OpenWrt – Rev 1

Subversion Repositories:
Rev:
From c5c72d252dc8e417388386d5767ea790ee8f5b44 Mon Sep 17 00:00:00 2001
From: Adam Wallis <awallis@codeaurora.org>
Date: Fri, 8 Dec 2017 17:59:13 +0200
Subject: [PATCH 191/224] usb: xhci: allow imod-interval to be configurable

The xHCI driver currently has the IMOD set to 160, which
translates to an IMOD interval of 40,000ns (160 * 250)ns

Commit 0cbd4b34cda9 ("xhci: mediatek: support MTK xHCI host controller")
introduced a QUIRK for the MTK platform to adjust this interval to 20,
which translates to an IMOD interval of 5,000ns (20 * 250)ns. This is
due to the fact that the MTK controller IMOD interval is 8 times
as much as defined in xHCI spec.

Instead of adding more quirk bits for additional platforms, this patch
introduces the ability for vendors to set the IMOD_INTERVAL as is
optimal for their platform. By using device_property_read_u32() on
"imod-interval-ns", the IMOD INTERVAL can be specified in nano seconds.
If no interval is specified, the default of 40,000ns (IMOD=160) will be
used.

No bounds checking has been implemented due to the fact that a vendor
may have violated the spec and would need to specify a value outside of
the max 8,000 IRQs/second limit specified in the xHCI spec.

Tested-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Adam Wallis <awallis@codeaurora.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.txt | 2 ++
 Documentation/devicetree/bindings/usb/usb-xhci.txt          | 1 +
 drivers/usb/host/xhci-mtk.c                                 | 9 +++++++++
 drivers/usb/host/xhci-pci.c                                 | 3 +++
 drivers/usb/host/xhci-plat.c                                | 5 +++++
 drivers/usb/host/xhci.c                                     | 6 +-----
 drivers/usb/host/xhci.h                                     | 2 ++
 7 files changed, 23 insertions(+), 5 deletions(-)

--- a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.txt
+++ b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.txt
@@ -46,6 +46,7 @@ Optional properties:
  - pinctrl-names : a pinctrl state named "default" must be defined
  - pinctrl-0 : pin control group
        See: Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
+ - imod-interval-ns: default interrupt moderation interval is 5000ns
 
 Example:
 usb30: usb@11270000 {
@@ -66,6 +67,7 @@ usb30: usb@11270000 {
        usb3-lpm-capable;
        mediatek,syscon-wakeup = <&pericfg>;
        mediatek,wakeup-src = <1>;
+       imod-interval-ns = <10000>;
 };
 
 2nd: dual-role mode with xHCI driver
--- a/Documentation/devicetree/bindings/usb/usb-xhci.txt
+++ b/Documentation/devicetree/bindings/usb/usb-xhci.txt
@@ -29,6 +29,7 @@ Optional properties:
   - clocks: reference to a clock
   - usb3-lpm-capable: determines if platform is USB3 LPM capable
   - quirk-broken-port-ped: set if the controller has broken port disable mechanism
+  - imod-interval-ns: default interrupt moderation interval is 5000ns
 
 Example:
        usb@f0931000 {
--- a/drivers/usb/host/xhci-mtk.c
+++ b/drivers/usb/host/xhci-mtk.c
@@ -629,6 +629,15 @@ static int xhci_mtk_probe(struct platfor
 
        xhci = hcd_to_xhci(hcd);
        xhci->main_hcd = hcd;
+
+       /*
+        * imod_interval is the interrupt moderation value in nanoseconds.
+        * The increment interval is 8 times as much as that defined in
+        * the xHCI spec on MTK's controller.
+        */
+       xhci->imod_interval = 5000;
+       device_property_read_u32(dev, "imod-interval-ns", &xhci->imod_interval);
+
        xhci->shared_hcd = usb_create_shared_hcd(driver, dev,
                        dev_name(dev), hcd);
        if (!xhci->shared_hcd) {
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -277,6 +277,9 @@ static int xhci_pci_setup(struct usb_hcd
        if (!xhci->sbrn)
                pci_read_config_byte(pdev, XHCI_SBRN_OFFSET, &xhci->sbrn);
 
+       /* imod_interval is the interrupt moderation value in nanoseconds. */
+       xhci->imod_interval = 40000;
+
        retval = xhci_gen_setup(hcd, xhci_pci_quirks);
        if (retval)
                return retval;
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -269,6 +269,11 @@ static int xhci_plat_probe(struct platfo
        if (device_property_read_bool(&pdev->dev, "quirk-broken-port-ped"))
                xhci->quirks |= XHCI_BROKEN_PORT_PED;
 
+       /* imod_interval is the interrupt moderation value in nanoseconds. */
+       xhci->imod_interval = 40000;
+       device_property_read_u32(sysdev, "imod-interval-ns",
+                                &xhci->imod_interval);
+
        hcd->usb_phy = devm_usb_get_phy_by_phandle(sysdev, "usb-phy", 0);
        if (IS_ERR(hcd->usb_phy)) {
                ret = PTR_ERR(hcd->usb_phy);
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -612,11 +612,7 @@ int xhci_run(struct usb_hcd *hcd)
                        "// Set the interrupt modulation register");
        temp = readl(&xhci->ir_set->irq_control);
        temp &= ~ER_IRQ_INTERVAL_MASK;
-       /*
-        * the increment interval is 8 times as much as that defined
-        * in xHCI spec on MTK's controller
-        */
-       temp |= (u32) ((xhci->quirks & XHCI_MTK_HOST) ? 20 : 160);
+       temp |= (xhci->imod_interval / 250) & ER_IRQ_INTERVAL_MASK;
        writel(temp, &xhci->ir_set->irq_control);
 
        /* Set the HCD state before we enable the irqs */
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1730,6 +1730,8 @@ struct xhci_hcd {
        u8              max_interrupters;
        u8              max_ports;
        u8              isoc_threshold;
+       /* imod_interval in ns (I * 250ns) */
+       u32             imod_interval;
        int             event_ring_max;
        /* 4KB min, 128MB max */
        int             page_size;