path: root/Documentation
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authorMurali Karicheri <m-karicheri2@ti.com>2014-05-01 15:04:53 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-05-28 13:04:46 -0700
commit06aa82e498c144c7784a6f3d3b55458b272d6146 (patch)
tree0055d789f294f29287ec4386ef3b81ef9eb4a181 /Documentation
parentab5e4e4108ca5d8326cb6b4b3a21b096a002f68f (diff)
serial: uart: add hw flow control support configuration
8250 uart driver currently supports only software assisted hw flow control. The software assisted hw flow control maintains a hw_stopped flag in the tty structure to stop and start transmission and use modem status interrupt for the event to drive the handshake signals. This is not needed if hw has flow control capabilities. This patch adds a DT attribute for enabling hw flow control for a uart port. Also skip stop and start if this flag is present in flag field of the port structure. Signed-off-by: Murali Karicheri <m-karicheri2@ti.com> CC: Rob Herring <robh+dt@kernel.org> CC: Pawel Moll <pawel.moll@arm.com> CC: Mark Rutland <mark.rutland@arm.com> CC: Ian Campbell <ijc+devicetree@hellion.org.uk> CC: Kumar Gala <galak@codeaurora.org> CC: Randy Dunlap <rdunlap@infradead.org> CC: Jiri Slaby <jslaby@suse.cz> CC: Santosh Shilimkar <santosh.shilimkar@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
1 files changed, 1 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/serial/of-serial.txt b/Documentation/devicetree/bindings/serial/of-serial.txt
index 1928a3e83cd0..77054772a8f4 100644
--- a/Documentation/devicetree/bindings/serial/of-serial.txt
+++ b/Documentation/devicetree/bindings/serial/of-serial.txt
@@ -37,6 +37,7 @@ Optional properties:
- auto-flow-control: one way to enable automatic flow control support. The
driver is allowed to detect support for the capability even without this
+- has-hw-flow-control: the hardware has flow control capability.