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path: root/drivers/usb/core/phy.c
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2018-04-22usb: core: phy: make it a no-op if CONFIG_GENERIC_PHY is disabledMartin Blumenstingl
If the generic PHY support is disabled the stub of devm_of_phy_get_by_index returns ENOSYS. This corner case isn't handled properly by usb_phy_roothub_add_phy and at least breaks USB support on Raspberry Pi (bcm2835_defconfig): dwc2 20980000.usb: dwc2_hcd_init() FAILED, returning -38 dwc2: probe of 20980000.usb failed with error -38 Let usb_phy_roothub_alloc() return in case CONFIG_GENERIC_PHY is disabled to fix this issue (compilers might even be smart enough to optimize away most of the code within usb_phy_roothub_alloc and usb_phy_roothub_add_phy if CONFIG_GENERIC_PHY is disabled). All existing usb_phy_roothub_* functions are already NULL-safe, so no special handling is required there. Fixes: 07dbff0ddbd8 ("usb: core: add a wrapper for the USB PHYs on the HCD") Reported-by: Stefan Wahren <stefan.wahren@i2se.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-22usb: core: use phy_exit during suspend if wake up is not supportedMartin Blumenstingl
If the USB controller can wake up the system (which is the case for example with the Mediatek USB3 IP) then we must not call phy_exit during suspend to ensure that the USB controller doesn't have to re-enumerate the devices during resume. However, if the USB controller cannot wake up the system (which is the case for example on various TI platforms using a dwc3 controller) then we must call phy_exit during suspend. Otherwise the PHY driver keeps the clocks enabled, which prevents the system from reaching the lowest power levels in the suspend state. Solve this by introducing two new functions in the PHY wrapper which are dedicated to the suspend and resume handling. If the controller can wake up the system the new usb_phy_roothub_suspend function will simply call usb_phy_roothub_power_off. However, if wake up is not supported by the controller it will also call usb_phy_roothub_exit. The also new usb_phy_roothub_resume function takes care of calling usb_phy_roothub_init (if the controller can't wake up the system) in addition to usb_phy_roothub_power_on. Fixes: 07dbff0ddbd86c ("usb: core: add a wrapper for the USB PHYs on the HCD") Fixes: 178a0bce05cbc1 ("usb: core: hcd: integrate the PHY wrapper into the HCD core") Reported-by: Roger Quadros <rogerq@ti.com> Suggested-by: Roger Quadros <rogerq@ti.com> Suggested-by: Chunfeng Yun <chunfeng.yun@mediatek.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Tested-by: Chunfeng Yun <chunfeng.yun@mediatek.com> Reviewed-by: Roger Quadros <rogerq@ti.com> Tested-by: Keerthy <j-keerthy@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-22usb: core: split usb_phy_roothub_{init,alloc}Martin Blumenstingl
Before this patch usb_phy_roothub_init served two purposes (from a caller's point of view - like hcd.c): - parsing the PHYs and allocating the list entries - calling phy_init on each list entry While this worked so far it has one disadvantage: if we need to call phy_init for each PHY instance then the existing code cannot be re-used. Solve this by splitting off usb_phy_roothub_alloc which only parses the PHYs and allocates the list entries. usb_phy_roothub_init then gets a struct usb_phy_roothub and only calls phy_init on each PHY instance (along with the corresponding cleanup if that failed somewhere). This is a preparation step for adding proper suspend support for some hardware that requires phy_exit to be called during suspend and phy_init to be called during resume. Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Tested-by: Chunfeng Yun <chunfeng.yun@mediatek.com> Reviewed-by: Roger Quadros <rogerq@ti.com> Tested-by: Keerthy <j-keerthy@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-22usb: core: phy: fix return value of usb_phy_roothub_exit()Martin Blumenstingl
usb_phy_roothub_exit() should return the error code from the phy_exit() call if exiting the PHY failed. However, since a wrong variable is used usb_phy_roothub_exit() currently always returns 0, even if one of the phy_exit calls returned an error. Clang also reports this bug: kernel/drivers/usb/core/phy.c:114:8: warning: explicitly assigning value of variable of type 'int' to itself [-Wself-assign] error, forbidden warning: phy.c:114 Fix this by assigning the error code from phy_exit() to the "ret" variable to propagate the error correctly. Fixes: 07dbff0ddbd86c ("usb: core: add a wrapper for the USB PHYs on the HCD") Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org> Tested-by: Keerthy <j-keerthy@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09usb: core: add a wrapper for the USB PHYs on the HCDMartin Blumenstingl
Many SoC platforms have separate devices for the USB PHY which are registered through the generic PHY framework. These PHYs have to be enabled to make the USB controller actually work. They also have to be disabled again on shutdown/suspend. Currently (at least) the following HCI platform drivers are using custom code to obtain all PHYs via devicetree for the roothub/controller and disable/enable them when required: - ehci-platform.c has ehci_platform_power_{on,off} - xhci-mtk.c has xhci_mtk_phy_{init,exit,power_on,power_off} - ohci-platform.c has ohci_platform_power_{on,off} With this new wrapper the USB PHYs can be specified directly in the USB controller's devicetree node (just like on the drivers listed above). This allows SoCs like the Amlogic Meson GXL family to operate correctly once this is wired up correctly. These SoCs use a dwc3 controller and require all USB PHYs to be initialized (if one of the USB PHYs it not initialized then none of USB port works at all). Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Tested-by: Yixun Lan <yixun.lan@amlogic.com> Cc: Chunfeng Yun <chunfeng.yun@mediatek.com> Tested-by: Neil Armstrong <narmstrong@baylibre.con> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>