DM9000驱动解析

* * 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 <[email protected]>: * Fixed phy reset. * Added tx/rx 32 bit mode. * Cleaned up for kernel merge. * * 03/03/2004 Sascha Hauer <[email protected]> * Port to 2.6 kernel * * 24-Sep-2004 Ben Dooks <[email protected]> * Cleanup of code to remove ifdefs * Allowed platform device data to influence access width * Reformatting areas of code * * 17-Mar-2005 Sascha Hauer <[email protected]> * * 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 <[email protected]> * * 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; /* * Initilize dm9000 board 配置DM9000芯片内部寄存器，使其能工作 */ static void dm9000_init_dm9000(struct net_device *dev) { board_info_t *db = (board_info_t *) dev->priv; PRINTK1("entering %s/n",__FUNCTION__); /* I/O mode 检查当前芯片的总线带宽8bit，16bit，32bit 芯片的总线带宽由硬件走线决定 */ db->io_mode = ior(db, DM9000_ISR) >> 6; /* ISR bit7:6 keeps I/O mode */ /* GPIO0 on pre-activate PHY 启动PHY*/ iow(db, DM9000_GPR, 0); /* REG_1F bit0 activate phyxcer */ iow(db, DM9000_GPCR, GPCR_GEP_CNTL); /* Let GPIO0 output */ iow(db, DM9000_GPR, 0); /* Enable PHY */ /* Program operating register */ /*清除发送配置选项*/ iow(db, DM9000_TCR, 0); /* TX Polling clear */ iow(db, DM9000_BPTR, 0x3f); /* Less 3Kb, 200us */ iow(db, DM9000_FCR, 0xff); /* Flow Control */ iow(db, DM9000_SMCR, 0); /* Special Mode */ /* clear TX status */ /*清除发送标志位*/ iow(db, DM9000_NSR, NSR_WAKEST | NSR_TX2END | NSR_TX1END); /*清除中断标志位*/ iow(db, DM9000_ISR, ISR_CLR_STATUS); /* Clear interrupt status */ /* Set address filter table */ dm9000_hash_table(dev); /* Activate DM9000 接收包大小不能超过1.5k,CRC错误的抛弃，使能接收*/ iow(db, DM9000_RCR, RCR_DIS_LONG | RCR_DIS_CRC | RCR_RXEN); /* Enable TX/RX interrupt mask 使用发送，接收中断。SRAM缓冲区指针自动回0 */ iow(db, DM9000_IMR, IMR_PAR | IMR_PTM | IMR_PRM); /* Init Driver variable */ db->tx_pkt_cnt = 0; db->queue_pkt_len = 0; dev->trans_start = 0; } /* * Hardware start transmission. * Send a packet to media from the upper layer. */ static int dm9000_start_xmit(struct sk_buff *skb, struct net_device *dev) { board_info_t *db = (board_info_t *) dev->priv; PRINTK3("dm9000_start_xmit/n"); if (db->tx_pkt_cnt > 1) return 1; /*停止接收*/ netif_stop_queue(dev); /* Disable all interrupts 关闭发送，接收中断*/ iow(db, DM9000_IMR, IMR_PAR); /* Move data to DM9000 TX RAM */ writeb(DM9000_MWCMD, db->io_addr); /*把skb的数据拷贝到DM9000的SRAM中*/ (db->outblk)(db->io_data, skb->data, skb->len); /*统计值加上相应的长度*/ db->stats.tx_bytes += skb->len; /* TX control: First packet immediately send, second packet queue */ if (db->tx_pkt_cnt == 0) { /* First Packet 发送的包增加*/ db->tx_pkt_cnt++; /* Set TX length to DM9000 设定DM9000需要发送的包长度*/ iow(db, DM9000_TXPLL, skb->len & 0xff); iow(db, DM9000_TXPLH, (skb->len >> 8) & 0xff); /* Issue TX polling command 设定发送请求，即启动发送*/ iow(db, DM9000_TCR, TCR_TXREQ); /* Cleared after TX complete */ /*启动时间*/ dev->trans_start = jiffies; /* save the time stamp */ } else { /*第二个包发送，在tx_done中实现*/ /* Second packet */ db->tx_pkt_cnt++; db->queue_pkt_len = skb->len; } /* free this SKB 发送完毕释放skb */ dev_kfree_skb(skb); /* Re-enable resource check 第一个包发送完毕，即内存拷贝完毕，不是实际总线上的 可以启动第二包拷贝到SRAM*/ if (db->tx_pkt_cnt == 1) netif_wake_queue(dev); /* Re-enable interrupt 重新启用中断，这时DM9000若发送完成，会产生发送完毕中断*/ iow(db, DM9000_IMR, IMR_PAR | IMR_PTM | IMR_PRM); return 0; } static void dm9000_shutdown(struct net_device *dev) { board_info_t *db = (board_info_t *) dev->priv; /* RESET device */ dm9000_phy_write(dev, 0, MII_BMCR, BMCR_RESET); /* PHY RESET */ /*关闭PHY*/ iow(db, DM9000_GPR, 0x01); /* Power-Down PHY */ /*屏蔽所有中断*/ iow(db, DM9000_IMR, IMR_PAR); /* Disable all interrupt */ /*禁用接收*/ iow(db, DM9000_RCR, 0x00); /* Disable RX */ } /* * Stop the interface. * The interface is stopped when it is brought. */ static int dm9000_stop(struct net_device *ndev) { board_info_t *db = (board_info_t *) ndev->priv; PRINTK1("entering %s/n",__FUNCTION__); /* deleted timer 删除内核定时器*/ del_timer(&db->timer); /*通知内核队列不可用*/ netif_stop_queue(ndev); /*linkstat 状态断路*/ netif_carrier_off(ndev); /* free interrupt 释放中断*/ free_irq(ndev->irq, ndev); /*硬件上关闭芯片*/ dm9000_shutdown(ndev); return 0; } /* * DM9000 interrupt handler * receive the packet to upper layer, free the transmitted packet */ static void dm9000_tx_done(struct net_device *dev, board_info_t * db) { int tx_status = ior(db, DM9000_NSR); /* Got TX status */ /*一个包已经发送完毕*/ if (tx_status & (NSR_TX2END | NSR_TX1END)) { /* One packet sent complete */ db->tx_pkt_cnt--; db->stats.tx_packets++; /* Queue packet check & send 当前还有一个包未发送，且在缓冲区中，是第二个包*/ if (db->tx_pkt_cnt > 0) { /*设定DM9000发送包的长度*/ iow(db, DM9000_TXPLL, db->queue_pkt_len & 0xff); iow(db, DM9000_TXPLH, (db->queue_pkt_len >> 8) & 0xff); /*启动发送*/ iow(db, DM9000_TCR, TCR_TXREQ); dev->trans_start = jiffies; } /*通知内核*/ netif_wake_queue(dev); } } static irqreturn_t dm9000_interrupt(int irq, void *dev_id) { struct net_device *dev = dev_id; board_info_t *db; int int_status; u8 reg_save; PRINTK3("entering %s/n",__FUNCTION__); if (!dev) { PRINTK1("dm9000_interrupt() without DEVICE arg/n"); return IRQ_HANDLED; } /* A real interrupt coming */ db = (board_info_t *) dev->priv; spin_lock(&db->lock); /* Save previous register address */ /*保存寄存器值*/ reg_save = readb(db->io_addr); /* Disable all interrupts 关闭所有中断*/ iow(db, DM9000_IMR, IMR_PAR); /* Got DM9000 interrupt status */ int_status = ior(db, DM9000_ISR); /* Got ISR */ iow(db, DM9000_ISR, int_status); /* Clear ISR status */ /* Received the coming packet 接收包中断*/ if (int_status & ISR_PRS) dm9000_rx(dev); /* Trnasmit Interrupt check 发送包中断*/ if (int_status & ISR_PTS) dm9000_tx_done(dev, db); /* Re-enable interrupt mask */ iow(db, DM9000_IMR, IMR_PAR | IMR_PTM | IMR_PRM); /* Restore previous register address */ writeb(reg_save, db->io_addr); spin_unlock(&db->lock); return IRQ_HANDLED; } /* * Get statistics from driver. 获取网卡接口统计信息 */ static struct net_device_stats * dm9000_get_stats(struct net_device *dev) { board_info_t *db = (board_info_t *) dev->priv; return &db->stats; } /* * A periodic timer routine * Dynamic media sense, allocated Rx buffer... */ static void dm9000_timer(unsigned long data) { struct net_device *dev = (struct net_device *) data; board_info_t *db = (board_info_t *) dev->priv; PRINTK3("dm9000_timer()/n"); /*检查mii接口*/ mii_check_media(&db->mii, netif_msg_link(db), 0); /* Set timer again 重新启动内核定时器，周期检查mii接口 */ db->timer.expires = DM9000_TIMER_WUT; add_timer(&db->timer); } /*DM9000接收包头，芯片提供 01，status，length low,length high*/ struct dm9000_rxhdr { u16 RxStatus; u16 RxLen; } __attribute__((__packed__)); /* * Received a packet and pass to upper layer */ static void dm9000_rx(struct net_device *dev) { board_info_t *db = (board_info_t *) dev->priv; struct dm9000_rxhdr rxhdr; struct sk_buff *skb; u8 rxbyte, *rdptr; bool GoodPacket; int RxLen; /* Check packet ready or not */ do { ior(db, DM9000_MRCMDX); /* Dummy read */ /* Get most updated data */ rxbyte = readb(db->io_data); /* Status check: this byte must be 0 or 1 接收包最长为1536 */ if (rxbyte > DM9000_PKT_RDY) { printk("status check failed: %d/n", rxbyte); iow(db, DM9000_RCR, 0x00); /* Stop Device */ iow(db, DM9000_ISR, IMR_PAR); /* Stop INT request */ return; } if (rxbyte != DM9000_PKT_RDY) return; /* A packet ready now & Get status/length */ GoodPacket = true; writeb(DM9000_MRCMD, db->io_addr); /*获取接收数据包头，共4字节，参考DM9000手册*/ (db->inblk)(db->io_data, &rxhdr, sizeof(rxhdr)); /*查看包长*/ RxLen = rxhdr.RxLen; /* Packet Status check 包长不能小于64字节*/ if (RxLen < 0x40) { GoodPacket = false; PRINTK1("Bad Packet received (runt)/n"); } /*包长不能大于1536字节*/ if (RxLen > DM9000_PKT_MAX) { PRINTK1("RST: RX Len:%x/n", RxLen); } /*接收的包有错误*/ if (rxhdr.RxStatus & 0xbf00) { GoodPacket = false; if (rxhdr.RxStatus & 0x100) { PRINTK1("fifo error/n"); db->stats.rx_fifo_errors++; } if (rxhdr.RxStatus & 0x200) { PRINTK1("crc error/n"); db->stats.rx_crc_errors++; } if (rxhdr.RxStatus & 0x8000) { PRINTK1("length error/n"); db->stats.rx_length_errors++; } } /* Move data from DM9000 接收的包没有任何问题时*/ if (GoodPacket && ((skb = dev_alloc_skb(RxLen + 4)) != NULL)) { skb_reserve(skb, 2); rdptr = (u8 *) skb_put(skb, RxLen - 4); /* Read received packet from RX SRAM */ /*数据从DM9000内存拷贝到skb*/ (db->inblk)(db->io_data, rdptr, RxLen); /*更新接收字节数统计*/ db->stats.rx_bytes += RxLen; /* Pass to upper layer */ skb->protocol = eth_type_trans(skb, dev); /*通知上层有新的skb收到*/ netif_rx(skb); /*接收包更新*/ db->stats.rx_packets++; } else { /* need to dump the packet's data */ (db->dumpblk)(db->io_data, RxLen); } } while (rxbyte == DM9000_PKT_RDY); } /* * Read a word data from SROM 从EEPROM9346中读取数据 16bit */ static u16 read_srom_word(board_info_t * db, int offset) { iow(db, DM9000_EPAR, offset); iow(db, DM9000_EPCR, EPCR_ERPRR); mdelay(8); /* according to the datasheet 200us should be enough, but it doesn't work */ iow(db, DM9000_EPCR, 0x0); return (ior(db, DM9000_EPDRL) + (ior(db, DM9000_EPDRH) << 8)); } #ifdef DM9000_PROGRAM_EEPROM /* * Write a word data to SROM 向EEPROM 9346中写数据 16bit */ static void write_srom_word(board_info_t * db, int offset, u16 val) { iow(db, DM9000_EPAR, offset); iow(db, DM9000_EPDRH, ((val >> 8) & 0xff)); iow(db, DM9000_EPDRL, (val & 0xff)); iow(db, DM9000_EPCR, EPCR_WEP | EPCR_ERPRW); mdelay(8); /* same shit */ iow(db, DM9000_EPCR, 0); } /* * Only for development: * Here we write static data to the eeprom in case * we don't have valid content on a new board */ static void program_eeprom(board_info_t * db) { u16 eeprom[] = { 0x0c00, 0x007f, 0x1300, /* MAC Address */ 0x0000, /* Autoload: accept nothing */ 0x0a46, 0x9000, /* Vendor / Product ID */ 0x0000, /* pin control */ 0x0000, }; /* Wake-up mode control */ int i; for (i = 0; i < 8; i++) write_srom_word(db, i, eeprom[i]); } #endif /* * Calculate the CRC valude of the Rx packet * flag = 1 : return the reverse CRC (for the received packet CRC) * 0 : return the normal CRC (for Hash Table index) 计算接收包的crc值 */ static unsigned long cal_CRC(unsigned char *Data, unsigned int Len, u8 flag) { u32 crc = ether_crc_le(Len, Data); if (flag) return ~crc; return crc; } /* * Set DM9000 multicast address */ static void dm9000_hash_table(struct net_device *dev) { board_info_t *db = (board_info_t *) dev->priv; struct dev_mc_list *mcptr = dev->mc_list; int mc_cnt = dev->mc_count; u32 hash_val; u16 i, oft, hash_table[4]; unsigned long flags; PRINTK2("dm9000_hash_table()/n"); spin_lock_irqsave(&db->lock,flags); for (i = 0, oft = 0x10; i < 6; i++, oft++) iow(db, oft, dev->dev_addr[i]); /* Clear Hash Table */ for (i = 0; i < 4; i++) hash_table[i] = 0x0; /* broadcast address */ hash_table[3] = 0x8000; /* the multicast address in Hash Table : 64 bits */ for (i = 0; i < mc_cnt; i++, mcptr = mcptr->next) { hash_val = cal_CRC((char *) mcptr->dmi_addr, 6, 0) & 0x3f; hash_table[hash_val / 16] |= (u16) 1 << (hash_val % 16); } /* Write the hash table to MAC MD table */ for (i = 0, oft = 0x16; i < 4; i++) { iow(db, oft++, hash_table[i] & 0xff); iow(db, oft++, (hash_table[i] >> 8) & 0xff); } spin_unlock_irqrestore(&db->lock,flags); } /* * Read a word from phyxcer 从PHY读取数据16bit */ static int dm9000_phy_read(struct net_device *dev, int phy_reg_unused, int reg) { board_info_t *db = (board_info_t *) dev->priv; unsigned long flags; unsigned int reg_save; int ret; spin_lock_irqsave(&db->lock,flags); /* Save previous register address */ reg_save = readb(db->io_addr); /* Fill the phyxcer register into REG_0C */ iow(db, DM9000_EPAR, DM9000_PHY | reg); iow(db, DM9000_EPCR, 0xc); /* Issue phyxcer read command */ udelay(100); /* Wait read complete */ iow(db, DM9000_EPCR, 0x0); /* Clear phyxcer read command */ /* The read data keeps on REG_0D & REG_0E */ ret = (ior(db, DM9000_EPDRH) << 8) | ior(db, DM9000_EPDRL); /* restore the previous address */ writeb(reg_save, db->io_addr); spin_unlock_irqrestore(&db->lock,flags); return ret; } /* * Write a word to phyxcer 向PHY写入数据16bit */ static void dm9000_phy_write(struct net_device *dev, int phyaddr_unused, int reg, int value) { board_info_t *db = (board_info_t *) dev->priv; unsigned long flags; unsigned long reg_save; spin_lock_irqsave(&db->lock,flags); /* Save previous register address */ reg_save = readb(db->io_addr); /* Fill the phyxcer register into REG_0C */ iow(db, DM9000_EPAR, DM9000_PHY | reg); /* Fill the written data into REG_0D & REG_0E */ iow(db, DM9000_EPDRL, (value & 0xff)); iow(db, DM9000_EPDRH, ((value >> 8) & 0xff)); iow(db, DM9000_EPCR, 0xa); /* Issue phyxcer write command */ udelay(500); /* Wait write complete */ iow(db, DM9000_EPCR, 0x0); /* Clear phyxcer write command */ /* restore the previous address */ writeb(reg_save, db->io_addr); spin_unlock_irqrestore(&db->lock,flags); } /*挂起网卡接口*/ static int dm9000_drv_suspend(struct platform_device *dev, pm_message_t state) { struct net_device *ndev = platform_get_drvdata(dev); if (ndev) { if (netif_running(ndev)) { /*内核临时删除接口*/ netif_device_detach(ndev); /*关闭设备*/ dm9000_shutdown(ndev); } } return 0; } static int dm9000_drv_resume(struct platform_device *dev) { struct net_device *ndev = platform_get_drvdata(dev); board_info_t *db = (board_info_t *) ndev->priv; if (ndev) { if (netif_running(ndev)) { /*复位设备*/ dm9000_reset(db); dm9000_init_dm9000(ndev); /*恢复接口*/ netif_device_attach(ndev); } } return 0; } static int dm9000_drv_remove(struct platform_device *pdev) { struct net_device *ndev = platform_get_drvdata(pdev); platform_set_drvdata(pdev, NULL); /*释放注册的网络接口*/ unregister_netdev(ndev); dm9000_release_board(pdev, (board_info_t *) ndev->priv); /*释放资源*/ free_netdev(ndev); /* free device structure */ PRINTK1("clean_module() exit/n"); return 0; } static struct platform_driver dm9000_driver = { .driver = { .name = "dm9000", .owner = THIS_MODULE, }, .probe = dm9000_probe, .remove = dm9000_drv_remove, .suspend = dm9000_drv_suspend, .resume = dm9000_drv_resume, }; static int __init dm9000_init(void) { printk(KERN_INFO "%s Ethernet Driver/n", CARDNAME); return platform_driver_register(&dm9000_driver); /* search board and register */ } static void __exit dm9000_cleanup(void) { platform_driver_unregister(&dm9000_driver); } module_init(dm9000_init); module_exit(dm9000_cleanup); MODULE_AUTHOR("Sascha Hauer, Ben Dooks"); MODULE_DESCRIPTION("Davicom DM9000 network driver"); MODULE_LICENSE("GPL");