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The Tegra USB complex has a particularly annoying misdesign: some of the UTMI pad configuration registers are global for all the 3 USB controllers on the chip, but those registers are located in the first controller's register space and will be cleared when the reset to the first controller is asserted. Currently, this means that if the 1st controller were to finish probing after the 2nd or 3rd controller, USB would not work at all. Fix this situation by always resetting the 1st controller before doing any other setup to any of the controllers, and then never ever reset the first controller again. As the UTMI registers are related to the PHY, the PHY driver should probably reset the Tegra controllers instead, but since old device trees only have reset phandles in the EHCI nodes, do it here, which means a bit of device tree groveling. Those old DTs also won't get the reset fix from this commit, so we'll dev_warn() them, but the driver will still keep probing successfully. Signed-off-by: Tuomas Tynkkynen <ttynkkynen@nvidia.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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atm | ||
c67x00 | ||
chipidea | ||
class | ||
common | ||
core | ||
dwc2 | ||
dwc3 | ||
early | ||
gadget | ||
host | ||
image | ||
misc | ||
mon | ||
musb | ||
phy | ||
renesas_usbhs | ||
serial | ||
storage | ||
wusbcore | ||
Kconfig | ||
Makefile | ||
README | ||
usb-skeleton.c |
To understand all the Linux-USB framework, you'll use these resources: * This source code. This is necessarily an evolving work, and includes kerneldoc that should help you get a current overview. ("make pdfdocs", and then look at "usb.pdf" for host side and "gadget.pdf" for peripheral side.) Also, Documentation/usb has more information. * The USB 2.0 specification (from www.usb.org), with supplements such as those for USB OTG and the various device classes. The USB specification has a good overview chapter, and USB peripherals conform to the widely known "Chapter 9". * Chip specifications for USB controllers. Examples include host controllers (on PCs, servers, and more); peripheral controllers (in devices with Linux firmware, like printers or cell phones); and hard-wired peripherals like Ethernet adapters. * Specifications for other protocols implemented by USB peripheral functions. Some are vendor-specific; others are vendor-neutral but just standardized outside of the www.usb.org team. Here is a list of what each subdirectory here is, and what is contained in them. core/ - This is for the core USB host code, including the usbfs files and the hub class driver ("khubd"). host/ - This is for USB host controller drivers. This includes UHCI, OHCI, EHCI, and others that might be used with more specialized "embedded" systems. gadget/ - This is for USB peripheral controller drivers and the various gadget drivers which talk to them. Individual USB driver directories. A new driver should be added to the first subdirectory in the list below that it fits into. image/ - This is for still image drivers, like scanners or digital cameras. ../input/ - This is for any driver that uses the input subsystem, like keyboard, mice, touchscreens, tablets, etc. ../media/ - This is for multimedia drivers, like video cameras, radios, and any other drivers that talk to the v4l subsystem. ../net/ - This is for network drivers. serial/ - This is for USB to serial drivers. storage/ - This is for USB mass-storage drivers. class/ - This is for all USB device drivers that do not fit into any of the above categories, and work for a range of USB Class specified devices. misc/ - This is for all USB device drivers that do not fit into any of the above categories.