bas_gigaset: suspend support

Add basic suspend/resume support to the bas_gigaset ISDN driver for the
Siemens Gigaset SX255 series of ISDN DECT bases.

Only the USB aspects are handled so far; the ISDN subsystem is not notified in
any way, for lack of information about how to do that.  The driver will refuse
to suspend if a connection is active.

Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Cc: Greg KH <gregkh@suse.de>
Cc: Hansjoerg Lipp <hjlipp@web.de>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/isdn/gigaset/bas-gigaset.c b/drivers/isdn/gigaset/bas-gigaset.c
index d60a6510e92bd09e2fed68834a4432d643aa2882..1c401b3f88e19e3ae6db9d2320ee0284f38ee9bd 100644 (file)
--- a/drivers/isdn/gigaset/bas-gigaset.c
+++ b/drivers/isdn/gigaset/bas-gigaset.c
@@ -73,6 +73,14 @@ static int gigaset_probe(struct usb_interface *interface,
 /* Function will be called if the device is unplugged */
 static void gigaset_disconnect(struct usb_interface *interface);
 
+/* functions called before/after suspend */
+static int gigaset_suspend(struct usb_interface *intf, pm_message_t message);
+static int gigaset_resume(struct usb_interface *intf);
+
+/* functions called before/after device reset */
+static int gigaset_pre_reset(struct usb_interface *intf);
+static int gigaset_post_reset(struct usb_interface *intf);
+
 static int atread_submit(struct cardstate *, int);
 static void stopurbs(struct bas_bc_state *);
 static int req_submit(struct bc_state *, int, int, int);
@@ -107,6 +115,7 @@ struct bas_cardstate {
        spinlock_t              lock;           /* locks all following */
        atomic_t                basstate;       /* bitmap (BS_*) */
        int                     pending;        /* uncompleted base request */
+       wait_queue_head_t       waitqueue;
        int                     rcvbuf_size;    /* size of AT receive buffer */
                                                /* 0: no receive in progress */
        int                     retry_cmd_in;   /* receive req retry count */
@@ -121,6 +130,7 @@ struct bas_cardstate {
 #define BS_ATTIMER     0x020   /* waiting for HD_READY_SEND_ATDATA */
 #define BS_ATRDPEND    0x040   /* urb_cmd_in in use */
 #define BS_ATWRPEND    0x080   /* urb_cmd_out in use */
+#define BS_SUSPEND     0x100   /* USB port suspended */
 
 
 static struct gigaset_driver *driver = NULL;
@@ -132,6 +142,11 @@ static struct usb_driver gigaset_usb_driver = {
        .probe =        gigaset_probe,
        .disconnect =   gigaset_disconnect,
        .id_table =     gigaset_table,
+       .suspend =      gigaset_suspend,
+       .resume =       gigaset_resume,
+       .reset_resume = gigaset_post_reset,
+       .pre_reset =    gigaset_pre_reset,
+       .post_reset =   gigaset_post_reset,
 };
 
 /* get message text for usb_submit_urb return code
@@ -465,6 +480,7 @@ static void read_ctrl_callback(struct urb *urb)
        int rc;
 
        update_basstate(ucs, 0, BS_ATRDPEND);
+       wake_up(&ucs->waitqueue);
 
        if (!ucs->rcvbuf_size) {
                dev_warn(cs->dev, "%s: no receive in progress\n", __func__);
@@ -551,17 +567,28 @@ static void read_ctrl_callback(struct urb *urb)
 static int atread_submit(struct cardstate *cs, int timeout)
 {
        struct bas_cardstate *ucs = cs->hw.bas;
+       int basstate;
        int ret;
 
        gig_dbg(DEBUG_USBREQ, "-------> HD_READ_ATMESSAGE (%d)",
                ucs->rcvbuf_size);
 
-       if (update_basstate(ucs, BS_ATRDPEND, 0) & BS_ATRDPEND) {
+       basstate = update_basstate(ucs, BS_ATRDPEND, 0);
+       if (basstate & BS_ATRDPEND) {
                dev_err(cs->dev,
                        "could not submit HD_READ_ATMESSAGE: URB busy\n");
                return -EBUSY;
        }
 
+       if (basstate & BS_SUSPEND) {
+               dev_notice(cs->dev,
+                          "HD_READ_ATMESSAGE not submitted, "
+                          "suspend in progress\n");
+               update_basstate(ucs, 0, BS_ATRDPEND);
+               /* treat like disconnect */
+               return -ENODEV;
+       }
+
        ucs->dr_cmd_in.bRequestType = IN_VENDOR_REQ;
        ucs->dr_cmd_in.bRequest = HD_READ_ATMESSAGE;
        ucs->dr_cmd_in.wValue = 0;
@@ -747,6 +774,7 @@ static void read_int_callback(struct urb *urb)
        }
 
        check_pending(ucs);
+       wake_up(&ucs->waitqueue);
 
 resubmit:
        rc = usb_submit_urb(urb, GFP_ATOMIC);
@@ -1416,6 +1444,8 @@ static void req_timeout(unsigned long data)
                dev_warn(bcs->cs->dev, "request 0x%02x timed out, clearing\n",
                         pending);
        }
+
+       wake_up(&ucs->waitqueue);
 }
 
 /* write_ctrl_callback
@@ -1456,7 +1486,9 @@ static void write_ctrl_callback(struct urb *urb)
                break;
 
        default:                                /* any failure */
-               if (++ucs->retry_ctrl > BAS_RETRY) {
+               /* don't retry if suspend requested */
+               if (++ucs->retry_ctrl > BAS_RETRY ||
+                   (atomic_read(&ucs->basstate) & BS_SUSPEND)) {
                        dev_err(&ucs->interface->dev,
                                "control request 0x%02x failed: %s\n",
                                ucs->dr_ctrl.bRequest,
@@ -1485,6 +1517,7 @@ static void write_ctrl_callback(struct urb *urb)
        del_timer(&ucs->timer_ctrl);
        ucs->pending = 0;
        spin_unlock_irqrestore(&ucs->lock, flags);
+       wake_up(&ucs->waitqueue);
 }
 
 /* req_submit
@@ -1570,6 +1603,14 @@ static int gigaset_init_bchannel(struct bc_state *bcs)
                return -ENODEV;
        }
 
+       if (atomic_read(&cs->hw.bas->basstate) & BS_SUSPEND) {
+               dev_notice(cs->dev,
+                          "not starting isochronous I/O, "
+                          "suspend in progress\n");
+               spin_unlock_irqrestore(&cs->lock, flags);
+               return -EHOSTUNREACH;
+       }
+
        if ((ret = starturbs(bcs)) < 0) {
                dev_err(cs->dev,
                        "could not start isochronous I/O for channel B%d: %s\n",
@@ -1682,6 +1723,7 @@ static void write_command_callback(struct urb *urb)
        unsigned long flags;
 
        update_basstate(ucs, 0, BS_ATWRPEND);
+       wake_up(&ucs->waitqueue);
 
        /* check status */
        switch (status) {
@@ -1705,6 +1747,13 @@ static void write_command_callback(struct urb *urb)
                                 ucs->retry_cmd_out);
                        break;
                }
+               if (atomic_read(&ucs->basstate) & BS_SUSPEND) {
+                       dev_warn(cs->dev,
+                                "command write: %s, "
+                                "won't retry - suspend requested\n",
+                                get_usb_statmsg(status));
+                       break;
+               }
                if (cs->cmdbuf == NULL) {
                        dev_warn(cs->dev,
                                 "command write: %s, "
@@ -1813,6 +1862,12 @@ static int start_cbsend(struct cardstate *cs)
        int rc;
        int retval = 0;
 
+       /* check if suspend requested */
+       if (atomic_read(&ucs->basstate) & BS_SUSPEND) {
+               gig_dbg(DEBUG_TRANSCMD|DEBUG_LOCKCMD, "suspending");
+               return -EHOSTUNREACH;
+       }
+
        /* check if AT channel is open */
        if (!(atomic_read(&ucs->basstate) & BS_ATOPEN)) {
                gig_dbg(DEBUG_TRANSCMD|DEBUG_LOCKCMD, "AT channel not open");
@@ -2099,6 +2154,7 @@ static int gigaset_initcshw(struct cardstate *cs)
        init_timer(&ucs->timer_ctrl);
        init_timer(&ucs->timer_atrdy);
        init_timer(&ucs->timer_cmd_in);
+       init_waitqueue_head(&ucs->waitqueue);
 
        return 1;
 }
@@ -2311,6 +2367,112 @@ static void gigaset_disconnect(struct usb_interface *interface)
        gigaset_unassign(cs);
 }
 
+/* gigaset_suspend
+ * This function is called before the USB connection is suspended.
+ */
+static int gigaset_suspend(struct usb_interface *intf, pm_message_t message)
+{
+       struct cardstate *cs = usb_get_intfdata(intf);
+       struct bas_cardstate *ucs = cs->hw.bas;
+       int basstate;
+       int rc;
+
+       /* set suspend flag; this stops AT command/response traffic */
+       if (update_basstate(ucs, BS_SUSPEND, 0) & BS_SUSPEND) {
+               gig_dbg(DEBUG_SUSPEND, "already suspended");
+               return 0;
+       }
+
+       /* wait a bit for blocking conditions to go away */
+       rc = wait_event_timeout(ucs->waitqueue,
+                       !(atomic_read(&ucs->basstate) &
+                         (BS_B1OPEN|BS_B2OPEN|BS_ATRDPEND|BS_ATWRPEND)),
+                       BAS_TIMEOUT*HZ/10);
+       gig_dbg(DEBUG_SUSPEND, "wait_event_timeout() -> %d", rc);
+
+       /* check for conditions preventing suspend */
+       basstate = atomic_read(&ucs->basstate);
+       if (basstate & (BS_B1OPEN|BS_B2OPEN|BS_ATRDPEND|BS_ATWRPEND)) {
+               dev_warn(cs->dev, "cannot suspend:\n");
+               if (basstate & BS_B1OPEN)
+                       dev_warn(cs->dev, " B channel 1 open\n");
+               if (basstate & BS_B2OPEN)
+                       dev_warn(cs->dev, " B channel 2 open\n");
+               if (basstate & BS_ATRDPEND)
+                       dev_warn(cs->dev, " receiving AT reply\n");
+               if (basstate & BS_ATWRPEND)
+                       dev_warn(cs->dev, " sending AT command\n");
+               update_basstate(ucs, 0, BS_SUSPEND);
+               return -EBUSY;
+       }
+
+       /* close AT channel if open */
+       if (basstate & BS_ATOPEN) {
+               gig_dbg(DEBUG_SUSPEND, "closing AT channel");
+               rc = req_submit(cs->bcs, HD_CLOSE_ATCHANNEL, 0, 0);
+               if (rc) {
+                       update_basstate(ucs, 0, BS_SUSPEND);
+                       return rc;
+               }
+               wait_event_timeout(ucs->waitqueue, !ucs->pending,
+                                  BAS_TIMEOUT*HZ/10);
+               /* in case of timeout, proceed anyway */
+       }
+
+       /* kill all URBs and timers that might still be pending */
+       usb_kill_urb(ucs->urb_ctrl);
+       usb_kill_urb(ucs->urb_int_in);
+       del_timer_sync(&ucs->timer_ctrl);
+
+       gig_dbg(DEBUG_SUSPEND, "suspend complete");
+       return 0;
+}
+
+/* gigaset_resume
+ * This function is called after the USB connection has been resumed.
+ */
+static int gigaset_resume(struct usb_interface *intf)
+{
+       struct cardstate *cs = usb_get_intfdata(intf);
+       struct bas_cardstate *ucs = cs->hw.bas;
+       int rc;
+
+       /* resubmit interrupt URB for spontaneous messages from base */
+       rc = usb_submit_urb(ucs->urb_int_in, GFP_KERNEL);
+       if (rc) {
+               dev_err(cs->dev, "could not resubmit interrupt URB: %s\n",
+                       get_usb_rcmsg(rc));
+               return rc;
+       }
+
+       /* clear suspend flag to reallow activity */
+       update_basstate(ucs, 0, BS_SUSPEND);
+
+       gig_dbg(DEBUG_SUSPEND, "resume complete");
+       return 0;
+}
+
+/* gigaset_pre_reset
+ * This function is called before the USB connection is reset.
+ */
+static int gigaset_pre_reset(struct usb_interface *intf)
+{
+       /* handle just like suspend */
+       return gigaset_suspend(intf, PMSG_ON);
+}
+
+/* gigaset_post_reset
+ * This function is called after the USB connection has been reset.
+ */
+static int gigaset_post_reset(struct usb_interface *intf)
+{
+       /* FIXME: send HD_DEVICE_INIT_ACK? */
+
+       /* resume operations */
+       return gigaset_resume(intf);
+}
+
+
 static const struct gigaset_ops gigops = {
        gigaset_write_cmd,
        gigaset_write_room,