[PATCH] prism54: Remove redundant assignment

[linux-2.6] / drivers / net / wireless / orinoco_plx.c

/* orinoco_plx.c
 *
 * Driver for Prism II devices which would usually be driven by orinoco_cs,
 * but are connected to the PCI bus by a PLX9052.
 *
 * Current maintainers (as of 29 September 2003) are:
 *      Pavel Roskin <proski AT gnu.org>
 * and  David Gibson <hermes AT gibson.dropbear.id.au>
 *
 * (C) Copyright David Gibson, IBM Corp. 2001-2003.
 * Copyright (C) 2001 Daniel Barlow
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License
 * at http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and
 * limitations under the License.
 *
 * Alternatively, the contents of this file may be used under the
 * terms of the GNU General Public License version 2 (the "GPL"), in
 * which case the provisions of the GPL are applicable instead of the
 * above.  If you wish to allow the use of your version of this file
 * only under the terms of the GPL and not to allow others to use your
 * version of this file under the MPL, indicate your decision by
 * deleting the provisions above and replace them with the notice and
 * other provisions required by the GPL.  If you do not delete the
 * provisions above, a recipient may use your version of this file
 * under either the MPL or the GPL.

 * Caution: this is experimental and probably buggy.  For success and
 * failure reports for different cards and adaptors, see
 * orinoco_plx_pci_id_table near the end of the file.  If you have a
 * card we don't have the PCI id for, and looks like it should work,
 * drop me mail with the id and "it works"/"it doesn't work".
 *
 * Note: if everything gets detected fine but it doesn't actually send
 * or receive packets, your first port of call should probably be to
 * try newer firmware in the card.  Especially if you're doing Ad-Hoc
 * modes.
 *
 * The actual driving is done by orinoco.c, this is just resource
 * allocation stuff.  The explanation below is courtesy of Ryan Niemi
 * on the linux-wlan-ng list at
 * http://archives.neohapsis.com/archives/dev/linux-wlan/2001-q1/0026.html
 *
 * The PLX9052-based cards (WL11000 and several others) are a
 * different beast than the usual PCMCIA-based PRISM2 configuration
 * expected by wlan-ng.  Here's the general details on how the WL11000
 * PCI adapter works:
 *
 * - Two PCI I/O address spaces, one 0x80 long which contains the
 * PLX9052 registers, and one that's 0x40 long mapped to the PCMCIA
 * slot I/O address space.
 *
 * - One PCI memory address space, mapped to the PCMCIA memory space
 * (containing the CIS).
 *
 * After identifying the I/O and memory space, you can read through
 * the memory space to confirm the CIS's device ID or manufacturer ID
 * to make sure it's the expected card.  qKeep in mind that the PCMCIA
 * spec specifies the CIS as the lower 8 bits of each word read from
 * the CIS, so to read the bytes of the CIS, read every other byte
 * (0,2,4,...). Passing that test, you need to enable the I/O address
 * space on the PCMCIA card via the PCMCIA COR register. This is the
 * first byte following the CIS. In my case (which may not have any
 * relation to what's on the PRISM2 cards), COR was at offset 0x800
 * within the PCI memory space. Write 0x41 to the COR register to
 * enable I/O mode and to select level triggered interrupts. To
 * confirm you actually succeeded, read the COR register back and make
 * sure it actually got set to 0x41, incase you have an unexpected
 * card inserted.
 *
 * Following that, you can treat the second PCI I/O address space (the
 * one that's not 0x80 in length) as the PCMCIA I/O space.
 *
 * Note that in the Eumitcom's source for their drivers, they register
 * the interrupt as edge triggered when registering it with the
 * Windows kernel. I don't recall how to register edge triggered on
 * Linux (if it can be done at all). But in some experimentation, I
 * don't see much operational difference between using either
 * interrupt mode. Don't mess with the interrupt mode in the COR
 * register though, as the PLX9052 wants level triggers with the way
 * the serial EEPROM configures it on the WL11000.
 *
 * There's some other little quirks related to timing that I bumped
 * into, but I don't recall right now. Also, there's two variants of
 * the WL11000 I've seen, revision A1 and T2. These seem to differ
 * slightly in the timings configured in the wait-state generator in
 * the PLX9052. There have also been some comments from Eumitcom that
 * cards shouldn't be hot swapped, apparently due to risk of cooking
 * the PLX9052. I'm unsure why they believe this, as I can't see
 * anything in the design that would really cause a problem, except
 * for crashing drivers not written to expect it. And having developed
 * drivers for the WL11000, I'd say it's quite tricky to write code
 * that will successfully deal with a hot unplug. Very odd things
 * happen on the I/O side of things. But anyway, be warned. Despite
 * that, I've hot-swapped a number of times during debugging and
 * driver development for various reasons (stuck WAIT# line after the
 * radio card's firmware locks up).
 *
 * Hope this is enough info for someone to add PLX9052 support to the
 * wlan-ng card. In the case of the WL11000, the PCI ID's are
 * 0x1639/0x0200, with matching subsystem ID's. Other PLX9052-based
 * manufacturers other than Eumitcom (or on cards other than the
 * WL11000) may have different PCI ID's.
 *
 * If anyone needs any more specific info, let me know. I haven't had
 * time to implement support myself yet, and with the way things are
 * going, might not have time for a while..
 */

#define DRIVER_NAME "orinoco_plx"
#define PFX DRIVER_NAME ": "

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/pci.h>
#include <pcmcia/cisreg.h>

#include "orinoco.h"

#define COR_OFFSET      (0x3e0) /* COR attribute offset of Prism2 PC card */
#define COR_VALUE       (COR_LEVEL_REQ | COR_FUNC_ENA) /* Enable PC card with interrupt in level trigger */
#define COR_RESET     (0x80)    /* reset bit in the COR register */
#define PLX_RESET_TIME  (500)   /* milliseconds */

#define PLX_INTCSR              0x4c /* Interrupt Control & Status Register */
#define PLX_INTCSR_INTEN        (1<<6) /* Interrupt Enable bit */

static const u8 cis_magic[] = {
        0x01, 0x03, 0x00, 0x00, 0xff, 0x17, 0x04, 0x67
};

/* Orinoco PLX specific data */
struct orinoco_plx_card {
        void __iomem *attr_mem;
};

/*
 * Do a soft reset of the card using the Configuration Option Register
 */
static int orinoco_plx_cor_reset(struct orinoco_private *priv)
{
        hermes_t *hw = &priv->hw;
        struct orinoco_plx_card *card = priv->card;
        u8 __iomem *attr_mem = card->attr_mem;
        unsigned long timeout;
        u16 reg;

        writeb(COR_VALUE | COR_RESET, attr_mem + COR_OFFSET);
        mdelay(1);

        writeb(COR_VALUE, attr_mem + COR_OFFSET);
        mdelay(1);

        /* Just in case, wait more until the card is no longer busy */
        timeout = jiffies + (PLX_RESET_TIME * HZ / 1000);
        reg = hermes_read_regn(hw, CMD);
        while (time_before(jiffies, timeout) && (reg & HERMES_CMD_BUSY)) {
                mdelay(1);
                reg = hermes_read_regn(hw, CMD);
        }

        /* Did we timeout ? */
        if (reg & HERMES_CMD_BUSY) {
                printk(KERN_ERR PFX "Busy timeout\n");
                return -ETIMEDOUT;
        }

        return 0;
}


static int orinoco_plx_init_one(struct pci_dev *pdev,
                                const struct pci_device_id *ent)
{
        int err = 0;
        u8 __iomem *attr_mem = NULL;
        u32 csr_reg, plx_addr;
        struct orinoco_private *priv = NULL;
        struct orinoco_plx_card *card;
        unsigned long pccard_ioaddr = 0;
        unsigned long pccard_iolen = 0;
        struct net_device *dev = NULL;
        void __iomem *mem;
        int i;

        err = pci_enable_device(pdev);
        if (err) {
                printk(KERN_ERR PFX "Cannot enable PCI device\n");
                return err;
        }

        err = pci_request_regions(pdev, DRIVER_NAME);
        if (err != 0) {
                printk(KERN_ERR PFX "Cannot obtain PCI resources\n");
                goto fail_resources;
        }

        /* Resource 1 is mapped to PLX-specific registers */
        plx_addr = pci_resource_start(pdev, 1);

        /* Resource 2 is mapped to the PCMCIA attribute memory */
        attr_mem = ioremap(pci_resource_start(pdev, 2),
                           pci_resource_len(pdev, 2));
        if (!attr_mem) {
                printk(KERN_ERR PFX "Cannot remap PCMCIA space\n");
                goto fail_map_attr;
        }

        /* Resource 3 is mapped to the PCMCIA I/O address space */
        pccard_ioaddr = pci_resource_start(pdev, 3);
        pccard_iolen = pci_resource_len(pdev, 3);

        mem = pci_iomap(pdev, 3, 0);
        if (!mem) {
                err = -ENOMEM;
                goto fail_map_io;
        }

        /* Allocate network device */
        dev = alloc_orinocodev(sizeof(*card), orinoco_plx_cor_reset);
        if (!dev) {
                printk(KERN_ERR PFX "Cannot allocate network device\n");
                err = -ENOMEM;
                goto fail_alloc;
        }

        priv = netdev_priv(dev);
        card = priv->card;
        card->attr_mem = attr_mem;
        dev->base_addr = pccard_ioaddr;
        SET_MODULE_OWNER(dev);
        SET_NETDEV_DEV(dev, &pdev->dev);

        hermes_struct_init(&priv->hw, mem, HERMES_16BIT_REGSPACING);

        printk(KERN_DEBUG PFX "Detected Orinoco/Prism2 PLX device "
               "at %s irq:%d, io addr:0x%lx\n", pci_name(pdev), pdev->irq,
               pccard_ioaddr);

        err = request_irq(pdev->irq, orinoco_interrupt, SA_SHIRQ,
                          dev->name, dev);
        if (err) {
                printk(KERN_ERR PFX "Cannot allocate IRQ %d\n", pdev->irq);
                err = -EBUSY;
                goto fail_irq;
        }
        dev->irq = pdev->irq;

        /* bjoern: We need to tell the card to enable interrupts, in
           case the serial eprom didn't do this already.  See the
           PLX9052 data book, p8-1 and 8-24 for reference. */
        csr_reg = inl(plx_addr + PLX_INTCSR);
        if (!(csr_reg & PLX_INTCSR_INTEN)) {
                csr_reg |= PLX_INTCSR_INTEN;
                outl(csr_reg, plx_addr + PLX_INTCSR);
                csr_reg = inl(plx_addr + PLX_INTCSR);
                if (!(csr_reg & PLX_INTCSR_INTEN)) {
                        printk(KERN_ERR PFX "Cannot enable interrupts\n");
                        goto fail;
                }
        }

        err = orinoco_plx_cor_reset(priv);
        if (err) {
                printk(KERN_ERR PFX "Initial reset failed\n");
                goto fail;
        }

        printk(KERN_DEBUG PFX "CIS: ");
        for (i = 0; i < 16; i++) {
                printk("%02X:", readb(attr_mem + 2*i));
        }
        printk("\n");

        /* Verify whether a supported PC card is present */
        /* FIXME: we probably need to be smarted about this */
        for (i = 0; i < sizeof(cis_magic); i++) {
                if (cis_magic[i] != readb(attr_mem +2*i)) {
                        printk(KERN_ERR PFX "The CIS value of Prism2 PC "
                               "card is unexpected\n");
                        err = -EIO;
                        goto fail;
                }
        }

        err = register_netdev(dev);
        if (err) {
                printk(KERN_ERR PFX "Cannot register network device\n");
                goto fail;
        }

        pci_set_drvdata(pdev, dev);

        return 0;

 fail:
        free_irq(pdev->irq, dev);

 fail_irq:
        pci_set_drvdata(pdev, NULL);
        free_orinocodev(dev);

 fail_alloc:
        pci_iounmap(pdev, mem);

 fail_map_io:
        iounmap(attr_mem);

 fail_map_attr:
        pci_release_regions(pdev);

 fail_resources:
        pci_disable_device(pdev);

        return err;
}

static void __devexit orinoco_plx_remove_one(struct pci_dev *pdev)
{
        struct net_device *dev = pci_get_drvdata(pdev);
        struct orinoco_private *priv = netdev_priv(dev);
        struct orinoco_plx_card *card = priv->card;
        u8 __iomem *attr_mem = card->attr_mem;

        BUG_ON(! dev);

        unregister_netdev(dev);
        free_irq(dev->irq, dev);
        pci_set_drvdata(pdev, NULL);
        free_orinocodev(dev);
        pci_iounmap(pdev, priv->hw.iobase);
        iounmap(attr_mem);
        pci_release_regions(pdev);
        pci_disable_device(pdev);
}


static struct pci_device_id orinoco_plx_pci_id_table[] = {
        {0x111a, 0x1023, PCI_ANY_ID, PCI_ANY_ID,},      /* Siemens SpeedStream SS1023 */
        {0x1385, 0x4100, PCI_ANY_ID, PCI_ANY_ID,},      /* Netgear MA301 */
        {0x15e8, 0x0130, PCI_ANY_ID, PCI_ANY_ID,},      /* Correga  - does this work? */
        {0x1638, 0x1100, PCI_ANY_ID, PCI_ANY_ID,},      /* SMC EZConnect SMC2602W,
                                                           Eumitcom PCI WL11000,
                                                           Addtron AWA-100 */
        {0x16ab, 0x1100, PCI_ANY_ID, PCI_ANY_ID,},      /* Global Sun Tech GL24110P */
        {0x16ab, 0x1101, PCI_ANY_ID, PCI_ANY_ID,},      /* Reported working, but unknown */
        {0x16ab, 0x1102, PCI_ANY_ID, PCI_ANY_ID,},      /* Linksys WDT11 */
        {0x16ec, 0x3685, PCI_ANY_ID, PCI_ANY_ID,},      /* USR 2415 */
        {0xec80, 0xec00, PCI_ANY_ID, PCI_ANY_ID,},      /* Belkin F5D6000 tested by
                                                           Brendan W. McAdams <rit AT jacked-in.org> */
        {0x10b7, 0x7770, PCI_ANY_ID, PCI_ANY_ID,},      /* 3Com AirConnect PCI tested by
                                                           Damien Persohn <damien AT persohn.net> */
        {0,},
};

MODULE_DEVICE_TABLE(pci, orinoco_plx_pci_id_table);

static struct pci_driver orinoco_plx_driver = {
        .name           = DRIVER_NAME,
        .id_table       = orinoco_plx_pci_id_table,
        .probe          = orinoco_plx_init_one,
        .remove         = __devexit_p(orinoco_plx_remove_one),
};

static char version[] __initdata = DRIVER_NAME " " DRIVER_VERSION
        " (Pavel Roskin <proski@gnu.org>,"
        " David Gibson <hermes@gibson.dropbear.id.au>,"
        " Daniel Barlow <dan@telent.net>)";
MODULE_AUTHOR("Daniel Barlow <dan@telent.net>");
MODULE_DESCRIPTION("Driver for wireless LAN cards using the PLX9052 PCI bridge");
MODULE_LICENSE("Dual MPL/GPL");

static int __init orinoco_plx_init(void)
{
        printk(KERN_DEBUG "%s\n", version);
        return pci_module_init(&orinoco_plx_driver);
}

static void __exit orinoco_plx_exit(void)
{
        pci_unregister_driver(&orinoco_plx_driver);
        ssleep(1);
}

module_init(orinoco_plx_init);
module_exit(orinoco_plx_exit);

/*
 * Local variables:
 *  c-indent-level: 8
 *  c-basic-offset: 8
 *  tab-width: 8
 * End:
 */