hostess_sv11.c

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/*
 *  Comtrol SV11 card driver
 *
 *  This is a slightly odd Z85230 synchronous driver. All you need to
 *  know basically is
 *
 *  Its a genuine Z85230
 *
 *  It supports DMA using two DMA channels in SYNC mode. The driver doesn't
 *  use these facilities
 *  
 *  The control port is at io+1, the data at io+3 and turning off the DMA
 *  is done by writing 0 to io+4
 *
 *  The hardware does the bus handling to avoid the need for delays between
 *  touching control registers.
 *
 *  Port B isn't wired (why - beats me)
 *
 *  Generic HDLC port Copyright (C) 2008 Krzysztof Halasa <[email protected]>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/delay.h>
#include <linux/hdlc.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <net/arp.h>

#include <asm/irq.h>
#include <asm/io.h>
#include <asm/dma.h>
#include <asm/byteorder.h>
#include "z85230.h"

static int dma;

/*
 *  Network driver support routines
 */

static inline struct z8530_dev* dev_to_sv(struct net_device *dev)
{
    return (struct z8530_dev *)dev_to_hdlc(dev)->priv;
}

/*
 *  Frame receive. Simple for our card as we do HDLC and there
 *  is no funny garbage involved
 */

static void hostess_input(struct z8530_channel *c, struct sk_buff *skb)
{
    /* Drop the CRC - it's not a good idea to try and negotiate it ;) */
    skb_trim(skb, skb->len - 2);
    skb->protocol = hdlc_type_trans(skb, c->netdevice);
    skb_reset_mac_header(skb);
    skb->dev = c->netdevice;
    /*
     *  Send it to the PPP layer. We don't have time to process
     *  it right now.
     */
    netif_rx(skb);
}

/*
 *  We've been placed in the UP state
 */

static int hostess_open(struct net_device *d)
{
    struct z8530_dev *sv11 = dev_to_sv(d);
    int err = -1;

    /*
     *  Link layer up
     */
    switch (dma) {
        case 0:
            err = z8530_sync_open(d, &sv11->chanA);
            break;
        case 1:
            err = z8530_sync_dma_open(d, &sv11->chanA);
            break;
        case 2:
            err = z8530_sync_txdma_open(d, &sv11->chanA);
            break;
    }

    if (err)
        return err;

    err = hdlc_open(d);
    if (err) {
        switch (dma) {
            case 0:
                z8530_sync_close(d, &sv11->chanA);
                break;
            case 1:
                z8530_sync_dma_close(d, &sv11->chanA);
                break;
            case 2:
                z8530_sync_txdma_close(d, &sv11->chanA);
                break;
        }
        return err;
    }
    sv11->chanA.rx_function = hostess_input;

    /*
     *  Go go go
     */

    netif_start_queue(d);
    return 0;
}

static int hostess_close(struct net_device *d)
{
    struct z8530_dev *sv11 = dev_to_sv(d);
    /*
     *  Discard new frames
     */
    sv11->chanA.rx_function = z8530_null_rx;

    hdlc_close(d);
    netif_stop_queue(d);

    switch (dma) {
        case 0:
            z8530_sync_close(d, &sv11->chanA);
            break;
        case 1:
            z8530_sync_dma_close(d, &sv11->chanA);
            break;
        case 2:
            z8530_sync_txdma_close(d, &sv11->chanA);
            break;
    }
    return 0;
}

static int hostess_ioctl(struct net_device *d, struct ifreq *ifr, int cmd)
{
    /* struct z8530_dev *sv11=dev_to_sv(d);
       z8530_ioctl(d,&sv11->chanA,ifr,cmd) */
    return hdlc_ioctl(d, ifr, cmd);
}

/*
 *  Passed network frames, fire them downwind.
 */

static netdev_tx_t hostess_queue_xmit(struct sk_buff *skb,
                        struct net_device *d)
{
    return z8530_queue_xmit(&dev_to_sv(d)->chanA, skb);
}

static int hostess_attach(struct net_device *dev, unsigned short encoding,
              unsigned short parity)
{
    if (encoding == ENCODING_NRZ && parity == PARITY_CRC16_PR1_CCITT)
        return 0;
    return -EINVAL;
}

/*
 *  Description block for a Comtrol Hostess SV11 card
 */

static const struct net_device_ops hostess_ops = {
    .ndo_open       = hostess_open,
    .ndo_stop       = hostess_close,
    .ndo_change_mtu = hdlc_change_mtu,
    .ndo_start_xmit = hdlc_start_xmit,
    .ndo_do_ioctl   = hostess_ioctl,
};

static struct z8530_dev *sv11_init(int iobase, int irq)
{
    struct z8530_dev *sv;
    struct net_device *netdev;
    /*
     *  Get the needed I/O space
     */

    if (!request_region(iobase, 8, "Comtrol SV11")) {
        pr_warn("I/O 0x%X already in use\n", iobase);
        return NULL;
    }

    sv = kzalloc(sizeof(struct z8530_dev), GFP_KERNEL);
    if (!sv)
        goto err_kzalloc;

    /*
     *  Stuff in the I/O addressing
     */

    sv->active = 0;

    sv->chanA.ctrlio = iobase + 1;
    sv->chanA.dataio = iobase + 3;
    sv->chanB.ctrlio = -1;
    sv->chanB.dataio = -1;
    sv->chanA.irqs = &z8530_nop;
    sv->chanB.irqs = &z8530_nop;

    outb(0, iobase + 4);        /* DMA off */

    /* We want a fast IRQ for this device. Actually we'd like an even faster
       IRQ ;) - This is one driver RtLinux is made for */

    if (request_irq(irq, z8530_interrupt, IRQF_DISABLED,
            "Hostess SV11", sv) < 0) {
        pr_warn("IRQ %d already in use\n", irq);
        goto err_irq;
    }

    sv->irq = irq;
    sv->chanA.private = sv;
    sv->chanA.dev = sv;
    sv->chanB.dev = sv;

    if (dma) {
        /*
         *  You can have DMA off or 1 and 3 thats the lot
         *  on the Comtrol.
         */
        sv->chanA.txdma = 3;
        sv->chanA.rxdma = 1;
        outb(0x03 | 0x08, iobase + 4);      /* DMA on */
        if (request_dma(sv->chanA.txdma, "Hostess SV/11 (TX)"))
            goto err_txdma;

        if (dma == 1)
            if (request_dma(sv->chanA.rxdma, "Hostess SV/11 (RX)"))
                goto err_rxdma;
    }

    /* Kill our private IRQ line the hostess can end up chattering
       until the configuration is set */
    disable_irq(irq);

    /*
     *  Begin normal initialise
     */

    if (z8530_init(sv)) {
        pr_err("Z8530 series device not found\n");
        enable_irq(irq);
        goto free_dma;
    }
    z8530_channel_load(&sv->chanB, z8530_dead_port);
    if (sv->type == Z85C30)
        z8530_channel_load(&sv->chanA, z8530_hdlc_kilostream);
    else
        z8530_channel_load(&sv->chanA, z8530_hdlc_kilostream_85230);

    enable_irq(irq);

    /*
     *  Now we can take the IRQ
     */

    sv->chanA.netdevice = netdev = alloc_hdlcdev(sv);
    if (!netdev)
        goto free_dma;

    dev_to_hdlc(netdev)->attach = hostess_attach;
    dev_to_hdlc(netdev)->xmit = hostess_queue_xmit;
    netdev->netdev_ops = &hostess_ops;
    netdev->base_addr = iobase;
    netdev->irq = irq;

    if (register_hdlc_device(netdev)) {
        pr_err("unable to register HDLC device\n");
        free_netdev(netdev);
        goto free_dma;
    }

    z8530_describe(sv, "I/O", iobase);
    sv->active = 1;
    return sv;

free_dma:
    if (dma == 1)
        free_dma(sv->chanA.rxdma);
err_rxdma:
    if (dma)
        free_dma(sv->chanA.txdma);
err_txdma:
    free_irq(irq, sv);
err_irq:
    kfree(sv);
err_kzalloc:
    release_region(iobase, 8);
    return NULL;
}

static void sv11_shutdown(struct z8530_dev *dev)
{
    unregister_hdlc_device(dev->chanA.netdevice);
    z8530_shutdown(dev);
    free_irq(dev->irq, dev);
    if (dma) {
        if (dma == 1)
            free_dma(dev->chanA.rxdma);
        free_dma(dev->chanA.txdma);
    }
    release_region(dev->chanA.ctrlio - 1, 8);
    free_netdev(dev->chanA.netdevice);
    kfree(dev);
}

static int io = 0x200;
static int irq = 9;

module_param(io, int, 0);
MODULE_PARM_DESC(io, "The I/O base of the Comtrol Hostess SV11 card");
module_param(dma, int, 0);
MODULE_PARM_DESC(dma, "Set this to 1 to use DMA1/DMA3 for TX/RX");
module_param(irq, int, 0);
MODULE_PARM_DESC(irq, "The interrupt line setting for the Comtrol Hostess SV11 card");

MODULE_AUTHOR("Alan Cox");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Modular driver for the Comtrol Hostess SV11");

static struct z8530_dev *sv11_unit;

int init_module(void)
{
    if ((sv11_unit = sv11_init(io, irq)) == NULL)
        return -ENODEV;
    return 0;
}

void cleanup_module(void)
{
    if (sv11_unit)
        sv11_shutdown(sv11_unit);
}