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USB: partial USB embedded host support
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This provides better support for USB "Embedded Host" functionality, which
is a subset of the USB OTG options:

 * External hub support can be disabled;

 * USB peripherals not whitelisted in "otg_whitelist.h" will be rejected
   during enumeration.

These options can allow some savings in software and support.

Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Robin Getz authored and Greg Kroah-Hartman committed Apr 25, 2008
1 parent b56394b commit 22552b2
Showing 1 changed file with 8 additions and 5 deletions.
13 changes: 8 additions & 5 deletions drivers/usb/core/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -111,14 +111,16 @@ config USB_OTG

config USB_OTG_WHITELIST
bool "Rely on OTG Targeted Peripherals List"
depends on USB_OTG
default y
depends on USB_OTG || EMBEDDED
default y if USB_OTG
default n if EMBEDDED
help
If you say Y here, the "otg_whitelist.h" file will be used as a
product whitelist, so USB peripherals not listed there will be
rejected during enumeration. This behavior is required by the
USB OTG specification for all devices not on your product's
"Targeted Peripherals List".
"Targeted Peripherals List". "Embedded Hosts" are likewise
allowed to support only a limited number of peripherals.

Otherwise, peripherals not listed there will only generate a
warning and enumeration will continue. That's more like what
Expand All @@ -127,9 +129,10 @@ config USB_OTG_WHITELIST

config USB_OTG_BLACKLIST_HUB
bool "Disable external hubs"
depends on USB_OTG
depends on USB_OTG || EMBEDDED
help
If you say Y here, then Linux will refuse to enumerate
external hubs. OTG hosts are allowed to reduce hardware
and software costs by not supporting external hubs.
and software costs by not supporting external hubs. So
are "Emedded Hosts" that don't offer OTG support.

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