cpia_pp.c

h内核

/*
 * cpia_pp CPiA Parallel Port driver
 *
 * Supports CPiA based parallel port Video Camera's.
 *
 * (C) Copyright 1999 Bas Huisman <[e-mail]>
 * (C) Copyright 1999-2000 Scott J. Bertin <[e-mail]>,
 * (C) Copyright 1999-2000 Peter Pregler <[e-mail]>
 *
 * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/* define _CPIA_DEBUG_ for verbose debug output (see cpia.h) */
/* #define _CPIA_DEBUG_  1 */  

#include <linux/config.h>

#include <linux/module.h>
#include <linux/init.h>

#include <linux/kernel.h>
#include <linux/parport.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/workqueue.h>
#include <linux/smp_lock.h>
#include <linux/sched.h>

#include <linux/kmod.h>

/* #define _CPIA_DEBUG_		define for verbose debug output */
#include "cpia.h"

static int cpia_pp_open(void *privdata);
static int cpia_pp_registerCallback(void *privdata, void (*cb) (void *cbdata),
                                    void *cbdata);
static int cpia_pp_transferCmd(void *privdata, u8 *command, u8 *data);
static int cpia_pp_streamStart(void *privdata);
static int cpia_pp_streamStop(void *privdata);
static int cpia_pp_streamRead(void *privdata, u8 *buffer, int noblock);
static int cpia_pp_close(void *privdata);


#define ABOUT "Parallel port driver for Vision CPiA based cameras"

#define PACKET_LENGTH  8

/* Magic numbers for defining port-device mappings */
#define PPCPIA_PARPORT_UNSPEC -4
#define PPCPIA_PARPORT_AUTO -3
#define PPCPIA_PARPORT_OFF -2
#define PPCPIA_PARPORT_NONE -1

#ifdef MODULE
static int parport_nr[PARPORT_MAX] = {[0 ... PARPORT_MAX - 1] = PPCPIA_PARPORT_UNSPEC};
static char *parport[PARPORT_MAX] = {NULL,};

MODULE_AUTHOR("B. Huisman <[e-mail]> & Peter Pregler <[e-mail]>");
MODULE_DESCRIPTION("Parallel port driver for Vision CPiA based cameras");
MODULE_LICENSE("GPL");

module_param_array(parport, charp, NULL, 0);
MODULE_PARM_DESC(parport, "'auto' or a list of parallel port numbers. Just like lp.");
#else
static int parport_nr[PARPORT_MAX] __initdata =
	{[0 ... PARPORT_MAX - 1] = PPCPIA_PARPORT_UNSPEC};
static int parport_ptr = 0;
#endif

struct pp_cam_entry {
	struct pardevice *pdev;
	struct parport *port;
	struct work_struct cb_task;
	int open_count;
	wait_queue_head_t wq_stream;
	/* image state flags */
	int image_ready;	/* we got an interrupt */
	int image_complete;	/* we have seen 4 EOI */

	int streaming; /* we are in streaming mode */
	int stream_irq;
};

static struct cpia_camera_ops cpia_pp_ops = 
{
	cpia_pp_open,
	cpia_pp_registerCallback,
	cpia_pp_transferCmd,
	cpia_pp_streamStart,
	cpia_pp_streamStop,
	cpia_pp_streamRead,
	cpia_pp_close,
	1,
	THIS_MODULE
};

static LIST_HEAD(cam_list);
static spinlock_t cam_list_lock_pp;

/* FIXME */
static void cpia_parport_enable_irq( struct parport *port ) {
	parport_enable_irq(port);
	mdelay(10);
	return;
}

static void cpia_parport_disable_irq( struct parport *port ) {
	parport_disable_irq(port);
	mdelay(10);
	return;
}

/* Special CPiA PPC modes: These are invoked by using the 1284 Extensibility
 * Link Flag during negotiation */  
#define UPLOAD_FLAG  0x08
#define NIBBLE_TRANSFER 0x01
#define ECP_TRANSFER 0x03

#define PARPORT_CHUNK_SIZE	PAGE_SIZE


/****************************************************************************
 *
 *  CPiA-specific  low-level parport functions for nibble uploads
 *
 ***************************************************************************/
/*  CPiA nonstandard "Nibble" mode (no nDataAvail signal after each byte). */
/* The standard kernel parport_ieee1284_read_nibble() fails with the CPiA... */

static size_t cpia_read_nibble (struct parport *port, 
			 void *buffer, size_t len, 
			 int flags)
{
	/* adapted verbatim, with one change, from 
	   parport_ieee1284_read_nibble() in drivers/parport/ieee1284-ops.c */

	unsigned char *buf = buffer;
	int i;
	unsigned char byte = 0;
	
	len *= 2; /* in nibbles */
	for (i=0; i < len; i++) {
		unsigned char nibble;

		/* The CPiA firmware suppresses the use of nDataAvail (nFault LO)
		 * after every second nibble to signal that more
		 * data is available.  (the total number of Bytes that
		 * should be sent is known; if too few are received, an error
		 * will be recorded after a timeout).  
		 * This is incompatible with parport_ieee1284_read_nibble(),
		 * which expects to find nFault LO after every second nibble.
		 */

		/* Solution: modify cpia_read_nibble to only check for 
		 * nDataAvail before the first nibble is sent.
		 */

		/* Does the error line indicate end of data? */
		if (((i /*& 1*/) == 0) &&
		    (parport_read_status(port) & PARPORT_STATUS_ERROR)) {
			port->physport->ieee1284.phase = IEEE1284_PH_HBUSY_DNA;
				DBG("%s: No more nibble data (%d bytes)\n",
				port->name, i/2);

			/* Go to reverse idle phase. */
			parport_frob_control (port,
					      PARPORT_CONTROL_AUTOFD,
					      PARPORT_CONTROL_AUTOFD);
			port->physport->ieee1284.phase = IEEE1284_PH_REV_IDLE;
			break;
		}

		/* Event 7: Set nAutoFd low. */
		parport_frob_control (port,
				      PARPORT_CONTROL_AUTOFD,
				      PARPORT_CONTROL_AUTOFD);

		/* Event 9: nAck goes low. */
		port->ieee1284.phase = IEEE1284_PH_REV_DATA;
		if (parport_wait_peripheral (port,
					     PARPORT_STATUS_ACK, 0)) {
			/* Timeout -- no more data? */
				 DBG("%s: Nibble timeout at event 9 (%d bytes)\n",
				 port->name, i/2);
			parport_frob_control (port, PARPORT_CONTROL_AUTOFD, 0);
			break;
		}


		/* Read a nibble. */
		nibble = parport_read_status (port) >> 3;
		nibble &= ~8;
		if ((nibble & 0x10) == 0)
			nibble |= 8;
		nibble &= 0xf;

		/* Event 10: Set nAutoFd high. */
		parport_frob_control (port, PARPORT_CONTROL_AUTOFD, 0);

		/* Event 11: nAck goes high. */
		if (parport_wait_peripheral (port,
					     PARPORT_STATUS_ACK,
					     PARPORT_STATUS_ACK)) {
			/* Timeout -- no more data? */
			DBG("%s: Nibble timeout at event 11\n",
				 port->name);
			break;
		}

		if (i & 1) {
			/* Second nibble */
			byte |= nibble << 4;
			*buf++ = byte;
		} else 
			byte = nibble;
	}

	i /= 2; /* i is now in bytes */

	if (i == len) {
		/* Read the last nibble without checking data avail. */
		port = port->physport;
		if (parport_read_status (port) & PARPORT_STATUS_ERROR)
			port->ieee1284.phase = IEEE1284_PH_HBUSY_DNA;
		else
			port->ieee1284.phase = IEEE1284_PH_HBUSY_DAVAIL;
	}

	return i;
}

/* CPiA nonstandard "Nibble Stream" mode (2 nibbles per cycle, instead of 1)
 * (See CPiA Data sheet p. 31) 
 * 
 * "Nibble Stream" mode used by CPiA for uploads to non-ECP ports is a 
 * nonstandard variant of nibble mode which allows the same (mediocre) 
 * data flow of 8 bits per cycle as software-enabled ECP by TRISTATE-capable 
 * parallel ports, but works also for  non-TRISTATE-capable ports.
 * (Standard nibble mode only send 4 bits per cycle)
 *
 */

static size_t cpia_read_nibble_stream(struct parport *port, 
			       void *buffer, size_t len, 
			       int flags)
{
	int i;
	unsigned char *buf = buffer;
	int endseen = 0;

	for (i=0; i < len; i++) {
		unsigned char nibble[2], byte = 0;
		int j;

		/* Image Data is complete when 4 consecutive EOI bytes (0xff) are seen */ 
		if (endseen > 3 )
			break;

		/* Event 7: Set nAutoFd low. */
		parport_frob_control (port,
				      PARPORT_CONTROL_AUTOFD,
				      PARPORT_CONTROL_AUTOFD);
		
		/* Event 9: nAck goes low. */
		port->ieee1284.phase = IEEE1284_PH_REV_DATA;
		if (parport_wait_peripheral (port,
					     PARPORT_STATUS_ACK, 0)) {
			/* Timeout -- no more data? */
				 DBG("%s: Nibble timeout at event 9 (%d bytes)\n",
				 port->name, i/2);
			parport_frob_control (port, PARPORT_CONTROL_AUTOFD, 0);
			break;
		}

		/* Read lower nibble */
		nibble[0] = parport_read_status (port) >>3;
		
		/* Event 10: Set nAutoFd high. */
		parport_frob_control (port, PARPORT_CONTROL_AUTOFD, 0);

		/* Event 11: nAck goes high. */
		if (parport_wait_peripheral (port,
					     PARPORT_STATUS_ACK,
					     PARPORT_STATUS_ACK)) {
			/* Timeout -- no more data? */
			DBG("%s: Nibble timeout at event 11\n",
				 port->name);
			break;
		}
		
		/* Read upper nibble */
		nibble[1] = parport_read_status (port) >>3;
		
		/* reassemble the byte */
		for (j = 0; j < 2 ; j++ ) {
			nibble[j] &= ~8;
			if ((nibble[j] & 0x10) == 0)
				nibble[j] |= 8;
			nibble[j] &= 0xf;
		}
		byte = (nibble[0] |(nibble[1] << 4));
		*buf++ = byte;

		if(byte == EOI)
		  endseen++;
		else
		  endseen = 0;
	}
	return i;
}

/****************************************************************************
 *
 *  EndTransferMode
 *
 ***************************************************************************/
static void EndTransferMode(struct pp_cam_entry *cam)
{
	parport_negotiate(cam->port, IEEE1284_MODE_COMPAT);
}

/****************************************************************************
 *
 *  ForwardSetup
 *
 ***************************************************************************/
static int ForwardSetup(struct pp_cam_entry *cam)
{
	int retry;
	
	/* The CPiA uses ECP protocol for Downloads from the Host to the camera. 
	 * This will be software-emulated if ECP hardware is not present
	 */

	/* the usual camera maximum response time is 10ms, but after receiving
	 * some commands, it needs up to 40ms. (Data Sheet p. 32)*/

	for(retry = 0; retry < 4; ++retry) {
		if(!parport_negotiate(cam->port, IEEE1284_MODE_ECP)) {
			break;
		}
		mdelay(10);
	}
	if(retry == 4) {
		DBG("Unable to negotiate IEEE1284 ECP Download mode\n");
		return -1;
	}
	return 0;
}
/****************************************************************************
 *
 *  ReverseSetup
 *
 ***************************************************************************/
static int ReverseSetup(struct pp_cam_entry *cam, int extensibility)
{
	int retry;
	int upload_mode, mode = IEEE1284_MODE_ECP;
	int transfer_mode = ECP_TRANSFER;

	if (!(cam->port->modes & PARPORT_MODE_ECP) &&
	     !(cam->port->modes & PARPORT_MODE_TRISTATE)) {
		mode = IEEE1284_MODE_NIBBLE;
		transfer_mode = NIBBLE_TRANSFER;
	}

	upload_mode = mode;
	if(extensibility) mode = UPLOAD_FLAG|transfer_mode|IEEE1284_EXT_LINK;

	/* the usual camera maximum response time is 10ms, but after 
	 * receiving some commands, it needs up to 40ms. */
		
	for(retry = 0; retry < 4; ++retry) {
		if(!parport_negotiate(cam->port, mode)) {
			break;
		}
		mdelay(10);
	}
	if(retry == 4) {
		if(extensibility)
			DBG("Unable to negotiate upload extensibility mode\n");
		else
			DBG("Unable to negotiate upload mode\n");
		return -1;
	}
	if(extensibility) cam->port->ieee1284.mode = upload_mode;
	return 0;
}

/****************************************************************************
 *
 *  WritePacket
 *
 ***************************************************************************/
static int WritePacket(struct pp_cam_entry *cam, const u8 *packet, size_t size)
{
	int retval=0;
	int size_written;

	if (packet == NULL) {
		return -EINVAL;
	}
	if (ForwardSetup(cam)) {
		DBG("Write failed in setup\n");
		return -EIO;
	}
	size_written = parport_write(cam->port, packet, size);
	if(size_written != size) {
		DBG("Write failed, wrote %d/%d\n", size_written, size);
		retval = -EIO;
	}
	EndTransferMode(cam);
	return retval;
}

/****************************************************************************
 *
 *  ReadPacket
 *
 ***************************************************************************/
static int ReadPacket(struct pp_cam_entry *cam, u8 *packet, size_t size)
{
	int retval=0;

	if (packet == NULL) {
		return -EINVAL;
	}
	if (ReverseSetup(cam, 0)) {
		return -EIO;
	}

	/* support for CPiA variant nibble reads */