aboutsummaryrefslogblamecommitdiffstats
path: root/drivers/net/korina.c
blob: 7aa05f81fe9e319c4683311f938ad0f4bee5c479 (plain) (tree)
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884





















































































                                                                            



                                                                          

















































































































































































































































                                                                            
                                             





















                                                                               
                                 




                                                 

                                                   


                                  


                                                                       





















                                                              
                                                  
                                                       


























                                                                           
                 


















                                                                            



























                                                                
                                        






























































































































































































































































































































































































































                                                                               
                

















                                                                             

                                




















































































                                                                           
                










































                                                                                

                   









                                   
























                                                                 

                                













                                                               
               






                                                                      














                                                                              
                            






                                                                                
                            






                                                                                
                            





                                                                          
                            



































                                                                 

                                  
                                        
                                                                 

                                        

                  










                                 
                 






                                                               


                                 































                                                           
/*
 *  Driver for the IDT RC32434 (Korina) on-chip ethernet controller.
 *
 *  Copyright 2004 IDT Inc. (rischelp@idt.com)
 *  Copyright 2006 Felix Fietkau <nbd@openwrt.org>
 *  Copyright 2008 Florian Fainelli <florian@openwrt.org>
 *
 *  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  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  You should have received a copy of the  GNU General Public License along
 *  with this program; if not, write  to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *  Writing to a DMA status register:
 *
 *  When writing to the status register, you should mask the bit you have
 *  been testing the status register with. Both Tx and Rx DMA registers
 *  should stick to this procedure.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/moduleparam.h>
#include <linux/sched.h>
#include <linux/ctype.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/in.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/errno.h>
#include <linux/platform_device.h>
#include <linux/mii.h>
#include <linux/ethtool.h>
#include <linux/crc32.h>

#include <asm/bootinfo.h>
#include <asm/system.h>
#include <asm/bitops.h>
#include <asm/pgtable.h>
#include <asm/segment.h>
#include <asm/io.h>
#include <asm/dma.h>

#include <asm/mach-rc32434/rb.h>
#include <asm/mach-rc32434/rc32434.h>
#include <asm/mach-rc32434/eth.h>
#include <asm/mach-rc32434/dma_v.h>

#define DRV_NAME        "korina"
#define DRV_VERSION     "0.10"
#define DRV_RELDATE     "04Mar2008"

#define STATION_ADDRESS_HIGH(dev) (((dev)->dev_addr[0] << 8) | \
				   ((dev)->dev_addr[1]))
#define STATION_ADDRESS_LOW(dev)  (((dev)->dev_addr[2] << 24) | \
				   ((dev)->dev_addr[3] << 16) | \
				   ((dev)->dev_addr[4] << 8)  | \
				   ((dev)->dev_addr[5]))

#define MII_CLOCK 1250000 	/* no more than 2.5MHz */

/* the following must be powers of two */
#define KORINA_NUM_RDS	64  /* number of receive descriptors */
#define KORINA_NUM_TDS	64  /* number of transmit descriptors */

/* KORINA_RBSIZE is the hardware's default maximum receive
 * frame size in bytes. Having this hardcoded means that there
 * is no support for MTU sizes greater than 1500. */
#define KORINA_RBSIZE	1536 /* size of one resource buffer = Ether MTU */
#define KORINA_RDS_MASK	(KORINA_NUM_RDS - 1)
#define KORINA_TDS_MASK	(KORINA_NUM_TDS - 1)
#define RD_RING_SIZE 	(KORINA_NUM_RDS * sizeof(struct dma_desc))
#define TD_RING_SIZE	(KORINA_NUM_TDS * sizeof(struct dma_desc))

#define TX_TIMEOUT 	(6000 * HZ / 1000)

enum chain_status { desc_filled, desc_empty };
#define IS_DMA_FINISHED(X)   (((X) & (DMA_DESC_FINI)) != 0)
#define IS_DMA_DONE(X)   (((X) & (DMA_DESC_DONE)) != 0)
#define RCVPKT_LENGTH(X)     (((X) & ETH_RX_LEN) >> ETH_RX_LEN_BIT)

/* Information that need to be kept for each board. */
struct korina_private {
	struct eth_regs *eth_regs;
	struct dma_reg *rx_dma_regs;
	struct dma_reg *tx_dma_regs;
	struct dma_desc *td_ring; /* transmit descriptor ring */
	struct dma_desc *rd_ring; /* receive descriptor ring  */

	struct sk_buff *tx_skb[KORINA_NUM_TDS];
	struct sk_buff *rx_skb[KORINA_NUM_RDS];

	int rx_next_done;
	int rx_chain_head;
	int rx_chain_tail;
	enum chain_status rx_chain_status;

	int tx_next_done;
	int tx_chain_head;
	int tx_chain_tail;
	enum chain_status tx_chain_status;
	int tx_count;
	int tx_full;

	int rx_irq;
	int tx_irq;
	int ovr_irq;
	int und_irq;

	spinlock_t lock;        /* NIC xmit lock */

	int dma_halt_cnt;
	int dma_run_cnt;
	struct napi_struct napi;
	struct mii_if_info mii_if;
	struct net_device *dev;
	int phy_addr;
};

extern unsigned int idt_cpu_freq;

static inline void korina_start_dma(struct dma_reg *ch, u32 dma_addr)
{
	writel(0, &ch->dmandptr);
	writel(dma_addr, &ch->dmadptr);
}

static inline void korina_abort_dma(struct net_device *dev,
					struct dma_reg *ch)
{
       if (readl(&ch->dmac) & DMA_CHAN_RUN_BIT) {
	       writel(0x10, &ch->dmac);

	       while (!(readl(&ch->dmas) & DMA_STAT_HALT))
		       dev->trans_start = jiffies;

	       writel(0, &ch->dmas);
       }

       writel(0, &ch->dmadptr);
       writel(0, &ch->dmandptr);
}

static inline void korina_chain_dma(struct dma_reg *ch, u32 dma_addr)
{
	writel(dma_addr, &ch->dmandptr);
}

static void korina_abort_tx(struct net_device *dev)
{
	struct korina_private *lp = netdev_priv(dev);

	korina_abort_dma(dev, lp->tx_dma_regs);
}

static void korina_abort_rx(struct net_device *dev)
{
	struct korina_private *lp = netdev_priv(dev);

	korina_abort_dma(dev, lp->rx_dma_regs);
}

static void korina_start_rx(struct korina_private *lp,
					struct dma_desc *rd)
{
	korina_start_dma(lp->rx_dma_regs, CPHYSADDR(rd));
}

static void korina_chain_rx(struct korina_private *lp,
					struct dma_desc *rd)
{
	korina_chain_dma(lp->rx_dma_regs, CPHYSADDR(rd));
}

/* transmit packet */
static int korina_send_packet(struct sk_buff *skb, struct net_device *dev)
{
	struct korina_private *lp = netdev_priv(dev);
	unsigned long flags;
	u32 length;
	u32 chain_index;
	struct dma_desc *td;

	spin_lock_irqsave(&lp->lock, flags);

	td = &lp->td_ring[lp->tx_chain_tail];

	/* stop queue when full, drop pkts if queue already full */
	if (lp->tx_count >= (KORINA_NUM_TDS - 2)) {
		lp->tx_full = 1;

		if (lp->tx_count == (KORINA_NUM_TDS - 2))
			netif_stop_queue(dev);
		else {
			dev->stats.tx_dropped++;
			dev_kfree_skb_any(skb);
			spin_unlock_irqrestore(&lp->lock, flags);

			return NETDEV_TX_BUSY;
		}
	}

	lp->tx_count++;

	lp->tx_skb[lp->tx_chain_tail] = skb;

	length = skb->len;
	dma_cache_wback((u32)skb->data, skb->len);

	/* Setup the transmit descriptor. */
	dma_cache_inv((u32) td, sizeof(*td));
	td->ca = CPHYSADDR(skb->data);
	chain_index = (lp->tx_chain_tail - 1) &
			KORINA_TDS_MASK;

	if (readl(&(lp->tx_dma_regs->dmandptr)) == 0) {
		if (lp->tx_chain_status == desc_empty) {
			/* Update tail */
			td->control = DMA_COUNT(length) |
					DMA_DESC_COF | DMA_DESC_IOF;
			/* Move tail */
			lp->tx_chain_tail = chain_index;
			/* Write to NDPTR */
			writel(CPHYSADDR(&lp->td_ring[lp->tx_chain_head]),
					&lp->tx_dma_regs->dmandptr);
			/* Move head to tail */
			lp->tx_chain_head = lp->tx_chain_tail;
		} else {
			/* Update tail */
			td->control = DMA_COUNT(length) |
					DMA_DESC_COF | DMA_DESC_IOF;
			/* Link to prev */
			lp->td_ring[chain_index].control &=
					~DMA_DESC_COF;
			/* Link to prev */
			lp->td_ring[chain_index].link =  CPHYSADDR(td);
			/* Move tail */
			lp->tx_chain_tail = chain_index;
			/* Write to NDPTR */
			writel(CPHYSADDR(&lp->td_ring[lp->tx_chain_head]),
					&(lp->tx_dma_regs->dmandptr));
			/* Move head to tail */
			lp->tx_chain_head = lp->tx_chain_tail;
			lp->tx_chain_status = desc_empty;
		}
	} else {
		if (lp->tx_chain_status == desc_empty) {
			/* Update tail */
			td->control = DMA_COUNT(length) |
					DMA_DESC_COF | DMA_DESC_IOF;
			/* Move tail */
			lp->tx_chain_tail = chain_index;
			lp->tx_chain_status = desc_filled;
			netif_stop_queue(dev);
		} else {
			/* Update tail */
			td->control = DMA_COUNT(length) |
					DMA_DESC_COF | DMA_DESC_IOF;
			lp->td_ring[chain_index].control &=
					~DMA_DESC_COF;
			lp->td_ring[chain_index].link =  CPHYSADDR(td);
			lp->tx_chain_tail = chain_index;
		}
	}
	dma_cache_wback((u32) td, sizeof(*td));

	dev->trans_start = jiffies;
	spin_unlock_irqrestore(&lp->lock, flags);

	return NETDEV_TX_OK;
}

static int mdio_read(struct net_device *dev, int mii_id, int reg)
{
	struct korina_private *lp = netdev_priv(dev);
	int ret;

	mii_id = ((lp->rx_irq == 0x2c ? 1 : 0) << 8);

	writel(0, &lp->eth_regs->miimcfg);
	writel(0, &lp->eth_regs->miimcmd);
	writel(mii_id | reg, &lp->eth_regs->miimaddr);
	writel(ETH_MII_CMD_SCN, &lp->eth_regs->miimcmd);

	ret = (int)(readl(&lp->eth_regs->miimrdd));
	return ret;
}

static void mdio_write(struct net_device *dev, int mii_id, int reg, int val)
{
	struct korina_private *lp = netdev_priv(dev);

	mii_id = ((lp->rx_irq == 0x2c ? 1 : 0) << 8);

	writel(0, &lp->eth_regs->miimcfg);
	writel(1, &lp->eth_regs->miimcmd);
	writel(mii_id | reg, &lp->eth_regs->miimaddr);
	writel(ETH_MII_CMD_SCN, &lp->eth_regs->miimcmd);
	writel(val, &lp->eth_regs->miimwtd);
}

/* Ethernet Rx DMA interrupt */
static irqreturn_t korina_rx_dma_interrupt(int irq, void *dev_id)
{
	struct net_device *dev = dev_id;
	struct korina_private *lp = netdev_priv(dev);
	u32 dmas, dmasm;
	irqreturn_t retval;

	dmas = readl(&lp->rx_dma_regs->dmas);
	if (dmas & (DMA_STAT_DONE | DMA_STAT_HALT | DMA_STAT_ERR)) {
		netif_rx_schedule(&lp->napi);

		dmasm = readl(&lp->rx_dma_regs->dmasm);
		writel(dmasm | (DMA_STAT_DONE |
				DMA_STAT_HALT | DMA_STAT_ERR),
				&lp->rx_dma_regs->dmasm);

		if (dmas & DMA_STAT_ERR)
			printk(KERN_ERR DRV_NAME "%s: DMA error\n", dev->name);

		retval = IRQ_HANDLED;
	} else
		retval = IRQ_NONE;

	return retval;
}

static int korina_rx(struct net_device *dev, int limit)
{
	struct korina_private *lp = netdev_priv(dev);
	struct dma_desc *rd = &lp->rd_ring[lp->rx_next_done];
	struct sk_buff *skb, *skb_new;
	u8 *pkt_buf;
	u32 devcs, pkt_len, dmas;
	int count;

	dma_cache_inv((u32)rd, sizeof(*rd));

	for (count = 0; count < limit; count++) {
		skb = lp->rx_skb[lp->rx_next_done];
		skb_new = NULL;

		devcs = rd->devcs;

		if ((KORINA_RBSIZE - (u32)DMA_COUNT(rd->control)) == 0)
			break;

		/* Update statistics counters */
		if (devcs & ETH_RX_CRC)
			dev->stats.rx_crc_errors++;
		if (devcs & ETH_RX_LOR)
			dev->stats.rx_length_errors++;
		if (devcs & ETH_RX_LE)
			dev->stats.rx_length_errors++;
		if (devcs & ETH_RX_OVR)
			dev->stats.rx_over_errors++;
		if (devcs & ETH_RX_CV)
			dev->stats.rx_frame_errors++;
		if (devcs & ETH_RX_CES)
			dev->stats.rx_length_errors++;
		if (devcs & ETH_RX_MP)
			dev->stats.multicast++;

		if ((devcs & ETH_RX_LD) != ETH_RX_LD) {
			/* check that this is a whole packet
			 * WARNING: DMA_FD bit incorrectly set
			 * in Rc32434 (errata ref #077) */
			dev->stats.rx_errors++;
			dev->stats.rx_dropped++;
		} else if ((devcs & ETH_RX_ROK)) {
			pkt_len = RCVPKT_LENGTH(devcs);

			/* must be the (first and) last
			 * descriptor then */
			pkt_buf = (u8 *)lp->rx_skb[lp->rx_next_done]->data;

			/* invalidate the cache */
			dma_cache_inv((unsigned long)pkt_buf, pkt_len - 4);

			/* Malloc up new buffer. */
			skb_new = netdev_alloc_skb(dev, KORINA_RBSIZE + 2);

			if (!skb_new)
				break;
			/* Do not count the CRC */
			skb_put(skb, pkt_len - 4);
			skb->protocol = eth_type_trans(skb, dev);

			/* Pass the packet to upper layers */
			netif_receive_skb(skb);
			dev->stats.rx_packets++;
			dev->stats.rx_bytes += pkt_len;

			/* Update the mcast stats */
			if (devcs & ETH_RX_MP)
				dev->stats.multicast++;

			lp->rx_skb[lp->rx_next_done] = skb_new;
		}

		rd->devcs = 0;

		/* Restore descriptor's curr_addr */
		if (skb_new)
			rd->ca = CPHYSADDR(skb_new->data);
		else
			rd->ca = CPHYSADDR(skb->data);

		rd->control = DMA_COUNT(KORINA_RBSIZE) |
			DMA_DESC_COD | DMA_DESC_IOD;
		lp->rd_ring[(lp->rx_next_done - 1) &
			KORINA_RDS_MASK].control &=
			~DMA_DESC_COD;

		lp->rx_next_done = (lp->rx_next_done + 1) & KORINA_RDS_MASK;
		dma_cache_wback((u32)rd, sizeof(*rd));
		rd = &lp->rd_ring[lp->rx_next_done];
		writel(~DMA_STAT_DONE, &lp->rx_dma_regs->dmas);
	}

	dmas = readl(&lp->rx_dma_regs->dmas);

	if (dmas & DMA_STAT_HALT) {
		writel(~(DMA_STAT_HALT | DMA_STAT_ERR),
				&lp->rx_dma_regs->dmas);

		lp->dma_halt_cnt++;
		rd->devcs = 0;
		skb = lp->rx_skb[lp->rx_next_done];
		rd->ca = CPHYSADDR(skb->data);
		dma_cache_wback((u32)rd, sizeof(*rd));
		korina_chain_rx(lp, rd);
	}

	return count;
}

static int korina_poll(struct napi_struct *napi, int budget)
{
	struct korina_private *lp =
		container_of(napi, struct korina_private, napi);
	struct net_device *dev = lp->dev;
	int work_done;

	work_done = korina_rx(dev, budget);
	if (work_done < budget) {
		netif_rx_complete(napi);

		writel(readl(&lp->rx_dma_regs->dmasm) &
			~(DMA_STAT_DONE | DMA_STAT_HALT | DMA_STAT_ERR),
			&lp->rx_dma_regs->dmasm);
	}
	return work_done;
}

/*
 * Set or clear the multicast filter for this adaptor.
 */
static void korina_multicast_list(struct net_device *dev)
{
	struct korina_private *lp = netdev_priv(dev);
	unsigned long flags;
	struct dev_mc_list *dmi = dev->mc_list;
	u32 recognise = ETH_ARC_AB;	/* always accept broadcasts */
	int i;

	/* Set promiscuous mode */
	if (dev->flags & IFF_PROMISC)
		recognise |= ETH_ARC_PRO;

	else if ((dev->flags & IFF_ALLMULTI) || (dev->mc_count > 4))
		/* All multicast and broadcast */
		recognise |= ETH_ARC_AM;

	/* Build the hash table */
	if (dev->mc_count > 4) {
		u16 hash_table[4];
		u32 crc;

		for (i = 0; i < 4; i++)
			hash_table[i] = 0;

		for (i = 0; i < dev->mc_count; i++) {
			char *addrs = dmi->dmi_addr;

			dmi = dmi->next;

			if (!(*addrs & 1))
				continue;

			crc = ether_crc_le(6, addrs);
			crc >>= 26;
			hash_table[crc >> 4] |= 1 << (15 - (crc & 0xf));
		}
		/* Accept filtered multicast */
		recognise |= ETH_ARC_AFM;

		/* Fill the MAC hash tables with their values */
		writel((u32)(hash_table[1] << 16 | hash_table[0]),
					&lp->eth_regs->ethhash0);
		writel((u32)(hash_table[3] << 16 | hash_table[2]),
					&lp->eth_regs->ethhash1);
	}

	spin_lock_irqsave(&lp->lock, flags);
	writel(recognise, &lp->eth_regs->etharc);
	spin_unlock_irqrestore(&lp->lock, flags);
}

static void korina_tx(struct net_device *dev)
{
	struct korina_private *lp = netdev_priv(dev);
	struct dma_desc *td = &lp->td_ring[lp->tx_next_done];
	u32 devcs;
	u32 dmas;

	spin_lock(&lp->lock);

	/* Process all desc that are done */
	while (IS_DMA_FINISHED(td->control)) {
		if (lp->tx_full == 1) {
			netif_wake_queue(dev);
			lp->tx_full = 0;
		}

		devcs = lp->td_ring[lp->tx_next_done].devcs;
		if ((devcs & (ETH_TX_FD | ETH_TX_LD)) !=
				(ETH_TX_FD | ETH_TX_LD)) {
			dev->stats.tx_errors++;
			dev->stats.tx_dropped++;

			/* Should never happen */
			printk(KERN_ERR DRV_NAME "%s: split tx ignored\n",
							dev->name);
		} else if (devcs & ETH_TX_TOK) {
			dev->stats.tx_packets++;
			dev->stats.tx_bytes +=
					lp->tx_skb[lp->tx_next_done]->len;
		} else {
			dev->stats.tx_errors++;
			dev->stats.tx_dropped++;

			/* Underflow */
			if (devcs & ETH_TX_UND)
				dev->stats.tx_fifo_errors++;

			/* Oversized frame */
			if (devcs & ETH_TX_OF)
				dev->stats.tx_aborted_errors++;

			/* Excessive deferrals */
			if (devcs & ETH_TX_ED)
				dev->stats.tx_carrier_errors++;

			/* Collisions: medium busy */
			if (devcs & ETH_TX_EC)
				dev->stats.collisions++;

			/* Late collision */
			if (devcs & ETH_TX_LC)
				dev->stats.tx_window_errors++;
		}

		/* We must always free the original skb */
		if (lp->tx_skb[lp->tx_next_done]) {
			dev_kfree_skb_any(lp->tx_skb[lp->tx_next_done]);
			lp->tx_skb[lp->tx_next_done] = NULL;
		}

		lp->td_ring[lp->tx_next_done].control = DMA_DESC_IOF;
		lp->td_ring[lp->tx_next_done].devcs = ETH_TX_FD | ETH_TX_LD;
		lp->td_ring[lp->tx_next_done].link = 0;
		lp->td_ring[lp->tx_next_done].ca = 0;
		lp->tx_count--;

		/* Go on to next transmission */
		lp->tx_next_done = (lp->tx_next_done + 1) & KORINA_TDS_MASK;
		td = &lp->td_ring[lp->tx_next_done];

	}

	/* Clear the DMA status register */
	dmas = readl(&lp->tx_dma_regs->dmas);
	writel(~dmas, &lp->tx_dma_regs->dmas);

	writel(readl(&lp->tx_dma_regs->dmasm) &
			~(DMA_STAT_FINI | DMA_STAT_ERR),
			&lp->tx_dma_regs->dmasm);

	spin_unlock(&lp->lock);
}

static irqreturn_t
korina_tx_dma_interrupt(int irq, void *dev_id)
{
	struct net_device *dev = dev_id;
	struct korina_private *lp = netdev_priv(dev);
	u32 dmas, dmasm;
	irqreturn_t retval;

	dmas = readl(&lp->tx_dma_regs->dmas);

	if (dmas & (DMA_STAT_FINI | DMA_STAT_ERR)) {
		korina_tx(dev);

		dmasm = readl(&lp->tx_dma_regs->dmasm);
		writel(dmasm | (DMA_STAT_FINI | DMA_STAT_ERR),
				&lp->tx_dma_regs->dmasm);

		if (lp->tx_chain_status == desc_filled &&
			(readl(&(lp->tx_dma_regs->dmandptr)) == 0)) {
			writel(CPHYSADDR(&lp->td_ring[lp->tx_chain_head]),
				&(lp->tx_dma_regs->dmandptr));
			lp->tx_chain_status = desc_empty;
			lp->tx_chain_head = lp->tx_chain_tail;
			dev->trans_start = jiffies;
		}
		if (dmas & DMA_STAT_ERR)
			printk(KERN_ERR DRV_NAME "%s: DMA error\n", dev->name);

		retval = IRQ_HANDLED;
	} else
		retval = IRQ_NONE;

	return retval;
}


static void korina_check_media(struct net_device *dev, unsigned int init_media)
{
	struct korina_private *lp = netdev_priv(dev);

	mii_check_media(&lp->mii_if, 0, init_media);

	if (lp->mii_if.full_duplex)
		writel(readl(&lp->eth_regs->ethmac2) | ETH_MAC2_FD,
						&lp->eth_regs->ethmac2);
	else
		writel(readl(&lp->eth_regs->ethmac2) & ~ETH_MAC2_FD,
						&lp->eth_regs->ethmac2);
}

static void korina_set_carrier(struct mii_if_info *mii)
{
	if (mii->force_media) {
		/* autoneg is off: Link is always assumed to be up */
		if (!netif_carrier_ok(mii->dev))
			netif_carrier_on(mii->dev);
	} else  /* Let MMI library update carrier status */
		korina_check_media(mii->dev, 0);
}

static int korina_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
{
	struct korina_private *lp = netdev_priv(dev);
	struct mii_ioctl_data *data = if_mii(rq);
	int rc;

	if (!netif_running(dev))
		return -EINVAL;
	spin_lock_irq(&lp->lock);
	rc = generic_mii_ioctl(&lp->mii_if, data, cmd, NULL);
	spin_unlock_irq(&lp->lock);
	korina_set_carrier(&lp->mii_if);

	return rc;
}

/* ethtool helpers */
static void netdev_get_drvinfo(struct net_device *dev,
			struct ethtool_drvinfo *info)
{
	struct korina_private *lp = netdev_priv(dev);

	strcpy(info->driver, DRV_NAME);
	strcpy(info->version, DRV_VERSION);
	strcpy(info->bus_info, lp->dev->name);
}

static int netdev_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
	struct korina_private *lp = netdev_priv(dev);
	int rc;

	spin_lock_irq(&lp->lock);
	rc = mii_ethtool_gset(&lp->mii_if, cmd);
	spin_unlock_irq(&lp->lock);

	return rc;
}

static int netdev_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
	struct korina_private *lp = netdev_priv(dev);
	int rc;

	spin_lock_irq(&lp->lock);
	rc = mii_ethtool_sset(&lp->mii_if, cmd);
	spin_unlock_irq(&lp->lock);
	korina_set_carrier(&lp->mii_if);

	return rc;
}

static u32 netdev_get_link(struct net_device *dev)
{
	struct korina_private *lp = netdev_priv(dev);

	return mii_link_ok(&lp->mii_if);
}

static struct ethtool_ops netdev_ethtool_ops = {
	.get_drvinfo            = netdev_get_drvinfo,
	.get_settings           = netdev_get_settings,
	.set_settings           = netdev_set_settings,
	.get_link               = netdev_get_link,
};

static void korina_alloc_ring(struct net_device *dev)
{
	struct korina_private *lp = netdev_priv(dev);
	int i;

	/* Initialize the transmit descriptors */
	for (i = 0; i < KORINA_NUM_TDS; i++) {
		lp->td_ring[i].control = DMA_DESC_IOF;
		lp->td_ring[i].devcs = ETH_TX_FD | ETH_TX_LD;
		lp->td_ring[i].ca = 0;
		lp->td_ring[i].link = 0;
	}
	lp->tx_next_done = lp->tx_chain_head = lp->tx_chain_tail =
			lp->tx_full = lp->tx_count = 0;
	lp->tx_chain_status = desc_empty;

	/* Initialize the receive descriptors */
	for (i = 0; i < KORINA_NUM_RDS; i++) {
		struct sk_buff *skb = lp->rx_skb[i];

		skb = dev_alloc_skb(KORINA_RBSIZE + 2);
		if (!skb)
			break;
		skb_reserve(skb, 2);
		lp->rx_skb[i] = skb;
		lp->rd_ring[i].control = DMA_DESC_IOD |
				DMA_COUNT(KORINA_RBSIZE);
		lp->rd_ring[i].devcs = 0;
		lp->rd_ring[i].ca = CPHYSADDR(skb->data);
		lp->rd_ring[i].link = CPHYSADDR(&lp->rd_ring[i+1]);
	}

	/* loop back */
	lp->rd_ring[i].link = CPHYSADDR(&lp->rd_ring[0]);
	lp->rx_next_done  = 0;

	lp->rd_ring[i].control |= DMA_DESC_COD;
	lp->rx_chain_head = 0;
	lp->rx_chain_tail = 0;
	lp->rx_chain_status = desc_empty;
}

static void korina_free_ring(struct net_device *dev)
{
	struct korina_private *lp = netdev_priv(dev);
	int i;

	for (i = 0; i < KORINA_NUM_RDS; i++) {
		lp->rd_ring[i].control = 0;
		if (lp->rx_skb[i])
			dev_kfree_skb_any(lp->rx_skb[i]);
		lp->rx_skb[i] = NULL;
	}

	for (i = 0; i < KORINA_NUM_TDS; i++) {
		lp->td_ring[i].control = 0;
		if (lp->tx_skb[i])
			dev_kfree_skb_any(lp->tx_skb[i]);
		lp->tx_skb[i] = NULL;
	}
}

/*
 * Initialize the RC32434 ethernet controller.
 */
static int korina_init(struct net_device *dev)
{
	struct korina_private *lp = netdev_priv(dev);

	/* Disable DMA */
	korina_abort_tx(dev);
	korina_abort_rx(dev);

	/* reset ethernet logic */
	writel(0, &lp->eth_regs->ethintfc);
	while ((readl(&lp->eth_regs->ethintfc) & ETH_INT_FC_RIP))
		dev->trans_start = jiffies;

	/* Enable Ethernet Interface */
	writel(ETH_INT_FC_EN, &lp->eth_regs->ethintfc);

	/* Allocate rings */
	korina_alloc_ring(dev);

	writel(0, &lp->rx_dma_regs->dmas);
	/* Start Rx DMA */
	korina_start_rx(lp, &lp->rd_ring[0]);

	writel(readl(&lp->tx_dma_regs->dmasm) &
			~(DMA_STAT_FINI | DMA_STAT_ERR),
			&lp->tx_dma_regs->dmasm);
	writel(readl(&lp->rx_dma_regs->dmasm) &
			~(DMA_STAT_DONE | DMA_STAT_HALT | DMA_STAT_ERR),
			&lp->rx_dma_regs->dmasm);

	/* Accept only packets destined for this Ethernet device address */
	writel(ETH_ARC_AB, &lp->eth_regs->etharc);

	/* Set all Ether station address registers to their initial values */
	writel(STATION_ADDRESS_LOW(dev), &lp->eth_regs->ethsal0);
	writel(STATION_ADDRESS_HIGH(dev), &lp->eth_regs->ethsah0);

	writel(STATION_ADDRESS_LOW(dev), &lp->eth_regs->ethsal1);
	writel(STATION_ADDRESS_HIGH(dev), &lp->eth_regs->ethsah1);

	writel(STATION_ADDRESS_LOW(dev), &lp->eth_regs->ethsal2);
	writel(STATION_ADDRESS_HIGH(dev), &lp->eth_regs->ethsah2);

	writel(STATION_ADDRESS_LOW(dev), &lp->eth_regs->ethsal3);
	writel(STATION_ADDRESS_HIGH(dev), &lp->eth_regs->ethsah3);


	/* Frame Length Checking, Pad Enable, CRC Enable, Full Duplex set */
	writel(ETH_MAC2_PE | ETH_MAC2_CEN | ETH_MAC2_FD,
			&lp->eth_regs->ethmac2);

	/* Back to back inter-packet-gap */
	writel(0x15, &lp->eth_regs->ethipgt);
	/* Non - Back to back inter-packet-gap */
	writel(0x12, &lp->eth_regs->ethipgr);

	/* Management Clock Prescaler Divisor
	 * Clock independent setting */
	writel(((idt_cpu_freq) / MII_CLOCK + 1) & ~1,
		       &lp->eth_regs->ethmcp);

	/* don't transmit until fifo contains 48b */
	writel(48, &lp->eth_regs->ethfifott);

	writel(ETH_MAC1_RE, &lp->eth_regs->ethmac1);

	napi_enable(&lp->napi);
	netif_start_queue(dev);

	return 0;
}

/*
 * Restart the RC32434 ethernet controller.
 * FIXME: check the return status where we call it
 */
static int korina_restart(struct net_device *dev)
{
	struct korina_private *lp = netdev_priv(dev);
	int ret;

	/*
	 * Disable interrupts
	 */
	disable_irq(lp->rx_irq);
	disable_irq(lp->tx_irq);
	disable_irq(lp->ovr_irq);
	disable_irq(lp->und_irq);

	writel(readl(&lp->tx_dma_regs->dmasm) |
				DMA_STAT_FINI | DMA_STAT_ERR,
				&lp->tx_dma_regs->dmasm);
	writel(readl(&lp->rx_dma_regs->dmasm) |
				DMA_STAT_DONE | DMA_STAT_HALT | DMA_STAT_ERR,
				&lp->rx_dma_regs->dmasm);

	korina_free_ring(dev);

	napi_disable(&lp->napi);

	ret = korina_init(dev);
	if (ret < 0) {
		printk(KERN_ERR DRV_NAME "%s: cannot restart device\n",
								dev->name);
		return ret;
	}
	korina_multicast_list(dev);

	enable_irq(lp->und_irq);
	enable_irq(lp->ovr_irq);
	enable_irq(lp->tx_irq);
	enable_irq(lp->rx_irq);

	return ret;
}

static void korina_clear_and_restart(struct net_device *dev, u32 value)
{
	struct korina_private *lp = netdev_priv(dev);

	netif_stop_queue(dev);
	writel(value, &lp->eth_regs->ethintfc);
	korina_restart(dev);
}

/* Ethernet Tx Underflow interrupt */
static irqreturn_t korina_und_interrupt(int irq, void *dev_id)
{
	struct net_device *dev = dev_id;
	struct korina_private *lp = netdev_priv(dev);
	unsigned int und;

	spin_lock(&lp->lock);

	und = readl(&lp->eth_regs->ethintfc);

	if (und & ETH_INT_FC_UND)
		korina_clear_and_restart(dev, und & ~ETH_INT_FC_UND);

	spin_unlock(&lp->lock);

	return IRQ_HANDLED;
}

static void korina_tx_timeout(struct net_device *dev)
{
	struct korina_private *lp = netdev_priv(dev);
	unsigned long flags;

	spin_lock_irqsave(&lp->lock, flags);
	korina_restart(dev);
	spin_unlock_irqrestore(&lp->lock, flags);
}

/* Ethernet Rx Overflow interrupt */
static irqreturn_t
korina_ovr_interrupt(int irq, void *dev_id)
{
	struct net_device *dev = dev_id;
	struct korina_private *lp = netdev_priv(dev);
	unsigned int ovr;

	spin_lock(&lp->lock);
	ovr = readl(&lp->eth_regs->ethintfc);

	if (ovr & ETH_INT_FC_OVR)
		korina_clear_and_restart(dev, ovr & ~ETH_INT_FC_OVR);

	spin_unlock(&lp->lock);

	return IRQ_HANDLED;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void korina_poll_controller(struct net_device *dev)
{
	disable_irq(dev->irq);
	korina_tx_dma_interrupt(dev->irq, dev);
	enable_irq(dev->irq);
}
#endif

static int korina_open(struct net_device *dev)
{
	struct korina_private *lp = netdev_priv(dev);
	int ret;

	/* Initialize */
	ret = korina_init(dev);
	if (ret < 0) {
		printk(KERN_ERR DRV_NAME "%s: cannot open device\n", dev->name);
		goto out;
	}

	/* Install the interrupt handler
	 * that handles the Done Finished
	 * Ovr and Und Events */
	ret = request_irq(lp->rx_irq, &korina_rx_dma_interrupt,
		IRQF_SHARED | IRQF_DISABLED, "Korina ethernet Rx", dev);
	if (ret < 0) {
		printk(KERN_ERR DRV_NAME "%s: unable to get Rx DMA IRQ %d\n",
		    dev->name, lp->rx_irq);
		goto err_release;
	}
	ret = request_irq(lp->tx_irq, &korina_tx_dma_interrupt,
		IRQF_SHARED | IRQF_DISABLED, "Korina ethernet Tx", dev);
	if (ret < 0) {
		printk(KERN_ERR DRV_NAME "%s: unable to get Tx DMA IRQ %d\n",
		    dev->name, lp->tx_irq);
		goto err_free_rx_irq;
	}

	/* Install handler for overrun error. */
	ret = request_irq(lp->ovr_irq, &korina_ovr_interrupt,
			IRQF_SHARED | IRQF_DISABLED, "Ethernet Overflow", dev);
	if (ret < 0) {
		printk(KERN_ERR DRV_NAME"%s: unable to get OVR IRQ %d\n",
		    dev->name, lp->ovr_irq);
		goto err_free_tx_irq;
	}

	/* Install handler for underflow error. */
	ret = request_irq(lp->und_irq, &korina_und_interrupt,
			IRQF_SHARED | IRQF_DISABLED, "Ethernet Underflow", dev);
	if (ret < 0) {
		printk(KERN_ERR DRV_NAME "%s: unable to get UND IRQ %d\n",
		    dev->name, lp->und_irq);
		goto err_free_ovr_irq;
	}
out:
	return ret;

err_free_ovr_irq:
	free_irq(lp->ovr_irq, dev);
err_free_tx_irq:
	free_irq(lp->tx_irq, dev);
err_free_rx_irq:
	free_irq(lp->rx_irq, dev);
err_release:
	korina_free_ring(dev);
	goto out;
}

static int korina_close(struct net_device *dev)
{
	struct korina_private *lp = netdev_priv(dev);
	u32 tmp;

	/* Disable interrupts */
	disable_irq(lp->rx_irq);
	disable_irq(lp->tx_irq);
	disable_irq(lp->ovr_irq);
	disable_irq(lp->und_irq);

	korina_abort_tx(dev);
	tmp = readl(&lp->tx_dma_regs->dmasm);
	tmp = tmp | DMA_STAT_FINI | DMA_STAT_ERR;
	writel(tmp, &lp->tx_dma_regs->dmasm);

	korina_abort_rx(dev);
	tmp = readl(&lp->rx_dma_regs->dmasm);
	tmp = tmp | DMA_STAT_DONE | DMA_STAT_HALT | DMA_STAT_ERR;
	writel(tmp, &lp->rx_dma_regs->dmasm);

	korina_free_ring(dev);

	napi_disable(&lp->napi);

	free_irq(lp->rx_irq, dev);
	free_irq(lp->tx_irq, dev);
	free_irq(lp->ovr_irq, dev);
	free_irq(lp->und_irq, dev);

	return 0;
}

static int korina_probe(struct platform_device *pdev)
{
	struct korina_device *bif = platform_get_drvdata(pdev);
	struct korina_private *lp;
	struct net_device *dev;
	struct resource *r;
	int rc;

	dev = alloc_etherdev(sizeof(struct korina_private));
	if (!dev) {
		printk(KERN_ERR DRV_NAME ": alloc_etherdev failed\n");
		return -ENOMEM;
	}
	SET_NETDEV_DEV(dev, &pdev->dev);
	lp = netdev_priv(dev);

	bif->dev = dev;
	memcpy(dev->dev_addr, bif->mac, 6);

	lp->rx_irq = platform_get_irq_byname(pdev, "korina_rx");
	lp->tx_irq = platform_get_irq_byname(pdev, "korina_tx");
	lp->ovr_irq = platform_get_irq_byname(pdev, "korina_ovr");
	lp->und_irq = platform_get_irq_byname(pdev, "korina_und");

	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "korina_regs");
	dev->base_addr = r->start;
	lp->eth_regs = ioremap_nocache(r->start, r->end - r->start);
	if (!lp->eth_regs) {
		printk(KERN_ERR DRV_NAME "cannot remap registers\n");
		rc = -ENXIO;
		goto probe_err_out;
	}

	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "korina_dma_rx");
	lp->rx_dma_regs = ioremap_nocache(r->start, r->end - r->start);
	if (!lp->rx_dma_regs) {
		printk(KERN_ERR DRV_NAME "cannot remap Rx DMA registers\n");
		rc = -ENXIO;
		goto probe_err_dma_rx;
	}

	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "korina_dma_tx");
	lp->tx_dma_regs = ioremap_nocache(r->start, r->end - r->start);
	if (!lp->tx_dma_regs) {
		printk(KERN_ERR DRV_NAME "cannot remap Tx DMA registers\n");
		rc = -ENXIO;
		goto probe_err_dma_tx;
	}

	lp->td_ring = kmalloc(TD_RING_SIZE + RD_RING_SIZE, GFP_KERNEL);
	if (!lp->td_ring) {
		printk(KERN_ERR DRV_NAME "cannot allocate descriptors\n");
		rc = -ENXIO;
		goto probe_err_td_ring;
	}

	dma_cache_inv((unsigned long)(lp->td_ring),
			TD_RING_SIZE + RD_RING_SIZE);

	/* now convert TD_RING pointer to KSEG1 */
	lp->td_ring = (struct dma_desc *)KSEG1ADDR(lp->td_ring);
	lp->rd_ring = &lp->td_ring[KORINA_NUM_TDS];

	spin_lock_init(&lp->lock);
	/* just use the rx dma irq */
	dev->irq = lp->rx_irq;
	lp->dev = dev;

	dev->open = korina_open;
	dev->stop = korina_close;
	dev->hard_start_xmit = korina_send_packet;
	dev->set_multicast_list = &korina_multicast_list;
	dev->ethtool_ops = &netdev_ethtool_ops;
	dev->tx_timeout = korina_tx_timeout;
	dev->watchdog_timeo = TX_TIMEOUT;
	dev->do_ioctl = &korina_ioctl;
#ifdef CONFIG_NET_POLL_CONTROLLER
	dev->poll_controller = korina_poll_controller;
#endif
	netif_napi_add(dev, &lp->napi, korina_poll, 64);

	lp->phy_addr = (((lp->rx_irq == 0x2c? 1:0) << 8) | 0x05);
	lp->mii_if.dev = dev;
	lp->mii_if.mdio_read = mdio_read;
	lp->mii_if.mdio_write = mdio_write;
	lp->mii_if.phy_id = lp->phy_addr;
	lp->mii_if.phy_id_mask = 0x1f;
	lp->mii_if.reg_num_mask = 0x1f;

	rc = register_netdev(dev);
	if (rc < 0) {
		printk(KERN_ERR DRV_NAME
			": cannot register net device %d\n", rc);
		goto probe_err_register;
	}
out:
	return rc;

probe_err_register:
	kfree(lp->td_ring);
probe_err_td_ring:
	iounmap(lp->tx_dma_regs);
probe_err_dma_tx:
	iounmap(lp->rx_dma_regs);
probe_err_dma_rx:
	iounmap(lp->eth_regs);
probe_err_out:
	free_netdev(dev);
	goto out;
}

static int korina_remove(struct platform_device *pdev)
{
	struct korina_device *bif = platform_get_drvdata(pdev);
	struct korina_private *lp = netdev_priv(bif->dev);

	iounmap(lp->eth_regs);
	iounmap(lp->rx_dma_regs);
	iounmap(lp->tx_dma_regs);

	platform_set_drvdata(pdev, NULL);
	unregister_netdev(bif->dev);
	free_netdev(bif->dev);

	return 0;
}

static struct platform_driver korina_driver = {
	.driver.name = "korina",
	.probe = korina_probe,
	.remove = korina_remove,
};

static int __init korina_init_module(void)
{
	return platform_driver_register(&korina_driver);
}

static void korina_cleanup_module(void)
{
	return platform_driver_unregister(&korina_driver);
}

module_init(korina_init_module);
module_exit(korina_cleanup_module);

MODULE_AUTHOR("Philip Rischel <rischelp@idt.com>");
MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>");
MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
MODULE_DESCRIPTION("IDT RC32434 (Korina) Ethernet driver");
MODULE_LICENSE("GPL");