CS8900A网卡驱动程序分析

lichao-runing@163.com /* CS8900a.h */ #define CONFIG_CERF_CS8900A 1 /* * cs8900a.c: A Crystal Semiconductor (Now Cirrus Logic) CS8900A driver for SMDK-s3c2410 (based on cs89x0.c) * * Author: Yong-iL Joh <tolkien@mizi.com> * Date : $Date: 2002/10/16 09:08:07 $ * * $Revision: 1.1.2.5 $ Wed Aug 14 2002 Yong-iL Joh <tolkien@mizi.com> - initial, based on cs89x0.c Wed Aug 16 2002 Yong-iL Joh <tolkien@mizi.com> - working! * * This file is subject to the terms and conditions of the GNU General Public * License. See the file COPYING in the main directory of this archive * for more details. */ #include <linux/config.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/errno.h> #include <linux/spinlock.h> #include <linux/ioport.h> #include <linux/netdevice.h> #include <linux/etherdevice.h> #include <linux/skbuff.h> #include <asm/io.h> #include <asm/irq.h> #include <asm/hardware.h>  lichao-runing@163.com #define IRQ_LAN IRQ_CS8900 /* 宏IRQ_LAN 定.网卡的中.. 宏IRQ_CS8900 在include/asm-arm/arch-arm/smdk.h 中定. #define IRQ_CS8900 IRQ_EINT9 宏IRQ_EINT9 定.位于include/asm-arm/arch/irqs.h 中 #define IRQ_EINT9 (5 +NORMAL_IRQ_OFFSET) #define NORMAL_IRQ_OFFSET 32 所以网卡的中...37。 */ #include "cs89x0.h" /* * Set this to zero to remove all the debug statements via * dead code elimination */ #undef DEBUGGING 4 #if DEBUGGING #define DPRINTK(n, args...) \ if (n <= DEBUGGING) { \ printk(args); \ } #else #define DPRINTK(n, args...) #endif #if DEBUGGING static char version[] __initdata = "cs89x0.c: v2.4.3-pre1 Russell Nelson <nelson@crynwr.com>, Andrew Morton <andrewm@uow.edu.au>\n"; #endif /* First, a few definitions that the brave might change. A zero-terminated list of I/O addresses to be probed. Some special flags.. Addr & 1 = Read back the address port, look for signature and reset the page window before probing Addr & 3 = Reset the page window and probe The CLPS eval board has the Cirrus chip at 0x80090300, in ARM IO space, but it is possible that a Cirrus board could be plugged into the ISA slots. */ static unsigned int netcard_portlist[] __initdata = { vCS8900_BASE + 0x300, 0}; /*  lichao-runing@163.com __initdata .志符和.量.明放在一起，表示gcc ..器在..的.候需 要把...量放在.data.init section 中，而..section 在.核完成初始化 之后，.被.放掉。 netcard_portlist[]..存放网卡端口的.地址，由于网 卡.接如下所示：  lichao-runing@163.com 如.中..所示，表明网卡映射到S3C2410 微.理器的BANK3 .，查. 微.理器手.可知，..的物理起始地址.0x19000000，由于在Linux 中使用 ..地址，所以必..其.....地址，在ARM-LINUX 中，0x19000000 .. 的.地址.0xd0000000。所以定.如下宏，分.表示CS8900 网卡存..物理起 始地址和..起始地址。 vCS8900_BASE 定.如下： /* CS8900a, nGCS3 */ #define pCS8900_BASE 0x19000000 #define vCS8900_BASE 0xd0000000 查.CS8900A 手.可知，其端口寄存器偏移量.0x300，所以CS8900a 端口 起始地址被定..：vCS8900_BASE + 0x300 */ /* The number of low I/O ports used by the ethercard. */ #define NETCARD_IO_EXTENT 0xfff /* we allow the user to override various values normally set in the EEPROM */ #define FORCE_RJ45 0x0001 /* pick one of these three */ #define FORCE_AUI 0x0002 #define FORCE_BNC 0x0004 /* 定.网卡接口.型，如果使用RJ45 水晶..接，.使用第一.宏。 */ #define FORCE_AUTO 0x0010 /* pick one of these three */ #define FORCE_HALF 0x0020 #define FORCE_FULL 0x0030 /* 定.网卡通.使用半.工通信、.是全.工通.，.是自...。 */ /* Information that need to be kept for each board. */ struct net_local { struct net_device_stats stats; int chip_type; /* one of: CS8900, CS8920, CS8920M */ char chip_revision; /* revision letter of the chip ('A'...) */ int send_cmd; /* the proper send command: TX_NOW, TX_AFTER_381, or TX_AFTER_ALL */  lichao-runing@163.com int auto_neg_cnf; /* auto-negotiation word from EEPROM */ int adapter_cnf; /* adapter configuration from EEPROM */ int isa_config; /* ISA configuration from EEPROM */ int irq_map; /* IRQ map from EEPROM */ int rx_mode; /* what mode are we in? 0, RX_MULTCAST_ACCEPT, or RX_ALL_ACCEPT */ int curr_rx_cfg; /* a copy of PP_RxCFG */ int linectl; /* either 0 or LOW_RX_SQUELCH, depending on configuration. */ int send_underrun; /* keep track of how many underruns in a row we get */ int force; /* force various values; see FORCE* above. */ spinlock_t lock; }; /* Index to functions, as function prototypes. */ extern int cs89x0_probe(struct net_device *dev); static int cs89x0_probe1(struct net_device *dev, int ioaddr); static int net_open(struct net_device *dev); static int net_send_packet(struct sk_buff *skb, struct net_device *dev); static void net_interrupt(int irq, void *dev_id, struct pt_regs *regs); static void set_multicast_list(struct net_device *dev); static void net_timeout(struct net_device *dev); static void net_rx(struct net_device *dev); static int net_close(struct net_device *dev); static struct net_device_stats *net_get_stats(struct net_device *dev); static void reset_chip(struct net_device *dev); static int set_mac_address(struct net_device *dev, void *addr); static void count_rx_errors(int status, struct net_local *lp); /* Example routines you must write ;->. */ #define tx_done(dev) 1 /* 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). Return 0 on success. */ int __init cs89x0_probe(struct net_device *dev) { int i;  lichao-runing@163.com SET_MODULE_OWNER(dev); DPRINTK(1, "cs89x0:cs89x0_probe(0x%x)\n", base_addr); BWSCON = (BWSCON & ~(BWSCON_ST3 | BWSCON_WS3 | BWSCON_DW3)) | (BWSCON_ST3 | BWSCON_WS3 | BWSCON_DW(3, BWSCON_DW_16)); BANKCON3= BANKCON_Tacs0 | BANKCON_Tcos4 | BANKCON_Tacc14 | BANKCON_Toch1 | BANKCON_Tcah4 | BANKCON_Tacp6 | BANKCON_PMC1; /* .置BANK3 存.体，使其和CS8900a 网卡的.性相一致。比如BWSCON_DW_16 . 置BANK3 位..16bit，.何...置呢？因.CS8900a 网卡就是工作在16bit 模式下，即 .据.度（由其..使用到的.据..度.定）.16bit。 */ set_external_irq(IRQ_CS8900, EXT_RISING_EDGE, GPIO_PULLUP_DIS); /* .置IRQ_CS8900 所占用中...性，上升沿触.，PULLUP .效。 */ for (i = 0; netcard_portlist[i]; i++) { if (cs89x0_probe1(dev, netcard_portlist[i]) == 0) return 0; /* 探.网卡，如果探.到网卡后，cs89x0_probe1 返回值.0，所以就退出for 循.。由此 可.，只能探.一.网卡。 */ } printk(KERN_WARNING "cs89x0: no cs8900 or cs8920 detected." "Be sure to disable PnP with SETUP\n"); return -ENODEV; /* 如果不能探.到网卡，就.打印..消息，并返回-ENODEV ...。 */ } //.取寄存器.容 inline int readreg(struct net_device *dev, int portno) { outw(portno, dev->base_addr + ADD_PORT); return inw(dev->base_addr + DATA_PORT); /* dev->base_addr 是..的基地址，ADD_PORT 是偏移地址，DATA_PORT 是.据。 #define ADD_PORT 0x000A #define DATA_PORT 0x000C 由于在此..中，CS8900A 工作在I/O 模式下，查.CS8900A 手.可知，在I/O 模式下，如果想要.取端口..portno 的寄存器（此寄存器系CS8900A .部寄存器）.容， .按照下列步.（.CS8900A 手.的P77 中的4.10.10 .）：  lichao-runing@163.com .. 首先，.端口.（即.部寄存器..）.入到偏移量.ADD_PORT 的寄存器 中，即.用outw 函..完成； .. 然后，.部寄存器的.容.被映射到偏移量.DATA_PORT 的.据寄存器中， 通.inw 函..其.出。 */ } //把value 值.入到端口..portno 的寄存器中 inline void writereg(struct net_device *dev, int portno, int value) { outw(portno, dev->base_addr + ADD_PORT); outw(value, dev->base_addr + DATA_PORT); /* dev->base_addr 是..的基地址，ADD_PORT 是偏移地址，DATA_PORT 是.据。 #define ADD_PORT 0x000A #define DATA_PORT 0x000C 由于在此..中，CS8900A 工作在I/O 模式下，查.CS8900A 手.可知，在I/O 模式下，如果