cregit-Linux how code gets into the kernel

Release 4.7 drivers/input/serio/parkbd.c

Directory: drivers/input/serio
/*
 *  Parallel port to Keyboard port adapter driver for Linux
 *
 *  Copyright (c) 1999-2004 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.
 */

/*
 * To connect an AT or XT keyboard to the parallel port, a fairly simple adapter
 * can be made:
 * 
 *  Parallel port            Keyboard port
 *
 *     +5V --------------------- +5V (4)
 *  
 *                 ______
 *     +5V -------|______|--.
 *                          |
 *     ACK (10) ------------|
 *                          |--- KBD CLOCK (5)
 *     STROBE (1) ---|<|----'
 *     
 *                 ______
 *     +5V -------|______|--.
 *                          |
 *     BUSY (11) -----------|
 *                          |--- KBD DATA (1)
 *     AUTOFD (14) --|<|----'
 *
 *     GND (18-25) ------------- GND (3)
 *     
 * The diodes can be fairly any type, and the resistors should be somewhere
 * around 5 kOhm, but the adapter will likely work without the resistors,
 * too.
 *
 * The +5V source can be taken either from USB, from mouse or keyboard ports,
 * or from a joystick port. Unfortunately, the parallel port of a PC doesn't
 * have a +5V pin, and feeding the keyboard from signal pins is out of question
 * with 300 mA power reqirement of a typical AT keyboard.
 */

#include <linux/module.h>
#include <linux/parport.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/serio.h>

MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
MODULE_DESCRIPTION("Parallel port to Keyboard port adapter driver");
MODULE_LICENSE("GPL");


static unsigned int parkbd_pp_no;
module_param_named(port, parkbd_pp_no, int, 0);
MODULE_PARM_DESC(port, "Parallel port the adapter is connected to (default is 0)");


static unsigned int parkbd_mode = SERIO_8042;
module_param_named(mode, parkbd_mode, uint, 0);
MODULE_PARM_DESC(mode, "Mode of operation: XT = 0/AT = 1 (default)");


#define PARKBD_CLOCK	0x01	
/* Strobe & Ack */

#define PARKBD_DATA	0x02	
/* AutoFd & Busy */


static int parkbd_buffer;

static int parkbd_counter;

static unsigned long parkbd_last;

static int parkbd_writing;

static unsigned long parkbd_start;


static struct pardevice *parkbd_dev;

static struct serio *parkbd_port;




static int parkbd_readlines(void)
{
	return (parport_read_status(parkbd_dev->port) >> 6) ^ 2;
}


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vojtech pavlikvojtech pavlik22100.00%1100.00%


Total22100.00%1100.00%






static void parkbd_writelines(int data)
{
	parport_write_control(parkbd_dev->port, (~data & 3) | 0x10);
}


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vojtech pavlikvojtech pavlik25100.00%1100.00%


Total25100.00%1100.00%






static int parkbd_write(struct serio *port, unsigned char c)
{
	unsigned char p;

	if (!parkbd_mode) return -1;

        p = c ^ (c >> 4);
	p = p ^ (p >> 2);
	p = p ^ (p >> 1);

	parkbd_counter = 0;
	parkbd_writing = 1;
	parkbd_buffer = c | (((int) (~p & 1)) << 8) | 0x600;

	parkbd_writelines(2);

	return 0;
}


Contributors
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vojtech pavlikvojtech pavlik96100.00%1100.00%


Total96100.00%1100.00%






static void parkbd_interrupt(void *dev_id)
{

	if (parkbd_writing) {

		if (parkbd_counter && ((parkbd_counter == 11) || time_after(jiffies, parkbd_last + HZ/100))) {
			parkbd_counter = 0;
			parkbd_buffer = 0;
			parkbd_writing = 0;
			parkbd_writelines(3);
			return;
		}

		parkbd_writelines(((parkbd_buffer >> parkbd_counter++) & 1) | 2);

		if (parkbd_counter == 11) {
			parkbd_counter = 0;
			parkbd_buffer = 0;
			parkbd_writing = 0;
			parkbd_writelines(3);
		}

	} else {

		if ((parkbd_counter == parkbd_mode + 10) || time_after(jiffies, parkbd_last + HZ/100)) {
			parkbd_counter = 0;
			parkbd_buffer = 0;
		}

		parkbd_buffer |= (parkbd_readlines() >> 1) << parkbd_counter++;

		if (parkbd_counter == parkbd_mode + 10)
			serio_interrupt(parkbd_port, (parkbd_buffer >> (2 - parkbd_mode)) & 0xff, 0);
	}

	parkbd_last = jiffies;
}


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vojtech pavlikvojtech pavlik177100.00%2100.00%


Total177100.00%2100.00%






static int parkbd_getport(struct parport *pp)
{
	struct pardev_cb parkbd_parport_cb;

	memset(&parkbd_parport_cb, 0, sizeof(parkbd_parport_cb));
	parkbd_parport_cb.irq_func = parkbd_interrupt;
	parkbd_parport_cb.flags = PARPORT_FLAG_EXCL;

	parkbd_dev = parport_register_dev_model(pp, "parkbd",
						&parkbd_parport_cb, 0);

	if (!parkbd_dev)
		return -ENODEV;

	if (parport_claim(parkbd_dev)) {
		parport_unregister_device(parkbd_dev);
		return -EBUSY;
	}

	parkbd_start = jiffies;

	return 0;
}


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vojtech pavlikvojtech pavlik5562.50%125.00%


sudip mukherjeesudip mukherjee3135.23%250.00%


al viroal viro22.27%125.00%


Total88100.00%4100.00%






static struct serio *parkbd_allocate_serio(void)
{
	struct serio *serio;

	serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
	if (serio) {
		serio->id.type = parkbd_mode;
		serio->write = parkbd_write,
		strlcpy(serio->name, "PARKBD AT/XT keyboard adapter", sizeof(serio->name));
		snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", parkbd_dev->port->name);
	}

	return serio;
}


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dmitry torokhovdmitry torokhov6674.16%250.00%


vojtech pavlikvojtech pavlik2224.72%125.00%


eric sesterhenneric sesterhenn11.12%125.00%


Total89100.00%4100.00%






static void parkbd_attach(struct parport *pp)
{
	if (pp->number != parkbd_pp_no) {
		pr_debug("Not using parport%d.\n", pp->number);
		return;
	}

	if (parkbd_getport(pp))
		return;

	parkbd_port = parkbd_allocate_serio();
	if (!parkbd_port) {
		parport_release(parkbd_dev);
		parport_unregister_device(parkbd_dev);
		return;
	}

	parkbd_writelines(3);

	serio_register_port(parkbd_port);

	printk(KERN_INFO "serio: PARKBD %s adapter on %s\n",
                        parkbd_mode ? "AT" : "XT", parkbd_dev->port->name);

	return;
}


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sudip mukherjeesudip mukherjee3740.66%240.00%


dmitry torokhovdmitry torokhov2931.87%120.00%


vojtech pavlikvojtech pavlik2426.37%120.00%


adrian bunkadrian bunk11.10%120.00%


Total91100.00%5100.00%






static void parkbd_detach(struct parport *port)
{
	if (!parkbd_port || port->number != parkbd_pp_no)
		return;

	parport_release(parkbd_dev);
	serio_unregister_port(parkbd_port);
	parport_unregister_device(parkbd_dev);
	parkbd_port = NULL;
}


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sudip mukherjeesudip mukherjee2252.38%133.33%


vojtech pavlikvojtech pavlik1945.24%133.33%


adrian bunkadrian bunk12.38%133.33%


Total42100.00%3100.00%




static struct parport_driver parkbd_parport_driver = {
	.name = "parkbd",
	.match_port = parkbd_attach,
	.detach = parkbd_detach,
	.devmodel = true,
};




static int __init parkbd_init(void)
{
	return parport_register_driver(&parkbd_parport_driver);
}


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sudip mukherjeesudip mukherjee16100.00%1100.00%


Total16100.00%1100.00%






static void __exit parkbd_exit(void)
{
	parport_unregister_driver(&parkbd_parport_driver);
}


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sudip mukherjeesudip mukherjee1493.33%150.00%


vojtech pavlikvojtech pavlik16.67%150.00%


Total15100.00%2100.00%




module_init(parkbd_init);

module_exit(parkbd_exit);

Overall Contributors
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vojtech pavlikvojtech pavlik52864.16%426.67%


sudip mukherjeesudip mukherjee14717.86%320.00%


dmitry torokhovdmitry torokhov13816.77%320.00%


tejun heotejun heo30.36%16.67%


al viroal viro20.24%16.67%


andrew mortonandrew morton20.24%16.67%


adrian bunkadrian bunk20.24%16.67%


eric sesterhenneric sesterhenn10.12%16.67%


Total823100.00%15100.00%

  
Directory: drivers/input/serio



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