From dbe0dbb7dfda52140d3469d7035a08dfa874fca2 Mon Sep 17 00:00:00 2001
From: David Brownell <david-b@pacbell.net>
Date: Sun, 10 Feb 2008 12:24:00 -0800
Subject: USB: defines for USB "Link Power Management" (LPM) ECN
There's a new PM-related change notice for the USB 2.0 specification
called "Link Power Management" (LPM). It defines a new "L1 Suspend"
state which resembles the current (L2) suspend state, except that it
can be entered and exited much more quickly. It should thus be more
useful for runtime PM, even though it doesn't mandate reduced power
draw from VBUS.
This patch provides the relevant #defines for usbcore. Actually
implementing these mechanisms requires host silicon that can generate
new USB packets, plus hubs handling some new requests and peripherals
which understand the new packets.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
include/linux/usb/ch9.h | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
(limited to 'include/linux/usb/ch9.h')
diff --git a/include/linux/usb/ch9.h b/include/linux/usb/ch9.h
index 7e1da17ca7ce..61fcbc2b97da 100644
--- a/include/linux/usb/ch9.h
+++ b/include/linux/usb/ch9.h
@@ -66,8 +66,8 @@
#define USB_RECIP_ENDPOINT 0x02
#define USB_RECIP_OTHER 0x03
/* From Wireless USB 1.0 */
-#define USB_RECIP_PORT 0x04
-#define USB_RECIP_RPIPE 0x05
+#define USB_RECIP_PORT 0x04
+#define USB_RECIP_RPIPE 0x05
/*
* Standard requests, for the bRequest field of a SETUP packet.
@@ -102,10 +102,16 @@
#define USB_REQ_LOOPBACK_DATA_READ 0x16
#define USB_REQ_SET_INTERFACE_DS 0x17
+/* The Link Power Mangement (LPM) ECN defines USB_REQ_TEST_AND_SET command,
+ * used by hubs to put ports into a new L1 suspend state, except that it
+ * forgot to define its number ...
+ */
+
/*
* USB feature flags are written using USB_REQ_{CLEAR,SET}_FEATURE, and
* are read as a bit array returned by USB_REQ_GET_STATUS. (So there
- * are at most sixteen features of each type.)
+ * are at most sixteen features of each type.) Hubs may also support a
+ * new USB_REQ_TEST_AND_SET_FEATURE to put ports into L1 suspend.
*/
#define USB_DEVICE_SELF_POWERED 0 /* (read only) */
#define USB_DEVICE_REMOTE_WAKEUP 1 /* dev may initiate wakeup */
@@ -575,6 +581,8 @@ enum usb_device_state {
/* NOTE: there are actually four different SUSPENDED
* states, returning to POWERED, DEFAULT, ADDRESS, or
* CONFIGURED respectively when SOF tokens flow again.
+ * At this level there's no difference between L1 and L2
+ * suspend states. (L2 being original USB 1.1 suspend.)
*/
};
--
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