[PATCH] USB: dummy_hcd: add suspend/resume support

This patch adds support to dummy_hcd for suspending and resuming the root
hub and the emulated platform devices.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 162 insertions, 17 deletions

diff --git a/drivers/usb/gadget/dummy_hcd.c b/drivers/usb/gadget/dummy_hcd.c
index c78c64ae87a..4d692670f28 100644
--- a/drivers/usb/gadget/dummy_hcd.c
+++ b/drivers/usb/gadget/dummy_hcd.c
@@ -65,7 +65,7 @@
 
 
 #define DRIVER_DESC     "USB Host+Gadget Emulator"
-#define DRIVER_VERSION  "17 Dec 2004"
+#define DRIVER_VERSION  "02 May 2005"
 
 static const char       driver_name [] = "dummy_hcd";
 static const char       driver_desc [] = "USB Host+Gadget Emulator";
@@ -150,6 +150,13 @@ struct urbp {
         struct list_head        urbp_list;
 };
 
+
+enum dummy_rh_state {
+        DUMMY_RH_RESET,
+        DUMMY_RH_SUSPENDED,
+        DUMMY_RH_RUNNING
+};
+
 struct dummy {
         spinlock_t                      lock;
 
@@ -163,6 +170,7 @@ struct dummy {
         struct dummy_request            fifo_req;
         u8                              fifo_buf [FIFO_SIZE];
         u16                             devstatus;
+        unsigned                        udc_suspended:1;
         unsigned                        pullup:1;
         unsigned                        active:1;
         unsigned                        old_active:1;
@@ -170,6 +178,7 @@ struct dummy {
         /*
          * MASTER/HOST side support
          */
+        enum dummy_rh_state             rh_state;
         struct timer_list               timer;
         u32                             port_status;
         u32                             old_status;
@@ -262,7 +271,9 @@ set_link_state (struct dummy *dum)
         dum->active = 0;
         if ((dum->port_status & USB_PORT_STAT_POWER) == 0)
                 dum->port_status = 0;
-        else if (!dum->pullup) {
+
+        /* UDC suspend must cause a disconnect */
+        else if (!dum->pullup || dum->udc_suspended) {
                 dum->port_status &= ~(USB_PORT_STAT_CONNECTION |
                                         USB_PORT_STAT_ENABLE |
                                         USB_PORT_STAT_LOW_SPEED |
@@ -276,7 +287,8 @@ set_link_state (struct dummy *dum)
                         dum->port_status |= (USB_PORT_STAT_C_CONNECTION << 16);
                 if ((dum->port_status & USB_PORT_STAT_ENABLE) == 0)
                         dum->port_status &= ~USB_PORT_STAT_SUSPEND;
-                else if ((dum->port_status & USB_PORT_STAT_SUSPEND) == 0)
+                else if ((dum->port_status & USB_PORT_STAT_SUSPEND) == 0 &&
+                                dum->rh_state != DUMMY_RH_SUSPENDED)
                         dum->active = 1;
         }
 
@@ -675,11 +687,16 @@ static int dummy_wakeup (struct usb_gadget *_gadget)
         struct dummy    *dum;
 
         dum = gadget_to_dummy (_gadget);
-        if (!(dum->port_status & USB_PORT_STAT_SUSPEND)
-                        || !(dum->devstatus &
-                                ( (1 << USB_DEVICE_B_HNP_ENABLE)
+        if (!(dum->devstatus &  ( (1 << USB_DEVICE_B_HNP_ENABLE)
                                 | (1 << USB_DEVICE_REMOTE_WAKEUP))))
                 return -EINVAL;
+        if ((dum->port_status & USB_PORT_STAT_CONNECTION) == 0)
+                return -ENOLINK;
+        if ((dum->port_status & USB_PORT_STAT_SUSPEND) == 0 &&
+                         dum->rh_state != DUMMY_RH_SUSPENDED)
+                return -EIO;
+
+        /* FIXME: What if the root hub is suspended but the port isn't? */
 
         /* hub notices our request, issues downstream resume, etc */
         dum->resuming = 1;
@@ -917,11 +934,50 @@ static int dummy_udc_remove (struct device *dev)
         return 0;
 }
 
+static int dummy_udc_suspend (struct device *dev, pm_message_t state,
+                u32 level)
+{
+        struct dummy    *dum = dev_get_drvdata(dev);
+
+        if (level != SUSPEND_DISABLE)
+                return 0;
+
+        dev_dbg (dev, "%s\n", __FUNCTION__);
+        spin_lock_irq (&dum->lock);
+        dum->udc_suspended = 1;
+        set_link_state (dum);
+        spin_unlock_irq (&dum->lock);
+
+        dev->power.power_state = state;
+        usb_hcd_poll_rh_status (dummy_to_hcd (dum));
+        return 0;
+}
+
+static int dummy_udc_resume (struct device *dev, u32 level)
+{
+        struct dummy    *dum = dev_get_drvdata(dev);
+
+        if (level != RESUME_ENABLE)
+                return 0;
+
+        dev_dbg (dev, "%s\n", __FUNCTION__);
+        spin_lock_irq (&dum->lock);
+        dum->udc_suspended = 0;
+        set_link_state (dum);
+        spin_unlock_irq (&dum->lock);
+
+        dev->power.power_state = PMSG_ON;
+        usb_hcd_poll_rh_status (dummy_to_hcd (dum));
+        return 0;
+}
+
 static struct device_driver dummy_udc_driver = {
         .name           = (char *) gadget_name,
         .bus            = &platform_bus_type,
         .probe          = dummy_udc_probe,
         .remove         = dummy_udc_remove,
+        .suspend        = dummy_udc_suspend,
+        .resume         = dummy_udc_resume,
 };
 
 /*-------------------------------------------------------------------------*/
@@ -980,7 +1036,16 @@ static int dummy_urb_enqueue (
 
 static int dummy_urb_dequeue (struct usb_hcd *hcd, struct urb *urb)
 {
-        /* giveback happens automatically in timer callback */
+        struct dummy    *dum;
+        unsigned long   flags;
+
+        /* giveback happens automatically in timer callback,
+         * so make sure the callback happens */
+        dum = hcd_to_dummy (hcd);
+        spin_lock_irqsave (&dum->lock, flags);
+        if (dum->rh_state != DUMMY_RH_RUNNING && !list_empty(&dum->urbp_list))
+                mod_timer (&dum->timer, jiffies);
+        spin_unlock_irqrestore (&dum->lock, flags);
         return 0;
 }
 
@@ -1222,7 +1287,8 @@ restart:
                 if (urb->status != -EINPROGRESS) {
                         /* likely it was just unlinked */
                         goto return_urb;
-                }
+                } else if (dum->rh_state != DUMMY_RH_RUNNING)
+                        continue;
                 type = usb_pipetype (urb->pipe);
 
                 /* used up this frame's non-periodic bandwidth?
@@ -1486,12 +1552,12 @@ return_urb:
                 goto restart;
         }
 
-        /* want a 1 msec delay here */
-        if (!list_empty (&dum->urbp_list))
-                mod_timer (&dum->timer, jiffies + msecs_to_jiffies(1));
-        else {
+        if (list_empty (&dum->urbp_list)) {
                 usb_put_dev (dum->udev);
                 dum->udev = NULL;
+        } else if (dum->rh_state == DUMMY_RH_RUNNING) {
+                /* want a 1 msec delay here */
+                mod_timer (&dum->timer, jiffies + msecs_to_jiffies(1));
         }
 
         spin_unlock_irqrestore (&dum->lock, flags);
@@ -1510,11 +1576,13 @@ static int dummy_hub_status (struct usb_hcd *hcd, char *buf)
 {
         struct dummy            *dum;
         unsigned long           flags;
-        int                     retval;
+        int                     retval = 0;
 
         dum = hcd_to_dummy (hcd);
 
         spin_lock_irqsave (&dum->lock, flags);
+        if (hcd->state != HC_STATE_RUNNING)
+                goto done;
 
         if (dum->resuming && time_after_eq (jiffies, dum->re_timeout)) {
                 dum->port_status |= (USB_PORT_STAT_C_SUSPEND << 16);
@@ -1522,14 +1590,15 @@ static int dummy_hub_status (struct usb_hcd *hcd, char *buf)
                 set_link_state (dum);
         }
 
-        if (!(dum->port_status & PORT_C_MASK))
-                retval = 0;
-        else {
+        if ((dum->port_status & PORT_C_MASK) != 0) {
                 *buf = (1 << 1);
                 dev_dbg (dummy_dev(dum), "port status 0x%08x has changes\n",
-                        dum->port_status);
+                                dum->port_status);
                 retval = 1;
+                if (dum->rh_state == DUMMY_RH_SUSPENDED)
+                        usb_hcd_resume_root_hub (hcd);
         }
+done:
         spin_unlock_irqrestore (&dum->lock, flags);
         return retval;
 }
@@ -1559,6 +1628,9 @@ static int dummy_hub_control (
         int             retval = 0;
         unsigned long   flags;
 
+        if (hcd->state != HC_STATE_RUNNING)
+                return -ETIMEDOUT;
+
         dum = hcd_to_dummy (hcd);
         spin_lock_irqsave (&dum->lock, flags);
         switch (typeReq) {
@@ -1658,6 +1730,7 @@ static int dummy_hub_control (
                         dum->port_status &= ~(USB_PORT_STAT_ENABLE
                                         | USB_PORT_STAT_LOW_SPEED
                                         | USB_PORT_STAT_HIGH_SPEED);
+                        dum->devstatus = 0;
                         /* 50msec reset signaling */
                         dum->re_timeout = jiffies + msecs_to_jiffies(50);
                         /* FALLS THROUGH */
@@ -1684,6 +1757,29 @@ static int dummy_hub_control (
         return retval;
 }
 
+static int dummy_hub_suspend (struct usb_hcd *hcd)
+{
+        struct dummy *dum = hcd_to_dummy (hcd);
+
+        spin_lock_irq (&dum->lock);
+        dum->rh_state = DUMMY_RH_SUSPENDED;
+        set_link_state (dum);
+        spin_unlock_irq (&dum->lock);
+        return 0;
+}
+
+static int dummy_hub_resume (struct usb_hcd *hcd)
+{
+        struct dummy *dum = hcd_to_dummy (hcd);
+
+        spin_lock_irq (&dum->lock);
+        dum->rh_state = DUMMY_RH_RUNNING;
+        set_link_state (dum);
+        if (!list_empty(&dum->urbp_list))
+                mod_timer (&dum->timer, jiffies);
+        spin_unlock_irq (&dum->lock);
+        return 0;
+}
 
 /*-------------------------------------------------------------------------*/
 
@@ -1751,6 +1847,7 @@ static int dummy_start (struct usb_hcd *hcd)
         init_timer (&dum->timer);
         dum->timer.function = dummy_timer;
         dum->timer.data = (unsigned long) dum;
+        dum->rh_state = DUMMY_RH_RUNNING;
 
         INIT_LIST_HEAD (&dum->urbp_list);
 
@@ -1803,6 +1900,8 @@ static const struct hc_driver dummy_hcd = {
 
         .hub_status_data =      dummy_hub_status,
         .hub_control =          dummy_hub_control,
+        .hub_suspend =          dummy_hub_suspend,
+        .hub_resume =           dummy_hub_resume,
 };
 
 static int dummy_hcd_probe (struct device *dev)
@@ -1836,11 +1935,57 @@ static int dummy_hcd_remove (struct device *dev)
         return 0;
 }
 
+static int dummy_hcd_suspend (struct device *dev, pm_message_t state,
+                u32 level)
+{
+        struct usb_hcd          *hcd;
+
+        if (level != SUSPEND_DISABLE)
+                return 0;
+
+        dev_dbg (dev, "%s\n", __FUNCTION__);
+        hcd = dev_get_drvdata (dev);
+
+#ifndef CONFIG_USB_SUSPEND
+        /* Otherwise this would never happen */
+        usb_lock_device (hcd->self.root_hub);
+        dummy_hub_suspend (hcd);
+        usb_unlock_device (hcd->self.root_hub);
+#endif
+
+        hcd->state = HC_STATE_SUSPENDED;
+        return 0;
+}
+
+static int dummy_hcd_resume (struct device *dev, u32 level)
+{
+        struct usb_hcd          *hcd;
+
+        if (level != RESUME_ENABLE)
+                return 0;
+
+        dev_dbg (dev, "%s\n", __FUNCTION__);
+        hcd = dev_get_drvdata (dev);
+        hcd->state = HC_STATE_RUNNING;
+
+#ifndef CONFIG_USB_SUSPEND
+        /* Otherwise this would never happen */
+        usb_lock_device (hcd->self.root_hub);
+        dummy_hub_resume (hcd);
+        usb_unlock_device (hcd->self.root_hub);
+#endif
+
+        usb_hcd_poll_rh_status (hcd);
+        return 0;
+}
+
 static struct device_driver dummy_hcd_driver = {
         .name           = (char *) driver_name,
         .bus            = &platform_bus_type,
         .probe          = dummy_hcd_probe,
         .remove         = dummy_hcd_remove,
+        .suspend        = dummy_hcd_suspend,
+        .resume         = dummy_hcd_resume,
 };
 
 /*-------------------------------------------------------------------------*/