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>
- 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 {
usb3-lpm-capable;
mediatek,syscon-wakeup = <&pericfg>;
mediatek,wakeup-src = <1>;
+ imod-interval-ns = <10000>;
};
2nd: dual-role mode with xHCI driver
- usb2-lpm-disable: indicate if we don't want to enable USB2 HW LPM
- 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 {
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) {
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;
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);
"// 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 */
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;