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>

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 70cccc7..9cd77a2 100644 (file)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2880,7 +2880,9 @@ hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
        }
 
        retval = 0;
-
+       /* notify HCD that we have a device connected and addressed */
+       if (hcd->driver->update_device)
+               hcd->driver->update_device(hcd, udev);
 fail:
        if (retval) {
                hub_port_disable(hub, port1, 0);

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 20ca6a9..baf9b64 100644 (file)
--- 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 */

diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index e7d3d8d..8a28dae 100644 (file)
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -790,6 +790,11 @@ static int ehci_hub_control (
                                          status_reg);
                        break;
                case USB_PORT_FEAT_C_CONNECTION:
+                       if (ehci->has_lpm) {
+                               /* clear PORTSC bits on disconnect */
+                               temp &= ~PORT_LPM;
+                               temp &= ~PORT_DEV_ADDR;
+                       }
                        ehci_writel(ehci, (temp & ~PORT_RWC_BITS) | PORT_CSC,
                                        status_reg);
                        break;

diff --git a/drivers/usb/host/ehci-lpm.c b/drivers/usb/host/ehci-lpm.c
new file mode 100644 (file)
index 0000000..b4d4d63
--- /dev/null
+++ b/drivers/usb/host/ehci-lpm.c
@@ -0,0 +1,83 @@
+/* ehci-lpm.c EHCI HCD LPM support code
+ * Copyright (c) 2008 - 2010,  Intel Corporation.
+ * Author: Jacob Pan <jacob.jun.pan@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+/* this file is part of ehci-hcd.c */
+static int ehci_lpm_set_da(struct ehci_hcd *ehci, int dev_addr, int port_num)
+{
+       u32 __iomem portsc;
+
+       ehci_dbg(ehci, "set dev address %d for port %d\n", dev_addr, port_num);
+       if (port_num > HCS_N_PORTS(ehci->hcs_params)) {
+               ehci_dbg(ehci, "invalid port number %d\n", port_num);
+               return -ENODEV;
+       }
+       portsc = ehci_readl(ehci, &ehci->regs->port_status[port_num-1]);
+       portsc &= ~PORT_DEV_ADDR;
+       portsc |= dev_addr<<25;
+       ehci_writel(ehci, portsc, &ehci->regs->port_status[port_num-1]);
+       return 0;
+}
+
+/*
+ * this function is used to check if the device support LPM
+ * if yes, mark the PORTSC register with PORT_LPM bit
+ */
+static int ehci_lpm_check(struct ehci_hcd *ehci, int port)
+{
+       u32 __iomem     *portsc ;
+       u32 val32;
+       int retval;
+
+       portsc = &ehci->regs->port_status[port-1];
+       val32 = ehci_readl(ehci, portsc);
+       if (!(val32 & PORT_DEV_ADDR)) {
+               ehci_dbg(ehci, "LPM: no device attached\n");
+               return -ENODEV;
+       }
+       val32 |= PORT_LPM;
+       ehci_writel(ehci, val32, portsc);
+       msleep(5);
+       val32 |= PORT_SUSPEND;
+       ehci_dbg(ehci, "Sending LPM 0x%08x to port %d\n", val32, port);
+       ehci_writel(ehci, val32, portsc);
+       /* wait for ACK */
+       msleep(10);
+       retval = handshake(ehci, &ehci->regs->port_status[port-1], PORT_SSTS,
+                       PORTSC_SUSPEND_STS_ACK, 125);
+       dbg_port(ehci, "LPM", port, val32);
+       if (retval != -ETIMEDOUT) {
+               ehci_dbg(ehci, "LPM: device ACK for LPM\n");
+               val32 |= PORT_LPM;
+               /*
+                * now device should be in L1 sleep, let's wake up the device
+                * so that we can complete enumeration.
+                */
+               ehci_writel(ehci, val32, portsc);
+               msleep(10);
+               val32 |= PORT_RESUME;
+               ehci_writel(ehci, val32, portsc);
+       } else {
+               ehci_dbg(ehci, "LPM: device does not ACK, disable LPM %d\n",
+                       retval);
+               val32 &= ~PORT_LPM;
+               retval = -ETIMEDOUT;
+               ehci_writel(ehci, val32, portsc);
+       }
+
+       return retval;
+}

diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c
index d43d176..a307d55 100644 (file)
--- a/drivers/usb/host/ehci-pci.c
+++ b/drivers/usb/host/ehci-pci.c
@@ -361,6 +361,22 @@ static int ehci_pci_resume(struct usb_hcd *hcd, bool hibernated)
 }
 #endif
 
+static int ehci_update_device(struct usb_hcd *hcd, struct usb_device *udev)
+{
+       struct ehci_hcd *ehci = hcd_to_ehci(hcd);
+       int rc = 0;
+
+       if (!udev->parent) /* udev is root hub itself, impossible */
+               rc = -1;
+       /* we only support lpm device connected to root hub yet */
+       if (ehci->has_lpm && !udev->parent->parent) {
+               rc = ehci_lpm_set_da(ehci, udev->devnum, udev->portnum);
+               if (!rc)
+                       rc = ehci_lpm_check(ehci, udev->portnum);
+       }
+       return rc;
+}
+
 static const struct hc_driver ehci_pci_hc_driver = {
        .description =          hcd_name,
        .product_desc =         "EHCI Host Controller",
@@ -407,6 +423,11 @@ static const struct hc_driver ehci_pci_hc_driver = {
        .relinquish_port =      ehci_relinquish_port,
        .port_handed_over =     ehci_port_handed_over,
 
+       /*
+        * call back when device connected and addressed
+        */
+       .update_device =        ehci_update_device,
+
        .clear_tt_buffer_complete       = ehci_clear_tt_buffer_complete,
 };
 

diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index bfaac16..21f30a0 100644 (file)
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -140,7 +140,7 @@ struct ehci_hcd {                   /* one per controller */
        #define OHCI_HCCTRL_LEN         0x4
        __hc32                  *ohci_hcctrl_reg;
        unsigned                has_hostpc:1;
-
+       unsigned                has_lpm:1;  /* support link power management */
        u8                      sbrn;           /* packed release number */
 
        /* irq statistics */

diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index 11b6381..9b867e6 100644 (file)
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -300,6 +300,10 @@ struct hc_driver {
        int     (*update_hub_device)(struct usb_hcd *, struct usb_device *hdev,
                        struct usb_tt *tt, gfp_t mem_flags);
        int     (*reset_device)(struct usb_hcd *, struct usb_device *);
+               /* Notifies the HCD after a device is connected and its
+                * address is set
+                */
+       int     (*update_device)(struct usb_hcd *, struct usb_device *);
 };
 
 extern int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb);