wl12xx: prevent scheduling while suspending (WoW enabled)

When WoW is enabled, the interface will stay up and the chip will
be powered on, so we have to flush/cancel any remaining work, and
prevent the irq handler from scheduling a new work until the system
is resumed.

Add 2 new flags:
* WL1271_FLAG_SUSPENDED - the system is (about to be) suspended.
* WL1271_FLAG_PENDING_WORK - there is a pending irq work which
   should be scheduled when the system is being resumed.

In order to wake-up the system while getting an irq, we initialize
the device as wakeup device, and calling pm_wakeup_event() upon
getting the interrupt (while the system is about to be suspended)

Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>
diff --git a/drivers/net/wireless/wl12xx/sdio.c b/drivers/net/wireless/wl12xx/sdio.c
index 5b03fd5e..41183db 100644
--- a/drivers/net/wireless/wl12xx/sdio.c
+++ b/drivers/net/wireless/wl12xx/sdio.c
@@ -82,6 +82,16 @@
 		complete(wl->elp_compl);
 		wl->elp_compl = NULL;
 	}
+
+	if (test_bit(WL1271_FLAG_SUSPENDED, &wl->flags)) {
+		/* don't enqueue a work right now. mark it as pending */
+		set_bit(WL1271_FLAG_PENDING_WORK, &wl->flags);
+		wl1271_debug(DEBUG_IRQ, "should not enqueue work");
+		disable_irq_nosync(wl->irq);
+		pm_wakeup_event(wl1271_sdio_wl_to_dev(wl), 0);
+		spin_unlock_irqrestore(&wl->wl_lock, flags);
+		return IRQ_HANDLED;
+	}
 	spin_unlock_irqrestore(&wl->wl_lock, flags);
 
 	return IRQ_WAKE_THREAD;
@@ -268,6 +278,7 @@
 	}
 
 	enable_irq_wake(wl->irq);
+	device_init_wakeup(wl1271_sdio_wl_to_dev(wl), 1);
 
 	disable_irq(wl->irq);
 
@@ -305,6 +316,7 @@
 	pm_runtime_get_noresume(&func->dev);
 
 	wl1271_unregister_hw(wl);
+	device_init_wakeup(wl1271_sdio_wl_to_dev(wl), 0);
 	disable_irq_wake(wl->irq);
 	free_irq(wl->irq, wl);
 	wl1271_free_hw(wl);
@@ -339,6 +351,9 @@
 			wl1271_error("error while trying to keep power");
 			goto out;
 		}
+
+		/* release host */
+		sdio_release_host(func);
 	}
 out:
 	return ret;
@@ -346,6 +361,15 @@
 
 static int wl1271_resume(struct device *dev)
 {
+	struct sdio_func *func = dev_to_sdio_func(dev);
+	struct wl1271 *wl = sdio_get_drvdata(func);
+
+	wl1271_debug(DEBUG_MAC80211, "wl1271 resume");
+	if (wl->wow_enabled) {
+		/* claim back host */
+		sdio_claim_host(func);
+	}
+
 	return 0;
 }