linux/Documentation/devicetree/bindings/usb/usb-ehci.txt
Hans de Goede 915974c34e ehci-platform: Change compatible string from usb-ehci to generic-ehci
The initial versions of the devicetree enablement patches for ehci-platform
used "ehci-platform" as compatible string. However this was disliked by various
reviewers because the platform bus is a Linux invention and devicetree is
supposed to be OS agnostic. After much discussion I gave up, added a:
"depends on !PPC_OF" to Kconfig to avoid a known conflict with PPC-OF platforms
and went with the generic usb-ehci as requested.

In retro-spect I should have chosen something different, the dts files for many
existing boards already claim to be compatible with "usb-ehci", ie they have:

	compatible = "ti,ehci-omap", "usb-ehci";

In theory this should not be a problem since the "ti,ehci-omap" entry takes
presedence, but in practice using a conflicting compatible string is an issue,
because it makes which driver gets used depend on driver registration order.

This patch changes the compatible string claimed by ehci-platform to
"generic-ehci", avoiding the driver registration / module loading ordering
problems, and removes the "depends on !PPC_OF" workaround.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-11 13:39:54 -08:00

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USB EHCI controllers
Required properties:
- compatible : should be "generic-ehci".
- reg : should contain at least address and length of the standard EHCI
register set for the device. Optional platform-dependent registers
(debug-port or other) can be also specified here, but only after
definition of standard EHCI registers.
- interrupts : one EHCI interrupt should be described here.
Optional properties:
- big-endian-regs : boolean, set this for hcds with big-endian registers
- big-endian-desc : boolean, set this for hcds with big-endian descriptors
- big-endian : boolean, for hcds with big-endian-regs + big-endian-desc
- clocks : a list of phandle + clock specifier pairs
- phys : phandle + phy specifier pair
- phy-names : "usb"
Example (Sequoia 440EPx):
ehci@e0000300 {
compatible = "ibm,usb-ehci-440epx", "usb-ehci";
interrupt-parent = <&UIC0>;
interrupts = <1a 4>;
reg = <0 e0000300 90 0 e0000390 70>;
big-endian;
};
Example (Allwinner sun4i A10 SoC):
ehci0: usb@01c14000 {
compatible = "allwinner,sun4i-a10-ehci", "generic-ehci";
reg = <0x01c14000 0x100>;
interrupts = <39>;
clocks = <&ahb_gates 1>;
phys = <&usbphy 1>;
phy-names = "usb";
};