wusb: do a proper channel stop

When stopping the WUSB channel the host should send Channel Stop IEs giving
the WUSB Channel Time of the last MMC.  Both WHCI and HWA hosts provide a
channel stop command for this.

Signed-off-by: David Vrabel <david.vrabel@csr.com>

drivers/usb/host/hwa-hc.c

@@ -171,11 +171,6 @@ static int hwahc_op_start(struct usb_hcd *usb_hcd)
 	if (result < 0)
 		goto error_set_cluster_id;
 
-	result = wa_nep_arm(&hwahc->wa, GFP_KERNEL);
-	if (result < 0) {
-		dev_err(dev, "cannot listen to notifications: %d\n", result);
-		goto error_stop;
-	}
 	usb_hcd->uses_new_polling = 1;
 	usb_hcd->poll_rh = 1;
 	usb_hcd->state = HC_STATE_RUNNING;
@@ -185,8 +180,6 @@ static int hwahc_op_start(struct usb_hcd *usb_hcd)
 	d_fnend(4, dev, "(hwahc %p) = %d\n", hwahc, result);
 	return result;
 
-error_stop:
-	__wa_stop(&hwahc->wa);
 error_set_cluster_id:
 	wusb_cluster_id_put(wusbhc->cluster_id);
 error_cluster_id_get:
@@ -194,39 +187,6 @@ static int hwahc_op_start(struct usb_hcd *usb_hcd)
 
 }
 
-/*
- * FIXME: break this function up
- */
-static int __hwahc_op_wusbhc_start(struct wusbhc *wusbhc)
-{
-	int result;
-	struct hwahc *hwahc = container_of(wusbhc, struct hwahc, wusbhc);
-	struct device *dev = &hwahc->wa.usb_iface->dev;
-
-	/* Set up a Host Info WUSB Information Element */
-	d_fnstart(4, dev, "(hwahc %p)\n", hwahc);
-	result = -ENOSPC;
-
-	result = __wa_set_feature(&hwahc->wa, WA_ENABLE);
-	if (result < 0) {
-		dev_err(dev, "error commanding HC to start: %d\n", result);
-		goto error_stop;
-	}
-	result = __wa_wait_status(&hwahc->wa, WA_ENABLE, WA_ENABLE);
-	if (result < 0) {
-		dev_err(dev, "error waiting for HC to start: %d\n", result);
-		goto error_stop;
-	}
-	result = 0;
-out:
-	d_fnend(4, dev, "(hwahc %p) = %d\n", hwahc, result);
-	return result;
-
-error_stop:
-	result = __wa_clear_feature(&hwahc->wa, WA_ENABLE);
-	goto out;
-}
-
 static int hwahc_op_suspend(struct usb_hcd *usb_hcd, pm_message_t msg)
 {
 	struct wusbhc *wusbhc = usb_hcd_to_wusbhc(usb_hcd);
@@ -246,18 +206,6 @@ static int hwahc_op_resume(struct usb_hcd *usb_hcd)
 	return -ENOSYS;
 }
 
-static void __hwahc_op_wusbhc_stop(struct wusbhc *wusbhc)
-{
-	int result;
-	struct hwahc *hwahc = container_of(wusbhc, struct hwahc, wusbhc);
-	struct device *dev = &hwahc->wa.usb_iface->dev;
-
-	d_fnstart(4, dev, "(hwahc %p)\n", hwahc);
-	/* Nothing for now */
-	d_fnend(4, dev, "(hwahc %p) = %d\n", hwahc, result);
-	return;
-}
-
 /*
  * No need to abort pipes, as when this is called, all the children
  * has been disconnected and that has done it [through
@@ -275,8 +223,6 @@ static void hwahc_op_stop(struct usb_hcd *usb_hcd)
 	d_fnstart(4, dev, "(hwahc %p)\n", hwahc);
 	mutex_lock(&wusbhc->mutex);
 	wusbhc_stop(wusbhc);
-	wa_nep_disarm(&hwahc->wa);
-	result = __wa_stop(&hwahc->wa);
 	wusb_cluster_id_put(wusbhc->cluster_id);
 	mutex_unlock(&wusbhc->mutex);
 	d_fnend(4, dev, "(hwahc %p) = %d\n", hwahc, result);
@@ -325,6 +271,54 @@ static void hwahc_op_endpoint_disable(struct usb_hcd *usb_hcd,
 	rpipe_ep_disable(&hwahc->wa, ep);
 }
 
+static int __hwahc_op_wusbhc_start(struct wusbhc *wusbhc)
+{
+	int result;
+	struct hwahc *hwahc = container_of(wusbhc, struct hwahc, wusbhc);
+	struct device *dev = &hwahc->wa.usb_iface->dev;
+
+	result = __wa_set_feature(&hwahc->wa, WA_ENABLE);
+	if (result < 0) {
+		dev_err(dev, "error commanding HC to start: %d\n", result);
+		goto error_stop;
+	}
+	result = __wa_wait_status(&hwahc->wa, WA_ENABLE, WA_ENABLE);
+	if (result < 0) {
+		dev_err(dev, "error waiting for HC to start: %d\n", result);
+		goto error_stop;
+	}
+	result = wa_nep_arm(&hwahc->wa, GFP_KERNEL);
+	if (result < 0) {
+		dev_err(dev, "cannot listen to notifications: %d\n", result);
+		goto error_stop;
+	}
+	return result;
+
+error_stop:
+	__wa_clear_feature(&hwahc->wa, WA_ENABLE);
+	return result;
+}
+
+static void __hwahc_op_wusbhc_stop(struct wusbhc *wusbhc, int delay)
+{
+	struct hwahc *hwahc = container_of(wusbhc, struct hwahc, wusbhc);
+	struct wahc *wa = &hwahc->wa;
+	u8 iface_no = wa->usb_iface->cur_altsetting->desc.bInterfaceNumber;
+	int ret;
+
+	ret = usb_control_msg(wa->usb_dev, usb_sndctrlpipe(wa->usb_dev, 0),
+			      WUSB_REQ_CHAN_STOP,
+			      USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
+			      delay * 1000,
+			      iface_no,
+			      NULL, 0, 1000 /* FIXME: arbitrary */);
+	if (ret == 0)
+		msleep(delay);
+
+	wa_nep_disarm(&hwahc->wa);
+	__wa_stop(&hwahc->wa);
+}
+
 /*
  * Set the UWB MAS allocation for the WUSB cluster
  *

drivers/usb/host/whci/whcd.h

@@ -136,7 +136,7 @@ int whc_do_gencmd(struct whc *whc, u32 cmd, u32 params, void *addr, size_t len);
 
 /* wusb.c */
 int whc_wusbhc_start(struct wusbhc *wusbhc);
-void whc_wusbhc_stop(struct wusbhc *wusbhc);
+void whc_wusbhc_stop(struct wusbhc *wusbhc, int delay);
 int whc_mmcie_add(struct wusbhc *wusbhc, u8 interval, u8 repeat_cnt,
 		  u8 handle, struct wuie_hdr *wuie);
 int whc_mmcie_rm(struct wusbhc *wusbhc, u8 handle);

drivers/usb/host/whci/whci-hc.h

@@ -410,6 +410,8 @@ struct dn_buf_entry {
 #  define WUSBDNTSCTRL_SLOTS(s)    ((s) << 0)
 
 #define WUSBTIME             0x68
+#  define WUSBTIME_CHANNEL_TIME_MASK 0x00ffffff
+
 #define WUSBBPST             0x6c
 #define WUSBDIBUPDATED       0x70
 

drivers/usb/host/whci/wusb.c

@@ -64,8 +64,9 @@ static int whc_update_di(struct whc *whc, int idx)
 }
 
 /*
- * WHCI starts and stops MMCs based on there being a valid GTK so
+ * WHCI starts MMCs based on there being a valid GTK so these need
- * these need only start/stop the asynchronous and periodic schedules.
+ * only start/stop the asynchronous and periodic schedules and send a
+ * channel stop command.
  */
 
 int whc_wusbhc_start(struct wusbhc *wusbhc)
@@ -78,12 +79,20 @@ int whc_wusbhc_start(struct wusbhc *wusbhc)
 	return 0;
 }
 
-void whc_wusbhc_stop(struct wusbhc *wusbhc)
+void whc_wusbhc_stop(struct wusbhc *wusbhc, int delay)
 {
 	struct whc *whc = wusbhc_to_whc(wusbhc);
+	u32 stop_time, now_time;
+	int ret;
 
 	pzl_stop(whc);
 	asl_stop(whc);
+
+	now_time = le_readl(whc->base + WUSBTIME) & WUSBTIME_CHANNEL_TIME_MASK;
+	stop_time = (now_time + ((delay * 8) << 7)) & 0x00ffffff;
+	ret = whc_do_gencmd(whc, WUSBGENCMDSTS_CHAN_STOP, stop_time, NULL, 0);
+	if (ret == 0)
+		msleep(delay);
 }
 
 int whc_mmcie_add(struct wusbhc *wusbhc, u8 interval, u8 repeat_cnt,

drivers/usb/wusbcore/mmc.c

@@ -250,18 +250,14 @@ static int __wusbhc_host_disconnect_ie(struct wusbhc *wusbhc)
  * wusbhc_stop - stop transmitting MMCs
  * @wusbhc: the HC to stop
  *
- * Send a Host Disconnect IE, wait, remove all the MMCs (stop sending MMCs).
+ * Stops the WUSB channel and removes the cluster reservation.
- *
- * If we can't allocate a Host Stop IE, screw it, we don't notify the
- * devices we are disconnecting...
  */
 void wusbhc_stop(struct wusbhc *wusbhc)
 {
 	if (wusbhc->active) {
 		wusbhc->active = 0;
-		wusbhc->stop(wusbhc);
+		wusbhc->stop(wusbhc, WUSB_CHANNEL_STOP_DELAY_MS);
 		wusbhc_sec_stop(wusbhc);
-		__wusbhc_host_disconnect_ie(wusbhc);
 		wusbhc_devconnect_stop(wusbhc);
 		wusbhc_rsv_terminate(wusbhc);
 	}

drivers/usb/wusbcore/wusbhc.h

@@ -64,6 +64,13 @@
 #include <linux/uwb.h>
 #include <linux/usb/wusb.h>
 
+/*
+ * Time from a WUSB channel stop request to the last transmitted MMC.
+ *
+ * This needs to be > 4.096 ms in case no MMCs can be transmitted in
+ * zone 0.
+ */
+#define WUSB_CHANNEL_STOP_DELAY_MS 8
 
 /**
  * Wireless USB device
@@ -198,21 +205,18 @@ struct wusb_port {
  * @mmcies_max	   Max number of Information Elements this HC can send
  *                 in its MMC. Read-only.
  *
+ * @start          Start the WUSB channel.
+ *
+ * @stop           Stop the WUSB channel after the specified number of
+ *                 milliseconds.  Channel Stop IEs should be transmitted
+ *                 as required by [WUSB] 4.16.2.1.
+ *
  * @mmcie_add	   HC specific operation (WHCI or HWA) for adding an
  *                 MMCIE.
  *
  * @mmcie_rm	   HC specific operation (WHCI or HWA) for removing an
  *                 MMCIE.
  *
- * @enc_types	   Array which describes the encryptions methods
- *                 supported by the host as described in WUSB1.0 --
- *                 one entry per supported method. As of WUSB1.0 there
- *                 is only four methods, we make space for eight just in
- *                 case they decide to add some more (and pray they do
- *                 it in sequential order). if 'enc_types[enc_method]
- *                 != 0', then it is supported by the host. enc_method
- *                 is USB_ENC_TYPE*.
- *
  * @set_ptk:       Set the PTK and enable encryption for a device. Or, if
  *                 the supplied key is NULL, disable encryption for that
  *                 device.
@@ -269,7 +273,7 @@ struct wusbhc {
 	u8 mmcies_max;
 	/* FIXME: make wusbhc_ops? */
 	int (*start)(struct wusbhc *wusbhc);
-	void (*stop)(struct wusbhc *wusbhc);
+	void (*stop)(struct wusbhc *wusbhc, int delay);
 	int (*mmcie_add)(struct wusbhc *wusbhc, u8 interval, u8 repeat_cnt,
 			 u8 handle, struct wuie_hdr *wuie);
 	int (*mmcie_rm)(struct wusbhc *wusbhc, u8 handle);

include/linux/usb/wusb-wa.h

@@ -51,6 +51,7 @@ enum {
 	WUSB_REQ_GET_TIME       = 25,
 	WUSB_REQ_SET_STREAM_IDX = 26,
 	WUSB_REQ_SET_WUSB_MAS   = 27,
+	WUSB_REQ_CHAN_STOP      = 28,
 };