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>

6 files changed, 130 insertions, 2 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 70cccc75a362..9cd77a2af821 100644
--- 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 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 */
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index e7d3d8def282..8a28dae8a375 100644
--- 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
index 000000000000..b4d4d63c13ed
--- /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 d43d176161aa..a307d550bdaf 100644
--- 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 bfaac1646365..21f30a0c3d2f 100644
--- 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 */