		printk(KERN_WARNING PREFIX "Device sent unknown record %x\n", p);
  		break;
  	}
  	goto out;
  
   report:
  	if ((p & HIL_CMDCT_POL) != idx - 1) {
  		printk(KERN_WARNING PREFIX
  			"Malformed poll packet %x (idx = %i)\n", p, idx);
  		goto out;
  	}
  
  	i = (ptr->data[0] & HIL_POL_AXIS_ALT) ? 3 : 0;
  	laxis = ptr->data[0] & HIL_POL_NUM_AXES_MASK;
  	laxis += i;
  
  	ax16 = ptr->idd[1] & HIL_IDD_HEADER_16BIT; /* 8 or 16bit resolution */
  	absdev = ptr->idd[1] & HIL_IDD_HEADER_ABS;
  
  	for (cnt = 1; i < laxis; i++) {
  		unsigned int lo,hi,val;
  		lo = ptr->data[cnt++] & HIL_PKT_DATA_MASK;
  		hi = ax16 ? (ptr->data[cnt++] & HIL_PKT_DATA_MASK) : 0;
  		if (absdev) {
  			val = lo + (hi<<8);
  #ifdef TABLET_AUTOADJUST
  			if (val < dev->absmin[ABS_X + i])
  				dev->absmin[ABS_X + i] = val;
  			if (val > dev->absmax[ABS_X + i])
  				dev->absmax[ABS_X + i] = val;
  #endif
  			if (i%3) val = dev->absmax[ABS_X + i] - val;
  			input_report_abs(dev, ABS_X + i, val);
  		} else {
  			val = (int) (((int8_t)lo) | ((int8_t)hi<<8));
  			if (i%3)
  				val *= -1;
  			input_report_rel(dev, REL_X + i, val);
  		}
  	}
  
  	while (cnt < idx - 1) {
  		unsigned int btn;
  		int up;
  		btn = ptr->data[cnt++];
  		up = btn & 1;
  		btn &= 0xfe;
  		if (btn == 0x8e)
  			continue; /* TODO: proximity == touch? */
  		else
  			if ((btn > 0x8c) || (btn < 0x80))
  				continue;
  		btn = (btn - 0x80) >> 1;
  		btn = ptr->btnmap[btn];
  		input_report_key(dev, btn, !up);
  	}
  	input_sync(dev);
   out:
  	ptr->idx4 = 0;
  	up(&ptr->sem);
  }
  
  static void hil_ptr_process_err(struct hil_ptr *ptr)
  {
  	printk(KERN_WARNING PREFIX "errored HIL packet\n");
  	ptr->idx4 = 0;
  	up(&ptr->sem);
  }
  
  static irqreturn_t hil_ptr_interrupt(struct serio *serio,
          unsigned char data, unsigned int flags)
  {
  	struct hil_ptr *ptr;
  	hil_packet packet;
  	int idx;
  
  	ptr = serio_get_drvdata(serio);
  	BUG_ON(ptr == NULL);
  
  	if (ptr->idx4 >= (HIL_PTR_MAX_LENGTH * sizeof(hil_packet))) {
  		hil_ptr_process_err(ptr);
  		return IRQ_HANDLED;
  	}
  	idx = ptr->idx4/4;
  	if (!(ptr->idx4 % 4))
  		ptr->data[idx] = 0;
  	packet = ptr->data[idx];
  	packet |= ((hil_packet)data) << ((3 - (ptr->idx4 % 4)) * 8);
  	ptr->data[idx] = packet;
  
  	/* Records of N 4-byte hil_packets must terminate with a command. */
  	if ((++(ptr->idx4)) % 4)
  		return IRQ_HANDLED;
  	if ((packet & 0xffff0000) != HIL_ERR_INT) {
  		hil_ptr_process_err(ptr);
  		return IRQ_HANDLED;
  	}
  	if (packet & HIL_PKT_CMD)
  		hil_ptr_process_record(ptr);
  
  	return IRQ_HANDLED;
  }
  
  static void hil_ptr_disconnect(struct serio *serio)
  {
  	struct hil_ptr *ptr;
  
  	ptr = serio_get_drvdata(serio);
  	BUG_ON(ptr == NULL);
  
  	serio_close(serio);
  	input_unregister_device(ptr->dev);
  	kfree(ptr);
  }
  
  static int hil_ptr_connect(struct serio *serio, struct serio_driver *driver)
  {
  	struct hil_ptr	 *ptr;
  	const char	 *txt;
  	unsigned int	 i, naxsets, btntype;
  	uint8_t		 did, *idd;
  
  	if (!(ptr = kzalloc(sizeof(struct hil_ptr), GFP_KERNEL)))
  		return -ENOMEM;
  
  	ptr->dev = input_allocate_device();
  	if (!ptr->dev)
  		goto bail0;
  
  	if (serio_open(serio, driver))
  		goto bail1;
  
  	serio_set_drvdata(serio, ptr);
  	ptr->serio = serio;
  
  	init_MUTEX_LOCKED(&ptr->sem);
  
  	/* Get device info.  MLC driver supplies devid/status/etc. */
  	serio->write(serio, 0);
  	serio->write(serio, 0);
  	serio->write(serio, HIL_PKT_CMD >> 8);
  	serio->write(serio, HIL_CMD_IDD);
  	down(&ptr->sem);
  
  	serio->write(serio, 0);
  	serio->write(serio, 0);
  	serio->write(serio, HIL_PKT_CMD >> 8);
  	serio->write(serio, HIL_CMD_RSC);
  	down(&ptr->sem);
  
  	serio->write(serio, 0);
  	serio->write(serio, 0);
  	serio->write(serio, HIL_PKT_CMD >> 8);
  	serio->write(serio, HIL_CMD_RNM);
  	down(&ptr->sem);
  
  	serio->write(serio, 0);
  	serio->write(serio, 0);
  	serio->write(serio, HIL_PKT_CMD >> 8);
  	serio->write(serio, HIL_CMD_EXD);
  	down(&ptr->sem);
  
  	up(&ptr->sem);
  
  	did = ptr->idd[0];
  	idd = ptr->idd + 1;
  	txt = "unknown";
  	if ((did & HIL_IDD_DID_TYPE_MASK) == HIL_IDD_DID_TYPE_REL) {
  		ptr->dev->evbit[0] = BIT(EV_REL);
  		txt = "relative";
  	}
  
  	if ((did & HIL_IDD_DID_TYPE_MASK) == HIL_IDD_DID_TYPE_ABS) {
  		ptr->dev->evbit[0] = BIT(EV_ABS);
  		txt = "absolute";
  	}
  	if (!ptr->dev->evbit[0])
  		goto bail2;
  
  	ptr->nbtn = HIL_IDD_NUM_BUTTONS(idd);
  	if (ptr->nbtn)
  		ptr->dev->evbit[0] |= BIT(EV_KEY);
  
  	naxsets = HIL_IDD_NUM_AXSETS(*idd);
  	ptr->naxes = HIL_IDD_NUM_AXES_PER_SET(*idd);
  
  	printk(KERN_INFO PREFIX "HIL pointer device found (did: 0x%02x, axis: %s)\n",
  			did, txt);
  	printk(KERN_INFO PREFIX "HIL pointer has %i buttons and %i sets of %i axes\n",
  			ptr->nbtn, naxsets, ptr->naxes);
  
  	btntype = BTN_MISC;
  	if ((did & HIL_IDD_DID_ABS_TABLET_MASK) == HIL_IDD_DID_ABS_TABLET)
  #ifdef TABLET_SIMULATES_MOUSE
  		btntype = BTN_TOUCH;
  #else
  		btntype = BTN_DIGI;
  #endif
  	if ((did & HIL_IDD_DID_ABS_TSCREEN_MASK) == HIL_IDD_DID_ABS_TSCREEN)
  		btntype = BTN_TOUCH;
  
  	if ((did & HIL_IDD_DID_REL_MOUSE_MASK) == HIL_IDD_DID_REL_MOUSE)
  		btntype = BTN_MOUSE;
  
  	for (i = 0; i < ptr->nbtn; i++) {
  		set_bit(btntype | i, ptr->dev->keybit);
  		ptr->btnmap[i] = btntype | i;
  	}
  
  	if (btntype == BTN_MOUSE) {
  		/* Swap buttons 2 and 3 */
  		ptr->btnmap[1] = BTN_MIDDLE;
  		ptr->btnmap[2] = BTN_RIGHT;
  	}
  
  	if ((did & HIL_IDD_DID_TYPE_MASK) == HIL_IDD_DID_TYPE_REL) {
  		for (i = 0; i < ptr->naxes; i++)
  			set_bit(REL_X + i, ptr->dev->relbit);
  		for (i = 3; (i < ptr->naxes + 3) && (naxsets > 1); i++)
  			set_bit(REL_X + i, ptr->dev->relbit);
  	} else {
  		for (i = 0; i < ptr->naxes; i++) {
  			set_bit(ABS_X + i, ptr->dev->absbit);
  			ptr->dev->absmin[ABS_X + i] = 0;
  			ptr->dev->absmax[ABS_X + i] =
  				HIL_IDD_AXIS_MAX((ptr->idd + 1), i);
  		}
  		for (i = 3; (i < ptr->naxes + 3) && (naxsets > 1); i++) {
  			set_bit(ABS_X + i, ptr->dev->absbit);
  			ptr->dev->absmin[ABS_X + i] = 0;
  			ptr->dev->absmax[ABS_X + i] =
  				HIL_IDD_AXIS_MAX((ptr->idd + 1), (i - 3));
  		}
  #ifdef TABLET_AUTOADJUST
  		for (i = 0; i < ABS_MAX; i++) {
  			int diff = ptr->dev->absmax[ABS_X + i] / 10;
  			ptr->dev->absmin[ABS_X + i] += diff;
  			ptr->dev->absmax[ABS_X + i] -= diff;
  		}
  #endif
  	}
  
  	ptr->dev->name = strlen(ptr->rnm) ? ptr->rnm : HIL_GENERIC_NAME;
  
  	ptr->dev->id.bustype	= BUS_HIL;
  	ptr->dev->id.vendor	= PCI_VENDOR_ID_HP;
  	ptr->dev->id.product	= 0x0001; /* TODO: get from ptr->rsc */
  	ptr->dev->id.version	= 0x0100; /* TODO: get from ptr->rsc */
  	ptr->dev->dev.parent	= &serio->dev;
  
  	input_register_device(ptr->dev);
  	printk(KERN_INFO "input: %s (%s), ID: %d\n",
  		ptr->dev->name,
  		(btntype == BTN_MOUSE) ? "HIL mouse":"HIL tablet or touchpad",
  		did);
  
  	return 0;
   bail2:
  	serio_close(serio);
   bail1:
  	input_free_device(ptr->dev);
   bail0:
  	kfree(ptr);
  	serio_set_drvdata(serio, NULL);
  	return -ENODEV;
  }
  
  static struct serio_device_id hil_ptr_ids[] = {
  	{
  		.type = SERIO_HIL_MLC,
  		.proto = SERIO_HIL,
  		.id = SERIO_ANY,
  		.extra = SERIO_ANY,
  	},
  	{ 0 }
  };
  
  static struct serio_driver hil_ptr_serio_driver = {
  	.driver		= {
  		.name	= "hil_ptr",
  	},
  	.description	= "HP HIL mouse/tablet driver",
  	.id_table	= hil_ptr_ids,
  	.connect	= hil_ptr_connect,
  	.disconnect	= hil_ptr_disconnect,
  	.interrupt	= hil_ptr_interrupt
  };
  
  static int __init hil_ptr_init(void)
  {
  	return serio_register_driver(&hil_ptr_serio_driver);
  }
  
  static void __exit hil_ptr_exit(void)
  {
  	serio_unregister_driver(&hil_ptr_serio_driver);
  }
  
  module_init(hil_ptr_init);
  module_exit(hil_ptr_exit);
  