fec.c

讲述linux的初始化过程

	/* First, grab all of the stats for the incoming packet.
	 * These get messed up if we get called due to a busy condition.
	 */
	bdp = fep->cur_rx;

while (!(bdp->cbd_sc & BD_ENET_RX_EMPTY)) {

#ifndef final_version
	/* Since we have allocated space to hold a complete frame,
	 * the last indicator should be set.
	 */
	if ((bdp->cbd_sc & BD_ENET_RX_LAST) == 0)
		printk("FEC ENET: rcv is not +last\n");
#endif

	/* Check for errors. */
	if (bdp->cbd_sc & (BD_ENET_RX_LG | BD_ENET_RX_SH | BD_ENET_RX_NO |
			   BD_ENET_RX_CR | BD_ENET_RX_OV)) {
		fep->stats.rx_errors++;       
		if (bdp->cbd_sc & (BD_ENET_RX_LG | BD_ENET_RX_SH)) {
		/* Frame too long or too short. */
			fep->stats.rx_length_errors++;
		}
		if (bdp->cbd_sc & BD_ENET_RX_NO)	/* Frame alignment */
			fep->stats.rx_frame_errors++;
		if (bdp->cbd_sc & BD_ENET_RX_CR)	/* CRC Error */
			fep->stats.rx_crc_errors++;
		if (bdp->cbd_sc & BD_ENET_RX_OV)	/* FIFO overrun */
			fep->stats.rx_crc_errors++;
	}

	/* Report late collisions as a frame error.
	 * On this error, the BD is closed, but we don't know what we
	 * have in the buffer.  So, just drop this frame on the floor.
	 */
	if (bdp->cbd_sc & BD_ENET_RX_CL) {
		fep->stats.rx_errors++;
		fep->stats.rx_frame_errors++;
		goto rx_processing_done;
	}

	/* Process the incoming frame.
	 */
	fep->stats.rx_packets++;
	pkt_len = bdp->cbd_datlen;
	fep->stats.rx_bytes += pkt_len;
	data = (__u8*)__va(bdp->cbd_bufaddr);

#ifdef CONFIG_FEC_PACKETHOOK
	/* Packet hook ... */
	if (fep->ph_rxhandler) {
		if (((struct ethhdr *)data)->h_proto == fep->ph_proto) {
			switch (fep->ph_rxhandler(data, pkt_len, regval,
						  fep->ph_priv)) {
			case 1:
				goto rx_processing_done;
				break;
			case 0:
				break;
			default:
				fep->stats.rx_errors++;
				goto rx_processing_done;
			}
		}
	}

	/* If it wasn't filtered - copy it to an sk buffer. */
#endif

	/* This does 16 byte alignment, exactly what we need.
	 * The packet length includes FCS, but we don't want to
	 * include that when passing upstream as it messes up
	 * bridging applications.
	 */
	skb = dev_alloc_skb(pkt_len-4);

	if (skb == NULL) {
		printk("%s: Memory squeeze, dropping packet.\n", dev->name);
		fep->stats.rx_dropped++;
	} else {
		skb->dev = dev;
		skb_put(skb,pkt_len-4);	/* Make room */
		eth_copy_and_sum(skb,
				 (unsigned char *)__va(bdp->cbd_bufaddr),
				 pkt_len-4, 0);
		skb->protocol=eth_type_trans(skb,dev);
		netif_rx(skb);
	}
  rx_processing_done:

	/* Clear the status flags for this buffer.
	*/
	bdp->cbd_sc &= ~BD_ENET_RX_STATS;

	/* Mark the buffer empty.
	*/
	bdp->cbd_sc |= BD_ENET_RX_EMPTY;

	/* Update BD pointer to next entry.
	*/
	if (bdp->cbd_sc & BD_ENET_RX_WRAP)
		bdp = fep->rx_bd_base;
	else
		bdp++;
	
#if 1
	/* Doing this here will keep the FEC running while we process
	 * incoming frames.  On a heavily loaded network, we should be
	 * able to keep up at the expense of system resources.
	 */
	fecp->fec_r_des_active = 0x01000000;
#endif
#ifdef CONFIG_FEC_PACKETHOOK
	/* Re-read register. Not exactly guaranteed to be correct,
	   but... */
	if (fep->ph_regaddr) regval = *fep->ph_regaddr;
#endif
   } /* while (!(bdp->cbd_sc & BD_ENET_RX_EMPTY)) */
	fep->cur_rx = (cbd_t *)bdp;

#if 0
	/* Doing this here will allow us to process all frames in the
	 * ring before the FEC is allowed to put more there.  On a heavily
	 * loaded network, some frames may be lost.  Unfortunately, this
	 * increases the interrupt overhead since we can potentially work
	 * our way back to the interrupt return only to come right back
	 * here.
	 */
	fecp->fec_r_des_active = 0x01000000;
#endif
}


static void
fec_enet_mii(struct net_device *dev)
{
	struct	fec_enet_private *fep;
	volatile fec_t	*ep;
	mii_list_t	*mip;
	uint		mii_reg;

	fep = (struct fec_enet_private *)dev->priv;
	ep = &(((immap_t *)IMAP_ADDR)->im_cpm.cp_fec);
	mii_reg = ep->fec_mii_data;
	
	if ((mip = mii_head) == NULL) {
		printk("MII and no head!\n");
		return;
	}

	if (mip->mii_func != NULL)
		(*(mip->mii_func))(mii_reg, dev);

	mii_head = mip->mii_next;
	mip->mii_next = mii_free;
	mii_free = mip;

	if ((mip = mii_head) != NULL)
		ep->fec_mii_data = mip->mii_regval;
}

static int
mii_queue(struct net_device *dev, int regval, void (*func)(uint, struct net_device *))
{
	struct fec_enet_private *fep;
	unsigned long	flags;
	mii_list_t	*mip;
	int		retval;

	/* Add PHY address to register command.
	*/
	fep = dev->priv;
	regval |= fep->phy_addr << 23;

	retval = 0;

	save_flags(flags);
	cli();

	if ((mip = mii_free) != NULL) {
		mii_free = mip->mii_next;
		mip->mii_regval = regval;
		mip->mii_func = func;
		mip->mii_next = NULL;
		if (mii_head) {
			mii_tail->mii_next = mip;
			mii_tail = mip;
		}
		else {
			mii_head = mii_tail = mip;
			(&(((immap_t *)IMAP_ADDR)->im_cpm.cp_fec))->fec_mii_data = regval;
		}
	}
	else {
		retval = 1;
	}

	restore_flags(flags);

	return(retval);
}

static void mii_do_cmd(struct net_device *dev, const phy_cmd_t *c)
{
	int k;

	if(!c)
		return;

	for(k = 0; (c+k)->mii_data != mk_mii_end; k++) 
		mii_queue(dev, (c+k)->mii_data, (c+k)->funct);
}

static void mii_parse_sr(uint mii_reg, struct net_device *dev)
{
	struct fec_enet_private *fep = dev->priv;
	volatile uint *s = &(fep->phy_status);

	*s &= ~(PHY_STAT_LINK | PHY_STAT_FAULT | PHY_STAT_ANC);

	if (mii_reg & 0x0004)
		*s |= PHY_STAT_LINK;
	if (mii_reg & 0x0010)
		*s |= PHY_STAT_FAULT;
	if (mii_reg & 0x0020)
		*s |= PHY_STAT_ANC;
}

static void mii_parse_cr(uint mii_reg, struct net_device *dev)
{
	struct fec_enet_private *fep = dev->priv;
	volatile uint *s = &(fep->phy_status);

	*s &= ~(PHY_CONF_ANE | PHY_CONF_LOOP);

	if (mii_reg & 0x1000)
		*s |= PHY_CONF_ANE;
	if (mii_reg & 0x4000)
		*s |= PHY_CONF_LOOP;
}

static void mii_parse_anar(uint mii_reg, struct net_device *dev)
{
	struct fec_enet_private *fep = dev->priv;
	volatile uint *s = &(fep->phy_status);

	*s &= ~(PHY_CONF_SPMASK);

	if (mii_reg & 0x0020)
		*s |= PHY_CONF_10HDX;
	if (mii_reg & 0x0040)
		*s |= PHY_CONF_10FDX;
	if (mii_reg & 0x0080)
		*s |= PHY_CONF_100HDX;
	if (mii_reg & 0x00100)
		*s |= PHY_CONF_100FDX;
}
#if 0
static void mii_disp_reg(uint mii_reg, struct net_device *dev)
{
	printk("reg %u = 0x%04x\n", (mii_reg >> 18) & 0x1f, mii_reg & 0xffff);
}
#endif

/* ------------------------------------------------------------------------- */
/* The Level one LXT970 is used by many boards				     */

#ifdef CONFIG_FEC_LXT970

#define MII_LXT970_MIRROR    16  /* Mirror register           */
#define MII_LXT970_IER       17  /* Interrupt Enable Register */
#define MII_LXT970_ISR       18  /* Interrupt Status Register */
#define MII_LXT970_CONFIG    19  /* Configuration Register    */
#define MII_LXT970_CSR       20  /* Chip Status Register      */

static void mii_parse_lxt970_csr(uint mii_reg, struct net_device *dev)
{
	struct fec_enet_private *fep = dev->priv;
	volatile uint *s = &(fep->phy_status);

	*s &= ~(PHY_STAT_SPMASK);

	if (mii_reg & 0x0800) {
		if (mii_reg & 0x1000)
			*s |= PHY_STAT_100FDX;
		else
			*s |= PHY_STAT_100HDX;
	}
	else {
		if (mii_reg & 0x1000)
			*s |= PHY_STAT_10FDX;
		else
			*s |= PHY_STAT_10HDX;
	}
}

static phy_info_t phy_info_lxt970 = {
	0x07810000, 
	"LXT970",

	(const phy_cmd_t []) {  /* config */
#if 0
//		{ mk_mii_write(MII_REG_ANAR, 0x0021), NULL },

		/* Set default operation of 100-TX....for some reason
		 * some of these bits are set on power up, which is wrong.
		 */
		{ mk_mii_write(MII_LXT970_CONFIG, 0), NULL },
#endif
		{ mk_mii_read(MII_REG_CR), mii_parse_cr },
		{ mk_mii_read(MII_REG_ANAR), mii_parse_anar },
		{ mk_mii_end, }
	},
	(const phy_cmd_t []) {  /* startup - enable interrupts */
		{ mk_mii_write(MII_LXT970_IER, 0x0002), NULL },
		{ mk_mii_write(MII_REG_CR, 0x1200), NULL }, /* autonegotiate */
		{ mk_mii_end, }
	},
	(const phy_cmd_t []) { /* ack_int */
		/* read SR and ISR to acknowledge */
		
		{ mk_mii_read(MII_REG_SR), mii_parse_sr },
		{ mk_mii_read(MII_LXT970_ISR), NULL },

		/* find out the current status */
		
		{ mk_mii_read(MII_LXT970_CSR), mii_parse_lxt970_csr },
		{ mk_mii_end, }
	},
	(const phy_cmd_t []) {  /* shutdown - disable interrupts */
		{ mk_mii_write(MII_LXT970_IER, 0x0000), NULL },
		{ mk_mii_end, }
	},
};
	
#endif /* CONFIG_FEC_LXT970 */

/* ------------------------------------------------------------------------- */
/* The Level one LXT971 is used on some of my custom boards                  */

#ifdef CONFIG_FEC_LXT971

/* register definitions for the 971 */

#define MII_LXT971_PCR       16  /* Port Control Register     */
#define MII_LXT971_SR2       17  /* Status Register 2         */
#define MII_LXT971_IER       18  /* Interrupt Enable Register */
#define MII_LXT971_ISR       19  /* Interrupt Status Register */
#define MII_LXT971_LCR       20  /* LED Control Register      */
#define MII_LXT971_TCR       30  /* Transmit Control Register */

/* 
 * I had some nice ideas of running the MDIO faster...
 * The 971 should support 8MHz and I tried it, but things acted really
 * wierd, so 2.5 MHz ought to be enough for anyone...
 */

static void mii_parse_lxt971_sr2(uint mii_reg, struct net_device *dev)
{
	struct fec_enet_private *fep = dev->priv;
	volatile uint *s = &(fep->phy_status);

	*s &= ~(PHY_STAT_SPMASK);

	if (mii_reg & 0x4000) {
		if (mii_reg & 0x0200)
			*s |= PHY_STAT_100FDX;
		else
			*s |= PHY_STAT_100HDX;
	}
	else {
		if (mii_reg & 0x0200)
			*s |= PHY_STAT_10FDX;
		else
			*s |= PHY_STAT_10HDX;
	}
	if (mii_reg & 0x0008)
		*s |= PHY_STAT_FAULT;
}

static phy_info_t phy_info_lxt971 = {
	0x0001378e, 
	"LXT971",
	
	(const phy_cmd_t []) {  /* config */  
		/* limit to 10MBit because my protorype board 
		 * doesn't work with 100. */

		{ mk_mii_write(MII_REG_ANAR, 0x061), NULL }, /* 10 MBit */
		{ mk_mii_read(MII_REG_CR), mii_parse_cr },
		{ mk_mii_read(MII_REG_ANAR), mii_parse_anar },
		{ mk_mii_end, }
	},
	(const phy_cmd_t []) {  /* startup - enable interrupts */
		{ mk_mii_write(MII_LXT971_IER, 0x00f2), NULL },
		{ mk_mii_write(MII_REG_CR, 0x1200), NULL }, /* autonegotiate */
	
		/* Somehow does the 971 tell me that the link is down
		 * the first read after power-up.
		 * read here to get a valid value in ack_int */

		{ mk_mii_read(MII_REG_SR), mii_parse_sr }, 
		{ mk_mii_end, }
	},
	(const phy_cmd_t []) { /* ack_int */
		/* find out the current status */

		{ mk_mii_read(MII_REG_SR), mii_parse_sr },
		{ mk_mii_read(MII_LXT971_SR2), mii_parse_lxt971_sr2 },
		
		/* we only need to read ISR to acknowledge */
		
		{ mk_mii_read(MII_LXT971_ISR), NULL },
		{ mk_mii_end, }
	},
	(const phy_cmd_t []) {  /* shutdown - disable interrupts */
		{ mk_mii_write(MII_LXT971_IER, 0x0000), NULL },
		{ mk_mii_end, }
	},
};

#endif /* CONFIG_FEC_LXT970 */


/* ------------------------------------------------------------------------- */
/* The Quality Semiconductor QS6612 is used on the RPX CLLF                  */

#ifdef CONFIG_FEC_QS6612

/* register definitions */

#define MII_QS6612_MCR       17  /* Mode Control Register      */
#define MII_QS6612_FTR       27  /* Factory Test Register      */
#define MII_QS6612_MCO       28  /* Misc. Control Register     */
#define MII_QS6612_ISR       29  /* Interrupt Source Register  */
#define MII_QS6612_IMR       30  /* Interrupt Mask Register    */
#define MII_QS6612_PCR       31  /* 100BaseTx PHY Control Reg. */

static void mii_parse_qs6612_pcr(uint mii_reg, struct net_device *dev)
{
	struct fec_enet_private *fep = dev->priv;
	volatile uint *s = &(fep->phy_status);

	*s &= ~(PHY_STAT_SPMASK);

	switch((mii_reg >> 2) & 7) {
	case 1: *s |= PHY_STAT_10HDX; break;
	case 2: *s |= PHY_STAT_100HDX; break;
	case 5: *s |= PHY_STAT_10FDX; break;
	case 6: *s |= PHY_STAT_100FDX; break;
	}
}

static phy_info_t phy_info_qs6612 = {
	0x00181440, 
	"QS6612",
	
	(const phy_cmd_t []) {  /* config */  
//	{ mk_mii_write(MII_REG_ANAR, 0x061), NULL }, /* 10 MBit */

		/* The PHY powers up isolated on the RPX, 
		 * so send a command to allow operation.
		 */

		{ mk_mii_write(MII_QS6612_PCR, 0x0dc0), NULL },

		/* parse cr and anar to get some info */

		{ mk_mii_read(MII_REG_CR), mii_parse_cr },
		{ mk_mii_read(MII_REG_ANAR), mii_parse_anar },
		{ mk_mii_end, }
	},
	(const phy_cmd_t []) {  /* startup - enable interrupts */
		{ mk_mii_write(MII_QS6612_IMR, 0x003a), NULL },
		{ mk_mii_write(MII_REG_CR, 0x1200), NULL }, /* autonegotiate */
		{ mk_mii_end, }
	},
	(const phy_cmd_t []) { /* ack_int */
		
		/* we need to read ISR, SR and ANER to acknowledge */
		
		{ mk_mii_read(MII_QS6612_ISR), NULL },
		{ mk_mii_read(MII_REG_SR), mii_parse_sr },
		{ mk_mii_read(MII_REG_ANER), NULL },

		/* read pcr to get info */

		{ mk_mii_read(MII_QS6612_PCR), mii_parse_qs6612_pcr },
		{ mk_mii_end, }
	},
	(const phy_cmd_t []) {  /* shutdown - disable interrupts */
		{ mk_mii_write(MII_QS6612_IMR, 0x0000), NULL },
		{ mk_mii_end, }
	},
};


#endif /* CONFIG_FEC_QS6612 */


static phy_info_t *phy_info[] = {

#ifdef CONFIG_FEC_LXT970
	&phy_info_lxt970,
#endif /* CONFIG_FEC_LXT970 */

#ifdef CONFIG_FEC_LXT971
	&phy_info_lxt971,
#endif /* CONFIG_FEC_LXT971 */

#ifdef CONFIG_FEC_QS6612
	&phy_info_qs6612,
#endif /* CONFIG_FEC_LXT971 */

	NULL
};

static void mii_display_status(struct net_device *dev)
{
	struct fec_enet_private *fep = dev->priv;
	volatile uint *s = &(fep->phy_status);

	if (!fep->link && !fep->old_link) {
		/* Link is still down - don't print anything */
		return;
	}

	printk("%s: status: ", dev->name);

	if (!fep->link) {
		printk("link down");
	} else {
		printk("link up");

		switch(*s & PHY_STAT_SPMASK) {
		case PHY_STAT_100FDX: printk(", 100MBit Full Duplex"); break;
		case PHY_STAT_100HDX: printk(", 100MBit Half Duplex"); break;
		case PHY_STAT_10FDX: printk(", 10MBit Full Duplex"); break;
		case PHY_STAT_10HDX: printk(", 10MBit Half Duplex"); break;
		default:
			printk(", Unknown speed/duplex");
		}

		if (*s & PHY_STAT_ANC)
			printk(", auto-negotiation complete");
	}

	if (*s & PHY_STAT_FAULT)
		printk(", remote fault");

	printk(".\n");
}

static void mii_display_config(struct net_device *dev)
{
	struct fec_enet_private *fep = dev->priv;
	volatile uint *s = &(fep->phy_status);

	printk("%s: config: auto-negotiation ", dev->name);

	if (*s & PHY_CONF_ANE)
		printk("on");
	else
		printk("off");

	if (*s & PHY_CONF_100FDX)
		printk(", 100FDX");
	if (*s & PHY_CONF_100HDX)
		printk(", 100HDX");
	if (*s & PHY_CONF_10FDX)
		printk(", 10FDX");
	if (*s & PHY_CONF_10HDX)
		printk(", 10HDX");
	if (!(*s & PHY_CONF_SPMASK))
		printk(", No speed/duplex selected?");

	if (*s & PHY_CONF_LOOP)
		printk(", loopback enabled");
	
	printk(".\n");

	fep->sequence_done = 1;
}

static void mii_relink(struct net_device *dev)
{
	struct fec_enet_private *fep = dev->priv;
	int duplex;

	fep->link = (fep->phy_status & PHY_STAT_LINK) ? 1 : 0;
	mii_display_status(dev);
	fep->old_link = fep->link;

	if (fep->link) {
		duplex = 0;
		if (fep->phy_status 
		    & (PHY_STAT_100FDX | PHY_STAT_10FDX))
			duplex = 1;
		fec_restart(dev, duplex);