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/*
* dm9000.c: Version 1.2 03/18/2003
*
* A Davicom DM9000 ISA NIC fast Ethernet driver for Linux.
* Copyright (C) 1997 Sten Wang
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* (C)Copyright 1997-1998 DAVICOM Semiconductor,Inc. All Rights Reserved.
*
* V0.11 06/20/2001 REG_0A bit3=1, default enable BP with DA match
* 06/22/2001 Support DM9801 progrmming
* E3: R25 = ((R24 + NF) & 0x00ff) | 0xf000
* E4: R25 = ((R24 + NF) & 0x00ff) | 0xc200
* R17 = (R17 & 0xfff0) | NF + 3
* E5: R25 = ((R24 + NF - 3) & 0x00ff) | 0xc200
* R17 = (R17 & 0xfff0) | NF
*
* v1.00 modify by simon 2001.9.5
* change for kernel 2.4.x
*
* v1.1 11/09/2001 fix force mode bug
*
* v1.2 03/18/2003 Weilun Huang :
* Fixed phy reset.
* Added tx/rx 32 bit mode.
* Cleaned up for kernel merge.
*
* 03/03/2004 Sascha Hauer
* Port to 2.6 kernel
*
* 24-Sep-2004 Ben Dooks
* Cleanup of code to remove ifdefs
* Allowed platform device data to influence access width
* Reformatting areas of code
*
* 17-Mar-2005 Sascha Hauer
* * removed 2.4 style module parameters
* * removed removed unused stat counter and fixed
* net_device_stats
* * introduced tx_timeout function
* * reworked locking
*
* 01-Jul-2005 Ben Dooks
* * fixed spinlock call without pointer
* * ensure spinlock is initialised
*/
＃i nclude <linux/module.h>
＃i nclude <linux/ioport.h>
＃i nclude <linux/netdevice.h>
＃i nclude <linux/etherdevice.h>
＃i nclude <linux/init.h>
＃i nclude <linux/skbuff.h>
＃i nclude <linux/spinlock.h>
＃i nclude <linux/crc32.h>
＃i nclude <linux/mii.h>
＃i nclude <linux/dm9000.h>
＃i nclude <linux/delay.h>
＃i nclude <linux/platform_device.h>
＃i nclude <asm/delay.h>
＃i nclude <asm/irq.h>
＃i nclude <asm/io.h>
＃i nclude "dm9000.h"
/* Board/System/Debug information/definition ---------------- */
#define DM9000_PHY 0x40 /* PHY address 0x01 */
#define CARDNAME "dm9000"
#define PFX CARDNAME ": "
#define DM9000_TIMER_WUT jiffies+(HZ*2) /* timer wakeup time : 2 second */
#define DM9000_DEBUG 0
#if DM9000_DEBUG > 2
#define PRINTK3(args...) printk(CARDNAME ": " args)
#else
#define PRINTK3(args...) do { } while(0)
#endif
#if DM9000_DEBUG > 1
#define PRINTK2(args...) printk(CARDNAME ": " args)
#else
#define PRINTK2(args...) do { } while(0)
#endif
#if DM9000_DEBUG > 0
#define PRINTK1(args...) printk(CARDNAME ": " args)
#define PRINTK(args...) printk(CARDNAME ": " args)
#else
#define PRINTK1(args...) do { } while(0)
#define PRINTK(args...) printk(KERN_DEBUG args)
#endif
/*
* Transmit timeout, default 5 seconds.
*/
static int watchdog = 5000;
module_param(watchdog, int, 0400);
MODULE_PARM_DESC(watchdog, "transmit timeout in milliseconds");
/*DM9000 含有16K SRAM作为FIFO buffer，3K用于transmitt,13k用于receive*/
/* Structure/enum declaration ------------------------------- */
typedef struct board_info {
/*命令地址寄存器地址*/
void __iomem *io_addr; /* Register I/O base address */
/*数据寄存器地址*/
void __iomem *io_data; /* Data I/O address */
u16 irq; /* IRQ */
u16 tx_pkt_cnt;
u16 queue_pkt_len;
u16 queue_start_addr;
u16 dbug_cnt;
u8 io_mode; /* 0:word, 2:byte */
u8 phy_addr;
void (*inblk)(void __iomem *port, void *data, int length);
void (*outblk)(void __iomem *port, void *data, int length);
void (*dumpblk)(void __iomem *port, int length);
struct resource *addr_res; /* resources found */
struct resource *data_res;
struct resource *addr_req; /* resources requested */
struct resource *data_req;
struct resource *irq_res;
struct timer_list timer;
struct net_device_stats stats;
unsigned char srom[128]; /*网卡上EERPOM的内容*/
spinlock_t lock;
struct mii_if_info mii; /*调试可能会用到*/
u32 msg_enable;
} board_info_t;
/* function declaration ------------------------------------- */
static int dm9000_probe(struct platform_device *);
static int dm9000_open(struct net_device *);
static int dm9000_start_xmit(struct sk_buff *, struct net_device *);
static int dm9000_stop(struct net_device *);
static void dm9000_timer(unsigned long);
static void dm9000_init_dm9000(struct net_device *);
static struct net_device_stats *dm9000_get_stats(struct net_device *);
static irqreturn_t dm9000_interrupt(int, void *);
static int dm9000_phy_read(struct net_device *dev, int phyaddr_unsused, int reg);
static void dm9000_phy_write(struct net_device *dev, int phyaddr_unused, int reg,
int value);
static u16 read_srom_word(board_info_t *, int);
static void dm9000_rx(struct net_device *);
static void dm9000_hash_table(struct net_device *);
//#define DM9000_PROGRAM_EEPROM
#ifdef DM9000_PROGRAM_EEPROM
static void program_eeprom(board_info_t * db);
#endif
/* DM9000 network board routine ---------------------------- */
static void
dm9000_reset(board_info_t * db)
{
PRINTK1("dm9000x: resetting\n");
/* RESET device */
/*指定DM9000当前的命令寄存器是NCR*/
writeb(DM9000_NCR, db->io_addr);
udelay(200);
/*向NCR寄存器写入复位标志，芯片复位*/
writeb(NCR_RST, db->io_data);
udelay(200);
}
/*
* Read a byte from I/O port
读取寄存器的值，reg表明寄存器的偏移量
这里用宏名表示
*/
static u8
ior(board_info_t * db, int reg)
{
writeb(reg, db->io_addr);
return readb(db->io_data);
}
/*
* Write a byte to I/O port
写寄存器的值，reg表明寄存器的偏移量
这里用宏名表示，value是写入数据
*/
static void
iow(board_info_t * db, int reg, int value)
{
writeb(reg, db->io_addr);
writeb(value, db->io_data);
}
/* routines for sending block to chip */
/*类似于内存拷贝
简单的理解为memcpy(reg,data,count)
count是以字节为单位的！
*/
static void dm9000_outblk_8bit(void __iomem *reg, void *data, int count)
{
writesb(reg, data, count);
}
static void dm9000_outblk_16bit(void __iomem *reg, void *data, int count)
{
writesw(reg, data, (count+1) >> 1);
}
static void dm9000_outblk_32bit(void __iomem *reg, void *data, int count)
{
writesl(reg, data, (count+3) >> 2);
}
/* input block from chip to memory */
/*类似于内存拷贝
简单的理解为memcpy(data,reg,count)
count是以字节为单位的！
*/
static void dm9000_inblk_8bit(void __iomem *reg, void *data, int count)
{
readsb(reg, data, count);
}
static void dm9000_inblk_16bit(void __iomem *reg, void *data, int count)
{
readsw(reg, data, (count+1) >> 1);
}
static void dm9000_inblk_32bit(void __iomem *reg, void *data, int count)
{
readsl(reg, data, (count+3) >> 2);
}
/* dump block from chip to null */
/*类似于内存清理，将reg指向的count清空。
多用于设备的接收缓存区清空
count是以字节为单位的！
*/
static void dm9000_dumpblk_8bit(void __iomem *reg, int count)
{
int i;
int tmp;
for (i = 0; i < count; i++)
tmp = readb(reg);
}
static void dm9000_dumpblk_16bit(void __iomem *reg, int count)
{
int i;
int tmp;
count = (count + 1) >> 1;
for (i = 0; i < count; i++)
tmp = readw(reg);
}
static void dm9000_dumpblk_32bit(void __iomem *reg, int count)
{
int i;
int tmp;
count = (count + 3) >> 2;
for (i = 0; i < count; i++)
tmp = readl(reg);
}
/* dm9000_set_io
*
* select the specified set of io routines to use with the
* device
根据芯片的外部总线带宽，指定对应的输入输出函数
*/
static void dm9000_set_io(struct board_info *db, int byte_width)
{
/* use the size of the data resource to work out what IO
* routines we want to use
*/
switch (byte_width) {
case 1:
db->dumpblk = dm9000_dumpblk_8bit;
db->outblk = dm9000_outblk_8bit;
db->inblk = dm9000_inblk_8bit;
break;
case 2:
db->dumpblk = dm9000_dumpblk_16bit;
db->outblk = dm9000_outblk_16bit;
db->inblk = dm9000_inblk_16bit;
break;
case 3:
printk(KERN_ERR PFX ": 3 byte IO, falling back to 16bit\n");
db->dumpblk = dm9000_dumpblk_16bit;
db->outblk = dm9000_outblk_16bit;
db->inblk = dm9000_inblk_16bit;
break;
case 4:
default:
db->dumpblk = dm9000_dumpblk_32bit;
db->outblk = dm9000_outblk_32bit;
db->inblk = dm9000_inblk_32bit;
break;
}
}
/*超时处理函数*/
/* Our watchdog timed out. Called by the networking layer */
static void dm9000_timeout(struct net_device *dev)
{
board_info_t *db = (board_info_t *) dev->priv;
u8 reg_save;
unsigned long flags;
/* Save previous register address */
reg_save = readb(db->io_addr);
spin_lock_irqsave(&db->lock,flags);
/*停止发送报文 */
netif_stop_queue(dev);
/*复位DM9000芯片*/
dm9000_reset(db);
/*初始化DM9000芯片*/
dm9000_init_dm9000(dev);
/* We can accept TX packets again */
/*重启发送*/
dev->trans_start = jiffies;
netif_wake_queue(dev);
/* Restore previous register address */
/*io_addr的恢复，保证了芯片的配置和初始值一致*/
writeb(reg_save, db->io_addr);
spin_unlock_irqrestore(&db->lock,flags);
}
#ifdef CONFIG_NET_POLL_CONTROLLER
/*
*Used by netconsole
*/
static void dm9000_poll_controller(struct net_device *dev)
{
disable_irq(dev->irq);
dm9000_interrupt(dev->irq,dev);
enable_irq(dev->irq);
}
#endif
/* dm9000_release_board
*
* release a board, and any mapped resources
释放资源
*/
static void
dm9000_release_board(struct platform_device *pdev, struct board_info *db)
{
if (db->data_res == NULL) {
if (db->addr_res != NULL)
release_mem_region((unsigned long)db->io_addr, 4);
return;
}
/* unmap our resources */
iounmap(db->io_addr);
iounmap(db->io_data);
/* release the resources */
if (db->data_req != NULL) {
release_resource(db->data_req);
kfree(db->data_req);
}
if (db->addr_req != NULL) {
release_resource(db->addr_req);
kfree(db->addr_req);
}
}
#define res_size(_r) (((_r)->end - (_r)->start) + 1)
/*
* Search DM9000 board, allocate space and register it
*/
static int
dm9000_probe(struct platform_device *pdev)
{
struct dm9000_plat_data *pdata = pdev->dev.platform_data;
struct board_info *db; /* Point a board information structure */
struct net_device *ndev;
unsigned long base;
int ret = 0;
int iosize;
int i;
u32 id_val;
/* 分配eth网卡资源，私有数据区保存board_info*/
ndev = alloc_etherdev(sizeof (struct board_info));
if (!ndev) {
printk("%s: could not allocate device.\n", CARDNAME);
return -ENOMEM;
}
/*忽略*/
SET_MODULE_OWNER(ndev);
SET_NETDEV_DEV(ndev, &pdev->dev);
PRINTK2("dm9000_probe()");
/* setup board info structure
bord info初始化为0 */
db = (struct board_info *) ndev->priv;
memset(db, 0, sizeof (*db));
/*初始化spinlock*/
spin_lock_init(&db->lock);
/*忽略*/
if (pdev->num_resources < 2) {
ret = -ENODEV;
goto out;
} else if (pdev->num_resources == 2) {
base = pdev->resource[0].start;
if (!request_mem_region(base, 4, ndev->name)) {
ret = -EBUSY;
goto out;
}
ndev->base_addr = base;
ndev->irq = pdev->resource[1].start;
db->io_addr = (void __iomem *)base;
db->io_data = (void __iomem *)(base + 4);
} else {
db->addr_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
db->data_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
db->irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (db->addr_res == NULL || db->data_res == NULL ||
db->irq_res == NULL) {
printk(KERN_ERR PFX "insufficient resources\n");
ret = -ENOENT;
goto out;
}
i = res_size(db->addr_res);
db->addr_req = request_mem_region(db->addr_res->start, i,
pdev->name);
if (db->addr_req == NULL) {
printk(KERN_ERR PFX "cannot claim address reg area\n");
ret = -EIO;
goto out;
}
db->io_addr = ioremap(db->addr_res->start, i);
if (db->io_addr == NULL) {
printk(KERN_ERR "failed to ioremap address reg\n");
ret = -EINVAL;
goto out;
}
iosize = res_size(db->data_res);
db->data_req = request_mem_region(db->data_res->start, iosize,
pdev->name);
if (db->data_req == NULL) {
printk(KERN_ERR PFX "cannot claim data reg area\n");
ret = -EIO;
goto out;
}
db->io_data = ioremap(db->data_res->start, iosize);
if (db->io_data == NULL) {
printk(KERN_ERR "failed to ioremap data reg\n");
ret = -EINVAL;
goto out;
}
/* fill in parameters for net-dev structure */
ndev->base_addr = (unsigned long)db->io_addr;
ndev->irq = db->irq_res->start;
/* ensure at least we have a default set of IO routines */
dm9000_set_io(db, iosize);
}
/* check to see if anything is being over-ridden */
if (pdata != NULL) {
/* check to see if the driver wants to over-ride the
* default IO width */
if (pdata->flags & DM9000_PLATF_8BITONLY)
dm9000_set_io(db, 1);
if (pdata->flags & DM9000_PLATF_16BITONLY)
dm9000_set_io(db, 2);
if (pdata->flags & DM9000_PLATF_32BITONLY)
dm9000_set_io(db, 4);
/* check to see if there are any IO routine
* over-rides */
if (pdata->inblk != NULL)
db->inblk = pdata->inblk;
if (pdata->outblk != NULL)
db->outblk = pdata->outblk;
if (pdata->dumpblk != NULL)
db->dumpblk = pdata->dumpblk;
}
/*根据board info信息，复位DM9000芯片*/
dm9000_reset(db);
/* try two times, DM9000 sometimes gets the first read wrong */
for (i = 0; i < 2; i++) {
id_val = ior(db, DM9000_VIDL);
id_val |= (u32)ior(db, DM9000_VIDH) << 8;
id_val |= (u32)ior(db, DM9000_PIDL) << 16;
id_val |= (u32)ior(db, DM9000_PIDH) << 24;
if (id_val == DM9000_ID)
break;
printk("%s: read wrong id 0x%08x\n", CARDNAME, id_val);
}
/*芯片的ID获取失败，驱动不匹配*/
if (id_val != DM9000_ID) {
printk("%s: wrong id: 0x%08x\n", CARDNAME, id_val);
goto release;
}
/* from this point we assume that we have found a DM9000 */
/* driver system function
将DM9000作为以太网卡初始化内部数据结构*/
ether_setup(ndev);
ndev->open = &dm9000_open;
ndev->hard_start_xmit = &dm9000_start_xmit;
ndev->tx_timeout = &dm9000_timeout;
ndev->watchdog_timeo = msecs_to_jiffies(watchdog); /*超时值*/
ndev->stop = &dm9000_stop;
ndev->get_stats = &dm9000_get_stats;
ndev->set_multicast_list = &dm9000_hash_table;
#ifdef CONFIG_NET_POLL_CONTROLLER
ndev->poll_controller = &dm9000_poll_controller;
#endif
#ifdef DM9000_PROGRAM_EEPROM
/*开发时，需要更新EERPOM的值*/
program_eeprom(db);
#endif
/*忽略*/
db->msg_enable = NETIF_MSG_LINK;
db->mii.phy_id_mask = 0x1f;
db->mii.reg_num_mask = 0x1f;
db->mii.force_media = 0;
db->mii.full_duplex = 0;
db->mii.dev = ndev;
db->mii.mdio_read = dm9000_phy_read; /*DM9000可以提供MII，外接PHY*/
db->mii.mdio_write = dm9000_phy_write;
/* 获取网卡上EEPROM9346的内容，走EERPOM接口 */
for (i = 0; i < 64; i++)
/*采用16bit读取方式*/
((u16 *) db->srom)[i] = read_srom_word(db, i);
/* Set Node Address
EEPROM的前6个字节为MAC地址
*/
for (i = 0; i < 6; i++)
ndev->dev_addr[i] = db->srom[i];
/*验证获取的MAC地址是否合法*/
if (!is_valid_ether_addr(ndev->dev_addr)) {
/* try reading from mac */
/*不合法，重新从DM9000的内部寄存器获取MAC，不走EEPROM接口*/
for (i = 0; i < 6; i++)
ndev->dev_addr[i] = ior(db, i+DM9000_PAR);
}
/*两种方式都失败，提示用ifconfig,驱动没有对应接口！*/
if (!is_valid_ether_addr(ndev->dev_addr))
printk("%s: Invalid ethernet MAC address. Please "
"set using ifconfig\n", ndev->name);
platform_set_drvdata(pdev, ndev);
/*注册接口到系统中，状态默认down，不可用*/
ret = register_netdev(ndev);
if (ret == 0) {
printk("%s: dm9000 at %p,%p IRQ %d MAC: ",
ndev->name, db->io_addr, db->io_data, ndev->irq);
for (i = 0; i < 5; i++)
printk("%02x:", ndev->dev_addr[i]);
printk("%02x\n", ndev->dev_addr[5]);
}
return 0;
release:
out:
printk("%s: not found (%d).\n", CARDNAME, ret);
/失败时，释放资源*/
dm9000_release_board(pdev, db);
free_netdev(ndev);
return ret;
}
/*
* Open the interface.
* The interface is opened whenever "ifconfig" actives it.
当使用ifconfig激活该网络接口时调用
*/
static int
dm9000_open(struct net_device *dev)
{
board_info_t *db = (board_info_t *) dev->priv;
PRINTK2("entering dm9000_open\n");
/*申请中断资源，注册中断函数*/
if (request_irq(dev->irq, &dm9000_interrupt, IRQF_SHARED, dev->name, dev))
return -EAGAIN;
/* Initialize DM9000 board */
/*复位DM9000芯片*/
dm9000_reset(db);
/*配置DM9000芯片内寄存器，使其能工作*/
dm9000_init_dm9000(dev);
/* Init driver variable */
db->dbug_cnt = 0;
/* set and active a timer process */
init_timer(&db->timer); /*初始化内核定时器*/
db->timer.expires = DM9000_TIMER_WUT; /*2s唤醒一次*/
db->timer.data = (unsigned long) dev;
db->timer.function = &dm9000_timer; /*内核定时器溢出回调函数*/
add_timer(&db->timer); /*启动内核定时器*/
/*检查mii接口状态*/
mii_check_media(&db->mii, netif_msg_link(db), 1);
/*启动发送队列*/
netif_start_queue(dev);
return 0;
}
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