daisy.c

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 *	@daisy.
 *
 *	If there is no device with the specified device number, -ENXIO
 *	is returned.  Otherwise, the values pointed to by @parport,
 *	@mux, and @daisy are set to the coordinates of the device,
 *	with -1 for coordinates with no value.
 *
 *	This function is not actually very useful, but this interface
 *	was suggested by IEEE 1284.3.
 **/

int parport_device_coords (int devnum, int *parport, int *mux, int *daisy)
{
	struct daisydev *dev = topology;

	while (dev && dev->devnum != devnum)
		dev = dev->next;

	if (!dev)
		return -ENXIO;

	if (parport) *parport = dev->port->portnum;
	if (mux) *mux = dev->port->muxport;
	if (daisy) *daisy = dev->daisy;
	return 0;
}

/* Send a daisy-chain-style CPP command packet. */
static int cpp_daisy (struct parport *port, int cmd)
{
	unsigned char s;

	parport_data_forward (port);
	parport_write_data (port, 0xaa); udelay (2);
	parport_write_data (port, 0x55); udelay (2);
	parport_write_data (port, 0x00); udelay (2);
	parport_write_data (port, 0xff); udelay (2);
	s = parport_read_status (port) & (PARPORT_STATUS_BUSY
					  | PARPORT_STATUS_PAPEROUT
					  | PARPORT_STATUS_SELECT
					  | PARPORT_STATUS_ERROR);
	if (s != (PARPORT_STATUS_BUSY
		  | PARPORT_STATUS_PAPEROUT
		  | PARPORT_STATUS_SELECT
		  | PARPORT_STATUS_ERROR)) {
		DPRINTK (KERN_DEBUG "%s: cpp_daisy: aa5500ff(%02x)\n",
			 port->name, s);
		return -ENXIO;
	}

	parport_write_data (port, 0x87); udelay (2);
	s = parport_read_status (port) & (PARPORT_STATUS_BUSY
					  | PARPORT_STATUS_PAPEROUT
					  | PARPORT_STATUS_SELECT
					  | PARPORT_STATUS_ERROR);
	if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) {
		DPRINTK (KERN_DEBUG "%s: cpp_daisy: aa5500ff87(%02x)\n",
			 port->name, s);
		return -ENXIO;
	}

	parport_write_data (port, 0x78); udelay (2);
	parport_write_data (port, cmd); udelay (2);
	parport_frob_control (port,
			      PARPORT_CONTROL_STROBE,
			      PARPORT_CONTROL_STROBE);
	udelay (1);
	parport_frob_control (port, PARPORT_CONTROL_STROBE, 0);
	udelay (1);
	s = parport_read_status (port);
	parport_write_data (port, 0xff); udelay (2);

	return s;
}

/* Send a mux-style CPP command packet. */
static int cpp_mux (struct parport *port, int cmd)
{
	unsigned char s;
	int rc;

	parport_data_forward (port);
	parport_write_data (port, 0xaa); udelay (2);
	parport_write_data (port, 0x55); udelay (2);
	parport_write_data (port, 0xf0); udelay (2);
	parport_write_data (port, 0x0f); udelay (2);
	parport_write_data (port, 0x52); udelay (2);
	parport_write_data (port, 0xad); udelay (2);
	parport_write_data (port, cmd); udelay (2);

	s = parport_read_status (port);
	if (!(s & PARPORT_STATUS_ACK)) {
		DPRINTK (KERN_DEBUG "%s: cpp_mux: aa55f00f52ad%02x(%02x)\n",
			 port->name, cmd, s);
		return -EIO;
	}

	rc = (((s & PARPORT_STATUS_SELECT   ? 1 : 0) << 0) |
	      ((s & PARPORT_STATUS_PAPEROUT ? 1 : 0) << 1) |
	      ((s & PARPORT_STATUS_BUSY     ? 0 : 1) << 2) |
	      ((s & PARPORT_STATUS_ERROR    ? 0 : 1) << 3));

	return rc;
}

void parport_daisy_deselect_all (struct parport *port)
{
	cpp_daisy (port, 0x30);
}

int parport_daisy_select (struct parport *port, int daisy, int mode)
{
	/* mode is currently ignored. FIXME? */
	return cpp_daisy (port, 0xe0 + daisy) & PARPORT_STATUS_ERROR;
}

static int mux_present (struct parport *port)
{
	return cpp_mux (port, 0x51) == 3;
}

static int num_mux_ports (struct parport *port)
{
	return cpp_mux (port, 0x58);
}

static int select_port (struct parport *port)
{
	int muxport = port->muxport;
	return cpp_mux (port, 0x60 + muxport) == muxport;
}

static int assign_addrs (struct parport *port)
{
	unsigned char s, last_dev;
	unsigned char daisy;
	int thisdev = numdevs;
	int detected;
	char *deviceid;

	parport_data_forward (port);
	parport_write_data (port, 0xaa); udelay (2);
	parport_write_data (port, 0x55); udelay (2);
	parport_write_data (port, 0x00); udelay (2);
	parport_write_data (port, 0xff); udelay (2);
	s = parport_read_status (port) & (PARPORT_STATUS_BUSY
					  | PARPORT_STATUS_PAPEROUT
					  | PARPORT_STATUS_SELECT
					  | PARPORT_STATUS_ERROR);
	if (s != (PARPORT_STATUS_BUSY
		  | PARPORT_STATUS_PAPEROUT
		  | PARPORT_STATUS_SELECT
		  | PARPORT_STATUS_ERROR)) {
		DPRINTK (KERN_DEBUG "%s: assign_addrs: aa5500ff(%02x)\n",
			 port->name, s);
		return 0;
	}

	parport_write_data (port, 0x87); udelay (2);
	s = parport_read_status (port) & (PARPORT_STATUS_BUSY
					  | PARPORT_STATUS_PAPEROUT
					  | PARPORT_STATUS_SELECT
					  | PARPORT_STATUS_ERROR);
	if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) {
		DPRINTK (KERN_DEBUG "%s: assign_addrs: aa5500ff87(%02x)\n",
			 port->name, s);
		return 0;
	}

	parport_write_data (port, 0x78); udelay (2);
	last_dev = 0; /* We've just been speaking to a device, so we
			 know there must be at least _one_ out there. */

	for (daisy = 0; daisy < 4; daisy++) {
		parport_write_data (port, daisy);
		udelay (2);
		parport_frob_control (port,
				      PARPORT_CONTROL_STROBE,
				      PARPORT_CONTROL_STROBE);
		udelay (1);
		parport_frob_control (port, PARPORT_CONTROL_STROBE, 0);
		udelay (1);

		if (last_dev)
			/* No more devices. */
			break;

		last_dev = !(parport_read_status (port)
			     & PARPORT_STATUS_BUSY);

		add_dev (numdevs++, port, daisy);
	}

	parport_write_data (port, 0xff); udelay (2);
	detected = numdevs - thisdev;
	DPRINTK (KERN_DEBUG "%s: Found %d daisy-chained devices\n", port->name,
		 detected);

	/* Ask the new devices to introduce themselves. */
	deviceid = kmalloc (1000, GFP_KERNEL);
	if (!deviceid) return 0;

	for (daisy = 0; thisdev < numdevs; thisdev++, daisy++)
		parport_device_id (thisdev, deviceid, 1000);

	kfree (deviceid);
	return detected;
}

/* Find a device with a particular manufacturer and model string,
   starting from a given device number.  Like the PCI equivalent,
   'from' itself is skipped. */

/**
 *	parport_find_device - find a specific device
 *	@mfg: required manufacturer string
 *	@mdl: required model string
 *	@from: previous device number found in search, or %NULL for
 *	       new search
 *
 *	This walks through the list of parallel port devices looking
 *	for a device whose 'MFG' string matches @mfg and whose 'MDL'
 *	string matches @mdl in their IEEE 1284 Device ID.
 *
 *	When a device is found matching those requirements, its device
 *	number is returned; if there is no matching device, a negative
 *	value is returned.
 *
 *	A new search it initiated by passing %NULL as the @from
 *	argument.  If @from is not %NULL, the search continues from
 *	that device.
 **/

int parport_find_device (const char *mfg, const char *mdl, int from)
{
	struct daisydev *d = topology; /* sorted by devnum */

	/* Find where to start. */
	while (d && d->devnum <= from)
		d = d->next;

	/* Search. */
	while (d) {
		struct parport_device_info *info;
		info = &d->port->probe_info[1 + d->daisy];
		if ((!mfg || !strcmp (mfg, info->mfr)) &&
		    (!mdl || !strcmp (mdl, info->model)))
			break;

		d = d->next;
	}

	if (d)
		return d->devnum;

	return -1;
}

/**
 *	parport_find_class - find a device in a specified class
 *	@cls: required class
 *	@from: previous device number found in search, or %NULL for
 *	       new search
 *
 *	This walks through the list of parallel port devices looking
 *	for a device whose 'CLS' string matches @cls in their IEEE
 *	1284 Device ID.
 *
 *	When a device is found matching those requirements, its device
 *	number is returned; if there is no matching device, a negative
 *	value is returned.
 *
 *	A new search it initiated by passing %NULL as the @from
 *	argument.  If @from is not %NULL, the search continues from
 *	that device.
 **/

int parport_find_class (parport_device_class cls, int from)
{
	struct daisydev *d = topology; /* sorted by devnum */

	/* Find where to start. */
	while (d && d->devnum <= from)
		d = d->next;

	/* Search. */
	while (d && d->port->probe_info[1 + d->daisy].class != cls)
		d = d->next;

	if (d)
		return d->devnum;

	return -1;
}