/*
 * Network device driver for Cell Processor-Based Blade
 *
 * (C) Copyright IBM Corp. 2005
 *
 * Authors : Utz Bacher <utz.bacher@de.ibm.com>
 *           Jens Osterkamp <Jens.Osterkamp@de.ibm.com>
 *
 * 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, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * 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.
 */

#include <linux/compiler.h>
#include <linux/crc32.h>
#include <linux/delay.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/firmware.h>
#include <linux/if_vlan.h>
#include <linux/in.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/ip.h>
#include <linux/kernel.h>
#include <linux/mii.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/device.h>
#include <linux/pci.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/tcp.h>
#include <linux/types.h>
#include <linux/vmalloc.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
#include <asm/bitops.h>
#include <asm/pci-bridge.h>
#include <net/checksum.h>

#include "spider_net.h"

MODULE_AUTHOR("Utz Bacher <utz.bacher@de.ibm.com> and Jens Osterkamp " \
	      "<Jens.Osterkamp@de.ibm.com>");
MODULE_DESCRIPTION("Spider Southbridge Gigabit Ethernet driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(VERSION);

static int rx_descriptors = SPIDER_NET_RX_DESCRIPTORS_DEFAULT;
static int tx_descriptors = SPIDER_NET_TX_DESCRIPTORS_DEFAULT;

module_param(rx_descriptors, int, 0444);
module_param(tx_descriptors, int, 0444);

MODULE_PARM_DESC(rx_descriptors, "number of descriptors used " \
		 "in rx chains");
MODULE_PARM_DESC(tx_descriptors, "number of descriptors used " \
		 "in tx chain");

char spider_net_driver_name[] = "spidernet";

static struct pci_device_id spider_net_pci_tbl[] = {
	{ PCI_VENDOR_ID_TOSHIBA_2, PCI_DEVICE_ID_TOSHIBA_SPIDER_NET,
	  PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0UL },
	{ 0, }
};

MODULE_DEVICE_TABLE(pci, spider_net_pci_tbl);

/**
 * spider_net_read_reg - reads an SMMIO register of a card
 * @card: device structure
 * @reg: register to read from
 *
 * returns the content of the specified SMMIO register.
 */
static inline u32
spider_net_read_reg(struct spider_net_card *card, u32 reg)
{
	u32 value;

	value = readl(card->regs + reg);
	value = le32_to_cpu(value);

	return value;
}

/**
 * spider_net_write_reg - writes to an SMMIO register of a card
 * @card: device structure
 * @reg: register to write to
 * @value: value to write into the specified SMMIO register
 */
static inline void
spider_net_write_reg(struct spider_net_card *card, u32 reg, u32 value)
{
	value = cpu_to_le32(value);
	writel(value, card->regs + reg);
}

/** spider_net_write_phy - write to phy register
 * @netdev: adapter to be written to
 * @mii_id: id of MII
 * @reg: PHY register
 * @val: value to be written to phy register
 *
 * spider_net_write_phy_register writes to an arbitrary PHY
 * register via the spider GPCWOPCMD register. We assume the queue does
 * not run full (not more than 15 commands outstanding).
 **/
static void
spider_net_write_phy(struct net_device *netdev, int mii_id,
		     int reg, int val)
{
	struct spider_net_card *card = netdev_priv(netdev);
	u32 writevalue;

	writevalue = ((u32)mii_id << 21) |
		((u32)reg << 16) | ((u32)val);

	spider_net_write_reg(card, SPIDER_NET_GPCWOPCMD, writevalue);
}

/** spider_net_read_phy - read from phy register
 * @netdev: network device to be read from
 * @mii_id: id of MII
 * @reg: PHY register
 *
 * Returns value read from PHY register
 *
 * spider_net_write_phy reads from an arbitrary PHY
 * register via the spider GPCROPCMD register
 **/
static int
spider_net_read_phy(struct net_device *netdev, int mii_id, int reg)
{
	struct spider_net_card *card = netdev_priv(netdev);
	u32 readvalue;

	readvalue = ((u32)mii_id << 21) | ((u32)reg << 16);
	spider_net_write_reg(card, SPIDER_NET_GPCROPCMD, readvalue);

	/* we don't use semaphores to wait for an SPIDER_NET_GPROPCMPINT
	 * interrupt, as we poll for the completion of the read operation
	 * in spider_net_read_phy. Should take about 50 us */
	do {
		readvalue = spider_net_read_reg(card, SPIDER_NET_GPCROPCMD);
	} while (readvalue & SPIDER_NET_GPREXEC);

	readvalue &= SPIDER_NET_GPRDAT_MASK;

	return readvalue;
}

/**
 * spider_net_rx_irq_off - switch off rx irq on this spider card
 * @card: device structure
 *
 * switches off rx irq by masking them out in the GHIINTnMSK register
 */
static void
spider_net_rx_irq_off(struct spider_net_card *card)
{
	u32 regvalue;

	regvalue = SPIDER_NET_INT0_MASK_VALUE & (~SPIDER_NET_RXINT);
	spider_net_write_reg(card, SPIDER_NET_GHIINT0MSK, regvalue);
}

/**
 * spider_net_rx_irq_on - switch on rx irq on this spider card
 * @card: device structure
 *
 * switches on rx irq by enabling them in the GHIINTnMSK register
 */
static void
spider_net_rx_irq_on(struct spider_net_card *card)
{
	u32 regvalue;

	regvalue = SPIDER_NET_INT0_MASK_VALUE | SPIDER_NET_RXINT;
	spider_net_write_reg(card, SPIDER_NET_GHIINT0MSK, regvalue);
}

/**
 * spider_net_set_promisc - sets the unicast address or the promiscuous mode
 * @card: card structure
 *
 * spider_net_set_promisc sets the unicast destination address filter and
 * thus either allows for non-promisc mode or promisc mode
 */
static void
spider_net_set_promisc(struct spider_net_card *card)
{
	u32 macu, macl;
	struct net_device *netdev = card->netdev;

	if (netdev->flags & IFF_PROMISC) {
		/* clear destination entry 0 */
		spider_net_write_reg(card, SPIDER_NET_GMRUAFILnR, 0);
		spider_net_write_reg(card, SPIDER_NET_GMRUAFILnR + 0x04, 0);
		spider_net_write_reg(card, SPIDER_NET_GMRUA0FIL15R,
				     SPIDER_NET_PROMISC_VALUE);
	} else {
		macu = netdev->dev_addr[0];
		macu <<= 8;
		macu |= netdev->dev_addr[1];
		memcpy(&macl, &netdev->dev_addr[2], sizeof(macl));

		macu |= SPIDER_NET_UA_DESCR_VALUE;
		spider_net_write_reg(card, SPIDER_NET_GMRUAFILnR, macu);
		spider_net_write_reg(card, SPIDER_NET_GMRUAFILnR + 0x04, macl);
		spider_net_write_reg(card, SPIDER_NET_GMRUA0FIL15R,
				     SPIDER_NET_NONPROMISC_VALUE);
	}
}

/**
 * spider_net_get_mac_address - read mac address from spider card
 * @card: device structure
 *
 * reads MAC address from GMACUNIMACU and GMACUNIMACL registers
 */
static int
spider_net_get_mac_address(struct net_device *netdev)
{
	struct spider_net_card *card = netdev_priv(netdev);
	u32 macl, macu;

	macl = spider_net_read_reg(card, SPIDER_NET_GMACUNIMACL);
	macu = spider_net_read_reg(card, SPIDER_NET_GMACUNIMACU);

	netdev->dev_addr[0] = (macu >> 24) & 0xff;
	netdev->dev_addr[1] = (macu >> 16) & 0xff;
	netdev->dev_addr[2] = (macu >> 8) & 0xff;
	netdev->dev_addr[3] = macu & 0xff;
	netdev->dev_addr[4] = (macl >> 8) & 0xff;
	netdev->dev_addr[5] = macl & 0xff;

	if (!is_valid_ether_addr(&netdev->dev_addr[0]))
		return -EINVAL;

	return 0;
}

/**
 * spider_net_get_descr_status -- returns the status of a descriptor
 * @descr: descriptor to look at
 *
 * returns the status as in the dmac_cmd_status field of the descriptor
 */
static inline int
spider_net_get_descr_status(struct spider_net_descr *descr)
{
	return descr->dmac_cmd_status & SPIDER_NET_DESCR_IND_PROC_MASK;
}

/**
 * spider_net_free_chain - free descriptor chain
 * @card: card structure
 * @chain: address of chain
 *
 */
static void
spider_net_free_chain(struct spider_net_card *card,
		      struct spider_net_descr_chain *chain)
{
	struct spider_net_descr *descr;

	for (descr = chain->tail; !descr->bus_addr; descr = descr->next) {
		pci_unmap_single(card->pdev, descr->bus_addr,
				 SPIDER_NET_DESCR_SIZE, PCI_DMA_BIDIRECTIONAL);
		descr->bus_addr = 0;
	}
}

/**
 * spider_net_init_chain - links descriptor chain
 * @card: card structure
 * @chain: address of chain
 * @start_descr: address of descriptor array
 * @no: number of descriptors
 *
 * we manage a circular list that mirrors the hardware structure,
 * except that the hardware uses bus addresses.
 *
 * returns 0 on success, <0 on failure
 */
static int
spider_net_init_chain(struct spider_net_card *card,
		       struct spider_net_descr_chain *chain,
		       struct spider_net_descr *start_descr,
		       int no)
{
	int i;
	struct spider_net_descr *descr;
	dma_addr_t buf;

	descr = start_descr;
	memset(descr, 0, sizeof(*descr) * no);

	/* set up the hardware pointers in each descriptor */
	for (i=0; i<no; i++, descr++) {
		descr->dmac_cmd_status = SPIDER_NET_DESCR_NOT_IN_USE;

		buf = pci_map_single(card->pdev, descr,
				     SPIDER_NET_DESCR_SIZE,
				     PCI_DMA_BIDIRECTIONAL);

		if (pci_dma_mapping_error(buf))
			goto iommu_error;

		descr->bus_addr = buf;
		descr->next = descr + 1;
		descr->prev = descr - 1;

	}
	/* do actual circular list */
	(descr-1)->next = start_descr;
	start_descr->prev = descr-1;

	spin_lock_init(&chain->lock);
	chain->head = start_descr;
	chain->tail = start_descr;

	return 0;

iommu_error:
	descr = start_descr;
	for (i=0; i < no; i++, descr++)
		if (descr->bus_addr)
			pci_unmap_single(card->pdev, descr->bus_addr,
					 SPIDER_NET_DESCR_SIZE,
					 PCI_DMA_BIDIRECTIONAL);
	return -ENOMEM;
}

/**
 * spider_net_free_rx_chain_contents - frees descr contents in rx chain
 * @card: card structure
 *
 * returns 0 on success, <0 on failure
 */
static void
spider_net_free_rx_chain_contents(struct spider_net_card *card)
{
	struct spider_net_descr *descr;

	descr = card->rx_chain.head;
	do {
		if (descr->skb) {
			dev_kfree_skb(descr->skb);
			pci_unmap_single(card->pdev, descr->buf_addr,
					 SPIDER_NET_MAX_FRAME,
					 PCI_DMA_BIDIRECTIONAL);
		}
		descr = descr->next;
	} while (descr != card->rx_chain.head);
}

/**
 * spider_net_prepare_rx_descr - reinitializes a rx descriptor
 * @card: card structure
 * @descr: descriptor to re-init
 *
 * return 0 on succes, <0 on failure
 *