USB: EHCI: EHCI 1.1 addendum: Basic LPM feature support

With this patch, the LPM capable EHCI host controller can put device
into L1 sleep state which is a mode that can enter/exit quickly, and
reduce power consumption.

Signed-off-by: Jacob Pan <jacob.jun.pan@intel.com>
Signed-off-by: Alek Du <alek.du@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 17 insertions, 0 deletions

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 20ca6a9ff213..baf9b648bb1f 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -101,6 +101,11 @@ static int ignore_oc = 0;
 module_param (ignore_oc, bool, S_IRUGO);
 MODULE_PARM_DESC (ignore_oc, "ignore bogus hardware overcurrent indications");
 
+/* for link power management(LPM) feature */
+static unsigned int hird;
+module_param(hird, int, S_IRUGO);
+MODULE_PARM_DESC(hird, "host initiated resume duration, +1 for each 75us\n");
+
 #define INTR_MASK (STS_IAA | STS_FATAL | STS_PCD | STS_ERR | STS_INT)
 
 /*-------------------------------------------------------------------------*/
@@ -305,6 +310,7 @@ static void end_unlink_async(struct ehci_hcd *ehci);
 static void ehci_work(struct ehci_hcd *ehci);
 
 #include "ehci-hub.c"
+#include "ehci-lpm.c"
 #include "ehci-mem.c"
 #include "ehci-q.c"
 #include "ehci-sched.c"
@@ -604,6 +610,17 @@ static int ehci_init(struct usb_hcd *hcd)
                 default:        BUG();
                 }
         }
+        if (HCC_LPM(hcc_params)) {
+                /* support link power management EHCI 1.1 addendum */
+                ehci_dbg(ehci, "support lpm\n");
+                ehci->has_lpm = 1;
+                if (hird > 0xf) {
+                        ehci_dbg(ehci, "hird %d invalid, use default 0",
+                        hird);
+                        hird = 0;
+                }
+                temp |= hird << 24;
+        }
         ehci->command = temp;
 
         /* Accept arbitrarily long scatter-gather lists */