/* atp.c: Attached (pocket) ethernet adapter driver for linux. */
static const char version[] =
"atp.c:v1.09=ac 2002/10/01 Donald Becker <becker@scyld.com>\n";
/* The user-configurable values.
These may be modified when a driver module is loaded.*/
static int debug = 1; /* 1 normal messages, 0 quiet .. 7 verbose. */
#define net_debug debug
/* Maximum events (Rx packets, etc.) to handle at each interrupt. */
static int max_interrupt_work = 15;
#define NUM_UNITS 2
/* The standard set of ISA module parameters. */
static int io[NUM_UNITS];
static int irq[NUM_UNITS];
static int xcvr[NUM_UNITS]; /* The data transfer mode. */
/* Operational parameters that are set at compile time. */
/* Time in jiffies before concluding the transmitter is hung. */
#define TX_TIMEOUT (400*HZ/1000)
/*
This file is a device driver for the RealTek (aka AT-Lan-Tec) pocket
ethernet adapter. This is a common low-cost OEM pocket ethernet
adapter, sold under many names.
Sources:
This driver was written from the packet driver assembly code provided by
Vincent Bono of AT-Lan-Tec. Ever try to figure out how a complicated
device works just from the assembly code? It ain't pretty. The following
description is written based on guesses and writing lots of special-purpose
code to test my theorized operation.
In 1997 Realtek made available the documentation for the second generation
RTL8012 chip, which has lead to several driver improvements.
http://www.realtek.com.tw/
Theory of Operation
The RTL8002 adapter seems to be built around a custom spin of the SEEQ
controller core. It probably has a 16K or 64K internal packet buffer, of
which the first 4K is devoted to transmit and the rest to receive.
The controller maintains the queue of received packet and the packet buffer
access pointer internally, with only 'reset to beginning' and 'skip to next
packet' commands visible. The transmit packet queue holds two (or more?)
packets: both 'retransmit this packet' (due to collision) and 'transmit next
packet' commands must be started by hand.
The station address is stored in a standard bit-serial EEPROM which must be
read (ughh) by the device driver. (Provisions have been made for
substituting a 74S288 PROM, but I haven't gotten reports of any models
using it.) Unlike built-in devices, a pocket adapter can temporarily lose
power without indication to the device driver. The major effect is that
the station address, receive filter (promiscuous, etc.) and transceiver
must be reset.
The controller itself has 16 registers, some of which use only the lower
bits. The registers are read and written 4 bits at a time. The four bit
register address is presented on the data lines along with a few additional
timing and control bits. The data is then read from status port or written
to the data port.
Correction: the controller has two banks of 16 registers. The second
bank contains only the multicast filter table (now used) and the EEPROM
access registers.
Since the bulk data transfer of the actual packets through the slow
parallel port dominates the driver's running time, four distinct data
(non-register) transfer modes are provided by the adapter, two in each
direction. In the first mode timing for the nibble transfers is
provided through the data port. In the second mode the same timing is
provided through the control port. In either case the data is read from
the status port and written to the data port, just as it is accessing
registers.
In addition to the basic data transfer methods, several more are modes are
created by adding some delay by doing multiple reads of the data to allow
it to stabilize. This delay seems to be needed on most machines.
The data transfer mode is stored in the 'dev->if_port' field. Its default
value is '4'. It may be overridden at boot-time using the third parameter
to the "ether=..." initialization.
The header file <atp.h> provides inline functions that encapsulate the
register and data access methods. These functions are hand-tuned to
generate reasonable object code. This header file also documents my
interpretations of the device registers.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/in.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/crc32.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
#include <linux/bitops.h>
#include <asm/io.h>
#include <asm/dma.h>
#include "atp.h"
MODULE_AUTHOR("Donald Becker <becker@scyld.com>");
MODULE_DESCRIPTION("RealTek RTL8002/8012 parallel port Ethernet driver");
MODULE_LICENSE("GPL");
module_param(max_interrupt_work, int, 0);
module_param(debug, int, 0);
module_param_array(io, int, NULL, 0);
module_param_array(irq, int, NULL, 0);
module_param_array(xcvr, int, NULL, 0);
MODULE_PARM_DESC(max_interrupt_work, "ATP maximum events handled per interrupt");
MODULE_PARM_DESC(debug, "ATP debug level (0-7)");
MODULE_PARM_DESC(io, "ATP I/O base address(es)");
MODULE_PARM_DESC(irq, "ATP IRQ number(s)");
MODULE_PARM_DESC(xcvr, "ATP transceiver(s) (0=internal, 1=external)");
/* The number of low I/O ports used by the ethercard. */
#define ETHERCARD_TOTAL_SIZE 3
/* Sequence to switch an 8012 from printer mux to ethernet mode. */
static char mux_8012[] = { 0xff, 0xf7, 0xff, 0xfb, 0xf3, 0xfb, 0xff, 0xf7,};
struct net_local {
spinlock_t lock;
struct net_device *next_module;
struct timer_list timer; /* Media selection timer. */
long last_rx_time; /* Last Rx, in jiffies, to handle Rx hang. */
int saved_tx_size;
unsigned int tx_unit_busy:1;
unsigned char re_tx, /* Number of packet retransmissions. */
addr_mode, /* Current Rx filter e.g. promiscuous, etc. */
pac_cnt_in_tx_buf;
};
/* This code, written by wwc@super.org, resets the adapter every
TIMED_CHECKER ticks. This recovers from an unknown error which
hangs the device. */
#define TIMED_CHECKER (HZ/4)
#ifdef TIMED_CHECKER
#include <linux/timer.h>
static void atp_timed_checker(unsigned long ignored);
#endif
/* Index to functions, as function prototypes. */
static int atp_probe1(long ioaddr);
static void get_node_ID(struct net_device *dev);
static unsigned short eeprom_op(long ioaddr, unsigned int cmd);
static int net_open(struct net_device *dev);
static void hardware_init(struct net_device *dev);
static void write_packet(long ioaddr, int length, unsigned char *packet, int pad, int mode);
static void trigger_send(long ioaddr, int length);
static netdev_tx_t atp_send_packet(struct sk_buff *skb,
struct net_device *dev);
static irqreturn_t atp_interrupt(int irq, void *dev_id);
static void net_rx(struct net_device *dev);
static void read_block(long ioaddr, int length, unsigned char *buffer, int data_mode);
static int net_close(struct net_device *dev);
static void set_rx_mode(struct net_device *dev);
static void tx_timeout(struct net_device *dev);
/* A list of all installed ATP devices, for removing the driver module. */
static struct net_device *root_atp_dev;
/* Check for a network adapter 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).
FIXME: we should use the parport layer for this
*/
static int __init atp_init(void)
{
int *port, ports[] = {0x378, 0x278, 0x3bc, 0};
int base_addr = io[0];
if (base_addr > 0x1ff) /* Check a single specified location. */
return atp_probe1(base_addr);
else if (base_addr == 1) /* Don't probe at all. */
return -ENXIO;
for (port = ports; *port; port++) {
long ioaddr = *port;
outb(0x57, ioaddr + PAR_DATA);
if (inb(ioaddr + PAR_DATA)
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