xircom_cb.c

linux-2.6.15.6

/*
 * xircom_cb: A driver for the (tulip-like) Xircom Cardbus ethernet cards 
 *
 * This software is (C) by the respective authors, and licensed under the GPL
 * License.
 *
 * Written by Arjan van de Ven for Red Hat, Inc.
 * Based on work by Jeff Garzik, Doug Ledford and Donald Becker 
 *
 *  	This software may be used and distributed according to the terms
 *      of the GNU General Public License, incorporated herein by reference.
 *
 *
 * 	$Id: xircom_cb.c,v 1.33 2001/03/19 14:02:07 arjanv Exp $
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/ethtool.h>
#include <linux/bitops.h>

#include <asm/uaccess.h>
#include <asm/io.h>

#ifdef DEBUG
#define enter(x)   printk("Enter: %s, %s line %i\n",x,__FILE__,__LINE__)
#define leave(x)   printk("Leave: %s, %s line %i\n",x,__FILE__,__LINE__)
#else
#define enter(x)   do {} while (0)
#define leave(x)   do {} while (0)
#endif


MODULE_DESCRIPTION("Xircom Cardbus ethernet driver");
MODULE_AUTHOR("Arjan van de Ven <[e-mail]>");
MODULE_LICENSE("GPL");



/* IO registers on the card, offsets */
#define CSR0	0x00
#define CSR1	0x08
#define CSR2	0x10
#define CSR3	0x18
#define CSR4	0x20
#define CSR5	0x28
#define CSR6	0x30
#define CSR7	0x38
#define CSR8	0x40
#define CSR9	0x48
#define CSR10	0x50
#define CSR11	0x58
#define CSR12	0x60
#define CSR13	0x68
#define CSR14	0x70
#define CSR15	0x78
#define CSR16	0x80

/* PCI registers */
#define PCI_POWERMGMT 	0x40

/* Offsets of the buffers within the descriptor pages, in bytes */

#define NUMDESCRIPTORS 4

static int bufferoffsets[NUMDESCRIPTORS] = {128,2048,4096,6144};


struct xircom_private {
	/* Send and receive buffers, kernel-addressable and dma addressable forms */

	unsigned int *rx_buffer;
	unsigned int *tx_buffer;

	dma_addr_t rx_dma_handle;
	dma_addr_t tx_dma_handle;

	struct sk_buff *tx_skb[4];

	unsigned long io_port;
	int open;
	
	/* transmit_used is the rotating counter that indicates which transmit
	   descriptor has to be used next */
	int transmit_used;

	/* Spinlock to serialize register operations.
	   It must be helt while manipulating the following registers:
	   CSR0, CSR6, CSR7, CSR9, CSR10, CSR15
	 */
	spinlock_t lock;


	struct pci_dev *pdev;
	struct net_device *dev;
	struct net_device_stats stats;
};


/* Function prototypes */
static int xircom_probe(struct pci_dev *pdev, const struct pci_device_id *id);
static void xircom_remove(struct pci_dev *pdev);
static irqreturn_t xircom_interrupt(int irq, void *dev_instance, struct pt_regs *regs);
static int xircom_start_xmit(struct sk_buff *skb, struct net_device *dev);
static int xircom_open(struct net_device *dev);
static int xircom_close(struct net_device *dev);
static void xircom_up(struct xircom_private *card);
static struct net_device_stats *xircom_get_stats(struct net_device *dev);
#ifdef CONFIG_NET_POLL_CONTROLLER
static void xircom_poll_controller(struct net_device *dev);
#endif

static void investigate_read_descriptor(struct net_device *dev,struct xircom_private *card, int descnr, unsigned int bufferoffset);
static void investigate_write_descriptor(struct net_device *dev, struct xircom_private *card, int descnr, unsigned int bufferoffset);
static void read_mac_address(struct xircom_private *card);
static void transceiver_voodoo(struct xircom_private *card);
static void initialize_card(struct xircom_private *card);
static void trigger_transmit(struct xircom_private *card);
static void trigger_receive(struct xircom_private *card);
static void setup_descriptors(struct xircom_private *card);
static void remove_descriptors(struct xircom_private *card);
static int link_status_changed(struct xircom_private *card);
static void activate_receiver(struct xircom_private *card);
static void deactivate_receiver(struct xircom_private *card);
static void activate_transmitter(struct xircom_private *card);
static void deactivate_transmitter(struct xircom_private *card);
static void enable_transmit_interrupt(struct xircom_private *card);
static void enable_receive_interrupt(struct xircom_private *card);
static void enable_link_interrupt(struct xircom_private *card);
static void disable_all_interrupts(struct xircom_private *card);
static int link_status(struct xircom_private *card);



static struct pci_device_id xircom_pci_table[] = {
	{0x115D, 0x0003, PCI_ANY_ID, PCI_ANY_ID,},
	{0,},
};
MODULE_DEVICE_TABLE(pci, xircom_pci_table);

static struct pci_driver xircom_ops = {
	.name		= "xircom_cb", 
	.id_table	= xircom_pci_table, 
	.probe		= xircom_probe, 
	.remove		= xircom_remove, 
	.suspend =NULL,
	.resume =NULL
};


#ifdef DEBUG
static void print_binary(unsigned int number)
{
	int i,i2;
	char buffer[64];
	memset(buffer,0,64);
	i2=0;
	for (i=31;i>=0;i--) {
		if (number & (1<<i))
			buffer[i2++]='1';
		else
			buffer[i2++]='0';
		if ((i&3)==0) 
			buffer[i2++]=' ';
	}
	printk("%s\n",buffer);
}
#endif

static void netdev_get_drvinfo(struct net_device *dev,
			       struct ethtool_drvinfo *info)
{
	struct xircom_private *private = netdev_priv(dev);

	strcpy(info->driver, "xircom_cb");
	strcpy(info->bus_info, pci_name(private->pdev));
}

static struct ethtool_ops netdev_ethtool_ops = {
	.get_drvinfo		= netdev_get_drvinfo,
};

/* xircom_probe is the code that gets called on device insertion.
   it sets up the hardware and registers the device to the networklayer.
   
   TODO: Send 1 or 2 "dummy" packets here as the card seems to discard the
         first two packets that get send, and pump hates that.
         
 */
static int __devinit xircom_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
	struct net_device *dev = NULL;
	struct xircom_private *private;
	unsigned char chip_rev;
	unsigned long flags;
	unsigned short tmp16;
	enter("xircom_probe");
	
	/* First do the PCI initialisation */

	if (pci_enable_device(pdev))
		return -ENODEV;

	/* disable all powermanagement */
	pci_write_config_dword(pdev, PCI_POWERMGMT, 0x0000);
	
	pci_set_master(pdev); /* Why isn't this done by pci_enable_device ?*/

	/* clear PCI status, if any */ 
	pci_read_config_word (pdev,PCI_STATUS, &tmp16); 
	pci_write_config_word (pdev, PCI_STATUS,tmp16);
	
	pci_read_config_byte(pdev, PCI_REVISION_ID, &chip_rev);
	
	if (!request_region(pci_resource_start(pdev, 0), 128, "xircom_cb")) {
		printk(KERN_ERR "xircom_probe: failed to allocate io-region\n");
		return -ENODEV;
	}

	/* 
	   Before changing the hardware, allocate the memory.
	   This way, we can fail gracefully if not enough memory
	   is available. 
	 */
	dev = alloc_etherdev(sizeof(struct xircom_private));
	if (!dev) {
		printk(KERN_ERR "xircom_probe: failed to allocate etherdev\n");
		goto device_fail;
	}
	private = netdev_priv(dev);
	
	/* Allocate the send/receive buffers */
	private->rx_buffer = pci_alloc_consistent(pdev,8192,&private->rx_dma_handle);
	if (private->rx_buffer == NULL) {
 		printk(KERN_ERR "xircom_probe: no memory for rx buffer \n");
		goto rx_buf_fail;
	}	
	private->tx_buffer = pci_alloc_consistent(pdev,8192,&private->tx_dma_handle);
	if (private->tx_buffer == NULL) {
		printk(KERN_ERR "xircom_probe: no memory for tx buffer \n");
		goto tx_buf_fail;
	}

	SET_MODULE_OWNER(dev);
	SET_NETDEV_DEV(dev, &pdev->dev);


	private->dev = dev;
	private->pdev = pdev;
	private->io_port = pci_resource_start(pdev, 0);
	spin_lock_init(&private->lock);
	dev->irq = pdev->irq;
	dev->base_addr = private->io_port;
	
	initialize_card(private);
	read_mac_address(private);
	setup_descriptors(private);
	
	dev->open = &xircom_open;
	dev->hard_start_xmit = &xircom_start_xmit;
	dev->stop = &xircom_close;
	dev->get_stats = &xircom_get_stats;
	dev->priv = private;
#ifdef CONFIG_NET_POLL_CONTROLLER
	dev->poll_controller = &xircom_poll_controller;
#endif
	SET_ETHTOOL_OPS(dev, &netdev_ethtool_ops);
	pci_set_drvdata(pdev, dev);

	if (register_netdev(dev)) {
		printk(KERN_ERR "xircom_probe: netdevice registration failed.\n");
		goto reg_fail;
	}
		
	printk(KERN_INFO "%s: Xircom cardbus revision %i at irq %i \n", dev->name, chip_rev, pdev->irq);
	/* start the transmitter to get a heartbeat */
	/* TODO: send 2 dummy packets here */
	transceiver_voodoo(private);
	
	spin_lock_irqsave(&private->lock,flags);
	activate_transmitter(private);
	activate_receiver(private);
	spin_unlock_irqrestore(&private->lock,flags);
	
	trigger_receive(private);
	
	leave("xircom_probe");
	return 0;

reg_fail:
	kfree(private->tx_buffer);
tx_buf_fail:
	kfree(private->rx_buffer);
rx_buf_fail:
	free_netdev(dev);
device_fail:
	return -ENODEV;
}


/*
 xircom_remove is called on module-unload or on device-eject.
 it unregisters the irq, io-region and network device.
 Interrupts and such are already stopped in the "ifconfig ethX down"
 code.
 */
static void __devexit xircom_remove(struct pci_dev *pdev)
{
	struct net_device *dev = pci_get_drvdata(pdev);
	struct xircom_private *card = netdev_priv(dev);

	enter("xircom_remove");
	pci_free_consistent(pdev,8192,card->rx_buffer,card->rx_dma_handle);
	pci_free_consistent(pdev,8192,card->tx_buffer,card->tx_dma_handle);

	release_region(dev->base_addr, 128);
	unregister_netdev(dev);
	free_netdev(dev);
	pci_set_drvdata(pdev, NULL);
	leave("xircom_remove");
} 

static irqreturn_t xircom_interrupt(int irq, void *dev_instance, struct pt_regs *regs)
{
	struct net_device *dev = (struct net_device *) dev_instance;
	struct xircom_private *card = netdev_priv(dev);
	unsigned int status;
	int i;

	enter("xircom_interrupt\n");

	spin_lock(&card->lock);
	status = inl(card->io_port+CSR5);

#ifdef DEBUG	
	print_binary(status);
	printk("tx status 0x%08x 0x%08x \n",card->tx_buffer[0],card->tx_buffer[4]);
	printk("rx status 0x%08x 0x%08x \n",card->rx_buffer[0],card->rx_buffer[4]);
#endif	
	/* Handle shared irq and hotplug */
	if (status == 0 || status == 0xffffffff) {
		spin_unlock(&card->lock);
		return IRQ_NONE;
	}

	if (link_status_changed(card)) {
		int newlink;
		printk(KERN_DEBUG "xircom_cb: Link status has changed \n");
		newlink = link_status(card);
		printk(KERN_INFO  "xircom_cb: Link is %i mbit \n",newlink);
		if (newlink)
			netif_carrier_on(dev);
		else
			netif_carrier_off(dev);
		
	}

	/* Clear all remaining interrupts */	
	status |= 0xffffffff; /* FIXME: make this clear only the
				        real existing bits */
	outl(status,card->io_port+CSR5);
	

	for (i=0;i<NUMDESCRIPTORS;i++) 
		investigate_write_descriptor(dev,card,i,bufferoffsets[i]);
	for (i=0;i<NUMDESCRIPTORS;i++) 
		investigate_read_descriptor(dev,card,i,bufferoffsets[i]);

	
	spin_unlock(&card->lock);
	leave("xircom_interrupt");
	return IRQ_HANDLED;
}

static int xircom_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct xircom_private *card;
	unsigned long flags;
	int nextdescriptor;
	int desc;
	enter("xircom_start_xmit");
	
	card = netdev_priv(dev);
	spin_lock_irqsave(&card->lock,flags);
	
	/* First see if we can free some descriptors */
	for (desc=0;desc<NUMDESCRIPTORS;desc++) 
		investigate_write_descriptor(dev,card,desc,bufferoffsets[desc]);
	
	
	nextdescriptor = (card->transmit_used +1) % (NUMDESCRIPTORS);
	desc = card->transmit_used;
	
	/* only send the packet if the descriptor is free */
	if (card->tx_buffer[4*desc]==0) {
			/* Copy the packet data; zero the memory first as the card
			   sometimes sends more than you ask it to. */
			
			memset(&card->tx_buffer[bufferoffsets[desc]/4],0,1536);
			memcpy(&(card->tx_buffer[bufferoffsets[desc]/4]),skb->data,skb->len);
	
	
			/* FIXME: The specification tells us that the length we send HAS to be a multiple of
			   4 bytes. */
			   
			card->tx_buffer[4*desc+1] = skb->len;
			if (desc == NUMDESCRIPTORS-1)
				card->tx_buffer[4*desc+1] |= (1<<25);  /* bit 25: last descriptor of the ring */

			card->tx_buffer[4*desc+1] |= 0xF0000000;
						 /* 0xF0... means want interrupts*/ 
			card->tx_skb[desc] = skb;
			
			wmb();
			/* This gives the descriptor to the card */