[PATCH v3 08/12] xhci: Add Intel extended cap / otg phy mux handling

Hans de Goede
2018-02-26T09:09:21Z

The xHCI controller on various Intel SoCs has an extended cap mmio-range
which contains registers to control the muxing to the xHCI (host mode)
or the dwc3 (device mode) and vbus-detection for the otg usb-phy.

Having a role-sw driver included in the xHCI code (under drivers/usb/host)
is not desirable. So this commit adds a simple handler for this extended
capability, which creates a platform device with the caps mmio region as
resource, this allows us to write a separate platform role-sw driver for
the role-switch.

Note this commit adds a call to the new xhci_ext_cap_init() function
to xhci_pci_probe(), it is added here because xhci_ext_cap_init() must
be called only once. If in the future we also want to handle ext-caps
on non pci xHCI HCDs from xhci_ext_cap_init() a call to it should also
be added to other bus probe paths.

Acked-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v2:
-Use SPDX license header
-Various small style cleanups / changes
-Add Heikki's Reviewed-by

Changes from some time ago when this patch was part of another patch-set:
-Check xHCI controller PCI device-id instead of only checking for the
Intel Extended capability ID, as the Extended capability ID is used on
other model Intel xHCI controllers too
-Add a new generic xhci_ext_cap_init() function and handle the new
XHCI_INTEL_CHT_USB_MUX quirk there.
-Stop using Cherry Trail / CHT in various places as other Intel SoCs
(e.g. Broxton / Apollo Lake) also have this
---
drivers/usb/host/Makefile | 2 +-
drivers/usb/host/xhci-ext-caps.c | 90 ++++++++++++++++++++++++++++++++++++++++
drivers/usb/host/xhci-ext-caps.h | 2 +
drivers/usb/host/xhci-pci.c | 5 +++
drivers/usb/host/xhci.h | 2 +
5 files changed, 100 insertions(+), 1 deletion(-)
create mode 100644 drivers/usb/host/xhci-ext-caps.c

diff --git a/drivers/usb/host/Makefile b/drivers/usb/host/Makefile
index 4ede4ce12366..8a8cffe0b445 100644
--- a/drivers/usb/host/Makefile
+++ b/drivers/usb/host/Makefile
@@ -11,7 +11,7 @@ fhci-y += fhci-mem.o fhci-tds.o fhci-sched.o

fhci-$(CONFIG_FHCI_DEBUG) += fhci-dbg.o

-xhci-hcd-y := xhci.o xhci-mem.o
+xhci-hcd-y := xhci.o xhci-mem.o xhci-ext-caps.o
xhci-hcd-y += xhci-ring.o xhci-hub.o xhci-dbg.o
xhci-hcd-y += xhci-trace.o

diff --git a/drivers/usb/host/xhci-ext-caps.c b/drivers/usb/host/xhci-ext-caps.c
new file mode 100644
index 000000000000..399113f9fc5c
--- /dev/null
+++ b/drivers/usb/host/xhci-ext-caps.c
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * XHCI extended capability handling
+ *
+ * Copyright (c) 2017 Hans de Goede <hdegoede@redhat.com>
+ */
+
+#include <linux/platform_device.h>
+#include "xhci.h"
+
+#define USB_SW_DRV_NAME "intel_xhci_usb_sw"
+#define USB_SW_RESOURCE_SIZE 0x400
+
+static void xhci_intel_unregister_pdev(void *arg)
+{
+ platform_device_unregister(arg);
+}
+
+static int xhci_create_intel_xhci_sw_pdev(struct xhci_hcd *xhci, u32 cap_offset)
+{
+ struct usb_hcd *hcd = xhci_to_hcd(xhci);
+ struct device *dev = hcd->self.controller;
+ struct platform_device *pdev;
+ struct resource res = { 0, };
+ int ret;
+
+ pdev = platform_device_alloc(USB_SW_DRV_NAME, PLATFORM_DEVID_NONE);
+ if (!pdev) {
+ xhci_err(xhci, "couldn't allocate %s platform device\n",
+ USB_SW_DRV_NAME);
+ return -ENOMEM;
+ }
+
+ res.start = hcd->rsrc_start + cap_offset;
+ res.end = res.start + USB_SW_RESOURCE_SIZE - 1;
+ res.name = USB_SW_DRV_NAME;
+ res.flags = IORESOURCE_MEM;
+
+ ret = platform_device_add_resources(pdev, &res, 1);
+ if (ret) {
+ dev_err(dev, "couldn't add resources to intel_xhci_usb_sw pdev\n");
+ platform_device_put(pdev);
+ return ret;
+ }
+
+ pdev->dev.parent = dev;
+
+ ret = platform_device_add(pdev);
+ if (ret) {
+ dev_err(dev, "couldn't register intel_xhci_usb_sw pdev\n");
+ platform_device_put(pdev);
+ return ret;
+ }
+
+ ret = devm_add_action_or_reset(dev, xhci_intel_unregister_pdev, pdev);
+ if (ret) {
+ dev_err(dev, "couldn't add unregister action for intel_xhci_usb_sw pdev\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+int xhci_ext_cap_init(struct xhci_hcd *xhci)
+{
+ void __iomem *base = &xhci->cap_regs->hc_capbase;
+ u32 offset, val;
+ int ret;
+
+ offset = xhci_find_next_ext_cap(base, 0, 0);
+
+ while (offset) {
+ val = readl(base + offset);
+
+ switch (XHCI_EXT_CAPS_ID(val)) {
+ case XHCI_EXT_CAPS_VENDOR_INTEL:
+ if (xhci->quirks & XHCI_INTEL_USB_ROLE_SW) {
+ ret = xhci_create_intel_xhci_sw_pdev(xhci,
+ offset);
+ if (ret)
+ return ret;
+ }
+ break;
+ }
+ offset = xhci_find_next_ext_cap(base, offset, 0);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(xhci_ext_cap_init);
diff --git a/drivers/usb/host/xhci-ext-caps.h b/drivers/usb/host/xhci-ext-caps.h
index 631e7cc62604..268328c20681 100644
--- a/drivers/usb/host/xhci-ext-caps.h
+++ b/drivers/usb/host/xhci-ext-caps.h
@@ -39,6 +39,8 @@
#define XHCI_EXT_CAPS_ROUTE 5
/* IDs 6-9 reserved */
#define XHCI_EXT_CAPS_DEBUG 10
+/* Vendor caps */
+#define XHCI_EXT_CAPS_VENDOR_INTEL 192
/* USB Legacy Support Capability - section 7.1.1 */
#define XHCI_HC_BIOS_OWNED (1 << 16)
#define XHCI_HC_OS_OWNED (1 << 24)
diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 6c79037876db..4486640d925c 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -164,6 +164,7 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
if (pdev->vendor == PCI_VENDOR_ID_INTEL &&
pdev->device == PCI_DEVICE_ID_INTEL_CHERRYVIEW_XHCI) {
xhci->quirks |= XHCI_SSIC_PORT_UNUSED;
+ xhci->quirks |= XHCI_INTEL_USB_ROLE_SW;
}
if (pdev->vendor == PCI_VENDOR_ID_INTEL &&
(pdev->device == PCI_DEVICE_ID_INTEL_CHERRYVIEW_XHCI ||
@@ -297,6 +298,10 @@ static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
goto dealloc_usb2_hcd;
}

+ retval = xhci_ext_cap_init(xhci);
+ if (retval)
+ goto put_usb3_hcd;
+
retval = usb_add_hcd(xhci->shared_hcd, dev->irq,
IRQF_SHARED);
if (retval)
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 96099a245c69..5917e3095e2a 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1825,6 +1825,7 @@ struct xhci_hcd {
/* Reserved. It was XHCI_U2_DISABLE_WAKE */
#define XHCI_ASMEDIA_MODIFY_FLOWCONTROL (1 << 28)
#define XHCI_HW_LPM_DISABLE (1 << 29)
+#define XHCI_INTEL_USB_ROLE_SW (1 << 30)

unsigned int num_active_eps;
unsigned int limit_active_eps;
@@ -2020,6 +2021,7 @@ int xhci_gen_setup(struct usb_hcd *hcd, xhci_get_quirks_t get_quirks);
void xhci_init_driver(struct hc_driver *drv,
const struct xhci_driver_overrides *over);
int xhci_disable_slot(struct xhci_hcd *xhci, u32 slot_id);
+int xhci_ext_cap_init(struct xhci_hcd *xhci);

int xhci_suspend(struct xhci_hcd *xhci, bool do_wakeup);
int xhci_resume(struct xhci_hcd *xhci, bool hibernated);
--
2.14.3