lwn.git/drivers/usb/dwc3/dwc3-qcom.c, branch docs-fixes

usb: dwc3: qcom: simplify error check in dwc3_qcom_find_num_ports()

2026-03-11T14:23:37+00:00

The platform_get_irq_byname_optional() function returns a non-zero IRQ number on success and a negative error code on failure. It never returns zero. The current implementation in the modern dwc3-qcom driver checks for a return value less than or equal to zero. Since zero is not a valid return value, simplify the check to only look for negative error codes. This aligns the logic with the standard return contract of the platform IRQ APIs. Signed-off-by: Zeeshan Ahmad Acked-by: Thinh Nguyen Link: https://patch.msgid.link/20260225065157.8952-1-zeeshanahmad022019@gmail.com Signed-off-by: Greg Kroah-Hartman

usb: dwc3: Add software-managed properties for flattened model

2025-10-13T07:11:50+00:00

Add software-managed properties for the flattened model, which does not need to use device tree properties to pass down information to the common DWC3 core. Add 'properties' in dwc3_probe_data and set default values for existing users (dwc3-qcom, dwc3-generic-plat). No functional changes. Acked-by: Thinh Nguyen Signed-off-by: Frank Li Link: https://lore.kernel.org/r/20250929-ls_dma_coherence-v5-2-2ebee578eb7e@nxp.com Signed-off-by: Greg Kroah-Hartman

usb: dwc3: qcom: Implement glue callbacks to facilitate runtime suspend

2025-09-12T12:04:20+00:00

On Qualcomm DWC3 dual-role controllers, the conndone/disconnect events in device mode are generated by controller when software writes to QSCRATCH registers in Qualcomm Glue layer rather than the vbus line being routed to dwc3 core IP for it to recognize and generate these events. UTMI_OTG_VBUS_VALID bit of QSCRATCH_HS_PHY_CTRL register needs to be set to generate a connection done event and to be cleared for the controller to generate a disconnect event during cable removal. When the disconnect is not generated upon cable removal, the "connected" flag of dwc3 is left marked as "true" and it blocks suspend routines and for that to happen upon cable removal, the cable disconnect notification coming in via set_role call need to be provided to the Qualcomm glue layer as well. Currently, the way DWC3 core and Qualcomm legacy glue driver are designed, there is no mechanism through which the DWC3 core can notify the Qualcomm glue layer of any role changes which it receives via role switch. To register these glue callbacks at probe time, for enabling core to notify glue layer, the legacy Qualcomm driver has no way to find out when the child driver probe was successful since it does not check for the same during of_platform_populate. Hence implement the following glue callbacks for flattened Qualcomm glue driver: 1. set_role: To pass role switching information from drd layer to glue. This information is needed to identify NONE/DEVICE mode switch and modify QSCRATCH to generate connect-done event on device mode entry and disconnect event on cable removal in device mode. 2. run_stop: When booting up in device mode, if autouspend is enabled and userspace doesn't write UDC on boot, controller enters autosuspend. After this, if the userspace writes to UDC in the future, run_stop notifier is required to enable UTMI_OTG_VBUS_VALID of QSCRATCH so that connect done event is generated after run_stop(1) is done to finish enumeration. Acked-by: Thinh Nguyen Signed-off-by: Krishna Kurapati Link: https://lore.kernel.org/r/20250907181412.2174616-3-krishna.kurapati@oss.qualcomm.com Signed-off-by: Greg Kroah-Hartman

usb: dwc3: qcom: Remove extcon functionality from glue layer

2025-08-13T14:55:42+00:00

Historically Qualcomm DWC3 glue driver supported both extcon and usb-role-switch kinds of notifications. When Bjorn contributed [1] the flattened representation for the DWC3 host controller, he also kept both extcon and usb-role-switch support in the flattened driver & bindings. Currently there are no in-kernel users for flattened DWC3 and extcon. As device's DT needs to be manually converted from legacy to the flat DWC3 representation, we can drop (legacy / deprecated) extcon support from the new DWC3 glue driver, significantly simplifying the code. This potentially affects flattening effort for the following platforms: Platforms currently using linux,extcon-usb-gpio device that need to switch to gpio-usb-b-connector: - apq8096-db820c, - msm8996-sony-xperia-tone-dora Platforms currently using linux,extcon-usb-gpio device that need to switch to gpio-usb-c-connector (not supported at this moment) or to implement typec support - msm8996-sony-xperia-tone-kagura - msm8996-sony-xperia-tone-keyaki - msm8998-fxtec-pro1 - msm8998-sony-xperia-yoshino-lilac - msm8998-sony-xperia-yoshino-maple - msm8998-sony-xperia-yoshino-poplar - sda660-inforce-ifc6560 - sdm630-sony-xperia-nile-discovery - sdm630-sony-xperia-nile-pioneer - sdm630-sony-xperia-nile-voyager - sdm660-xiaomi-lavender - sm6125-sony-xperia-seine-pdx201 - sm6125-xiaomi-ginkgo - sm6125-xiaomi-laurel-sprout Platforms using TI TUSB320L chip need to switch to represent the USB-C connector properly (and to have a typec-class driver for the TUSB320L chip): - msm8996-xiaomi-gemini - msm8996pro-xiaomi-natrium - msm8996pro-xiaomi-scoprpio Commit message suggested by Dmitry Baryshkov. [1]: https://lore.kernel.org/all/20250414-dwc3-refactor-v7-0-f015b358722d@oss.qualcomm.com/ Signed-off-by: Krishna Kurapati Acked-by: Thinh Nguyen Reviewed-by: Dmitry Baryshkov Reviewed-by: Konrad Dybcio Link: https://lore.kernel.org/r/20250729092708.3628187-1-krishna.kurapati@oss.qualcomm.com Signed-off-by: Greg Kroah-Hartman

usb: dwc3: qcom: Add shutdown handler

2025-08-13T14:52:46+00:00

Currently during system reboot, SMMU disables its translations while devices like USB may still be actively using DMA buffers. This can lead to NOC errors and system crashes due to invalid memory access. Address this by adding a shutdown callback to dwc3-qcom, which ensures proper teardown of UDC stack and prevents DWC3 controller from accessing memory after SMMU translation is disabled. Reuse the existing remove callback for this purpose. Signed-off-by: Prashanth K Acked-by: Thinh Nguyen Link: https://lore.kernel.org/r/20250725062158.2418961-1-prashanth.k@oss.qualcomm.com Signed-off-by: Greg Kroah-Hartman

usb: dwc3: qcom: Don't leave BCR asserted

2025-07-13T15:30:59+00:00

Leaving the USB BCR asserted prevents the associated GDSC to turn on. This blocks any subsequent attempts of probing the device, e.g. after a probe deferral, with the following showing in the log: [ 1.332226] usb30_prim_gdsc status stuck at 'off' Leave the BCR deasserted when exiting the driver to avoid this issue. Cc: stable Fixes: a4333c3a6ba9 ("usb: dwc3: Add Qualcomm DWC3 glue driver") Acked-by: Thinh Nguyen Reviewed-by: Konrad Dybcio Signed-off-by: Krishna Kurapati Link: https://lore.kernel.org/r/20250709132900.3408752-1-krishna.kurapati@oss.qualcomm.com Signed-off-by: Greg Kroah-Hartman

usb: dwc3: qcom: Use bulk clock API and devres

2025-05-21T11:10:23+00:00

The Qualcomm DWC3 glue driver duplicates the logic of the bulk clock API to acquire, prepare, and unprepare the controller's clocks. It also manages the life cycle of these handled explicitly. Transition to the bulk clock API and manage the resources using devres, to clean up the code. The resource acquisition is moved above the initial reset pulse, to handle resource issues before the state is touched - other than this, this no functional change. Signed-off-by: Bjorn Andersson Acked-by: Thinh Nguyen Link: https://lore.kernel.org/r/20250508-dwc3-clk-bulk-v2-1-bad3427e88d4@oss.qualcomm.com Signed-off-by: Greg Kroah-Hartman

usb: dwc3: qcom: Fix error handling in probe

2025-04-25T11:22:25+00:00

There are two issues: 1) Return -EINVAL if platform_get_resource() fails. Don't return success. 2) The devm_ioremap() function doesn't return error pointers, it returns NULL. Update the check. Fixes: 1881a32fe14d ("usb: dwc3: qcom: Transition to flattened model") Signed-off-by: Dan Carpenter Reviewed-by: Bjorn Andersson Acked-by: Thinh Nguyen Link: https://lore.kernel.org/r/aAijmfAph0FlTqg6@stanley.mountain Signed-off-by: Greg Kroah-Hartman

usb: dwc3: qcom: use modern PM macros

2025-04-25T11:22:00+00:00

The use of the old SET_SYSTEM_SLEEP_PM_OPS/SET_RUNTIME_PM_OPS macros without __maybe_unused annotations causes warnings when build testing without CONFIG_PM: drivers/usb/dwc3/dwc3-qcom.c:421:12: error: unused function 'dwc3_qcom_suspend' [-Werror,-Wunused-function] 421 | static int dwc3_qcom_suspend(struct dwc3_qcom *qcom, bool wakeup) | ^~~~~~~~~~~~~~~~~ drivers/usb/dwc3/dwc3-qcom.c:457:12: error: unused function 'dwc3_qcom_resume' [-Werror,-Wunused-function] 457 | static int dwc3_qcom_resume(struct dwc3_qcom *qcom, bool wakeup) Change these to the modern SYSTEM_SLEEP_PM_OPS/RUNTIME_PM_OPS/pm_ptr macros, which avoids the warnings and improves readability at the same time. Fixes: 1881a32fe14d ("usb: dwc3: qcom: Transition to flattened model") Signed-off-by: Arnd Bergmann Reviewed-by: Abel Vesa Acked-by: Thinh Nguyen Link: https://lore.kernel.org/r/20250423162613.2082417-1-arnd@kernel.org Signed-off-by: Greg Kroah-Hartman

usb: dwc3: qcom: Transition to flattened model

2025-04-15T12:29:19+00:00

The USB IP-block found in most Qualcomm platforms is modelled in the Linux kernel as 3 different independent device drivers, but as shown by the already existing layering violations in the Qualcomm glue driver they can not be operated independently. With the current implementation, the glue driver registers the core and has no way to know when this is done. As a result, e.g. the suspend callbacks needs to guard against NULL pointer dereferences when trying to peek into the struct dwc3 found in the drvdata of the child. Even with these checks, there are no way to fully protect ourselves from the race conditions that occur if the DWC3 is unbound. Missing from the upstream Qualcomm USB support is handling of role switching, in which the glue needs to be notified upon DRD mode changes. Several attempts has been made through the years to register callbacks etc, but they always fall short when it comes to handling of the core's probe deferral on resources etc. Moving to a model where the DWC3 core is instantiated in a synchronous fashion avoids above described race conditions. It is however not feasible to do so without also flattening the DeviceTree binding, as assumptions are made in the DWC3 core and frameworks used that the device's associated of_node will the that of the core. Furthermore, the DeviceTree binding is a direct representation of the Linux driver model, and doesn't necessarily describe "the USB IP-block". The Qualcomm DWC3 glue driver is therefor transitioned to initialize and operate the DWC3 within the one device context, in synchronous fashion. To provide a limited time backwards compatibility, a snapshot of the driver is retained in a previous commit. As such no care is taken in the dwc3-qcom driver for the qcom,dwc3 backwards compatibility. Acked-by: Thinh Nguyen Tested-by: Neil Armstrong # on SM8650-QRD Signed-off-by: Bjorn Andersson Link: https://lore.kernel.org/r/20250414-dwc3-refactor-v7-6-f015b358722d@oss.qualcomm.com Signed-off-by: Greg Kroah-Hartman