V4L/DVB (6715): ivtv: Remove unnecessary register update

[linux-2.6/verdex.git] / drivers / usb / core / hcd-pci.c

/*
 * (C) Copyright David Brownell 2000-2002
 * 
 * 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 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/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/usb.h>

#include <asm/io.h>
#include <asm/irq.h>

#ifdef CONFIG_PPC_PMAC
#include <asm/machdep.h>
#include <asm/pmac_feature.h>
#include <asm/pci-bridge.h>
#include <asm/prom.h>
#endif

#include "usb.h"
#include "hcd.h"


/* PCI-based HCs are common, but plenty of non-PCI HCs are used too */


/*-------------------------------------------------------------------------*/

/* configure so an HC device and id are always provided */
/* always called with process context; sleeping is OK */

/**
 * usb_hcd_pci_probe - initialize PCI-based HCDs
 * @dev: USB Host Controller being probed
 * @id: pci hotplug id connecting controller to HCD framework
 * Context: !in_interrupt()
 *
 * Allocates basic PCI resources for this USB host controller, and
 * then invokes the start() method for the HCD associated with it
 * through the hotplug entry's driver_data.
 *
 * Store this function in the HCD's struct pci_driver as probe().
 */
int usb_hcd_pci_probe (struct pci_dev *dev, const struct pci_device_id *id)
{
        struct hc_driver        *driver;
        struct usb_hcd          *hcd;
        int                     retval;

        if (usb_disabled())
                return -ENODEV;

        if (!id || !(driver = (struct hc_driver *) id->driver_data))
                return -EINVAL;

        if (pci_enable_device (dev) < 0)
                return -ENODEV;
        dev->current_state = PCI_D0;
        dev->dev.power.power_state = PMSG_ON;
        
        if (!dev->irq) {
                dev_err (&dev->dev,
                        "Found HC with no IRQ.  Check BIOS/PCI %s setup!\n",
                        pci_name(dev));
                retval = -ENODEV;
                goto err1;
        }

        hcd = usb_create_hcd (driver, &dev->dev, pci_name(dev));
        if (!hcd) {
                retval = -ENOMEM;
                goto err1;
        }

        if (driver->flags & HCD_MEMORY) {       // EHCI, OHCI
                hcd->rsrc_start = pci_resource_start (dev, 0);
                hcd->rsrc_len = pci_resource_len (dev, 0);
                if (!request_mem_region (hcd->rsrc_start, hcd->rsrc_len,
                                driver->description)) {
                        dev_dbg (&dev->dev, "controller already in use\n");
                        retval = -EBUSY;
                        goto err2;
                }
                hcd->regs = ioremap_nocache (hcd->rsrc_start, hcd->rsrc_len);
                if (hcd->regs == NULL) {
                        dev_dbg (&dev->dev, "error mapping memory\n");
                        retval = -EFAULT;
                        goto err3;
                }

        } else {                                // UHCI
                int     region;

                for (region = 0; region < PCI_ROM_RESOURCE; region++) {
                        if (!(pci_resource_flags (dev, region) &
                                        IORESOURCE_IO))
                                continue;

                        hcd->rsrc_start = pci_resource_start (dev, region);
                        hcd->rsrc_len = pci_resource_len (dev, region);
                        if (request_region (hcd->rsrc_start, hcd->rsrc_len,
                                        driver->description))
                                break;
                }
                if (region == PCI_ROM_RESOURCE) {
                        dev_dbg (&dev->dev, "no i/o regions available\n");
                        retval = -EBUSY;
                        goto err1;
                }
        }

        pci_set_master (dev);

        retval = usb_add_hcd(hcd, dev->irq, IRQF_DISABLED | IRQF_SHARED);
        if (retval != 0)
                goto err4;
        return retval;

 err4:
        if (driver->flags & HCD_MEMORY) {
                iounmap (hcd->regs);
 err3:
                release_mem_region (hcd->rsrc_start, hcd->rsrc_len);
        } else
                release_region (hcd->rsrc_start, hcd->rsrc_len);
 err2:
        usb_put_hcd (hcd);
 err1:
        pci_disable_device (dev);
        dev_err (&dev->dev, "init %s fail, %d\n", pci_name(dev), retval);
        return retval;
} 
EXPORT_SYMBOL (usb_hcd_pci_probe);


/* may be called without controller electrically present */
/* may be called with controller, bus, and devices active */

/**
 * usb_hcd_pci_remove - shutdown processing for PCI-based HCDs
 * @dev: USB Host Controller being removed
 * Context: !in_interrupt()
 *
 * Reverses the effect of usb_hcd_pci_probe(), first invoking
 * the HCD's stop() method.  It is always called from a thread
 * context, normally "rmmod", "apmd", or something similar.
 *
 * Store this function in the HCD's struct pci_driver as remove().
 */
void usb_hcd_pci_remove (struct pci_dev *dev)
{
        struct usb_hcd          *hcd;

        hcd = pci_get_drvdata(dev);
        if (!hcd)
                return;

        usb_remove_hcd (hcd);
        if (hcd->driver->flags & HCD_MEMORY) {
                iounmap (hcd->regs);
                release_mem_region (hcd->rsrc_start, hcd->rsrc_len);
        } else {
                release_region (hcd->rsrc_start, hcd->rsrc_len);
        }
        usb_put_hcd (hcd);
        pci_disable_device(dev);
}
EXPORT_SYMBOL (usb_hcd_pci_remove);


#ifdef  CONFIG_PM

/**
 * usb_hcd_pci_suspend - power management suspend of a PCI-based HCD
 * @dev: USB Host Controller being suspended
 * @message: semantics in flux
 *
 * Store this function in the HCD's struct pci_driver as suspend().
 */
int usb_hcd_pci_suspend (struct pci_dev *dev, pm_message_t message)
{
        struct usb_hcd          *hcd;
        int                     retval = 0;
        int                     has_pci_pm;

        hcd = pci_get_drvdata(dev);

        /* Root hub suspend should have stopped all downstream traffic,
         * and all bus master traffic.  And done so for both the interface
         * and the stub usb_device (which we check here).  But maybe it
         * didn't; writing sysfs power/state files ignores such rules...
         *
         * We must ignore the FREEZE vs SUSPEND distinction here, because
         * otherwise the swsusp will save (and restore) garbage state.
         */
        if (!(hcd->state == HC_STATE_SUSPENDED ||
                        hcd->state == HC_STATE_HALT))
                return -EBUSY;

        if (hcd->driver->suspend) {
                retval = hcd->driver->suspend(hcd, message);
                suspend_report_result(hcd->driver->suspend, retval);
                if (retval)
                        goto done;
        }
        synchronize_irq(dev->irq);

        /* FIXME until the generic PM interfaces change a lot more, this
         * can't use PCI D1 and D2 states.  For example, the confusion
         * between messages and states will need to vanish, and messages
         * will need to provide a target system state again.
         *
         * It'll be important to learn characteristics of the target state,
         * especially on embedded hardware where the HCD will often be in
         * charge of an external VBUS power supply and one or more clocks.
         * Some target system states will leave them active; others won't.
         * (With PCI, that's often handled by platform BIOS code.)
         */

        /* even when the PCI layer rejects some of the PCI calls
         * below, HCs can try global suspend and reduce DMA traffic.
         * PM-sensitive HCDs may already have done this.
         */
        has_pci_pm = pci_find_capability(dev, PCI_CAP_ID_PM);

        /* Downstream ports from this root hub should already be quiesced, so
         * there will be no DMA activity.  Now we can shut down the upstream
         * link (except maybe for PME# resume signaling) and enter some PCI
         * low power state, if the hardware allows.
         */
        if (hcd->state == HC_STATE_SUSPENDED) {

                /* no DMA or IRQs except when HC is active */
                if (dev->current_state == PCI_D0) {
                        pci_save_state (dev);
                        pci_disable_device (dev);
                }

                if (!has_pci_pm) {
                        dev_dbg (hcd->self.controller, "--> PCI D0/legacy\n");
                        goto done;
                }

                /* NOTE:  dev->current_state becomes nonzero only here, and
                 * only for devices that support PCI PM.  Also, exiting
                 * PCI_D3 (but not PCI_D1 or PCI_D2) is allowed to reset
                 * some device state (e.g. as part of clock reinit).
                 */
                retval = pci_set_power_state (dev, PCI_D3hot);
                suspend_report_result(pci_set_power_state, retval);
                if (retval == 0) {
                        int wake = device_can_wakeup(&hcd->self.root_hub->dev);

                        wake = wake && device_may_wakeup(hcd->self.controller);

                        dev_dbg (hcd->self.controller, "--> PCI D3%s\n",
                                        wake ? "/wakeup" : "");

                        /* Ignore these return values.  We rely on pci code to
                         * reject requests the hardware can't implement, rather
                         * than coding the same thing.
                         */
                        (void) pci_enable_wake (dev, PCI_D3hot, wake);
                        (void) pci_enable_wake (dev, PCI_D3cold, wake);
                } else {
                        dev_dbg (&dev->dev, "PCI D3 suspend fail, %d\n",
                                        retval);
                        (void) usb_hcd_pci_resume (dev);
                }

        } else if (hcd->state != HC_STATE_HALT) {
                dev_dbg (hcd->self.controller, "hcd state %d; not suspended\n",
                        hcd->state);
                WARN_ON(1);
                retval = -EINVAL;
        }

done:
        if (retval == 0) {
                dev->dev.power.power_state = PMSG_SUSPEND;

#ifdef CONFIG_PPC_PMAC
                /* Disable ASIC clocks for USB */
                if (machine_is(powermac)) {
                        struct device_node      *of_node;

                        of_node = pci_device_to_OF_node (dev);
                        if (of_node)
                                pmac_call_feature(PMAC_FTR_USB_ENABLE,
                                                        of_node, 0, 0);
                }
#endif
        }

        return retval;
}
EXPORT_SYMBOL (usb_hcd_pci_suspend);

/**
 * usb_hcd_pci_resume - power management resume of a PCI-based HCD
 * @dev: USB Host Controller being resumed
 *
 * Store this function in the HCD's struct pci_driver as resume().
 */
int usb_hcd_pci_resume (struct pci_dev *dev)
{
        struct usb_hcd          *hcd;
        int                     retval;

        hcd = pci_get_drvdata(dev);
        if (hcd->state != HC_STATE_SUSPENDED) {
                dev_dbg (hcd->self.controller, 
                                "can't resume, not suspended!\n");
                return 0;
        }

#ifdef CONFIG_PPC_PMAC
        /* Reenable ASIC clocks for USB */
        if (machine_is(powermac)) {
                struct device_node *of_node;

                of_node = pci_device_to_OF_node (dev);
                if (of_node)
                        pmac_call_feature (PMAC_FTR_USB_ENABLE,
                                                of_node, 0, 1);
        }
#endif

        /* NOTE:  chip docs cover clean "real suspend" cases (what Linux
         * calls "standby", "suspend to RAM", and so on).  There are also
         * dirty cases when swsusp fakes a suspend in "shutdown" mode.
         */
        if (dev->current_state != PCI_D0) {
#ifdef  DEBUG
                int     pci_pm;
                u16     pmcr;

                pci_pm = pci_find_capability(dev, PCI_CAP_ID_PM);
                pci_read_config_word(dev, pci_pm + PCI_PM_CTRL, &pmcr);
                pmcr &= PCI_PM_CTRL_STATE_MASK;
                if (pmcr) {
                        /* Clean case:  power to USB and to HC registers was
                         * maintained; remote wakeup is easy.
                         */
                        dev_dbg(hcd->self.controller, "resume from PCI D%d\n",
                                        pmcr);
                } else {
                        /* Clean:  HC lost Vcc power, D0 uninitialized
                         *   + Vaux may have preserved port and transceiver
                         *     state ... for remote wakeup from D3cold
                         *   + or not; HCD must reinit + re-enumerate
                         *
                         * Dirty: D0 semi-initialized cases with swsusp
                         *   + after BIOS init
                         *   + after Linux init (HCD statically linked)
                         */
                        dev_dbg(hcd->self.controller,
                                "PCI D0, from previous PCI D%d\n",
                                dev->current_state);
                }
#endif
                /* yes, ignore these results too... */
                (void) pci_enable_wake (dev, dev->current_state, 0);
                (void) pci_enable_wake (dev, PCI_D3cold, 0);
        } else {
                /* Same basic cases: clean (powered/not), dirty */
                dev_dbg(hcd->self.controller, "PCI legacy resume\n");
        }

        /* NOTE:  the PCI API itself is asymmetric here.  We don't need to
         * pci_set_power_state(PCI_D0) since that's part of re-enabling;
         * but that won't re-enable bus mastering.  Yet pci_disable_device()
         * explicitly disables bus mastering...
         */
        retval = pci_enable_device (dev);
        if (retval < 0) {
                dev_err (hcd->self.controller,
                        "can't re-enable after resume, %d!\n", retval);
                return retval;
        }
        pci_set_master (dev);
        pci_restore_state (dev);

        dev->dev.power.power_state = PMSG_ON;

        clear_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);

        if (hcd->driver->resume) {
                retval = hcd->driver->resume(hcd);
                if (retval) {
                        dev_err (hcd->self.controller,
                                "PCI post-resume error %d!\n", retval);
                        usb_hc_died (hcd);
                }
        }

        return retval;
}
EXPORT_SYMBOL (usb_hcd_pci_resume);

#endif  /* CONFIG_PM */

/**
 * usb_hcd_pci_shutdown - shutdown host controller
 * @dev: USB Host Controller being shutdown
 */
void usb_hcd_pci_shutdown (struct pci_dev *dev)
{
        struct usb_hcd          *hcd;

        hcd = pci_get_drvdata(dev);
        if (!hcd)
                return;

        if (hcd->driver->shutdown)
                hcd->driver->shutdown(hcd);
}
EXPORT_SYMBOL (usb_hcd_pci_shutdown);