/*
	drivers/net/tulip/pnic2.c

	Copyright 2000,2001  The Linux Kernel Team
	Written/copyright 1994-2001 by Donald Becker.
        Modified to hep support PNIC_II by Kevin B. Hendricks

	This software may be used and distributed according to the terms
	of the GNU General Public License, incorporated herein by reference.

	Please refer to Documentation/DocBook/tulip-user.{pdf,ps,html}
	for more information on this driver.

        Please submit bugs to http://bugzilla.kernel.org/ .
*/


/* Understanding the PNIC_II - everything is this file is based
 * on the PNIC_II_PDF datasheet which is sorely lacking in detail
 *
 * As I understand things, here are the registers and bits that
 * explain the masks and constants used in this file that are
 * either different from the 21142/3 or important for basic operation.
 *
 *
 * CSR 6  (mask = 0xfe3bd1fd of bits not to change)
 * -----
 * Bit 24    - SCR
 * Bit 23    - PCS
 * Bit 22    - TTM (Trasmit Threshold Mode)
 * Bit 18    - Port Select
 * Bit 13    - Start - 1, Stop - 0 Transmissions
 * Bit 11:10 - Loop Back Operation Mode
 * Bit 9     - Full Duplex mode (Advertise 10BaseT-FD is CSR14<7> is set)
 * Bit 1     - Start - 1, Stop - 0 Receive
 *
 *
 * CSR 14  (mask = 0xfff0ee39 of bits not to change)
 * ------
 * Bit 19    - PAUSE-Pause
 * Bit 18    - Advertise T4
 * Bit 17    - Advertise 100baseTx-FD
 * Bit 16    - Advertise 100baseTx-HD
 * Bit 12    - LTE - Link Test Enable
 * Bit 7     - ANE - Auto Negotiate Enable
 * Bit 6     - HDE - Advertise 10baseT-HD
 * Bit 2     - Reset to Power down - kept as 1 for normal operation
 * Bit 1     -  Loop Back enable for 10baseT MCC
 *
 *
 * CSR 12
 * ------
 * Bit 25    - Partner can do T4
 * Bit 24    - Partner can do 100baseTx-FD
 * Bit 23    - Partner can do 100baseTx-HD
 * Bit 22    - Partner can do 10baseT-FD
 * Bit 21    - Partner can do 10baseT-HD
 * Bit 15    - LPN is 1 if all above bits are valid other wise 0
 * Bit 14:12 - autonegotiation state (write 001 to start autonegotiate)
 * Bit 3     - Autopolarity state
 * Bit 2     - LS10B - link state of 10baseT 0 - good, 1 - failed
 * Bit 1     - LS100B - link state of 100baseT 0 - good, 1 - failed
 *
 *
 * Data Port Selection Info
 *-------------------------
 *
 * CSR14<7>   CSR6<18>    CSR6<22>    CSR6<23>    CSR6<24>   MODE/PORT
 *   1           0           0 (X)       0 (X)       1        NWAY
 *   0           0           1           0 (X)       0        10baseT
 *   0           1           0           1           1 (X)    100baseT
 *
 *
 */


#include "tulip.h"
#include <linux/delay.h>


void pnic2_timer(unsigned long data)
{
	struct net_device *dev = (struct net_device *)data;
	struct tulip_private *tp = netdev_priv(dev);
	void __iomem *ioaddr = tp->base_addr;
	int next_tick = 60*HZ;

	if (tulip_debug > 3)
		dev_info(&dev->dev, "PNIC2 negotiation status %08x\n",
			 ioread32(ioaddr + CSR12));

	if (next_tick) {
		mod_timer(&tp->timer, RUN_AT(next_tick));
	}
}


void pnic2_start_nway(struct net_device *dev)
{
	struct tulip_private *tp = netdev_priv(dev);
	void __iomem *ioaddr = tp->base_addr;
        int csr14;
        int csr12;

        /* set up what to advertise during the negotiation */

        /* load in csr14  and mask off bits not to touch
         * comment at top of file explains mask value
         */
	csr14 = (ioread32(ioaddr + CSR14) & 0xfff0ee39);

        /* bit 17 - advetise 100baseTx-FD */
        if (tp->sym_advertise & 0x0100) csr14 |= 0x00020000;

        /* bit 16 - advertise 100baseTx-HD */
        if (tp->sym_advertise & 0x0080) csr14 |= 0x00010000;

        /* bit 6 - advertise 10baseT-HD */
        if (tp->sym_advertise & 0x0020) csr14 |= 0x00000040;

        /* Now set bit 12 Link Test Enable, Bit 7 Autonegotiation Enable
         * and bit 0 Don't PowerDown 10baseT
         */
        csr14 |= 0x00001184;

	if (tulip_debug > 1)
		printk(KERN_DEBUG "%s: Restarting PNIC2 autonegotiation, csr14=%08x\n",
		       dev->name, csr14);

        /* tell pnic2_lnk_change we are doing an nway negotiation */
	dev->if_port = 0;
	tp->nway = tp->mediasense = 1;
	tp->nwayset = tp->lpar = 0;

        /* now we have to set up csr6 for NWAY state */

	tp->csr6 = ioread32(ioaddr + CSR6);
	if (tulip_debug > 1)
		printk(KERN_DEBUG "%s: On Entry to Nway, csr6=%08x\n",
		       dev->name, tp->csr6);

        /* mask off any bits not to touch
         * comment at top of file explains mask value
         */
	tp->csr6 = tp->csr6 & 0xfe3bd1fd;

        /* don't forget that bit 9 is also used for advertising */
        /* advertise 10baseT-FD for the negotiation (bit 9) */
        if (tp->sym_advertise & 0x0040) tp->csr6 |= 0x00000200;

        /* set bit 24 for nway negotiation mode ...
         * see Data Port Selection comment at top of file
         * and "Stop" - reset both Transmit (bit 13) and Receive (bit 1)
         */
        tp->csr6 |= 0x01000000;
	iowrite32(csr14, ioaddr + CSR14);
	iowrite32(tp->csr6, ioaddr + CSR6);
        udelay(100);

        /* all set up so now force the negotiation to begin */

        /* read in current values and mask off all but the
	 * Autonegotiation bits 14:12.  Writing a 001 to those bits
         * should start the autonegotiation
         */
        csr12 = (ioread32(ioaddr + CSR12) & 0xffff8fff);
        csr12 |= 0x1000;
	iowrite32(csr12, ioaddr + CSR12);
}


void pnic2_lnk_change(struct net_device *dev, int csr5)
{
	struct tulip_private *tp = netdev_priv(dev);
	void __iomem *ioaddr = tp->base_addr;
        int csr14;

        /* read the staus register to find out what is up */
	int csr12 = ioread32(ioaddr + CSR12);

	if (tulip_debug > 1)
		dev_info(&dev->dev,
			 "PNIC2 link status interrupt %08x,  CSR5 %x, %08x\n",
			 csr12, csr5, ioread32(ioaddr + CSR14));

	/* If NWay finished and we have a negotiated partner capability.
         * check bits 14:12 for bit pattern 101 - all is good
         */
	if (tp->nway  &&  !tp->nwayset) {

	        /* we did an auto negotiation */

                if ((csr12 & 0x7000) == 0x5000) {

	               /* negotiation ended successfully */

	               /* get the link partners reply and mask out all but
                        * bits 24-21 which show the partners capabilities
                        * and match those to what we advertised
                        *
                        * then begin to interpret the results of the negotiation.
                        * Always go in this order : (we are ignoring T4 for now)
                        *     100baseTx-FD, 100baseTx-HD, 10baseT-FD, 10baseT-HD
                        */

		        int negotiated = ((csr12 >> 16) & 0x01E0) & tp->sym_advertise;
		        tp->lpar = (csr12 >> 16);
		        tp->nwayset = 1;

                        if (negotiated & 0x0100)        dev->if_port = 5;
		        else if (negotiated & 0x0080)	dev->if_port = 3;
		        else if (negotiated & 0x0040)	dev->if_port = 4;
			else if (negotiated & 0x0020)	dev->if_port = 0;
			else {
			     if (tulip_debug > 1)
				     dev_info(&dev->dev,
					      "funny autonegotiate result csr12 %08x advertising %04x\n",
					      csr12, tp->sym_advertise);
			     tp->nwayset = 0;
			     /* so check  if 100baseTx link state is okay */
			     if ((csr12 & 2) == 0  &&  (tp->sym_advertise & 0x0180))
			       dev->if_port = 3;
			}

			/* now record the duplex that was negotiated */
			tp->full_duplex = 0;
			if ((dev->if_port == 4) || (dev->if_port == 5))
			       tp->full_duplex = 1;

			if (tulip_debug > 1) {
			       if (tp->nwayset)
				       dev_info(&dev->dev,
						"Switching to %s based on link negotiation %04x & %04x = %04x\n",
						medianame[dev->if_port],
						tp->sym_advertise, tp->lpar,
						negotiated);
			}

                        /* remember to turn off bit 7 - autonegotiate
                         * enable so we can properly end nway mode and
                         * set duplex (ie. use csr6<9> again)
                         */
	                csr14 = (ioread32(ioaddr + CSR14) & 0xffffff7f);
                        iowrite32(csr14,ioaddr + CSR14);


                        /* now set the data port and operating mode
			 * (see the Data Port Selection comments at
			 * the top of the file
			 */

			/* get current csr6 and mask off bits not to touch */
			/* see comment at top of file */

			tp->csr6 = (ioread32(ioaddr + CSR6) & 0xfe3bd1fd);

			/* so if using if_port 3 or 5 then select the 100baseT
			 * port else select the 10baseT port.
			 * See the Data Port Selection table at the top
			 * of the file which was taken from the PNIC_II.PDF
			 * datasheet
			 */
			if (dev->if_port & 1) tp->csr6 |= 0x01840000;
			else tp->csr6 |= 0x00400000;

			/* now set the full duplex bit appropriately */
			if (tp->full_duplex) tp->csr6 |= 0x00000200;

			iowrite32(1, ioaddr + CSR13);

			if (tulip_debug > 2)
			        printk(KERN_DEBUG "%s: Setting CSR6 %08x/%x CSR12 %08x\n",
				       dev->name, tp->csr6,
				       ioread32(ioaddr + CSR6), ioread32(ioaddr + CSR12));

			/* now the following actually writes out the
			 * new csr6 values
			 */
			tulip_start_rxtx(tp);

                        return;

	        } else {
	                dev_info(&dev->dev,
				 "Autonegotiation failed, using %s, link beat status %04x\n",
				 medianame[dev->if_port], csr12);

                        /* remember to turn off bit 7 - autonegotiate
                         * enable so we don't forget
                         */
	                csr14 = (ioread32(ioaddr + CSR14) & 0xffffff7f);
                        iowrite32(csr14,ioaddr + CSR14);

                        /* what should we do when autonegotiate fails?
                         * should we try again or default to baseline
                         * case.  I just don't know.
                         *
                         * for now default to some baseline case
                         */

	                 dev->if_port = 0;
                         tp->nway = 0;
                         tp->nwayset = 1;

                         /* set to 10baseTx-HD - see Data Port Selection
                          * comment given at the top of the file
                          */
	                 tp->csr6 = (ioread32(ioaddr + CSR6) & 0xfe3bd1fd);
                         tp->csr6 |= 0x00400000;

	                 tulip_restart_rxtx(tp);

                         return;

		}
	}

	if ((tp->nwayset  &&  (csr5 & 0x08000000) &&
	     (dev->if_port == 3  ||  dev->if_port == 5) &&
	     (csr12 & 2) == 2) || (tp->nway && (csr5 & (TPLnkFail)))) {

		/* Link blew? Maybe restart NWay. */

		if (tulip_debug > 2)
			printk(KERN_DEBUG "%s: Ugh! Link blew?\n", dev->name);

		del_timer_sync(&tp->timer);
		pnic2_start_nway(dev);
		tp->timer.expires = RUN_AT(3*HZ);
		add_timer(&tp->timer);

                return;
	}


        if (dev->if_port == 3  ||  dev->if_port == 5) {

	        /* we are at 100mb and a potential link change occurred */

		if (tulip_debug > 1)
			dev_info(&dev->dev, "PNIC2 %s link beat %s\n",
				 medianame[dev->if_port],
				 (csr12 & 2) ? "failed" : "good");

                /* check 100 link beat */

                tp->nway = 0;
                tp->nwayset = 1;

                /* if failed then try doing an nway to get in sync */
		if ((csr12 & 2)  &&  ! tp->medialock) {
			del_timer_sync(&tp->timer);
			pnic2_start_nway(dev);
			tp->timer.expires = RUN_AT(3*HZ);
       			add_timer(&tp->timer);
                }

                return;
        }

	if (dev->if_port == 0  ||  dev->if_port == 4) {

	        /* we are at 10mb and a potential link change occurred */

		if (tulip_debug > 1)
			dev_info(&dev->dev, "PNIC2 %s link beat %s\n",
				 medianame[dev->if_port],
				 (csr12 & 4) ? "failed" : "good");


                tp->nway = 0;
                tp->nwayset = 1;

                /* if failed, try doing an nway to get in sync */
		if ((csr12 & 4)  &&  ! tp->medialock) {
			del_timer_sync(&tp->timer);
			pnic2_start_nway(dev);
			tp->timer.expires = RUN_AT(3*HZ);
       			add_timer(&tp->timer);
                }

                return;
        }


	if (tulip_debug > 1)
		dev_info(&dev->dev, "PNIC2 Link Change Default?\n");

        /* if all else fails default to trying 10baseT-HD */
	dev->if_port = 0;

        /* make sure autonegotiate enable is off */
	csr14 = (ioread32(ioaddr + CSR14) & 0xffffff7f);
        iowrite32(csr14,ioaddr + CSR14);

        /* set to 10baseTx-HD - see Data Port Selection
         * comment given at the top of the file
         */
	tp->csr6 = (ioread32(ioaddr + CSR6) & 0xfe3bd1fd);
        tp->csr6 |= 0x00400000;

	tulip_restart_rxtx(tp);
}