patch-1.3.53 linux/drivers/net/skeleton.c

• Lines: 485
• Date: Sat Dec 30 21:00:40 1995
• Orig file: v1.3.52/linux/drivers/net/skeleton.c
• Orig date: Sat Nov 25 19:04:46 1995

diff -u --recursive --new-file v1.3.52/linux/drivers/net/skeleton.c linux/drivers/net/skeleton.c
@@ -1,43 +1,43 @@
-/* skeleton.c: A network driver outline for linux. */
-/*
-	Written 1993-94 by Donald Becker.
-
-	Copyright 1993 United States Government as represented by the
-	Director, National Security Agency.
-
-	This software may be used and distributed according to the terms
-	of the GNU Public License, incorporated herein by reference.
-
-	The author may be reached as becker@CESDIS.gsfc.nasa.gov, or C/O
-	Center of Excellence in Space Data and Information Sciences
-	   Code 930.5, Goddard Space Flight Center, Greenbelt MD 20771
-
-	This file is an outline for writing a network device driver for the
-	the Linux operating system.
-
-	To write (or understand) a driver, have a look at the "loopback.c" file to
-	get a feel of what is going on, and then use the code below as a skeleton
-	for the new driver.
-
-*/
+/* skeleton.c: A network driver outline for linux.
+ *
+ *	Written 1993-94 by Donald Becker.
+ *
+ *	Copyright 1993 United States Government as represented by the
+ *	Director, National Security Agency.
+ *
+ *	This software may be used and distributed according to the terms
+ *	of the GNU Public License, incorporated herein by reference.
+ *
+ *	The author may be reached as becker@CESDIS.gsfc.nasa.gov, or C/O
+ *	Center of Excellence in Space Data and Information Sciences
+ *	   Code 930.5, Goddard Space Flight Center, Greenbelt MD 20771
+ *
+ *	This file is an outline for writing a network device driver for the
+ *	the Linux operating system.
+ *
+ *	To write (or understand) a driver, have a look at the "loopback.c" file to
+ *	get a feel of what is going on, and then use the code below as a skeleton
+ *	for the new driver.
+ *
+ */
 
 static const char *version =
 	"skeleton.c:v1.51 9/24/94 Donald Becker (becker@cesdis.gsfc.nasa.gov)\n";
 
 /*
-  Sources:
-	List your sources of programming information to document that
-	the driver is your own creation, and give due credit to others
-	that contributed to the work.  Remember that GNU project code
-	cannot use proprietary or trade secret information.	 Interface
-	definitions are generally considered non-copyrightable to the
-	extent that the same names and structures must be used to be
-	compatible.
-
-	Finally, keep in mind that the Linux kernel is has an API, not
-	ABI.  Proprietary object-code-only distributions are not permitted
-	under the GPL.
-*/
+ *  Sources:
+ *	List your sources of programming information to document that
+ *	the driver is your own creation, and give due credit to others
+ *	that contributed to the work. Remember that GNU project code
+ *	cannot use proprietary or trade secret information. Interface
+ *	definitions are generally considered non-copyrightable to the
+ *	extent that the same names and structures must be used to be
+ *	compatible.
+ *
+ *	Finally, keep in mind that the Linux kernel is has an API, not
+ *	ABI. Proprietary object-code-only distributions are not permitted
+ *	under the GPL.
+ */
 
 #include <linux/module.h>
 
@@ -61,12 +61,14 @@
 #include <linux/etherdevice.h>
 #include <linux/skbuff.h>
 
-/* The name of the card. Is used for messages and in the requests for
+/*
+ * The name of the card. Is used for messages and in the requests for
  * io regions, irqs and dma channels
  */
 static const char* cardname = "netcard";
 
 /* First, a few definitions that the brave might change. */
+
 /* A zero-terminated list of I/O addresses to be probed. */
 static unsigned int netcard_portlist[] =
    { 0x200, 0x240, 0x280, 0x2C0, 0x300, 0x320, 0x340, 0};
@@ -83,7 +85,7 @@
 /* Information that need to be kept for each board. */
 struct net_local {
 	struct enet_statistics stats;
-	long open_time;				/* Useless example local info. */
+	long open_time;			/* Useless example local info. */
 };
 
 /* The station (ethernet) address prefix, used for IDing the board. */
@@ -109,16 +111,18 @@
 extern void	hardware_send_packet(short ioaddr, char *buf, int length);
 extern void chipset_init(struct device *dev, int startp);
 
-
-/* Check for a network adaptor of this type, and return '0' iff one exists.
-   If dev->base_addr == 0, probe all likely locations.
-   If dev->base_addr == 1, always return failure.
-   If dev->base_addr == 2, allocate space for the device and return success
-   (detachable devices only).
-   */
+/*
+ * Check for a network adaptor of this type, and return '0' iff one exists.
+ * If dev->base_addr == 0, probe all likely locations.
+ * If dev->base_addr == 1, always return failure.
+ * If dev->base_addr == 2, allocate space for the device and return success
+ * (detachable devices only).
+ */
 #ifdef HAVE_DEVLIST
-/* Support for a alternate probe manager, which will eliminate the
-   boilerplate below. */
+/*
+ * Support for a alternate probe manager,
+ * which will eliminate the boilerplate below.
+ */
 struct netdev_entry netcard_drv =
 {cardname, netcard_probe1, NETCARD_IO_EXTENT, netcard_portlist};
 #else
@@ -128,9 +132,9 @@
 	int i;
 	int base_addr = dev ? dev->base_addr : 0;
 
-	if (base_addr > 0x1ff)		/* Check a single specified location. */
+	if (base_addr > 0x1ff)    /* Check a single specified location. */
 		return netcard_probe1(dev, base_addr);
-	else if (base_addr != 0)	/* Don't probe at all. */
+	else if (base_addr != 0)  /* Don't probe at all. */
 		return -ENXIO;
 
 	for (i = 0; netcard_portlist[i]; i++) {
@@ -145,18 +149,21 @@
 }
 #endif
 
-/* This is the real probe routine.  Linux has a history of friendly device
-   probes on the ISA bus.  A good device probes avoids doing writes, and
-   verifies that the correct device exists and functions.  */
-
+/*
+ * This is the real probe routine. Linux has a history of friendly device
+ * probes on the ISA bus. A good device probes avoids doing writes, and
+ * verifies that the correct device exists and functions.
+ */
 static int netcard_probe1(struct device *dev, int ioaddr)
 {
 	static unsigned version_printed = 0;
 	int i;
 
-	/* For ethernet adaptors the first three octets of the station address 
-	   contains the manufacturer's unique code.  That might be a good probe
-	   method. Ideally you would add additional checks.  */ 
+	/*
+	 * For ethernet adaptors the first three octets of the station address 
+	 * contains the manufacturer's unique code. That might be a good probe
+	 * method. Ideally you would add additional checks.
+	 */ 
 	if (inb(ioaddr + 0) != SA_ADDR0
 		||	 inb(ioaddr + 1) != SA_ADDR1
 		||	 inb(ioaddr + 2) != SA_ADDR2) {
@@ -165,7 +172,8 @@
 
 	/* Allocate a new 'dev' if needed. */
 	if (dev == NULL) {
-		/* Don't allocate the private data here, it is done later
+		/*
+		 * Don't allocate the private data here, it is done later
 		 * This makes it easier to free the memory when this driver
 		 * is used as a module.
 		 */
@@ -187,14 +195,16 @@
 		printk(" %2.2x", dev->dev_addr[i] = inb(ioaddr + i));
 
 #ifdef jumpered_interrupts
-	/* If this board has jumpered interrupts, snarf the interrupt vector
-	   now.	 There is no point in waiting since no other device can use
-	   the interrupt, and this marks the irq as busy.
-	   Jumpered interrupts are typically not reported by the boards, and
-	   we must used autoIRQ to find them. */
+	/*
+	 * If this board has jumpered interrupts, allocate the interrupt
+	 * vector now. There is no point in waiting since no other device
+	 * can use the interrupt, and this marks the irq as busy. Jumpered
+	 * interrupts are typically not reported by the boards, and we must
+	 * used autoIRQ to find them.
+	 */
 
 	if (dev->irq == -1)
-		;			/* Do nothing: a user-level program will set it. */
+		;	/* Do nothing: a user-level program will set it. */
 	else if (dev->irq < 2) {	/* "Auto-IRQ" */
 		autoirq_setup(0);
 		/* Trigger an interrupt here. */
@@ -203,8 +213,9 @@
 		if (net_debug >= 2)
 			printk(" autoirq is %d", dev->irq);
 	} else if (dev->irq == 2)
-		/* Fixup for users that don't know that IRQ 2 is really IRQ 9,
-		 * or don't know which one to set.
+		/*
+		 * Fixup for users that don't know that IRQ 2 is really
+		 * IRQ9, or don't know which one to set.
 		 */
 		dev->irq = 9;
 
@@ -218,8 +229,10 @@
 	}
 #endif	/* jumpered interrupt */
 #ifdef jumpered_dma
-	/* If we use a jumpered DMA channel, that should be probed for and
-	   allocated here as well.  See lance.c for an example. */
+	/*
+	 * If we use a jumpered DMA channel, that should be probed for and
+	 * allocated here as well. See lance.c for an example.
+	 */
 	if (dev->dma == 0) {
 		if (request_dma(dev->dma, cardname)) {
 			printk("DMA %d allocation failed.\n", dev->dma);
@@ -237,7 +250,10 @@
 		/* Re-read the DMA status registers. */
 		new_dma_status = ((inb(DMA1_STAT_REG) >> 4) & 0x0f) |
 			(inb(DMA2_STAT_REG) & 0xf0);
-		/* Eliminate the old and floating requests and DMA4, the cascade. */
+		/*
+		 * Eliminate the old and floating requests,
+		 * and DMA4 the cascade.
+		 */
 		new_dma_status ^= dma_status;
 		new_dma_status &= ~0x10;
 		for (i = 7; i > 0; i--)
@@ -280,34 +296,37 @@
 	return 0;
 }
 
-
-/* Open/initialize the board.  This is called (in the current kernel)
-   sometime after booting when the 'ifconfig' program is run.
-
-   This routine should set everything up anew at each open, even
-   registers that "should" only need to be set once at boot, so that
-   there is non-reboot way to recover if something goes wrong.
-   */
+/*
+ * Open/initialize the board. This is called (in the current kernel)
+ * sometime after booting when the 'ifconfig' program is run.
+ *
+ * This routine should set everything up anew at each open, even
+ * registers that "should" only need to be set once at boot, so that
+ * there is non-reboot way to recover if something goes wrong.
+ */
 static int
 net_open(struct device *dev)
 {
 	struct net_local *lp = (struct net_local *)dev->priv;
 	int ioaddr = dev->base_addr;
-
-	/* This is used if the interrupt line can turned off (shared).
-	   See 3c503.c for an example of selecting the IRQ at config-time. */
+	/*
+	 * This is used if the interrupt line can turned off (shared).
+	 * See 3c503.c for an example of selecting the IRQ at config-time.
+	 */
 	if (request_irq(dev->irq, &net_interrupt, 0, cardname)) {
 		return -EAGAIN;
 	}
-
-	/* Always snarf the DMA channel after the IRQ, and clean up on failure. */
+	/*
+	 * Always allocate the DMA channel after the IRQ,
+	 * and clean up on failure.
+	 */
 	if (request_dma(dev->dma, cardname)) {
 		free_irq(dev->irq);
 		return -EAGAIN;
 	}
 	irq2dev_map[dev->irq] = dev;
 
-	/* Reset the hardware here.  Don't forget to set the station address. */
+	/* Reset the hardware here. Don't forget to set the station address. */
 	/*chipset_init(dev, 1);*/
 	outb(0x00, ioaddr);
 	lp->open_time = jiffies;
@@ -328,8 +347,10 @@
 	int ioaddr = dev->base_addr;
 
 	if (dev->tbusy) {
-		/* If we get here, some higher level has decided we are broken.
-		   There should really be a "kick me" function call instead. */
+		/*
+		 * If we get here, some higher level has decided we are broken.
+		 * There should really be a "kick me" function call instead.
+		 */
 		int tickssofar = jiffies - dev->trans_start;
 		if (tickssofar < 5)
 			return 1;
@@ -340,17 +361,19 @@
 		dev->tbusy=0;
 		dev->trans_start = jiffies;
 	}
-
-	/* If some higher layer thinks we've missed an tx-done interrupt
-	   we are passed NULL. Caution: dev_tint() handles the cli()/sti()
-	   itself. */
+	/*
+	 * If some higher layer thinks we've missed an tx-done interrupt
+	 * we are passed NULL. Caution: dev_tint() handles the cli()/sti()
+	 * itself.
+	 */
 	if (skb == NULL) {
 		dev_tint(dev);
 		return 0;
 	}
-
-	/* Block a timer-based transmit from overlapping.  This could better be
-	   done with atomic_swap(1, dev->tbusy), but set_bit() works as well. */
+	/*
+	 * Block a timer-based transmit from overlapping. This could better be
+	 * done with atomic_swap(1, dev->tbusy), but set_bit() works as well.
+	 */
 	if (set_bit(0, (void*)&dev->tbusy) != 0)
 		printk(KERN_WARNING "%s: Transmitter access conflict.\n", dev->name);
 	else {
@@ -368,9 +391,11 @@
 
 	return 0;
 }
-
-/* The typical workload of the driver:
-   Handle the network interface interrupts. */
+
+/*
+ * The typical workload of the driver:
+ *   Handle the network interface interrupts.
+ */
 static void
 net_interrupt(int irq, struct pt_regs * regs)
 {
@@ -453,9 +478,11 @@
 		}
 	} while (--boguscount);
 
-	/* If any worth-while packets have been received, dev_rint()
-	   has done a mark_bh(NET_BH) for us and will work on them
-	   when we get to the bottom-half routine. */
+	/*
+	 * If any worth-while packets have been received, dev_rint()
+	 * has done a mark_bh(NET_BH) for us and will work on them
+	 * when we get to the bottom-half routine.
+	 */
 	return;
 }
 
@@ -476,7 +503,7 @@
 	disable_dma(dev->dma);
 
 	/* If not IRQ or DMA jumpered, free up the line. */
-	outw(0x00, ioaddr+0);		/* Release the physical interrupt line. */
+	outw(0x00, ioaddr+0);	/* Release the physical interrupt line. */
 
 	free_irq(dev->irq);
 	free_dma(dev->dma);
@@ -491,8 +518,10 @@
 
 }
 
-/* Get the current statistics.	This may be called with the card open or
-   closed. */
+/*
+ * Get the current statistics.
+ * This may be called with the card open or closed.
+ */
 static struct enet_statistics *
 net_get_stats(struct device *dev)
 {
@@ -507,38 +536,45 @@
 	return &lp->stats;
 }
 
-/* Set or clear the multicast filter for this adaptor.
-   num_addrs == -1	Promiscuous mode, receive all packets
-   num_addrs == 0	Normal mode, clear multicast list
-   num_addrs > 0	Multicast mode, receive normal and MC packets, and do
-			best-effort filtering.
+/*
+ * Set or clear the multicast filter for this adaptor.
+ * num_addrs == -1	Promiscuous mode, receive all packets
+ * num_addrs == 0	Normal mode, clear multicast list
+ * num_addrs > 0	Multicast mode, receive normal and MC packets,
+ *			and do best-effort filtering.
  */
 static void
 set_multicast_list(struct device *dev)
 {
 	short ioaddr = dev->base_addr;
-	if (dev->flags&IFF_PROMISC) {
-		outw(MULTICAST|PROMISC, ioaddr);		/* Enable promiscuous mode */
+	if (dev->flags&IFF_PROMISC)
+	{
+		/* Enable promiscuous mode */
+		outw(MULTICAST|PROMISC, ioaddr);
 	}
 	else if((dev->flags&IFF_ALLMULTI) || dev->mc_count > HW_MAX_ADDRS)
 	{
+		/* Disable promiscuous mode, use normal mode. */
 		hardware_set_filter(NULL);
-		outw(MULTICAST, ioaddr);		/* Disable promiscuous mode, use normal mode */
+
+		outw(MULTICAST, ioaddr);
 	}
 	else if(dev->mc_count)
 	{
-		hardware_set_filter(dev->mc_list);	/* Walk the address list and load the filter */
+		/* Walk the address list, and load the filter */
+		hardware_set_filter(dev->mc_list);
+
 		outw(MULTICAST, ioaddr);
 	}
 	else 
 		outw(0, ioaddr);
 }
-
+
 #ifdef MODULE
 
 static char devicename[9] = { 0, };
 static struct device this_device = {
-	devicename, /* device name is inserted by linux/drivers/net/net_init.c */
+	devicename, /* will be inserted by linux/drivers/net/net_init.c */
 	0, 0, 0, 0,
 	0, 0,  /* I/O address, IRQ */
 	0, 0, 0, NULL, netcard_probe };
@@ -556,7 +592,7 @@
 		printk(KERN_WARNING "%s: You shouldn't use auto-probing with insmod!\n",
 			   cardname);
 
-	/* copy the parameters from insmod into the device structure */
+	/* Copy the parameters from insmod into the device structure. */
 	this_device.base_addr = io;
 	this_device.irq       = irq;
 	this_device.dma       = dma;
@@ -572,12 +608,11 @@
 cleanup_module(void)
 {
 	/* No need to check MOD_IN_USE, as sys_delete_module() checks. */
-
 	unregister_netdev(&this_device);
-
-	/* If we don't do this, we can't re-insmod it later. */
-	/* Release irq/dma here, when you have jumpered versions and snarfed
-	 * them in net_probe1().
+	/*
+	 * If we don't do this, we can't re-insmod it later.
+	 * Release irq/dma here, when you have jumpered versions and
+	 * allocate them in net_probe1().
 	 */
 	/*
 	   free_irq(this_device.irq);
@@ -590,10 +625,12 @@
 }
 
 #endif /* MODULE */
-
+
 /*
  * Local variables:
- *  compile-command: "gcc -D__KERNEL__ -Wall -Wstrict-prototypes -Wwrite-strings -Wredundant-decls -O2 -m486 -c skeleton.c"
+ *  compile-command:
+ *	gcc -D__KERNEL__ -Wall -Wstrict-prototypes -Wwrite-strings
+ *	-Wredundant-decls -O2 -m486 -c skeleton.c
  *  version-control: t
  *  kept-new-versions: 5
  *  tab-width: 4