linux/drivers/usb/host/xhci-pci.c
Sarah Sharp 69e848c209 Intel xhci: Support EHCI/xHCI port switching.
The Intel Panther Point chipsets contain an EHCI and xHCI host controller
that shares some number of skew-dependent ports.  These ports can be
switched from the EHCI to the xHCI host (and vice versa) by a hardware MUX
that is controlled by registers in the xHCI PCI configuration space.  The
USB 3.0 SuperSpeed terminations on the xHCI ports can be controlled
separately from the USB 2.0 data wires.

This switchover mechanism is there to support users who do a custom
install of certain non-Linux operating systems that don't have official
USB 3.0 support.  By default, the ports are under EHCI, SuperSpeed
terminations are off, and USB 3.0 devices will show up under the EHCI
controller at reduced speeds.  (This was more palatable for the marketing
folks than having completely dead USB 3.0 ports if no xHCI drivers are
available.)  Users should be able to turn on xHCI by default through a
BIOS option, but users are happiest when they don't have to change random
BIOS settings.

This patch introduces a driver method to switchover the ports from EHCI to
xHCI before the EHCI driver finishes PCI enumeration.  We want to switch
the ports over before the USB core has the chance to enumerate devices
under EHCI, or boot from USB mass storage will fail if the boot device
connects under EHCI first, and then gets disconnected when the port
switches over to xHCI.

Add code to the xHCI PCI quirk to switch the ports from EHCI to xHCI.  The
PCI quirks code will run before any other PCI probe function is called, so
this avoids the issue with boot devices.

Another issue is with BIOS behavior during system resume from hibernate.
If the BIOS doesn't support xHCI, it may switch the devices under EHCI to
allow use of the USB keyboard, mice, and mass storage devices.  It's
supposed to remember the value of the port routing registers and switch
them back when the OS attempts to take control of the xHCI host controller,
but we all know not to trust BIOS writers.

Make both the xHCI driver and the EHCI driver attempt to switchover the
ports in their PCI resume functions.  We can't guarantee which PCI device
will be resumed first, so this avoids any race conditions.  Writing a '1'
to an already set port switchover bit or a '0' to a cleared port switchover
bit should have no effect.

The xHCI PCI configuration registers will be documented in the EDS-level
chipset spec, which is not public yet.  I have permission from legal and
the Intel chipset group to release this patch early to allow good Linux
support at product launch.  I've tried to document the registers as much
as possible, so please let me know if anything is unclear.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
2011-05-27 12:07:36 -07:00

363 lines
10 KiB
C

/*
* xHCI host controller driver PCI Bus Glue.
*
* Copyright (C) 2008 Intel Corp.
*
* Author: Sarah Sharp
* Some code borrowed from the Linux EHCI driver.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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/pci.h>
#include <linux/slab.h>
#include "xhci.h"
/* Device for a quirk */
#define PCI_VENDOR_ID_FRESCO_LOGIC 0x1b73
#define PCI_DEVICE_ID_FRESCO_LOGIC_PDK 0x1000
static const char hcd_name[] = "xhci_hcd";
/* called after powerup, by probe or system-pm "wakeup" */
static int xhci_pci_reinit(struct xhci_hcd *xhci, struct pci_dev *pdev)
{
/*
* TODO: Implement finding debug ports later.
* TODO: see if there are any quirks that need to be added to handle
* new extended capabilities.
*/
/* PCI Memory-Write-Invalidate cycle support is optional (uncommon) */
if (!pci_set_mwi(pdev))
xhci_dbg(xhci, "MWI active\n");
xhci_dbg(xhci, "Finished xhci_pci_reinit\n");
return 0;
}
/* called during probe() after chip reset completes */
static int xhci_pci_setup(struct usb_hcd *hcd)
{
struct xhci_hcd *xhci;
struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
int retval;
u32 temp;
hcd->self.sg_tablesize = TRBS_PER_SEGMENT - 2;
if (usb_hcd_is_primary_hcd(hcd)) {
xhci = kzalloc(sizeof(struct xhci_hcd), GFP_KERNEL);
if (!xhci)
return -ENOMEM;
*((struct xhci_hcd **) hcd->hcd_priv) = xhci;
xhci->main_hcd = hcd;
/* Mark the first roothub as being USB 2.0.
* The xHCI driver will register the USB 3.0 roothub.
*/
hcd->speed = HCD_USB2;
hcd->self.root_hub->speed = USB_SPEED_HIGH;
/*
* USB 2.0 roothub under xHCI has an integrated TT,
* (rate matching hub) as opposed to having an OHCI/UHCI
* companion controller.
*/
hcd->has_tt = 1;
} else {
/* xHCI private pointer was set in xhci_pci_probe for the second
* registered roothub.
*/
xhci = hcd_to_xhci(hcd);
temp = xhci_readl(xhci, &xhci->cap_regs->hcc_params);
if (HCC_64BIT_ADDR(temp)) {
xhci_dbg(xhci, "Enabling 64-bit DMA addresses.\n");
dma_set_mask(hcd->self.controller, DMA_BIT_MASK(64));
} else {
dma_set_mask(hcd->self.controller, DMA_BIT_MASK(32));
}
return 0;
}
xhci->cap_regs = hcd->regs;
xhci->op_regs = hcd->regs +
HC_LENGTH(xhci_readl(xhci, &xhci->cap_regs->hc_capbase));
xhci->run_regs = hcd->regs +
(xhci_readl(xhci, &xhci->cap_regs->run_regs_off) & RTSOFF_MASK);
/* Cache read-only capability registers */
xhci->hcs_params1 = xhci_readl(xhci, &xhci->cap_regs->hcs_params1);
xhci->hcs_params2 = xhci_readl(xhci, &xhci->cap_regs->hcs_params2);
xhci->hcs_params3 = xhci_readl(xhci, &xhci->cap_regs->hcs_params3);
xhci->hcc_params = xhci_readl(xhci, &xhci->cap_regs->hc_capbase);
xhci->hci_version = HC_VERSION(xhci->hcc_params);
xhci->hcc_params = xhci_readl(xhci, &xhci->cap_regs->hcc_params);
xhci_print_registers(xhci);
/* Look for vendor-specific quirks */
if (pdev->vendor == PCI_VENDOR_ID_FRESCO_LOGIC &&
pdev->device == PCI_DEVICE_ID_FRESCO_LOGIC_PDK &&
pdev->revision == 0x0) {
xhci->quirks |= XHCI_RESET_EP_QUIRK;
xhci_dbg(xhci, "QUIRK: Fresco Logic xHC needs configure"
" endpoint cmd after reset endpoint\n");
}
if (pdev->vendor == PCI_VENDOR_ID_NEC)
xhci->quirks |= XHCI_NEC_HOST;
/* AMD PLL quirk */
if (pdev->vendor == PCI_VENDOR_ID_AMD && usb_amd_find_chipset_info())
xhci->quirks |= XHCI_AMD_PLL_FIX;
/* Make sure the HC is halted. */
retval = xhci_halt(xhci);
if (retval)
goto error;
xhci_dbg(xhci, "Resetting HCD\n");
/* Reset the internal HC memory state and registers. */
retval = xhci_reset(xhci);
if (retval)
goto error;
xhci_dbg(xhci, "Reset complete\n");
temp = xhci_readl(xhci, &xhci->cap_regs->hcc_params);
if (HCC_64BIT_ADDR(temp)) {
xhci_dbg(xhci, "Enabling 64-bit DMA addresses.\n");
dma_set_mask(hcd->self.controller, DMA_BIT_MASK(64));
} else {
dma_set_mask(hcd->self.controller, DMA_BIT_MASK(32));
}
xhci_dbg(xhci, "Calling HCD init\n");
/* Initialize HCD and host controller data structures. */
retval = xhci_init(hcd);
if (retval)
goto error;
xhci_dbg(xhci, "Called HCD init\n");
pci_read_config_byte(pdev, XHCI_SBRN_OFFSET, &xhci->sbrn);
xhci_dbg(xhci, "Got SBRN %u\n", (unsigned int) xhci->sbrn);
/* Find any debug ports */
retval = xhci_pci_reinit(xhci, pdev);
if (!retval)
return retval;
error:
kfree(xhci);
return retval;
}
/*
* We need to register our own PCI probe function (instead of the USB core's
* function) in order to create a second roothub under xHCI.
*/
static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
int retval;
struct xhci_hcd *xhci;
struct hc_driver *driver;
struct usb_hcd *hcd;
driver = (struct hc_driver *)id->driver_data;
/* Register the USB 2.0 roothub.
* FIXME: USB core must know to register the USB 2.0 roothub first.
* This is sort of silly, because we could just set the HCD driver flags
* to say USB 2.0, but I'm not sure what the implications would be in
* the other parts of the HCD code.
*/
retval = usb_hcd_pci_probe(dev, id);
if (retval)
return retval;
/* USB 2.0 roothub is stored in the PCI device now. */
hcd = dev_get_drvdata(&dev->dev);
xhci = hcd_to_xhci(hcd);
xhci->shared_hcd = usb_create_shared_hcd(driver, &dev->dev,
pci_name(dev), hcd);
if (!xhci->shared_hcd) {
retval = -ENOMEM;
goto dealloc_usb2_hcd;
}
/* Set the xHCI pointer before xhci_pci_setup() (aka hcd_driver.reset)
* is called by usb_add_hcd().
*/
*((struct xhci_hcd **) xhci->shared_hcd->hcd_priv) = xhci;
retval = usb_add_hcd(xhci->shared_hcd, dev->irq,
IRQF_DISABLED | IRQF_SHARED);
if (retval)
goto put_usb3_hcd;
/* Roothub already marked as USB 3.0 speed */
return 0;
put_usb3_hcd:
usb_put_hcd(xhci->shared_hcd);
dealloc_usb2_hcd:
usb_hcd_pci_remove(dev);
return retval;
}
static void xhci_pci_remove(struct pci_dev *dev)
{
struct xhci_hcd *xhci;
xhci = hcd_to_xhci(pci_get_drvdata(dev));
if (xhci->shared_hcd) {
usb_remove_hcd(xhci->shared_hcd);
usb_put_hcd(xhci->shared_hcd);
}
usb_hcd_pci_remove(dev);
kfree(xhci);
}
#ifdef CONFIG_PM
static int xhci_pci_suspend(struct usb_hcd *hcd, bool do_wakeup)
{
struct xhci_hcd *xhci = hcd_to_xhci(hcd);
int retval = 0;
if (hcd->state != HC_STATE_SUSPENDED ||
xhci->shared_hcd->state != HC_STATE_SUSPENDED)
return -EINVAL;
retval = xhci_suspend(xhci);
return retval;
}
static int xhci_pci_resume(struct usb_hcd *hcd, bool hibernated)
{
struct xhci_hcd *xhci = hcd_to_xhci(hcd);
struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
int retval = 0;
/* The BIOS on systems with the Intel Panther Point chipset may or may
* not support xHCI natively. That means that during system resume, it
* may switch the ports back to EHCI so that users can use their
* keyboard to select a kernel from GRUB after resume from hibernate.
*
* The BIOS is supposed to remember whether the OS had xHCI ports
* enabled before resume, and switch the ports back to xHCI when the
* BIOS/OS semaphore is written, but we all know we can't trust BIOS
* writers.
*
* Unconditionally switch the ports back to xHCI after a system resume.
* We can't tell whether the EHCI or xHCI controller will be resumed
* first, so we have to do the port switchover in both drivers. Writing
* a '1' to the port switchover registers should have no effect if the
* port was already switched over.
*/
if (usb_is_intel_switchable_xhci(pdev))
usb_enable_xhci_ports(pdev);
retval = xhci_resume(xhci, hibernated);
return retval;
}
#endif /* CONFIG_PM */
static const struct hc_driver xhci_pci_hc_driver = {
.description = hcd_name,
.product_desc = "xHCI Host Controller",
.hcd_priv_size = sizeof(struct xhci_hcd *),
/*
* generic hardware linkage
*/
.irq = xhci_irq,
.flags = HCD_MEMORY | HCD_USB3 | HCD_SHARED,
/*
* basic lifecycle operations
*/
.reset = xhci_pci_setup,
.start = xhci_run,
#ifdef CONFIG_PM
.pci_suspend = xhci_pci_suspend,
.pci_resume = xhci_pci_resume,
#endif
.stop = xhci_stop,
.shutdown = xhci_shutdown,
/*
* managing i/o requests and associated device resources
*/
.urb_enqueue = xhci_urb_enqueue,
.urb_dequeue = xhci_urb_dequeue,
.alloc_dev = xhci_alloc_dev,
.free_dev = xhci_free_dev,
.alloc_streams = xhci_alloc_streams,
.free_streams = xhci_free_streams,
.add_endpoint = xhci_add_endpoint,
.drop_endpoint = xhci_drop_endpoint,
.endpoint_reset = xhci_endpoint_reset,
.check_bandwidth = xhci_check_bandwidth,
.reset_bandwidth = xhci_reset_bandwidth,
.address_device = xhci_address_device,
.update_hub_device = xhci_update_hub_device,
.reset_device = xhci_discover_or_reset_device,
/*
* scheduling support
*/
.get_frame_number = xhci_get_frame,
/* Root hub support */
.hub_control = xhci_hub_control,
.hub_status_data = xhci_hub_status_data,
.bus_suspend = xhci_bus_suspend,
.bus_resume = xhci_bus_resume,
};
/*-------------------------------------------------------------------------*/
/* PCI driver selection metadata; PCI hotplugging uses this */
static const struct pci_device_id pci_ids[] = { {
/* handle any USB 3.0 xHCI controller */
PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_USB_XHCI, ~0),
.driver_data = (unsigned long) &xhci_pci_hc_driver,
},
{ /* end: all zeroes */ }
};
MODULE_DEVICE_TABLE(pci, pci_ids);
/* pci driver glue; this is a "new style" PCI driver module */
static struct pci_driver xhci_pci_driver = {
.name = (char *) hcd_name,
.id_table = pci_ids,
.probe = xhci_pci_probe,
.remove = xhci_pci_remove,
/* suspend and resume implemented later */
.shutdown = usb_hcd_pci_shutdown,
#ifdef CONFIG_PM_SLEEP
.driver = {
.pm = &usb_hcd_pci_pm_ops
},
#endif
};
int xhci_register_pci(void)
{
return pci_register_driver(&xhci_pci_driver);
}
void xhci_unregister_pci(void)
{
pci_unregister_driver(&xhci_pci_driver);
}