gamecon.c

讲述linux的初始化过程

/*
 * $Id: gamecon.c,v 1.5 2000/06/25 09:56:58 vojtech Exp $
 *
 *  Copyright (c) 1999-2000 Vojtech Pavlik
 *
 *  Based on the work of:
 *  	Andree Borrmann		John Dahlstrom
 *  	David Kuder
 *
 *  Sponsored by SuSE
 */

/*
 * NES, SNES, N64, Multi1, Multi2, PSX gamepad driver for Linux
 */

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or 
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Should you need to contact me, the author, you can do so either by
 * e-mail - mail your message to <[e-mail]>, or by paper mail:
 * Vojtech Pavlik, Ucitelska 1576, Prague 8, 182 00 Czech Republic
 */

#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/parport.h>
#include <linux/input.h>

MODULE_AUTHOR("Vojtech Pavlik <[e-mail]>");
MODULE_PARM(gc, "2-6i");
MODULE_PARM(gc_2,"2-6i");
MODULE_PARM(gc_3,"2-6i");

#define GC_SNES		1
#define GC_NES		2
#define GC_NES4		3
#define GC_MULTI	4
#define GC_MULTI2	5
#define GC_N64		6	
#define GC_PSX		7

#define GC_MAX		7

#define GC_REFRESH_TIME	HZ/100
 
struct gc {
	struct pardevice *pd;
	struct input_dev dev[5];
	struct timer_list timer;
	unsigned char pads[GC_PSX + 1];
	int used;
};

static struct gc *gc_base[3];

static int gc[] __initdata = { -1, 0, 0, 0, 0, 0 };
static int gc_2[] __initdata = { -1, 0, 0, 0, 0, 0 };
static int gc_3[] __initdata = { -1, 0, 0, 0, 0, 0 };

static int gc_status_bit[] = { 0x40, 0x80, 0x20, 0x10, 0x08 };

static char *gc_names[] = { NULL, "SNES pad", "NES pad", "NES FourPort", "Multisystem joystick",
				"Multisystem 2-button joystick", "N64 controller", "PSX pad",
				"PSX NegCon", "PSX Analog contoller" };
/*
 * N64 support.
 */

static unsigned char gc_n64_bytes[] = { 0, 1, 13, 15, 14, 12, 10, 11, 2, 3 };
static short gc_n64_btn[] = { BTN_A, BTN_B, BTN_C, BTN_X, BTN_Y, BTN_Z, BTN_TL, BTN_TR, BTN_TRIGGER, BTN_START };

#define GC_N64_LENGTH		32		/* N64 bit length, not including stop bit */
#define GC_N64_REQUEST_LENGTH	37		/* transmit request sequence is 9 bits long */
#define GC_N64_DELAY		133		/* delay between transmit request, and response ready (us) */
#define GC_N64_REQUEST		0x1dd1111111ULL /* the request data command (encoded for 000000011) */
#define GC_N64_DWS		3		/* delay between write segments (required for sound playback because of ISA DMA) */
						/* GC_N64_DWS > 24 is known to fail */ 
#define GC_N64_POWER_W		0xe2		/* power during write (transmit request) */
#define GC_N64_POWER_R		0xfd		/* power during read */
#define GC_N64_OUT		0x1d		/* output bits to the 4 pads */
						/* Reading the main axes of any N64 pad is known to fail if the corresponding bit */
						/* in GC_N64_OUT is pulled low on the output port (by any routine) for more */
						/* than 123 us */
#define GC_N64_CLOCK		0x02		/* clock bits for read */

/* 
 * gc_n64_read_packet() reads an N64 packet. 
 * Each pad uses one bit per byte. So all pads connected to this port are read in parallel.
 */

static void gc_n64_read_packet(struct gc *gc, unsigned char *data)
{
	int i;
	unsigned long flags;

/*
 * Request the pad to transmit data
 */

	__save_flags(flags);
	__cli();
	for (i = 0; i < GC_N64_REQUEST_LENGTH; i++) {
		parport_write_data(gc->pd->port, GC_N64_POWER_W | ((GC_N64_REQUEST >> i) & 1 ? GC_N64_OUT : 0));
		udelay(GC_N64_DWS);
	}
	__restore_flags(flags);

/*
 * Wait for the pad response to be loaded into the 33-bit register of the adapter
 */

	udelay(GC_N64_DELAY);

/*
 * Grab data (ignoring the last bit, which is a stop bit)
 */

	for (i = 0; i < GC_N64_LENGTH; i++) {
		parport_write_data(gc->pd->port, GC_N64_POWER_R);
		data[i] = parport_read_status(gc->pd->port);
		parport_write_data(gc->pd->port, GC_N64_POWER_R | GC_N64_CLOCK);
	 }

/*
 * We must wait 200 ms here for the controller to reinitialize before the next read request.
 * No worries as long as gc_read is polled less frequently than this.
 */

}

/*
 * NES/SNES support.
 */

#define GC_NES_DELAY	6	/* Delay between bits - 6us */
#define GC_NES_LENGTH	8	/* The NES pads use 8 bits of data */
#define GC_SNES_LENGTH	12	/* The SNES true length is 16, but the last 4 bits are unused */

#define GC_NES_POWER	0xfc
#define GC_NES_CLOCK	0x01
#define GC_NES_LATCH	0x02

static unsigned char gc_nes_bytes[] = { 0, 1, 2, 3 };
static unsigned char gc_snes_bytes[] = { 8, 0, 2, 3, 9, 1, 10, 11 };
static short gc_snes_btn[] = { BTN_A, BTN_B, BTN_SELECT, BTN_START, BTN_X, BTN_Y, BTN_TL, BTN_TR };

/*
 * gc_nes_read_packet() reads a NES/SNES packet.
 * Each pad uses one bit per byte. So all pads connected to
 * this port are read in parallel.
 */

static void gc_nes_read_packet(struct gc *gc, int length, unsigned char *data)
{
	int i;

	parport_write_data(gc->pd->port, GC_NES_POWER | GC_NES_CLOCK | GC_NES_LATCH);
	udelay(GC_NES_DELAY * 2);
	parport_write_data(gc->pd->port, GC_NES_POWER | GC_NES_CLOCK);

	for (i = 0; i < length; i++) {
		udelay(GC_NES_DELAY);
		parport_write_data(gc->pd->port, GC_NES_POWER);
		data[i] = parport_read_status(gc->pd->port) ^ 0x7f;
		udelay(GC_NES_DELAY);
		parport_write_data(gc->pd->port, GC_NES_POWER | GC_NES_CLOCK);
	}
}

/*
 * Multisystem joystick support
 */

#define GC_MULTI_LENGTH		5	/* Multi system joystick packet length is 5 */
#define GC_MULTI2_LENGTH	6	/* One more bit for one more button */

/*
 * gc_multi_read_packet() reads a Multisystem joystick packet.
 */

static void gc_multi_read_packet(struct gc *gc, int length, unsigned char *data)
{
	int i;

	for (i = 0; i < length; i++) {
		parport_write_data(gc->pd->port, ~(1 << i));
		data[i] = parport_read_status(gc->pd->port) ^ 0x7f;
	}
}

/*
 * PSX support
 */

#define GC_PSX_DELAY	10
#define GC_PSX_LENGTH	8	/* talk to the controller in bytes */

#define GC_PSX_MOUSE	0x12	/* PSX Mouse */
#define GC_PSX_NEGCON	0x23	/* NegCon pad */
#define GC_PSX_NORMAL	0x41	/* Standard Digital controller */
#define GC_PSX_ANALOGR	0x73	/* Analog controller in Red mode */
#define GC_PSX_ANALOGG	0x53	/* Analog controller in Green mode */

#define GC_PSX_CLOCK	0x04	/* Pin 3 */
#define GC_PSX_COMMAND	0x01	/* Pin 1 */
#define GC_PSX_POWER	0xf8	/* Pins 5-9 */
#define GC_PSX_SELECT	0x02	/* Pin 2 */
#define GC_PSX_NOPOWER  0x04

static short gc_psx_abs[] = { ABS_X, ABS_Y, ABS_RX, ABS_RY, ABS_HAT0X, ABS_HAT0Y };
static short gc_psx_btn[] = { BTN_TL, BTN_TR, BTN_TL2, BTN_TR2, BTN_A, BTN_B, BTN_X, BTN_Y,
				BTN_START, BTN_SELECT, BTN_THUMB, BTN_THUMB2 };

/*
 * gc_psx_command() writes 8bit command and reads 8bit data from
 * the psx pad.
 */

static int gc_psx_command(struct gc *gc, int b)
{
	int i, cmd, ret = 0;

	cmd = (b & 1) ? GC_PSX_COMMAND : 0;
	for (i = 0; i < 8; i++) {
		parport_write_data(gc->pd->port, cmd | GC_PSX_POWER);
		udelay(GC_PSX_DELAY);
		ret |= ((parport_read_status(gc->pd->port) ^ 0x80) & gc->pads[GC_PSX]) ? (1 << i) : 0;
		cmd = (b & 1) ? GC_PSX_COMMAND : 0;
		parport_write_data(gc->pd->port, cmd | GC_PSX_CLOCK | GC_PSX_POWER);
		udelay(GC_PSX_DELAY);
		b >>= 1;
	}
	return ret;
}

/*
 * gc_psx_read_packet() reads a whole psx packet and returns
 * device identifier code.
 */

static int gc_psx_read_packet(struct gc *gc, int length, unsigned char *data)
{
	int i, ret;
	unsigned long flags;

	__save_flags(flags);
	__cli();

	parport_write_data(gc->pd->port, GC_PSX_POWER);

	parport_write_data(gc->pd->port, GC_PSX_CLOCK | GC_PSX_SELECT | GC_PSX_POWER);	/* Select pad */
	udelay(GC_PSX_DELAY * 2);
	gc_psx_command(gc, 0x01);							/* Access pad */
	ret = gc_psx_command(gc, 0x42);							/* Get device id */
	if (gc_psx_command(gc, 0) == 'Z')						/* okay? */
		for (i = 0; i < length; i++)
			data[i] = gc_psx_command(gc, 0);
	else ret = -1;

	parport_write_data(gc->pd->port, GC_PSX_SELECT | GC_PSX_CLOCK | GC_PSX_POWER);
	__restore_flags(flags);

	return ret;
}

/*
 * gc_timer() reads and analyzes console pads data.
 */

#define GC_MAX_LENGTH GC_N64_LENGTH

static void gc_timer(unsigned long private)
{
	struct gc *gc = (void *) private;
	struct input_dev *dev = gc->dev;
	unsigned char data[GC_MAX_LENGTH];
	int i, j, s;

/*
 * N64 pads - must be read first, any read confuses them for 200 us
 */

	if (gc->pads[GC_N64]) {

		gc_n64_read_packet(gc, data);

		for (i = 0; i < 5; i++) {

			s = gc_status_bit[i];

			if (s & gc->pads[GC_N64] & ~(data[8] | data[9])) {
	
				signed char axes[2];
				axes[0] = axes[1] = 0;

				for (j = 0; j < 8; j++) {
					if (data[23 - j] & s) axes[0] |= 1 << j; 
					if (data[31 - j] & s) axes[1] |= 1 << j; 
				}

				input_report_abs(dev + i, ABS_X,  axes[0]);
				input_report_abs(dev + i, ABS_Y, -axes[1]);

				input_report_abs(dev + i, ABS_HAT0X, !!(s & data[7]) - !!(s & data[6]));
				input_report_abs(dev + i, ABS_HAT0Y, !!(s & data[5]) - !!(s & data[4]));

				for (j = 0; j < 10; j++)
					input_report_key(dev + i, gc_n64_btn[j], s & data[gc_n64_bytes[j]]);
			}
		}
	}

/*
 * NES and SNES pads
 */

	if (gc->pads[GC_NES] || gc->pads[GC_SNES]) {

		gc_nes_read_packet(gc, gc->pads[GC_SNES] ? GC_SNES_LENGTH : GC_NES_LENGTH, data);