/*
 * Linux ARCnet driver - COM20020 chipset support
 *
 * Written 1997 by David Woodhouse.
 * Written 1994-1999 by Avery Pennarun.
 * Written 1999 by Martin Mares <mj@ucw.cz>.
 * Derived from skeleton.c by Donald Becker.
 *
 * Special thanks to Contemporary Controls, Inc. (www.ccontrols.com)
 *  for sponsoring the further development of this driver.
 *
 * **********************
 *
 * The original copyright of skeleton.c was as follows:
 *
 * skeleton.c Written 1993 by Donald Becker.
 * Copyright 1993 United States Government as represented by the
 * Director, National Security Agency.  This software may only be used
 * and distributed according to the terms of the GNU General Public License as
 * modified by SRC, incorporated herein by reference.
 *
 * **********************
 *
 * For more details, see drivers/net/arcnet.c
 *
 * **********************
 */

#define pr_fmt(fmt) "arcnet:" KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/ioport.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>

#include "arcdevice.h"
#include "com20020.h"

static const char * const clockrates[] = {
        "XXXXXXX", "XXXXXXXX", "XXXXXX", "2.5 Mb/s",
        "1.25Mb/s", "625 Kb/s", "312.5 Kb/s", "156.25 Kb/s",
        "Reserved", "Reserved", "Reserved"
};

static void com20020_command(struct net_device *dev, int command);
static int com20020_status(struct net_device *dev);
static void com20020_setmask(struct net_device *dev, int mask);
static int com20020_reset(struct net_device *dev, int really_reset);
static void com20020_copy_to_card(struct net_device *dev, int bufnum,
                                  int offset, void *buf, int count);
static void com20020_copy_from_card(struct net_device *dev, int bufnum,
                                    int offset, void *buf, int count);
static void com20020_set_mc_list(struct net_device *dev);
static void com20020_close(struct net_device *);

static void com20020_copy_from_card(struct net_device *dev, int bufnum,
                                    int offset, void *buf, int count)
{
        int ioaddr = dev->base_addr, ofs = 512 * bufnum + offset;

        /* set up the address register */
        arcnet_outb((ofs >> 8) | RDDATAflag | AUTOINCflag,
                    ioaddr, COM20020_REG_W_ADDR_HI);
        arcnet_outb(ofs & 0xff, ioaddr, COM20020_REG_W_ADDR_LO);

        /* copy the data */
        TIME(dev, "insb", count,
             arcnet_insb(ioaddr, COM20020_REG_RW_MEMDATA, buf, count));
}

static void com20020_copy_to_card(struct net_device *dev, int bufnum,
                                  int offset, void *buf, int count)
{
        int ioaddr = dev->base_addr, ofs = 512 * bufnum + offset;

        /* set up the address register */
        arcnet_outb((ofs >> 8) | AUTOINCflag, ioaddr, COM20020_REG_W_ADDR_HI);
        arcnet_outb(ofs & 0xff, ioaddr, COM20020_REG_W_ADDR_LO);

        /* copy the data */
        TIME(dev, "outsb", count,
             arcnet_outsb(ioaddr, COM20020_REG_RW_MEMDATA, buf, count));
}

/* Reset the card and check some basic stuff during the detection stage. */
int com20020_check(struct net_device *dev)
{
        int ioaddr = dev->base_addr, status;
        struct arcnet_local *lp = netdev_priv(dev);

        arcnet_outb(XTOcfg(3) | RESETcfg, ioaddr, COM20020_REG_W_CONFIG);
        udelay(5);
        arcnet_outb(XTOcfg(3), ioaddr, COM20020_REG_W_CONFIG);
        mdelay(RESETtime);

        lp->setup = lp->clockm ? 0 : (lp->clockp << 1);
        lp->setup2 = (lp->clockm << 4) | 8;

        /* CHECK: should we do this for SOHARD cards ? */
        /* Enable P1Mode for backplane mode */
        lp->setup = lp->setup | P1MODE;

        com20020_set_subaddress(lp, ioaddr, SUB_SETUP1);
        arcnet_outb(lp->setup, ioaddr, COM20020_REG_W_XREG);

        if (lp->clockm != 0) {
                com20020_set_subaddress(lp, ioaddr, SUB_SETUP2);
                arcnet_outb(lp->setup2, ioaddr, COM20020_REG_W_XREG);

                /* must now write the magic "restart operation" command */
                mdelay(1);
                arcnet_outb(STARTIOcmd, ioaddr, COM20020_REG_W_COMMAND);
        }

        lp->config = (lp->timeout << 3) | (lp->backplane << 2) | SUB_NODE;
        /* set node ID to 0x42 (but transmitter is disabled, so it's okay) */
        arcnet_outb(lp->config, ioaddr, COM20020_REG_W_CONFIG);
        arcnet_outb(0x42, ioaddr, COM20020_REG_W_XREG);

        status = arcnet_inb(ioaddr, COM20020_REG_R_STATUS);

        if ((status & 0x99) != (NORXflag | TXFREEflag | RESETflag)) {
                arc_printk(D_NORMAL, dev, "status invalid (%Xh).\n", status);
                return -ENODEV;
        }
        arc_printk(D_INIT_REASONS, dev, "status after reset: %X\n", status);

        arcnet_outb(CFLAGScmd | RESETclear | CONFIGclear,
                    ioaddr, COM20020_REG_W_COMMAND);
        status = arcnet_inb(ioaddr, COM20020_REG_R_STATUS);
        arc_printk(D_INIT_REASONS, dev, "status after reset acknowledged: %X\n",
                   status);

        /* Read first location of memory */
        arcnet_outb(0 | RDDATAflag | AUTOINCflag,
                    ioaddr, COM20020_REG_W_ADDR_HI);
        arcnet_outb(0, ioaddr, COM20020_REG_W_ADDR_LO);

        status = arcnet_inb(ioaddr, COM20020_REG_RW_MEMDATA);
        if (status != TESTvalue) {
                arc_printk(D_NORMAL, dev, "Signature byte not found (%02Xh != D1h).\n",
                           status);
                return -ENODEV;
        }
        return 0;
}

static int com20020_set_hwaddr(struct net_device *dev, void *addr)
{
        int ioaddr = dev->base_addr;
        struct arcnet_local *lp = netdev_priv(dev);
        struct sockaddr *hwaddr = addr;

        dev_addr_set(dev, hwaddr->sa_data);
        com20020_set_subaddress(lp, ioaddr, SUB_NODE);
        arcnet_outb(dev->dev_addr[0], ioaddr, COM20020_REG_W_XREG);

        return 0;
}

static int com20020_netdev_open(struct net_device *dev)
{
        int ioaddr = dev->base_addr;
        struct arcnet_local *lp = netdev_priv(dev);

        lp->config |= TXENcfg;
        arcnet_outb(lp->config, ioaddr, COM20020_REG_W_CONFIG);

        return arcnet_open(dev);
}

static int com20020_netdev_close(struct net_device *dev)
{
        int ioaddr = dev->base_addr;
        struct arcnet_local *lp = netdev_priv(dev);

        arcnet_close(dev);

        /* disable transmitter */
        lp->config &= ~TXENcfg;
        arcnet_outb(lp->config, ioaddr, COM20020_REG_W_CONFIG);
        return 0;
}

const struct net_device_ops com20020_netdev_ops = {
        .ndo_open       = com20020_netdev_open,
        .ndo_stop       = com20020_netdev_close,
        .ndo_start_xmit = arcnet_send_packet,
        .ndo_tx_timeout = arcnet_timeout,
        .ndo_set_mac_address = com20020_set_hwaddr,
        .ndo_set_rx_mode = com20020_set_mc_list,
};

/* Set up the struct net_device associated with this card.  Called after
 * probing succeeds.
 */
int com20020_found(struct net_device *dev, int shared)
{
        struct arcnet_local *lp;
        int ioaddr = dev->base_addr;

        /* Initialize the rest of the device structure. */

        lp = netdev_priv(dev);

        lp->hw.owner = THIS_MODULE;
        lp->hw.command = com20020_command;
        lp->hw.status = com20020_status;
        lp->hw.intmask = com20020_setmask;
        lp->hw.reset = com20020_reset;
        lp->hw.copy_to_card = com20020_copy_to_card;
        lp->hw.copy_from_card = com20020_copy_from_card;
        lp->hw.close = com20020_close;

        /* FIXME: do this some other way! */
        if (!dev->dev_addr[0])
                arcnet_set_addr(dev, arcnet_inb(ioaddr, 8));

        com20020_set_subaddress(lp, ioaddr, SUB_SETUP1);
        arcnet_outb(lp->setup, ioaddr, COM20020_REG_W_XREG);

        if (lp->card_flags & ARC_CAN_10MBIT) {
                com20020_set_subaddress(lp, ioaddr, SUB_SETUP2);
                arcnet_outb(lp->setup2, ioaddr, COM20020_REG_W_XREG);

                /* must now write the magic "restart operation" command */
                mdelay(1);
                arcnet_outb(STARTIOcmd, ioaddr, COM20020_REG_W_COMMAND);
        }

        lp->config = (lp->timeout << 3) | (lp->backplane << 2) | SUB_NODE;
        /* Default 0x38 + register: Node ID */
        arcnet_outb(lp->config, ioaddr, COM20020_REG_W_CONFIG);
        arcnet_outb(dev->dev_addr[0], ioaddr, COM20020_REG_W_XREG);

        /* reserve the irq */
        if (request_irq(dev->irq, arcnet_interrupt, shared,
                        "arcnet (COM20020)", dev)) {
                arc_printk(D_NORMAL, dev, "Can't get IRQ %d!\n", dev->irq);
                return -ENODEV;
        }

        arc_printk(D_NORMAL, dev, "%s: station %02Xh found at %03lXh, IRQ %d.\n",
                   lp->card_name, dev->dev_addr[0], dev->base_addr, dev->irq);

        if (lp->backplane)
                arc_printk(D_NORMAL, dev, "Using backplane mode.\n");

        if (lp->timeout != 3)
                arc_printk(D_NORMAL, dev, "Using extended timeout value of %d\n",
                           lp->timeout);

        arc_printk(D_NORMAL, dev, "Using CKP %d - data rate %s\n",
                   lp->setup >> 1,
                   clockrates[3 -
                              ((lp->setup2 & 0xF0) >> 4) +
                              ((lp->setup & 0x0F) >> 1)]);
                        /* The clockrates array index looks very fragile.
                         * It seems like it could have negative indexing.
                         */

        if (register_netdev(dev)) {
                free_irq(dev->irq, dev);
                return -EIO;
        }
        return 0;
}

/* Do a hardware reset on the card, and set up necessary registers.
 *
 * This should be called as little as possible, because it disrupts the
 * token on the network (causes a RECON) and requires a significant delay.
 *
 * However, it does make sure the card is in a defined state.
 */
static int com20020_reset(struct net_device *dev, int really_reset)
{
        struct arcnet_local *lp = netdev_priv(dev);
        u_int ioaddr = dev->base_addr;
        u_char inbyte;

        arc_printk(D_DEBUG, dev, "%s: %d: %s: dev: %p, lp: %p, dev->name: %s\n",
                   __FILE__, __LINE__, __func__, dev, lp, dev->name);
        arc_printk(D_INIT, dev, "Resetting %s (status=%02Xh)\n",
                   dev->name, arcnet_inb(ioaddr, COM20020_REG_R_STATUS));

        arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);
        lp->config |= (lp->timeout << 3) | (lp->backplane << 2);
        /* power-up defaults */
        arcnet_outb(lp->config, ioaddr, COM20020_REG_W_CONFIG);
        arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);

        if (really_reset) {
                /* reset the card */
                arcnet_outb(lp->config | RESETcfg, ioaddr, COM20020_REG_W_CONFIG);
                udelay(5);
                arcnet_outb(lp->config, ioaddr, COM20020_REG_W_CONFIG);
                mdelay(RESETtime * 2);
                                /* COM20020 seems to be slower sometimes */
        }
        /* clear flags & end reset */
        arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);
        arcnet_outb(CFLAGScmd | RESETclear | CONFIGclear,
                    ioaddr, COM20020_REG_W_COMMAND);

        /* verify that the ARCnet signature byte is present */
        arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);

        com20020_copy_from_card(dev, 0, 0, &inbyte, 1);
        arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);
        if (inbyte != TESTvalue) {
                arc_printk(D_DEBUG, dev, "%s: %d: %s\n",
                           __FILE__, __LINE__, __func__);
                arc_printk(D_NORMAL, dev, "reset failed: TESTvalue not present.\n");
                return 1;
        }
        /* enable extended (512-byte) packets */
        arcnet_outb(CONFIGcmd | EXTconf, ioaddr, COM20020_REG_W_COMMAND);

        arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);

        /* done!  return success. */
        return 0;
}

static void com20020_setmask(struct net_device *dev, int mask)
{
        u_int ioaddr = dev->base_addr;

        arc_printk(D_DURING, dev, "Setting mask to %x at %x\n", mask, ioaddr);
        arcnet_outb(mask, ioaddr, COM20020_REG_W_INTMASK);
}

static void com20020_command(struct net_device *dev, int cmd)
{
        u_int ioaddr = dev->base_addr;

        arcnet_outb(cmd, ioaddr, COM20020_REG_W_COMMAND);
}

static int com20020_status(struct net_device *dev)
{
        u_int ioaddr = dev->base_addr;

        return arcnet_inb(ioaddr, COM20020_REG_R_STATUS) +
                (arcnet_inb(ioaddr, COM20020_REG_R_DIAGSTAT) << 8);
}

static void com20020_close(struct net_device *dev)
{
        struct arcnet_local *lp = netdev_priv(dev);
        int ioaddr = dev->base_addr;

        /* disable transmitter */
        lp->config &= ~TXENcfg;
        arcnet_outb(lp->config, ioaddr, COM20020_REG_W_CONFIG);
}

/* Set or clear the multicast filter for this adaptor.
 * num_addrs == -1    Promiscuous mode, receive all packets
 * num_addrs == 0       Normal mode, clear multicast list
 * num_addrs > 0        Multicast mode, receive normal and MC packets, and do
 *                      best-effort filtering.
 *      FIXME - do multicast stuff, not just promiscuous.
 */
static void com20020_set_mc_list(struct net_device *dev)
{
        struct arcnet_local *lp = netdev_priv(dev);
        int ioaddr = dev->base_addr;

        if ((dev->flags & IFF_PROMISC) && (dev->flags & IFF_UP)) {
                /* Enable promiscuous mode */
                if (!(lp->setup & PROMISCset))
                        arc_printk(D_NORMAL, dev, "Setting promiscuous flag...\n");
                com20020_set_subaddress(lp, ioaddr, SUB_SETUP1);
                lp->setup |= PROMISCset;
                arcnet_outb(lp->setup, ioaddr, COM20020_REG_W_XREG);
        } else {
                /* Disable promiscuous mode, use normal mode */
                if ((lp->setup & PROMISCset))
                        arc_printk(D_NORMAL, dev, "Resetting promiscuous flag...\n");
                com20020_set_subaddress(lp, ioaddr, SUB_SETUP1);
                lp->setup &= ~PROMISCset;
                arcnet_outb(lp->setup, ioaddr, COM20020_REG_W_XREG);
        }
}

#if defined(CONFIG_ARCNET_COM20020_PCI_MODULE) || \
    defined(CONFIG_ARCNET_COM20020_ISA_MODULE) || \
    defined(CONFIG_ARCNET_COM20020_CS_MODULE)
EXPORT_SYMBOL(com20020_check);
EXPORT_SYMBOL(com20020_found);
EXPORT_SYMBOL(com20020_netdev_ops);
#endif

MODULE_DESCRIPTION("ARCnet COM20020 chipset core driver");
MODULE_LICENSE("GPL");