ebf20de453
This patch (as1547) rearranges the Power Management parts of the ehci-tegra driver to match the conventions used in other EHCI platform drivers. In particular, the controller should not be powered down by the root hub's suspend routine; the controller's power level should be managed by the controller's own PM methods. The end result of the patch is that the standard ehci_bus_suspend() and ehci_bus_resume() methods can be used instead of special-purpose routines. The driver now uses the standard dev_pm_ops methods instead of legacy power management. Since there is no supported wakeup mechanism for the controller, runtime suspend is forbidden by default (this can be overridden via sysfs, if desired). These adjustments are needed in order to make ehci-tegra compatible with recent changes to the USB core. The core now checks the root hub's status following bus suspend; if the controller is automatically powered down during bus suspend then the check will fail and the root hub will be resumed immediately. Doing the controller power-down in a separate method avoids this problem. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Stephen Warren <swarren@wwwdotorg.org> Tested-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
||
---|---|---|
.. | ||
atm | ||
c67x00 | ||
class | ||
core | ||
dwc3 | ||
early | ||
gadget | ||
host | ||
image | ||
misc | ||
mon | ||
musb | ||
otg | ||
renesas_usbhs | ||
serial | ||
storage | ||
wusbcore | ||
Kconfig | ||
Makefile | ||
README | ||
usb-common.c | ||
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.