uss720.c

linux-2.6.15.6

/*****************************************************************************/

/*
 *	uss720.c  --  USS720 USB Parport Cable.
 *
 *	Copyright (C) 1999, 2005
 *	    Thomas Sailer ([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.
 *
 *  Based on parport_pc.c
 *
 *  History:
 *   0.1  04.08.1999  Created
 *   0.2  07.08.1999  Some fixes mainly suggested by Tim Waugh
 *		      Interrupt handling currently disabled because
 *		      usb_request_irq crashes somewhere within ohci.c
 *		      for no apparent reason (that is for me, anyway)
 *		      ECP currently untested
 *   0.3  10.08.1999  fixing merge errors
 *   0.4  13.08.1999  Added Vendor/Product ID of Brad Hard's cable
 *   0.5  20.09.1999  usb_control_msg wrapper used
 *        Nov01.2000  usb_device_table support by Adam J. Richter
 *        08.04.2001  Identify version on module load.  gb
 *   0.6  02.09.2005  Fix "scheduling in interrupt" problem by making save/restore
 *                    context asynchronous
 *
 */

/*****************************************************************************/

#include <linux/module.h>
#include <linux/socket.h>
#include <linux/parport.h>
#include <linux/init.h>
#include <linux/usb.h>
#include <linux/delay.h>
#include <linux/completion.h>
#include <linux/kref.h>

/*
 * Version Information
 */
#define DRIVER_VERSION "v0.6"
#define DRIVER_AUTHOR "Thomas M. Sailer, [e-mail]"
#define DRIVER_DESC "USB Parport Cable driver for Cables using the Lucent Technologies USS720 Chip"

/* --------------------------------------------------------------------- */

struct parport_uss720_private {
	struct usb_device *usbdev;
	struct parport *pp;
	struct kref ref_count;
	__u8 reg[7];  /* USB registers */
	struct list_head asynclist;
	spinlock_t asynclock;
};

struct uss720_async_request {
	struct parport_uss720_private *priv;
	struct kref ref_count;
	struct list_head asynclist;
	struct completion compl;
	struct urb *urb;
	struct usb_ctrlrequest dr;
	__u8 reg[7];
};

/* --------------------------------------------------------------------- */

static void destroy_priv(struct kref *kref)
{
	struct parport_uss720_private *priv = container_of(kref, struct parport_uss720_private, ref_count);

	usb_put_dev(priv->usbdev);
	kfree(priv);
	dbg("destroying priv datastructure");
}

static void destroy_async(struct kref *kref)
{
	struct uss720_async_request *rq = container_of(kref, struct uss720_async_request, ref_count);
	struct parport_uss720_private *priv = rq->priv;
	unsigned long flags;

	if (likely(rq->urb))
		usb_free_urb(rq->urb);
	spin_lock_irqsave(&priv->asynclock, flags);
	list_del_init(&rq->asynclist);
	spin_unlock_irqrestore(&priv->asynclock, flags);
	kfree(rq);
	kref_put(&priv->ref_count, destroy_priv);
}

/* --------------------------------------------------------------------- */

static void async_complete(struct urb *urb, struct pt_regs *ptregs)
{
	struct uss720_async_request *rq;
	struct parport *pp;
	struct parport_uss720_private *priv;

	rq = urb->context;
	priv = rq->priv;
	pp = priv->pp;
	if (urb->status) {
		err("async_complete: urb error %d", urb->status);
	} else if (rq->dr.bRequest == 3) {
		memcpy(priv->reg, rq->reg, sizeof(priv->reg));
#if 0
		dbg("async_complete regs %02x %02x %02x %02x %02x %02x %02x",
		    (unsigned int)priv->reg[0], (unsigned int)priv->reg[1], (unsigned int)priv->reg[2],
		    (unsigned int)priv->reg[3], (unsigned int)priv->reg[4], (unsigned int)priv->reg[5],
		    (unsigned int)priv->reg[6]);
#endif
		/* if nAck interrupts are enabled and we have an interrupt, call the interrupt procedure */
		if (rq->reg[2] & rq->reg[1] & 0x10 && pp)
			parport_generic_irq(0, pp, NULL);
	}
	complete(&rq->compl);
	kref_put(&rq->ref_count, destroy_async);
}

static struct uss720_async_request *submit_async_request(struct parport_uss720_private *priv,
							 __u8 request, __u8 requesttype, __u16 value, __u16 index,
							 gfp_t mem_flags)
{
	struct usb_device *usbdev;
	struct uss720_async_request *rq;
	unsigned long flags;
	int ret;

	if (!priv)
		return NULL;
	usbdev = priv->usbdev;
	if (!usbdev)
		return NULL;
	rq = kmalloc(sizeof(struct uss720_async_request), mem_flags);
	if (!rq) {
		err("submit_async_request out of memory");
		return NULL;
	}
	kref_init(&rq->ref_count);
	INIT_LIST_HEAD(&rq->asynclist);
	init_completion(&rq->compl);
	kref_get(&priv->ref_count);
	rq->priv = priv;
	rq->urb = usb_alloc_urb(0, mem_flags);
	if (!rq->urb) {
		kref_put(&rq->ref_count, destroy_async);
		err("submit_async_request out of memory");
		return NULL;
	}
	rq->dr.bRequestType = requesttype;
	rq->dr.bRequest = request;
	rq->dr.wValue = cpu_to_le16(value);
	rq->dr.wIndex = cpu_to_le16(index);
	rq->dr.wLength = cpu_to_le16((request == 3) ? sizeof(rq->reg) : 0);
	usb_fill_control_urb(rq->urb, usbdev, (requesttype & 0x80) ? usb_rcvctrlpipe(usbdev, 0) : usb_sndctrlpipe(usbdev, 0),
			     (unsigned char *)&rq->dr,
			     (request == 3) ? rq->reg : NULL, (request == 3) ? sizeof(rq->reg) : 0, async_complete, rq);
	/* rq->urb->transfer_flags |= URB_ASYNC_UNLINK; */
	spin_lock_irqsave(&priv->asynclock, flags);
	list_add_tail(&rq->asynclist, &priv->asynclist);
	spin_unlock_irqrestore(&priv->asynclock, flags);
	ret = usb_submit_urb(rq->urb, mem_flags);
	if (!ret) {
		kref_get(&rq->ref_count);
		return rq;
	}
	kref_put(&rq->ref_count, destroy_async);
	err("submit_async_request submit_urb failed with %d", ret);
	return NULL;
}

static unsigned int kill_all_async_requests_priv(struct parport_uss720_private *priv)
{
	struct uss720_async_request *rq;
	unsigned long flags;
	unsigned int ret = 0;

	spin_lock_irqsave(&priv->asynclock, flags);
	list_for_each_entry(rq, &priv->asynclist, asynclist) {
		usb_unlink_urb(rq->urb);
		ret++;
	}
	spin_unlock_irqrestore(&priv->asynclock, flags);
	return ret;
}

/* --------------------------------------------------------------------- */

static int get_1284_register(struct parport *pp, unsigned char reg, unsigned char *val, gfp_t mem_flags)
{
	struct parport_uss720_private *priv;
	struct uss720_async_request *rq;
	static const unsigned char regindex[9] = {
		4, 0, 1, 5, 5, 0, 2, 3, 6
	};
	int ret;

	if (!pp)
		return -EIO;
	priv = pp->private_data;
	rq = submit_async_request(priv, 3, 0xc0, ((unsigned int)reg) << 8, 0, mem_flags);
	if (!rq) {
		err("get_1284_register(%u) failed", (unsigned int)reg);
		return -EIO;
	}
	if (!val) {
		kref_put(&rq->ref_count, destroy_async);
		return 0;
	}
	if (wait_for_completion_timeout(&rq->compl, HZ)) {
		ret = rq->urb->status;
		*val = priv->reg[(reg >= 9) ? 0 : regindex[reg]];
		if (ret)
			warn("get_1284_register: usb error %d", ret);
		kref_put(&rq->ref_count, destroy_async);
		return ret;
	}
	warn("get_1284_register timeout");
	kill_all_async_requests_priv(priv);
	return -EIO;
}

static int set_1284_register(struct parport *pp, unsigned char reg, unsigned char val, gfp_t mem_flags)
{
	struct parport_uss720_private *priv;
	struct uss720_async_request *rq;

	if (!pp)
		return -EIO;
	priv = pp->private_data;
	rq = submit_async_request(priv, 4, 0x40, (((unsigned int)reg) << 8) | val, 0, mem_flags);
	if (!rq) {
		err("set_1284_register(%u,%u) failed", (unsigned int)reg, (unsigned int)val);
		return -EIO;
	}
	kref_put(&rq->ref_count, destroy_async);
	return 0;
}

/* --------------------------------------------------------------------- */

/* ECR modes */
#define ECR_SPP 00
#define ECR_PS2 01
#define ECR_PPF 02
#define ECR_ECP 03
#define ECR_EPP 04

/* Safely change the mode bits in the ECR */
static int change_mode(struct parport *pp, int m)
{
	struct parport_uss720_private *priv = pp->private_data;
	int mode;
	__u8 reg;

	if (get_1284_register(pp, 6, &reg, GFP_KERNEL))
		return -EIO;
	/* Bits <7:5> contain the mode. */
	mode = (priv->reg[2] >> 5) & 0x7;
	if (mode == m)
		return 0;
	/* We have to go through mode 000 or 001 */
	if (mode > ECR_PS2 && m > ECR_PS2)
		if (change_mode(pp, ECR_PS2))
			return -EIO;

	if (m <= ECR_PS2 && !(priv->reg[1] & 0x20)) {
		/* This mode resets the FIFO, so we may
		 * have to wait for it to drain first. */
		unsigned long expire = jiffies + pp->physport->cad->timeout;
		switch (mode) {
		case ECR_PPF: /* Parallel Port FIFO mode */
		case ECR_ECP: /* ECP Parallel Port mode */
			/* Poll slowly. */
			for (;;) {
				if (get_1284_register(pp, 6, &reg, GFP_KERNEL))
					return -EIO;
				if (priv->reg[2] & 0x01)
					break;
				if (time_after_eq (jiffies, expire))
					/* The FIFO is stuck. */
					return -EBUSY;
				msleep_interruptible(10);
				if (signal_pending (current))
					break;
			}
		}
	}
	/* Set the mode. */
	if (set_1284_register(pp, 6, m << 5, GFP_KERNEL))
		return -EIO;
	if (get_1284_register(pp, 6, &reg, GFP_KERNEL))
		return -EIO;
	return 0;
}

/*
 * Clear TIMEOUT BIT in EPP MODE
 */
static int clear_epp_timeout(struct parport *pp)
{
	unsigned char stat;

	if (get_1284_register(pp, 1, &stat, GFP_KERNEL))
		return 1;
	return stat & 1;
}

/*
 * Access functions.
 */
#if 0
static int uss720_irq(int usbstatus, void *buffer, int len, void *dev_id)
{
	struct parport *pp = (struct parport *)dev_id;
	struct parport_uss720_private *priv = pp->private_data;	

	if (usbstatus != 0 || len < 4 || !buffer)
		return 1;
	memcpy(priv->reg, buffer, 4);
	/* if nAck interrupts are enabled and we have an interrupt, call the interrupt procedure */
	if (priv->reg[2] & priv->reg[1] & 0x10)
		parport_generic_irq(0, pp, NULL);
	return 1;
}
#endif

static void parport_uss720_write_data(struct parport *pp, unsigned char d)
{
	set_1284_register(pp, 0, d, GFP_KERNEL);
}

static unsigned char parport_uss720_read_data(struct parport *pp)
{
	unsigned char ret;

	if (get_1284_register(pp, 0, &ret, GFP_KERNEL))
		return 0;
	return ret;
}

static void parport_uss720_write_control(struct parport *pp, unsigned char d)
{
	struct parport_uss720_private *priv = pp->private_data;	

	d = (d & 0xf) | (priv->reg[1] & 0xf0);
	if (set_1284_register(pp, 2, d, GFP_KERNEL))
		return;
	priv->reg[1] = d;
}

static unsigned char parport_uss720_read_control(struct parport *pp)
{
	struct parport_uss720_private *priv = pp->private_data;	
	return priv->reg[1] & 0xf; /* Use soft copy */
}

static unsigned char parport_uss720_frob_control(struct parport *pp, unsigned char mask, unsigned char val)
{
	struct parport_uss720_private *priv = pp->private_data;	
	unsigned char d;

	mask &= 0x0f;
	val &= 0x0f;
	d = (priv->reg[1] & (~mask)) ^ val;
	if (set_1284_register(pp, 2, d, GFP_KERNEL))
		return 0;
	priv->reg[1] = d;
	return d & 0xf;
}

static unsigned char parport_uss720_read_status(struct parport *pp)
{
	unsigned char ret;

	if (get_1284_register(pp, 1, &ret, GFP_KERNEL))
		return 0;
	return ret & 0xf8;
}

static void parport_uss720_disable_irq(struct parport *pp)
{
	struct parport_uss720_private *priv = pp->private_data;	
	unsigned char d;

	d = priv->reg[1] & ~0x10;
	if (set_1284_register(pp, 2, d, GFP_KERNEL))
		return;
	priv->reg[1] = d;
}

static void parport_uss720_enable_irq(struct parport *pp)
{
	struct parport_uss720_private *priv = pp->private_data;