patch-2.3.10 linux/drivers/misc/parport_ieee1284.c

• Lines: 556
• Date: Wed Jul 7 12:55:47 1999
• Orig file: v2.3.9/linux/drivers/misc/parport_ieee1284.c
• Orig date: Mon May 10 10:26:31 1999

diff -u --recursive --new-file v2.3.9/linux/drivers/misc/parport_ieee1284.c linux/drivers/misc/parport_ieee1284.c
@@ -4,12 +4,73 @@
  * Authors: Phil Blundell <Philip.Blundell@pobox.com>
  *          Carsten Gross <carsten@sol.wohnheim.uni-ulm.de>
  *	    Jose Renau <renau@acm.org>
+ *          Tim Waugh <tim@cyberelk.demon.co.uk> (largely rewritten)
+ *
+ * This file is responsible for IEEE 1284 negotiation, and for handing
+ * read/write requests to low-level drivers.
  */
 
+#include <linux/config.h>
 #include <linux/tasks.h>
 #include <linux/parport.h>
 #include <linux/delay.h>
 #include <linux/kernel.h>
+#include <linux/interrupt.h>
+
+#undef DEBUG /* undef me for production */
+
+#ifdef CONFIG_LP_CONSOLE
+#undef DEBUG /* Don't want a garbled console */
+#endif
+
+#ifdef DEBUG
+#define DPRINTK(stuff...) printk (stuff)
+#else
+#define DPRINTK(stuff...)
+#endif
+
+/* Make parport_wait_peripheral wake up.
+ * It will be useful to call this from an interrupt handler. */
+void parport_ieee1284_wakeup (struct parport *port)
+{
+	up (&port->physport->ieee1284.irq);
+}
+
+static struct parport *port_from_cookie[PARPORT_MAX];
+static void timeout_waiting_on_port (unsigned long cookie)
+{
+	parport_ieee1284_wakeup (port_from_cookie[cookie % PARPORT_MAX]);
+}
+
+/* Wait for a parport_ieee1284_wakeup.
+ * 0:      success
+ * <0:     error (exit as soon as possible)
+ * >0:     timed out
+ */
+int parport_wait_event (struct parport *port, signed long timeout)
+{
+	int ret;
+	struct timer_list timer;
+
+	if (!port->physport->cad->timeout)
+		/* Zero timeout is special, and we can't down() the
+		   semaphore. */
+		return 1;
+
+	init_timer (&timer);
+	timer.expires = jiffies + timeout;
+	timer.function = timeout_waiting_on_port;
+	port_from_cookie[port->number % PARPORT_MAX] = port;
+	timer.data = port->number;
+
+	add_timer (&timer);
+	ret = down_interruptible (&port->physport->ieee1284.irq);
+	if (!del_timer (&timer) && !ret)
+		/* Timed out. */
+		ret = 1;
+
+	return ret;
+}
 
 /* Wait for Status line(s) to change in 35 ms - see IEEE1284-1994 page 24 to
  * 25 for this. After this time we can create a timeout because the
@@ -19,53 +80,446 @@
  * are able to eat the time up to 40ms.
  */ 
 
-int parport_wait_peripheral(struct parport *port, unsigned char mask, 
-	unsigned char result)
+int parport_wait_peripheral(struct parport *port,
+			    unsigned char mask, 
+			    unsigned char result)
 {
 	int counter;
-	unsigned char status; 
-	
-	for (counter = 0; counter < 20; counter++) {
-		status = parport_read_status(port);
+	long deadline;
+	unsigned char status;
+
+	counter = port->physport->spintime; /* usecs of fast polling */
+	if (!port->physport->cad->timeout)
+		/* A zero timeout is "special": busy wait for the
+		   entire 35ms. */
+		counter = 35000;
+
+	/* Fast polling.
+	 *
+	 * This should be adjustable.
+	 * How about making a note (in the device structure) of how long
+	 * it takes, so we know for next time?
+	 */
+	for (counter /= 5; counter > 0; counter--) {
+		status = parport_read_status (port);
 		if ((status & mask) == result)
 			return 0;
-		udelay(25);
+		if (signal_pending (current))
+			return -EINTR;
 		if (current->need_resched)
-			schedule();
+			break;
+		udelay(5);
 	}
-	current->state = TASK_INTERRUPTIBLE;
-	schedule_timeout(HZ/25);				/* wait for 40ms */
-	status = parport_read_status(port);
-	return ((status & mask) == result)?0:1;
+
+	if (!port->physport->cad->timeout)
+		/* We may be in an interrupt handler, so we can't poll
+		 * slowly anyway. */
+		return 1;
+
+	/* 40ms of slow polling. */
+	deadline = jiffies + (HZ + 24) / 25;
+	while (time_before (jiffies, deadline)) {
+		int ret;
+
+		if (signal_pending (current))
+			return -EINTR;
+
+		/* Wait for 10ms (or until an interrupt occurs if
+		 * the handler is set) */
+		if ((ret = parport_wait_event (port, (HZ + 99) / 100)) < 0)
+			return ret;
+
+		status = parport_read_status (port);
+		if ((status & mask) == result)
+			return 0;
+
+		if (!ret) {
+			/* parport_wait_event didn't time out, but the
+			 * peripheral wasn't actually ready either.
+			 * Wait for another 10ms. */
+			current->state = TASK_INTERRUPTIBLE;
+			schedule_timeout ((HZ+ 99) / 100);
+		}
+	}
+
+	return 1;
+}
+
+#ifdef CONFIG_PARPORT_1284
+/* Terminate a negotiated mode. */
+static void parport_ieee1284_terminate (struct parport *port)
+{
+	port = port->physport;
+
+	port->ieee1284.phase = IEEE1284_PH_TERMINATE;
+
+	/* EPP terminates differently. */
+	switch (port->ieee1284.mode) {
+	case IEEE1284_MODE_EPP:
+	case IEEE1284_MODE_EPPSL:
+	case IEEE1284_MODE_EPPSWE:
+		/* Terminate from EPP mode. */
+
+		/* Event 68: Set nInit low */
+		parport_frob_control (port,
+				      PARPORT_CONTROL_INIT,
+				      PARPORT_CONTROL_INIT);
+		udelay (50);
+
+		/* Event 69: Set nInit high, nSelectIn low */
+		parport_frob_control (port,
+				      PARPORT_CONTROL_SELECT,
+				      PARPORT_CONTROL_SELECT);
+		break;
+		
+	default:
+		/* Terminate from all other modes. */
+
+		/* Event 22: Set nSelectIn low, nAutoFd high */
+		parport_frob_control (port,
+				      PARPORT_CONTROL_SELECT
+				      | PARPORT_CONTROL_AUTOFD,
+				      PARPORT_CONTROL_SELECT);
+
+		/* Event 24: nAck goes low */
+		parport_wait_peripheral (port, PARPORT_STATUS_ACK, 0);
+
+		/* Event 25: Set nAutoFd low */
+		parport_frob_control (port,
+				      PARPORT_CONTROL_AUTOFD,
+				      PARPORT_CONTROL_AUTOFD);
+
+		/* Event 27: nAck goes high */
+		parport_wait_peripheral (port,
+					 PARPORT_STATUS_ACK, 
+					 PARPORT_STATUS_ACK);
+
+		/* Event 29: Set nAutoFd high */
+		parport_frob_control (port, PARPORT_CONTROL_AUTOFD, 0);
+	}
+
+	port->ieee1284.mode = IEEE1284_MODE_COMPAT;
+	port->ieee1284.phase = IEEE1284_PH_FWD_IDLE;
+
+	DPRINTK (KERN_DEBUG "%s: In compatibility (forward idle) mode\n",
+		 port->name);
 }		
+#endif /* IEEE1284 support */
 
-/* Test if the peripheral is IEEE 1284 compliant.
+/* Negotiate an IEEE 1284 mode.
  * return values are:
- *   0 - handshake failed; peripheral is not compliant (or none present)
- *   1 - handshake OK; IEEE1284 peripheral present but no data available
- *   2 - handshake OK; IEEE1284 peripheral and data available
+ *   0 - handshake OK; IEEE1284 peripheral and mode available
+ *  -1 - handshake failed; peripheral is not compliant (or none present)
+ *   1 - handshake OK; IEEE1284 peripheral present but mode not available
  */
-int parport_ieee1284_nibble_mode_ok(struct parport *port, unsigned char mode) 
+int parport_negotiate (struct parport *port, int mode)
 {
-	/* make sure it's a valid state, set nStrobe & nAutoFeed high */
-	parport_frob_control (port, (1|2), 0);
-	udelay(1);
-	parport_write_data(port, mode);
-	udelay(400);
-	/* nSelectIn high, nAutoFd low */
-	parport_frob_control(port, (2|8), 2);
-	if (parport_wait_peripheral(port, 0x78, 0x38)) {
-		parport_frob_control(port, (2|8), 8);
+#ifndef CONFIG_PARPORT_1284
+	if (mode == IEEE1284_MODE_COMPAT)
+		return 0;
+	printk (KERN_ERR "parport: IEEE1284 not supported in this kernel\n");
+	return -1;
+#else
+	int m = mode;
+	unsigned char xflag;
+
+	port = port->physport;
+
+	/* Is there anything to do? */
+	if (port->ieee1284.mode == mode)
+		return 0;
+
+	/* Go to compability forward idle mode */
+	if (port->ieee1284.mode != IEEE1284_MODE_COMPAT)
+		parport_ieee1284_terminate (port);
+
+	if (mode == IEEE1284_MODE_COMPAT)
+		/* Compatibility mode: no negotiation. */
 		return 0; 
+
+	switch (mode) {
+	case IEEE1284_MODE_ECPSWE:
+		m = IEEE1284_MODE_ECP;
+		break;
+	case IEEE1284_MODE_EPPSL:
+	case IEEE1284_MODE_EPPSWE:
+		m = IEEE1284_MODE_EPP;
+		break;
+	case IEEE1284_MODE_BECP:
+		return -ENOSYS; /* FIXME (implement BECP) */
 	}
-	/* nStrobe low */
-	parport_frob_control (port, 1, 1);
-	udelay(1);				     /* Strobe wait */
-	/* nStrobe high, nAutoFeed low, last step before transferring 
-	 *  reverse data */
-	parport_frob_control (port, (1|2), 0);
+
+	port->ieee1284.phase = IEEE1284_PH_NEGOTIATION;
+
+	/* Start off with nStrobe and nAutoFd high, and nSelectIn low */
+	parport_frob_control (port,
+			      PARPORT_CONTROL_STROBE
+			      | PARPORT_CONTROL_AUTOFD
+			      | PARPORT_CONTROL_SELECT,
+			      PARPORT_CONTROL_SELECT);
 	udelay(1);
-	/* Data available? */
-	parport_wait_peripheral (port, PARPORT_STATUS_ACK, PARPORT_STATUS_ACK);
-	return (parport_read_status(port) & PARPORT_STATUS_ERROR)?1:2;
+
+	/* Event 0: Set data */
+	parport_write_data (port, m);
+	udelay (400); /* Shouldn't need to wait this long. */
+
+	/* Event 1: Set nSelectIn high, nAutoFd low */
+	parport_frob_control (port,
+			      PARPORT_CONTROL_SELECT
+			      | PARPORT_CONTROL_AUTOFD,
+			      PARPORT_CONTROL_AUTOFD);
+
+	/* Event 2: PError, Select, nFault go high, nAck goes low */
+	if (parport_wait_peripheral (port,
+				     PARPORT_STATUS_ERROR
+				     | PARPORT_STATUS_SELECT
+				     | PARPORT_STATUS_PAPEROUT
+				     | PARPORT_STATUS_ACK,
+				     PARPORT_STATUS_ERROR
+				     | PARPORT_STATUS_SELECT
+				     | PARPORT_STATUS_PAPEROUT)) {
+		/* Timeout */
+		parport_frob_control (port,
+				      PARPORT_CONTROL_SELECT
+				      | PARPORT_CONTROL_AUTOFD,
+				      PARPORT_CONTROL_SELECT);
+		DPRINTK (KERN_DEBUG
+			 "%s: Peripheral not IEEE1284 compliant (0x%02X)\n",
+			 port->name, parport_read_status (port));
+		port->ieee1284.phase = IEEE1284_PH_FWD_IDLE;
+		return -1; /* Not IEEE1284 compliant */
+	}
+
+	/* Event 3: Set nStrobe low */
+	parport_frob_control (port,
+			      PARPORT_CONTROL_STROBE,
+			      PARPORT_CONTROL_STROBE);
+
+	/* Event 4: Set nStrobe and nAutoFd high */
+	udelay (5);
+	parport_frob_control (port,
+			      PARPORT_CONTROL_STROBE
+			      | PARPORT_CONTROL_AUTOFD,
+			      0);
+
+	/* Event 6: nAck goes high */
+	if (parport_wait_peripheral (port,
+				     PARPORT_STATUS_ACK
+				     | PARPORT_STATUS_PAPEROUT,
+				     PARPORT_STATUS_ACK)) {
+		if (parport_read_status (port) & PARPORT_STATUS_ACK)
+			printk (KERN_DEBUG
+				"%s: working around buggy peripheral: tell "
+				"Tim what make it is\n", port->name);
+		DPRINTK (KERN_DEBUG
+			 "%s: Mode 0x%02x not supported? (0x%02x)\n",
+			 port->name, mode, port->ops->read_status (port));
+		parport_ieee1284_terminate (port);
+		return 1;
+	}
+
+	xflag = parport_read_status (port) & PARPORT_STATUS_SELECT;
+
+	/* xflag should be high for all modes other than nibble (0). */
+	if (mode && !xflag) {
+		/* Mode not supported. */
+		DPRINTK (KERN_DEBUG "%s: Mode 0x%02x not supported\n",
+			 port->name, mode);
+		parport_ieee1284_terminate (port);
+		return 1;
+	}
+
+	/* Mode is supported */
+	DPRINTK (KERN_DEBUG "%s: In mode 0x%02x\n", port->name, mode);
+	port->ieee1284.mode = mode;
+
+	/* But ECP is special */
+	if (mode & IEEE1284_MODE_ECP) {
+		port->ieee1284.phase = IEEE1284_PH_ECP_SETUP;
+
+		/* Event 30: Set nAutoFd low */
+		parport_frob_control (port,
+				      PARPORT_CONTROL_AUTOFD,
+				      PARPORT_CONTROL_AUTOFD);
+
+		/* Event 31: PError goes high. */
+		parport_wait_peripheral (port,
+					 PARPORT_STATUS_PAPEROUT,
+					 PARPORT_STATUS_PAPEROUT);
+		/* (Should check that this works..) */
+
+		port->ieee1284.phase = IEEE1284_PH_FWD_IDLE;
+		DPRINTK (KERN_DEBUG "%s: ECP direction: forward\n",
+			 port->name);
+	} else switch (mode) {
+	case IEEE1284_MODE_NIBBLE:
+	case IEEE1284_MODE_BYTE:
+		port->ieee1284.phase = IEEE1284_PH_REV_IDLE;
+		break;
+	default:
+		port->ieee1284.phase = IEEE1284_PH_FWD_IDLE;
+	}
+
+
+	return 0;
+#endif /* IEEE1284 support */
+}
+
+/* Acknowledge that the peripheral has data available.
+ * Events 18-20, in order to get from Reverse Idle phase
+ * to Host Busy Data Available.
+ * This will most likely be called from an interrupt.
+ * Returns zero if data was available.
+ */
+#ifdef CONFIG_PARPORT_1284
+static int parport_ieee1284_ack_data_avail (struct parport *port)
+{
+	if (parport_read_status (port) & PARPORT_STATUS_ERROR)
+		/* Event 18 didn't happen. */
+		return -1;
+
+	/* Event 20: nAutoFd goes high. */
+	port->ops->frob_control (port, PARPORT_CONTROL_AUTOFD, 0);
+	port->ieee1284.phase = IEEE1284_PH_HBUSY_DAVAIL;
+	return 0;
+}
+#endif /* IEEE1284 support */
+
+/* Handle an interrupt. */
+void parport_ieee1284_interrupt (int which, void *handle, struct pt_regs *regs)
+{
+	struct parport *port = handle;
+	parport_ieee1284_wakeup (port);
+
+#ifdef CONFIG_PARPORT_1284
+	if (port->ieee1284.phase == IEEE1284_PH_REV_IDLE) {
+		/* An interrupt in this phase means that data
+		 * is now available. */
+		DPRINTK (KERN_DEBUG "%s: Data available\n", port->name);
+		parport_ieee1284_ack_data_avail (port);
+	}
+#endif /* IEEE1284 support */
+}
+
+/* Write a block of data. */
+ssize_t parport_write (struct parport *port, const void *buffer, size_t len)
+{
+#ifndef CONFIG_PARPORT_1284
+	return port->ops->compat_write_data (port, buffer, len, 0);
+#else
+	ssize_t retval;
+	int mode = port->ieee1284.mode;
+	size_t (*fn) (struct parport *, const void *, size_t, int);
+
+	/* Ignore the device-ID-request bit. */
+	mode &= ~IEEE1284_DEVICEID;
+
+	/* Use the mode we're in. */
+	switch (mode) {
+	case IEEE1284_MODE_NIBBLE:
+		parport_negotiate (port, IEEE1284_MODE_COMPAT);
+	case IEEE1284_MODE_COMPAT:
+		DPRINTK (KERN_DEBUG "%s: Using compatibility mode\n",
+			 port->name);
+		fn = port->ops->compat_write_data;
+		break;
+
+	case IEEE1284_MODE_EPP:
+		DPRINTK (KERN_DEBUG "%s: Using EPP mode\n", port->name);
+		fn = port->ops->epp_write_data;
+		break;
+
+	case IEEE1284_MODE_ECP:
+	case IEEE1284_MODE_ECPRLE:
+		DPRINTK (KERN_DEBUG "%s: Using ECP mode\n", port->name);
+		fn = port->ops->ecp_write_data;
+		break;
+
+	case IEEE1284_MODE_ECPSWE:
+		DPRINTK (KERN_DEBUG "%s: Using software-emulated ECP mode\n",
+			 port->name);
+		/* The caller has specified that it must be emulated,
+		 * even if we have ECP hardware! */
+		fn = parport_ieee1284_ecp_write_data;
+		break;
+
+	default:
+		DPRINTK (KERN_DEBUG "%s: Unknown mode 0x%02x\n", port->name,
+			port->ieee1284.mode);
+		return -ENOSYS;
+	}
+
+	retval = (*fn) (port, buffer, len, 0);
+	DPRINTK (KERN_DEBUG "%s: wrote %d/%d bytes\n", port->name, retval,
+		 len);
+	return retval;
+#endif /* IEEE1284 support */
+}
+
+/* Read a block of data. */
+ssize_t parport_read (struct parport *port, void *buffer, size_t len)
+{
+#ifndef CONFIG_PARPORT_1284
+	printk (KERN_ERR "parport: IEEE1284 not supported in this kernel\n");
+	return -ENODEV;
+#else
+	int mode = port->physport->ieee1284.mode;
+	size_t (*fn) (struct parport *, void *, size_t, int);
+
+	/* Ignore the device-ID-request bit. */
+	mode &= ~IEEE1284_DEVICEID;
+
+	/* Use the mode we're in. */
+	switch (mode) {
+	case IEEE1284_MODE_COMPAT:
+		if (parport_negotiate (port, IEEE1284_MODE_NIBBLE))
+			return -EIO;
+	case IEEE1284_MODE_NIBBLE:
+		DPRINTK (KERN_DEBUG "%s: Using nibble mode\n", port->name);
+		fn = port->ops->nibble_read_data;
+		break;
+
+	case IEEE1284_MODE_BYTE:
+		DPRINTK (KERN_DEBUG "%s: Using byte mode\n", port->name);
+		fn = port->ops->byte_read_data;
+		break;
+
+	case IEEE1284_MODE_EPP:
+		DPRINTK (KERN_DEBUG "%s: Using EPP mode\n", port->name);
+		fn = port->ops->epp_read_data;
+		break;
+
+	case IEEE1284_MODE_ECP:
+	case IEEE1284_MODE_ECPRLE:
+		DPRINTK (KERN_DEBUG "%s: Using ECP mode\n", port->name);
+		fn = port->ops->ecp_read_data;
+		break;
+
+	case IEEE1284_MODE_ECPSWE:
+		DPRINTK (KERN_DEBUG "%s: Using software-emulated ECP mode\n",
+			 port->name);
+		fn = parport_ieee1284_ecp_read_data;
+		break;
+
+	default:
+		DPRINTK (KERN_DEBUG "%s: Unknown mode 0x%02x\n", port->name,
+			 port->physport->ieee1284.mode);
+		return -ENOSYS;
+	}
+
+	return (*fn) (port, buffer, len, 0);
+#endif /* IEEE1284 support */
+}
+
+/* Set the amount of time we wait while nothing's happening. */
+long parport_set_timeout (struct pardevice *dev, long inactivity)
+{
+	long int old = dev->timeout;
+
+	dev->timeout = inactivity;
+
+	if (dev->port->physport->cad == dev)
+		parport_ieee1284_wakeup (dev->port);
+
+	return old;
 }