S3C2440驱动简析——DM9000网卡驱动（5）

     本文是DM9000网卡驱动的最后一篇，具体分析dm9000_ethtool_ops里所实现的工作。为了支持ethtool，其中的函数主要是用于查询和设置网卡参数（当然也有的驱动程序可能不支持ethtool）。

 

static const struct ethtool_ops dm9000_ethtool_ops = {.get_drvinfo= dm9000_get_drvinfo,.get_settings= dm9000_get_settings,.set_settings= dm9000_set_settings,.get_msglevel= dm9000_get_msglevel,.set_msglevel= dm9000_set_msglevel,.nway_reset= dm9000_nway_reset,.get_link= dm9000_get_link,.get_wol= dm9000_get_wol,.set_wol= dm9000_set_wol, .get_eeprom_len= dm9000_get_eeprom_len, .get_eeprom= dm9000_get_eeprom, .set_eeprom= dm9000_set_eeprom,.get_rx_csum= dm9000_get_rx_csum,.set_rx_csum= dm9000_set_rx_csum,.get_tx_csum= ethtool_op_get_tx_csum,.set_tx_csum= dm9000_set_tx_csum,};

 

下面我们来逐个分析每一项的操作

 

1.dm9000_get_drvinfo

static void dm9000_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info){board_info_t *dm = to_dm9000_board(dev);strcpy(info->driver, CARDNAME);strcpy(info->version, DRV_VERSION);strcpy(info->bus_info, to_platform_device(dm->dev)->name);}

顾名思义，函数完成了把网络设备net_device通过成员name绑定到info。

 

2.dm9000_get_settings

static int dm9000_get_settings(struct net_device *dev, struct ethtool_cmd *cmd){board_info_t *dm = to_dm9000_board(dev);mii_ethtool_gset(&dm->mii, cmd);return 0;}

里面的主角mii_ethtool_gset代码如下

int mii_ethtool_gset(struct mii_if_info *mii, struct ethtool_cmd *ecmd){struct net_device *dev = mii->dev;u16 bmcr, bmsr, ctrl1000 = 0, stat1000 = 0;u32 nego;ecmd->supported = (SUPPORTED_10baseT_Half | SUPPORTED_10baseT_Full | SUPPORTED_100baseT_Half | SUPPORTED_100baseT_Full | SUPPORTED_Autoneg | SUPPORTED_TP | SUPPORTED_MII);if (mii->supports_gmii)ecmd->supported |= SUPPORTED_1000baseT_Half |SUPPORTED_1000baseT_Full;/* only supports twisted-pair */ecmd->port = PORT_MII;/* only supports internal transceiver */ecmd->transceiver = XCVR_INTERNAL;/* this isn't fully supported at higher layers */ecmd->phy_address = mii->phy_id;ecmd->mdio_support = MDIO_SUPPORTS_C22;ecmd->advertising = ADVERTISED_TP | ADVERTISED_MII;bmcr = mii->mdio_read(dev, mii->phy_id, MII_BMCR);bmsr = mii->mdio_read(dev, mii->phy_id, MII_BMSR);if (mii->supports_gmii) { ctrl1000 = mii->mdio_read(dev, mii->phy_id, MII_CTRL1000);stat1000 = mii->mdio_read(dev, mii->phy_id, MII_STAT1000);}if (bmcr & BMCR_ANENABLE) {ecmd->advertising |= ADVERTISED_Autoneg;ecmd->autoneg = AUTONEG_ENABLE;ecmd->advertising |= mii_get_an(mii, MII_ADVERTISE);if (ctrl1000 & ADVERTISE_1000HALF)ecmd->advertising |= ADVERTISED_1000baseT_Half;if (ctrl1000 & ADVERTISE_1000FULL)ecmd->advertising |= ADVERTISED_1000baseT_Full;if (bmsr & BMSR_ANEGCOMPLETE) {ecmd->lp_advertising = mii_get_an(mii, MII_LPA);if (stat1000 & LPA_1000HALF)ecmd->lp_advertising |=ADVERTISED_1000baseT_Half;if (stat1000 & LPA_1000FULL)ecmd->lp_advertising |=ADVERTISED_1000baseT_Full;} else {ecmd->lp_advertising = 0;}nego = ecmd->advertising & ecmd->lp_advertising;if (nego & (ADVERTISED_1000baseT_Full | ADVERTISED_1000baseT_Half)) {ecmd->speed = SPEED_1000;ecmd->duplex = !!(nego & ADVERTISED_1000baseT_Full);} else if (nego & (ADVERTISED_100baseT_Full | ADVERTISED_100baseT_Half)) {ecmd->speed = SPEED_100;ecmd->duplex = !!(nego & ADVERTISED_100baseT_Full);} else {ecmd->speed = SPEED_10;ecmd->duplex = !!(nego & ADVERTISED_10baseT_Full);}} else {ecmd->autoneg = AUTONEG_DISABLE;ecmd->speed = ((bmcr & BMCR_SPEED1000 &&(bmcr & BMCR_SPEED100) == 0) ? SPEED_1000 : (bmcr & BMCR_SPEED100) ? SPEED_100 : SPEED_10);ecmd->duplex = (bmcr & BMCR_FULLDPLX) ? DUPLEX_FULL : DUPLEX_HALF;}mii->full_duplex = ecmd->duplex;/* ignore maxtxpkt, maxrxpkt for now */return 0;}

函数实现从mii接口取得的状态信息赋值到传入的结构体ecmd。

 

3.dm9000_set_settings

static int dm9000_set_settings(struct net_device *dev, struct ethtool_cmd *cmd){board_info_t *dm = to_dm9000_board(dev);return mii_ethtool_sset(&dm->mii, cmd);}

分析主角mii_ethtool_sset

int mii_ethtool_sset(struct mii_if_info *mii, struct ethtool_cmd *ecmd){struct net_device *dev = mii->dev;if (ecmd->speed != SPEED_10 && ecmd->speed != SPEED_100 && ecmd->speed != SPEED_1000)return -EINVAL;if (ecmd->duplex != DUPLEX_HALF && ecmd->duplex != DUPLEX_FULL)return -EINVAL;if (ecmd->port != PORT_MII)return -EINVAL;if (ecmd->transceiver != XCVR_INTERNAL)return -EINVAL;if (ecmd->phy_address != mii->phy_id)return -EINVAL;if (ecmd->autoneg != AUTONEG_DISABLE && ecmd->autoneg != AUTONEG_ENABLE)return -EINVAL;if ((ecmd->speed == SPEED_1000) && (!mii->supports_gmii))return -EINVAL;/* ignore supported, maxtxpkt, maxrxpkt */if (ecmd->autoneg == AUTONEG_ENABLE) {u32 bmcr, advert, tmp;u32 advert2 = 0, tmp2 = 0;if ((ecmd->advertising & (ADVERTISED_10baseT_Half | ADVERTISED_10baseT_Full | ADVERTISED_100baseT_Half | ADVERTISED_100baseT_Full | ADVERTISED_1000baseT_Half | ADVERTISED_1000baseT_Full)) == 0)return -EINVAL;/* advertise only what has been requested */advert = mii->mdio_read(dev, mii->phy_id, MII_ADVERTISE);tmp = advert & ~(ADVERTISE_ALL | ADVERTISE_100BASE4);if (mii->supports_gmii) {advert2 = mii->mdio_read(dev, mii->phy_id, MII_CTRL1000);tmp2 = advert2 & ~(ADVERTISE_1000HALF | ADVERTISE_1000FULL);}if (ecmd->advertising & ADVERTISED_10baseT_Half)tmp |= ADVERTISE_10HALF;if (ecmd->advertising & ADVERTISED_10baseT_Full)tmp |= ADVERTISE_10FULL;if (ecmd->advertising & ADVERTISED_100baseT_Half)tmp |= ADVERTISE_100HALF;if (ecmd->advertising & ADVERTISED_100baseT_Full)tmp |= ADVERTISE_100FULL;if (mii->supports_gmii) {if (ecmd->advertising & ADVERTISED_1000baseT_Half)tmp2 |= ADVERTISE_1000HALF;if (ecmd->advertising & ADVERTISED_1000baseT_Full)tmp2 |= ADVERTISE_1000FULL;}if (advert != tmp) {mii->mdio_write(dev, mii->phy_id, MII_ADVERTISE, tmp);mii->advertising = tmp;}if ((mii->supports_gmii) && (advert2 != tmp2))mii->mdio_write(dev, mii->phy_id, MII_CTRL1000, tmp2);/* turn on autonegotiation, and force a renegotiate */bmcr = mii->mdio_read(dev, mii->phy_id, MII_BMCR);bmcr |= (BMCR_ANENABLE | BMCR_ANRESTART);mii->mdio_write(dev, mii->phy_id, MII_BMCR, bmcr);mii->force_media = 0;} else {u32 bmcr, tmp;/* turn off auto negotiation, set speed and duplexity */bmcr = mii->mdio_read(dev, mii->phy_id, MII_BMCR);tmp = bmcr & ~(BMCR_ANENABLE | BMCR_SPEED100 | BMCR_SPEED1000 | BMCR_FULLDPLX);if (ecmd->speed == SPEED_1000)tmp |= BMCR_SPEED1000;else if (ecmd->speed == SPEED_100)tmp |= BMCR_SPEED100;if (ecmd->duplex == DUPLEX_FULL) {tmp |= BMCR_FULLDPLX;mii->full_duplex = 1;} elsemii->full_duplex = 0;if (bmcr != tmp)mii->mdio_write(dev, mii->phy_id, MII_BMCR, tmp);mii->force_media = 1;}return 0;}

其作用与mii_ethtool_gset恰好相反，取传入的结构体ecmd的信息写入mii接口里。

 

4.dm9000_get_msglevel

static u32 dm9000_get_msglevel(struct net_device *dev){board_info_t *dm = to_dm9000_board(dev);return dm->msg_enable;}

返回结构体board_info_t 里成员msg_enable的状态。

 

5.dm9000_set_msglevel

static void dm9000_set_msglevel(struct net_device *dev, u32 value){board_info_t *dm = to_dm9000_board(dev);dm->msg_enable = value;}

设置msg_enable的状态

 

6.dm9000_nway_reset

static int dm9000_nway_reset(struct net_device *dev){board_info_t *dm = to_dm9000_board(dev);return mii_nway_restart(&dm->mii);}

mii_nway_restrart函数代码如下

int mii_nway_restart (struct mii_if_info *mii){int bmcr;int r = -EINVAL;/* if autoneg is off, it's an error */bmcr = mii->mdio_read(mii->dev, mii->phy_id, MII_BMCR);if (bmcr & BMCR_ANENABLE) {bmcr |= BMCR_ANRESTART;mii->mdio_write(mii->dev, mii->phy_id, MII_BMCR, bmcr);r = 0;}return r;}

重新启动nway功能，其中nway指通信速率通过双方协商，协商的结果是两个设备中能同时支持的最大速度和最好的双工模式，这个技术被称为Auto Negotiation或者NWAY。

 

7.dm9000_get_link

static u32 dm9000_get_link(struct net_device *dev){board_info_t *dm = to_dm9000_board(dev);u32 ret;if (dm->flags & DM9000_PLATF_EXT_PHY) ret = mii_link_ok(&dm->mii); //返回1，链接状态OK。返回0，失败。elseret = dm9000_read_locked(dm, DM9000_NSR) & NSR_LINKST ? 1 : 0;return ret;}

函数作用显而易见，返回链接状态。

 

8.dm9000_get_wol

static void dm9000_get_wol(struct net_device *dev, struct ethtool_wolinfo *w){board_info_t *dm = to_dm9000_board(dev);memset(w, 0, sizeof(struct ethtool_wolinfo));/* note, we could probably support wake-phy too */w->supported = dm->wake_supported ? WAKE_MAGIC : 0;w->wolopts = dm->wake_state;}

ethtool_wolinfo结构体如下

struct ethtool_wolinfo {__u32cmd;__u32supported;__u32wolopts;__u8sopass[SOPASS_MAX]; /* SecureOn(tm) password */};

把网络设备的成员wake_supported和wake_state传送到ethtool_wolinfo结构体的supported和wolopts里。

 

9.dm9000_set_wol

static int dm9000_set_wol(struct net_device *dev, struct ethtool_wolinfo *w){board_info_t *dm = to_dm9000_board(dev);unsigned long flags;u32 opts = w->wolopts;u32 wcr = 0;if (!dm->wake_supported)return -EOPNOTSUPP;if (opts & ~WAKE_MAGIC)return -EINVAL;if (opts & WAKE_MAGIC)wcr |= WCR_MAGICEN;mutex_lock(&dm->addr_lock);spin_lock_irqsave(&dm->lock, flags);iow(dm, DM9000_WCR, wcr);spin_unlock_irqrestore(&dm->lock, flags);mutex_unlock(&dm->addr_lock);if (dm->wake_state != opts) {/* change in wol state, update IRQ state */if (!dm->wake_state)set_irq_wake(dm->irq_wake, 1);else if (dm->wake_state & !opts)set_irq_wake(dm->irq_wake, 0);}dm->wake_state = opts;return 0;}

dm9000_set_wol函数完成更新中断状态，并读回wake_state（对应dm9000_get_wol）

 

10.dm9000_get_eeprom_len

static int dm9000_get_eeprom_len(struct net_device *dev){return 128;}

eeprom长度默认128bytes

 

11.dm9000_get_eeprom

static int dm9000_get_eeprom(struct net_device *dev, struct ethtool_eeprom *ee, u8 *data){board_info_t *dm = to_dm9000_board(dev);int offset = ee->offset;int len = ee->len;int i;/* EEPROM access is aligned to two bytes */if ((len & 1) != 0 || (offset & 1) != 0)return -EINVAL;if (dm->flags & DM9000_PLATF_NO_EEPROM) //检查有没有EEPROM的信息return -ENOENT;ee->magic = DM_EEPROM_MAGIC;for (i = 0; i < len; i += 2) //读取EEPROM数据，并存放在data指针指向的区域dm9000_read_eeprom(dm, (offset + i) / 2, data + i);return 0;}

读取eeprom内容

 

12.dm9000_set_eeprom

static int dm9000_set_eeprom(struct net_device *dev, struct ethtool_eeprom *ee, u8 *data){board_info_t *dm = to_dm9000_board(dev);int offset = ee->offset;int len = ee->len;int i;/* EEPROM access is aligned to two bytes */if ((len & 1) != 0 || (offset & 1) != 0)return -EINVAL;if (dm->flags & DM9000_PLATF_NO_EEPROM)return -ENOENT;if (ee->magic != DM_EEPROM_MAGIC)return -EINVAL;for (i = 0; i < len; i += 2)dm9000_write_eeprom(dm, (offset + i) / 2, data + i);return 0;}

对应读取，本函数完成写入的工作

 

13.dm9000_get_rx_csum

static uint32_t dm9000_get_rx_csum(struct net_device *dev){board_info_t *dm = to_dm9000_board(dev);return dm->rx_csum;}

说来惭愧，还不知道rx_csum所代表的具体含义，是接收的什么呢？希望有前辈指点一二

 

14.dm9000_set_rx_csum

static int dm9000_set_rx_csum(struct net_device *dev, uint32_t data){board_info_t *dm = to_dm9000_board(dev);unsigned long flags;int ret;spin_lock_irqsave(&dm->lock, flags);ret = dm9000_set_rx_csum_unlocked(dev, data);spin_unlock_irqrestore(&dm->lock, flags);return ret;}

其中dm9000_set_rx_csum_unlocked代码如下

static int dm9000_set_rx_csum_unlocked(struct net_device *dev, uint32_t data){board_info_t *dm = to_dm9000_board(dev);if (dm->can_csum) {dm->rx_csum = data;iow(dm, DM9000_RCSR, dm->rx_csum ? RCSR_CSUM : 0);return 0;}return -EOPNOTSUPP;}

设置rx_csum吧~

 

15.ethtool_op_get_tx_csum

u32 ethtool_op_get_tx_csum(struct net_device *dev){return (dev->features & NETIF_F_ALL_CSUM) != 0;}

呵呵，有接收自然就有发送

 

16.dm9000_set_tx_csum

static int dm9000_set_tx_csum(struct net_device *dev, uint32_t data){board_info_t *dm = to_dm9000_board(dev);int ret = -EOPNOTSUPP;if (dm->can_csum)ret = ethtool_op_set_tx_csum(dev, data);return ret;}

核心工作在于ret = ethtool_op_set_tx_csum(dev, data);
int ethtool_op_set_tx_csum(struct net_device *dev, u32 data){if (data)dev->features |= NETIF_F_IP_CSUM;elsedev->features &= ~NETIF_F_IP_CSUM;return 0;}

通过传入的参数data设置tx_csum是0或1，具体作用还不清楚。

 

 

 

呼呼，我还是以蜗牛般的速度、豆腐渣式的分析把DM9000网卡驱动完整的过了一遍。与其说是分析，更贴切来说，应该是贴出代码，提供一个针对这个驱动讨论的平台罢了。很多枝节功能由于本人功力有限，还理所不能及，如有令到各位看官感觉不知所云，实在抱歉，以后定当更加努力，提供更高质量的学习记录给大家分享！

 

 

 

本系列课程链接地址

DM9000网卡驱动（1）http://blog.csdn.net/jarvis_xian/archive/2011/06/10/6537446.aspx
DM9000网卡驱动（2）http://blog.csdn.net/jarvis_xian/archive/2011/06/12/6539931.aspx
DM9000网卡驱动（3）http://blog.csdn.net/jarvis_xian/archive/2011/06/13/6542411.aspx
DM9000网卡驱动（4）http://blog.csdn.net/jarvis_xian/archive/2011/06/15/6545109.aspx
DM9000网卡驱动（5）http://blog.csdn.net/jarvis_xian/archive/2011/06/15/6547203.aspx