| Message ID | 20250113-dwc3-refactor-v3-0-d1722075df7b@oss.qualcomm.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | usb: dwc3: qcom: Flatten dwc3 structure | expand |
On Mon, Jan 13, 2025 at 09:11:33PM -0800, Bjorn Andersson wrote: > 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. > > Missing from the upstream Qualcomm USB support is proper 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. > > Furhtermore, the DeviceTree binding is a direct representation of the > Linux driver model, and doesn't necessarily describe "the USB IP-block". > > This series therefor attempts to flatten the driver split, and operate > the glue and core out of the same platform_device instance. And in order > to do this, the DeviceTree representation of the IP block is flattened. > > To avoid littering the dwc3-qcom driver with the migration code - which > we should be able to drop again in a LTS or two - this is now placed in > drivers/of/overlays. > > A patch to convert a single platform - sc8280xp - is included in the > series. The broader conversion will be submitted in a follow up series. Is it not possible to use the same overlays also fixup the .dts files at build time? Rob
On Tue, Jan 14, 2025 at 11:44:52AM -0600, Rob Herring wrote: > On Mon, Jan 13, 2025 at 09:11:33PM -0800, Bjorn Andersson wrote: > > 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. > > > > Missing from the upstream Qualcomm USB support is proper 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. > > > > Furhtermore, the DeviceTree binding is a direct representation of the > > Linux driver model, and doesn't necessarily describe "the USB IP-block". > > > > This series therefor attempts to flatten the driver split, and operate > > the glue and core out of the same platform_device instance. And in order > > to do this, the DeviceTree representation of the IP block is flattened. > > > > To avoid littering the dwc3-qcom driver with the migration code - which > > we should be able to drop again in a LTS or two - this is now placed in > > drivers/of/overlays. > > > > A patch to convert a single platform - sc8280xp - is included in the > > series. The broader conversion will be submitted in a follow up series. > > Is it not possible to use the same overlays also fixup the .dts files at > build time? > I presume so. What would the benefit of that be, over fixing up the source asap? Regards, Bjorn
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. Missing from the upstream Qualcomm USB support is proper 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. Furhtermore, the DeviceTree binding is a direct representation of the Linux driver model, and doesn't necessarily describe "the USB IP-block". This series therefor attempts to flatten the driver split, and operate the glue and core out of the same platform_device instance. And in order to do this, the DeviceTree representation of the IP block is flattened. To avoid littering the dwc3-qcom driver with the migration code - which we should be able to drop again in a LTS or two - this is now placed in drivers/of/overlays. A patch to convert a single platform - sc8280xp - is included in the series. The broader conversion will be submitted in a follow up series. --- Changes in v3: - Replaced the handcoded migration logic of compatible, reg, interrupts, phys with overlays. - Move the migration logic (and overlays) to a new drivers/of/overlays directory and apply this at postcore, so that it takes effect prior to the relevant platform_devices are created - struct dwc3 is embedded in the glue context, rather than having a separate object allocated - The hack of using of_address_to_resource() to avoid platform_resource being stale is removed (thanks to applying migration at postcore) - Link to v2: https://lore.kernel.org/r/20240811-dwc3-refactor-v2-0-91f370d61ad2@quicinc.com Changes in v2: - Rewrite after ACPI removal, multiport support and interrupt fixes - Completely changed strategy for DeviceTree binding, as previous idea of using snps,dwc3 as a generic fallback required unreasonable changes to that binding. - Abandoned idea of supporting both flattened and unflattened device model in the one driver. As Johan pointed out, it will leave the race condition holes and will make the code harder to understand. Furthermore, the role switching logic that we intend to introduce following this would have depended on the user updating their DeviceTree blobs. - Per above, introduced the dynamic DeviceTree rewrite - Link to v1: https://lore.kernel.org/all/20231016-dwc3-refactor-v1-0-ab4a84165470@quicinc.com/ --- Bjorn Andersson (12): dt-bindings: usb: snps,dwc3: Split core description dt-bindings: usb: Introduce qcom,snps-dwc3 of: dynamic: Add of_changeset_add_prop_copy() of: overlays: Introduce dwc3 flattening overlay of: overlays: dwc3-flattening: Add Qualcomm Arm32 overlays of: overlays: dwc3-flattening: Add Qualcomm Arm64 board overlays of: overlays: dwc3-flattening: Provide overlay symbols usb: dwc3: core: Expose core driver as library usb: dwc3: core: Don't touch resets and clocks usb: dwc3: qcom: Don't rely on drvdata during probe usb: dwc3: qcom: Transition to flattened model arm64: dts: qcom: sc8280x: Flatten the USB nodes .../devicetree/bindings/usb/qcom,dwc3.yaml | 13 +- .../devicetree/bindings/usb/qcom,snps-dwc3.yaml | 618 ++++++++ .../devicetree/bindings/usb/snps,dwc3-common.yaml | 415 ++++++ .../devicetree/bindings/usb/snps,dwc3.yaml | 391 +---- arch/arm64/boot/dts/qcom/sa8295p-adp.dts | 12 +- arch/arm64/boot/dts/qcom/sa8540p-ride.dts | 5 +- arch/arm64/boot/dts/qcom/sc8280xp-crd.dts | 12 +- .../boot/dts/qcom/sc8280xp-huawei-gaokun3.dts | 10 +- .../dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts | 11 +- .../boot/dts/qcom/sc8280xp-microsoft-arcata.dts | 10 +- .../boot/dts/qcom/sc8280xp-microsoft-blackrock.dts | 18 +- arch/arm64/boot/dts/qcom/sc8280xp.dtsi | 157 +- drivers/of/Kconfig | 2 + drivers/of/Makefile | 2 + drivers/of/dynamic.c | 20 + drivers/of/overlays/Kconfig | 15 + drivers/of/overlays/Makefile | 3 + drivers/of/overlays/dwc3-flattening/Makefile | 94 ++ .../of/overlays/dwc3-flattening/dwc3-flattening.c | 1552 ++++++++++++++++++++ .../of/overlays/dwc3-flattening/dwc3-flattening.h | 188 +++ .../overlays/dwc3-flattening/dwc3-qcom_apq8094.dts | 32 + .../overlays/dwc3-flattening/dwc3-qcom_apq8096.dts | 60 + .../dwc3-qcom_apq8096_inforce_ifc6640.dts | 58 + .../overlays/dwc3-flattening/dwc3-qcom_ipq4018.dts | 36 + .../dwc3-qcom_ipq4018_8dev_jalapeno.dts | 38 + .../overlays/dwc3-flattening/dwc3-qcom_ipq4019.dts | 38 + .../overlays/dwc3-flattening/dwc3-qcom_ipq5018.dts | 28 + .../overlays/dwc3-flattening/dwc3-qcom_ipq5332.dts | 32 + .../overlays/dwc3-flattening/dwc3-qcom_ipq5424.dts | 58 + .../overlays/dwc3-flattening/dwc3-qcom_ipq6018.dts | 54 + .../overlays/dwc3-flattening/dwc3-qcom_ipq8064.dts | 40 + .../overlays/dwc3-flattening/dwc3-qcom_ipq8074.dts | 58 + .../overlays/dwc3-flattening/dwc3-qcom_ipq9574.dts | 29 + .../overlays/dwc3-flattening/dwc3-qcom_msm8953.dts | 32 + .../overlays/dwc3-flattening/dwc3-qcom_msm8992.dts | 32 + .../overlays/dwc3-flattening/dwc3-qcom_msm8994.dts | 32 + .../overlays/dwc3-flattening/dwc3-qcom_msm8996.dts | 58 + .../dwc3-qcom_msm8996_oneplus_oneplus3.dts | 56 + .../dwc3-qcom_msm8996_oneplus_oneplus3t.dts | 56 + .../dwc3-qcom_msm8996_sony_dora_row.dts | 57 + .../dwc3-qcom_msm8996_sony_kagura_row.dts | 57 + .../dwc3-qcom_msm8996_sony_keyaki_row.dts | 57 + .../dwc3-qcom_msm8996_xiaomi_gemini.dts | 56 + .../dwc3-qcom_msm8996_xiaomi_natrium.dts | 56 + .../dwc3-qcom_msm8996_xiaomi_scorpio.dts | 56 + .../overlays/dwc3-flattening/dwc3-qcom_msm8998.dts | 34 + .../dwc3-qcom_msm8998_fxtec_pro1.dts | 35 + .../dwc3-qcom_msm8998_oneplus_cheeseburger.dts | 32 + .../dwc3-qcom_msm8998_oneplus_dumpling.dts | 32 + .../dwc3-qcom_msm8998_sony_xperia_lilac.dts | 35 + .../dwc3-qcom_msm8998_sony_xperia_maple.dts | 35 + .../dwc3-qcom_msm8998_sony_xperia_poplar.dts | 35 + .../dwc3-qcom_msm8998_xiaomi_sagit.dts | 32 + .../overlays/dwc3-flattening/dwc3-qcom_qcm2290.dts | 32 + .../overlays/dwc3-flattening/dwc3-qcom_qcm6490.dts | 63 + .../overlays/dwc3-flattening/dwc3-qcom_qcs404.dts | 56 + .../overlays/dwc3-flattening/dwc3-qcom_qcs615.dts | 62 + .../overlays/dwc3-flattening/dwc3-qcom_qcs8300.dts | 62 + .../overlays/dwc3-flattening/dwc3-qcom_qdu1000.dts | 38 + .../overlays/dwc3-flattening/dwc3-qcom_qru1000.dts | 38 + .../overlays/dwc3-flattening/dwc3-qcom_sa8155p.dts | 71 + .../overlays/dwc3-flattening/dwc3-qcom_sa8540p.dts | 129 ++ .../overlays/dwc3-flattening/dwc3-qcom_sa8775p.dts | 90 ++ .../dwc3-flattening/dwc3-qcom_sar2130p.dts | 39 + .../overlays/dwc3-flattening/dwc3-qcom_sc7180.dts | 39 + .../overlays/dwc3-flattening/dwc3-qcom_sc7280.dts | 63 + .../overlays/dwc3-flattening/dwc3-qcom_sc8180x.dts | 109 ++ .../dwc3-flattening/dwc3-qcom_sc8280xp.dts | 129 ++ .../dwc3-qcom_sc8280xp_microsoft_blackrock.dts | 121 ++ .../overlays/dwc3-flattening/dwc3-qcom_sda660.dts | 59 + .../overlays/dwc3-flattening/dwc3-qcom_sdm450.dts | 33 + .../overlays/dwc3-flattening/dwc3-qcom_sdm630.dts | 57 + .../overlays/dwc3-flattening/dwc3-qcom_sdm632.dts | 32 + .../overlays/dwc3-flattening/dwc3-qcom_sdm636.dts | 59 + .../overlays/dwc3-flattening/dwc3-qcom_sdm660.dts | 57 + .../overlays/dwc3-flattening/dwc3-qcom_sdm670.dts | 36 + .../overlays/dwc3-flattening/dwc3-qcom_sdm845.dts | 64 + .../dwc3-qcom_sdm845_lenovo_yoga_c630.dts | 67 + .../dwc3-flattening/dwc3-qcom_sdm845_lg_judyln.dts | 67 + .../dwc3-flattening/dwc3-qcom_sdm845_lg_judyp.dts | 67 + .../dwc3-qcom_sdm845_qcom_sdm845_mtp.dts | 67 + .../dwc3-qcom_sdm845_samsung_starqltechn.dts | 67 + .../dwc3-qcom_sdm845_samsung_w737.dts | 67 + .../dwc3-qcom_sdm845_shift_axolotl.dts | 67 + .../dwc3-qcom_sdm845_thundercomm_db845c.dts | 67 + .../dwc3-qcom_sdm845_xiaomi_beryllium.dts | 67 + .../dwc3-qcom_sdm845_xiaomi_beryllium_ebbg.dts | 67 + .../overlays/dwc3-flattening/dwc3-qcom_sdx55.dts | 38 + .../overlays/dwc3-flattening/dwc3-qcom_sdx65.dts | 38 + .../overlays/dwc3-flattening/dwc3-qcom_sdx75.dts | 36 + .../overlays/dwc3-flattening/dwc3-qcom_sm4250.dts | 37 + .../dwc3-qcom_sm4250_oneplus_billie2.dts | 35 + .../overlays/dwc3-flattening/dwc3-qcom_sm6115.dts | 37 + .../dwc3-qcom_sm6115_lenovo_j606f.dts | 35 + .../overlays/dwc3-flattening/dwc3-qcom_sm6125.dts | 36 + .../overlays/dwc3-flattening/dwc3-qcom_sm6350.dts | 39 + .../overlays/dwc3-flattening/dwc3-qcom_sm6375.dts | 36 + .../overlays/dwc3-flattening/dwc3-qcom_sm7125.dts | 39 + .../overlays/dwc3-flattening/dwc3-qcom_sm7225.dts | 39 + .../overlays/dwc3-flattening/dwc3-qcom_sm7325.dts | 60 + .../overlays/dwc3-flattening/dwc3-qcom_sm8150.dts | 67 + .../overlays/dwc3-flattening/dwc3-qcom_sm8250.dts | 67 + .../dwc3-qcom_sm8250_xiaomi_elish.dts | 64 + .../overlays/dwc3-flattening/dwc3-qcom_sm8350.dts | 67 + .../dwc3-qcom_sm8350_microsoft_surface_duo2.dts | 67 + .../dwc3-qcom_sm8350_qcom_sm8350_hdk.dts | 69 + .../dwc3-qcom_sm8350_qcom_sm8350_mtp.dts | 67 + .../dwc3-qcom_sm8350_sony_pdx214_generic.dts | 67 + .../dwc3-qcom_sm8350_sony_pdx215_generic.dts | 67 + .../overlays/dwc3-flattening/dwc3-qcom_sm8450.dts | 39 + .../overlays/dwc3-flattening/dwc3-qcom_sm8550.dts | 39 + .../overlays/dwc3-flattening/dwc3-qcom_sm8650.dts | 39 + .../dwc3-flattening/dwc3-qcom_x1e80100.dts | 153 ++ .../dwc3-qcom_x1e80100_hp_omnibook_x14.dts | 149 ++ drivers/usb/dwc3/core.c | 167 ++- drivers/usb/dwc3/dwc3-qcom.c | 149 +- drivers/usb/dwc3/glue.h | 22 + include/linux/of.h | 3 + 118 files changed, 8389 insertions(+), 670 deletions(-) --- base-commit: 6ecd20965bdc21b265a0671ccf36d9ad8043f5ab change-id: 20231016-dwc3-refactor-931e3b08a8b9 Best regards,