text: /*
   * Penmount serial touchscreen driver
   *
   * Copyright (c) 2006 Rick Koch <n1gp@hotmail.com>
   *
   * Based on ELO driver (drivers/input/touchscreen/elo.c)
   * Copyright (c) 2004 Vojtech Pavlik
   */
  
  /*
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 as published
   * by the Free Software Foundation.
   */
  
  #include <linux/errno.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/input.h>
  #include <linux/serio.h>
  #include <linux/init.h>
  
  #define DRIVER_DESC	"Penmount serial touchscreen driver"
  
  MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>");
  MODULE_DESCRIPTION(DRIVER_DESC);
  MODULE_LICENSE("GPL");
  
  /*
   * Definitions & global arrays.
   */
  
  #define	PM_MAX_LENGTH	5
  
  /*
   * Per-touchscreen data.
   */
  
  struct pm {
  	struct input_dev *dev;
  	struct serio *serio;
  	int idx;
  	unsigned char data[PM_MAX_LENGTH];
  	char phys[32];
  };
  
  static irqreturn_t pm_interrupt(struct serio *serio,
  		unsigned char data, unsigned int flags)
  {
  	struct pm *pm = serio_get_drvdata(serio);
  	struct input_dev *dev = pm->dev;
  
  	pm->data[pm->idx] = data;
  
  	if (pm->data[0] & 0x80) {
  		if (PM_MAX_LENGTH == ++pm->idx) {
  			input_report_abs(dev, ABS_X, pm->data[2] * 128 + pm->data[1]);
  			input_report_abs(dev, ABS_Y, pm->data[4] * 128 + pm->data[3]);
  			input_report_key(dev, BTN_TOUCH, !!(pm->data[0] & 0x40));
  			input_sync(dev);
  			pm->idx = 0;
  		}
  	}
  
  	return IRQ_HANDLED;
  }
  
  /*
   * pm_disconnect() is the opposite of pm_connect()
   */
  
  static void pm_disconnect(struct serio *serio)
  {
  	struct pm *pm = serio_get_drvdata(serio);
  
  	input_get_device(pm->dev);
  	input_unregister_device(pm->dev);
  	serio_close(serio);
  	serio_set_drvdata(serio, NULL);
  	input_put_device(pm->dev);
  	kfree(pm);
  }
  
  /*
   * pm_connect() is the routine that is called when someone adds a
   * new serio device that supports Gunze protocol and registers it as
   * an input device.
   */
  
  static int pm_connect(struct serio *serio, struct serio_driver *drv)
  {
  	struct pm *pm;
  	struct input_dev *input_dev;
  	int err;
  
  	pm = kzalloc(sizeof(struct pm), GFP_KERNEL);
  	input_dev = input_allocate_device();
  	if (!pm || !input_dev) {
  		err = -ENOMEM;
  		goto fail1;
  	}
  
  	pm->serio = serio;
  	pm->dev = input_dev;
  	snprintf(pm->phys, sizeof(pm->phys), "%s/input0", serio->phys);
  
  	input_dev->name = "Penmount Serial TouchScreen";
  	input_dev->phys = pm->phys;
  	input_dev->id.bustype = BUS_RS232;
  	input_dev->id.vendor = SERIO_PENMOUNT;
  	input_dev->id.product = 0;
  	input_dev->id.version = 0x0100;
  	input_dev->dev.parent = &serio->dev;
  
          input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
          input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
          input_set_abs_params(pm->dev, ABS_X, 0, 0x3ff, 0, 0);
          input_set_abs_params(pm->dev, ABS_Y, 0, 0x3ff, 0, 0);
  
  	serio_set_drvdata(serio, pm);
  
  	err = serio_open(serio, drv);
  	if (err)
  		goto fail2;
  
  	err = input_register_device(pm->dev);
  	if (err)
  		goto fail3;
  
  	return 0;
  
   fail3:	serio_close(serio);
   fail2:	serio_set_drvdata(serio, NULL);
   fail1:	input_free_device(input_dev);
  	kfree(pm);
  	return err;
  }
  
  /*
   * The serio driver structure.
   */
  
  static struct serio_device_id pm_serio_ids[] = {
  	{
  		.type	= SERIO_RS232,
  		.proto	= SERIO_PENMOUNT,
  		.id	= SERIO_ANY,
  		.extra	= SERIO_ANY,
  	},
  	{ 0 }
  };
  
  MODULE_DEVICE_TABLE(serio, pm_serio_ids);
  
  static struct serio_driver pm_drv = {
  	.driver		= {
  		.name	= "penmountlpc",
  	},
  	.description	= DRIVER_DESC,
  	.id_table	= pm_serio_ids,
  	.interrupt	= pm_interrupt,
  	.connect	= pm_connect,
  	.disconnect	= pm_disconnect,
  };
  
  /*
   * The functions for inserting/removing us as a module.
   */
  
  static int __init pm_init(void)
  {
  	return serio_register_driver(&pm_drv);
  }
  
  static void __exit pm_exit(void)
  {
  	serio_unregister_driver(&pm_drv);
  }
  
  module_init(pm_init);
  module_exit(pm_exit);
  