USB: wusb: add wusb_phy_rate sysfs file to host controllers

Add the wusb_phy_rate sysfs file to Wireless USB host controllers. This
sets the maximum PHY rate that will be used for all connected devices.

Signed-off-by: David Vrabel <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/ABI/testing/sysfs-class-uwb_rc-wusbhc

···
                 Since this relates to security (specifically, the
                 lifetime of PTKs and GTKs) it should not be changed
                 from the default.
+
+What:           /sys/class/uwb_rc/uwbN/wusbhc/wusb_phy_rate
+Date:           August 2009
+KernelVersion:  2.6.32
+Contact:        David Vrabel <[e-mail]>
+Description:
+                The maximum PHY rate to use for all connected devices.
+                This is only of limited use for testing and
+                development as the hardware's automatic rate
+                adaptation is better then this simple control.
+
+                Refer to [ECMA-368] section 10.3.1.1 for the value to
+                use.

drivers/usb/host/whci/qset.c

···
  *        state
  * @urb:  an urb for a transfer to this endpoint
  */
-static void qset_fill_qh(struct whc_qset *qset, struct urb *urb)
+static void qset_fill_qh(struct whc *whc, struct whc_qset *qset, struct urb *urb)
 {
 	struct usb_device *usb_dev = urb->dev;
+	struct wusb_dev *wusb_dev = usb_dev->wusb_dev;
 	struct usb_wireless_ep_comp_descriptor *epcd;
 	bool is_out;
+	uint8_t phy_rate;
 
 	is_out = usb_pipeout(urb->pipe);
 
···
 	} else {
 		qset->max_seq = 2;
 		qset->max_burst = 1;
+	}
+
+	/*
+	 * Initial PHY rate is 53.3 Mbit/s for control endpoints or
+	 * the maximum supported by the device for other endpoints
+	 * (unless limited by the user).
+	 */
+	if (usb_pipecontrol(urb->pipe))
+		phy_rate = UWB_PHY_RATE_53;
+	else {
+		uint16_t phy_rates;
+
+		phy_rates = le16_to_cpu(wusb_dev->wusb_cap_descr->wPHYRates);
+		phy_rate = fls(phy_rates) - 1;
+		if (phy_rate > whc->wusbhc.phy_rate)
+			phy_rate = whc->wusbhc.phy_rate;
 	}
 
 	qset->qh.info1 = cpu_to_le32(
···
 	 * strength and can presumably guess the Tx power required
 	 * from that? */
 	qset->qh.info3 = cpu_to_le32(
-		QH_INFO3_TX_RATE_53_3
+		QH_INFO3_TX_RATE(phy_rate)
 		| QH_INFO3_TX_PWR(0) /* 0 == max power */
 		);
 
···
 
 		qset->ep = urb->ep;
 		urb->ep->hcpriv = qset;
-		qset_fill_qh(qset, urb);
+		qset_fill_qh(whc, qset, urb);
 	}
 	return qset;
 }

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

···
 #define QH_INFO3_MAX_DELAY(d)    ((d) << 0)  /* maximum stream delay in 125 us units (isoc only) */
 #define QH_INFO3_INTERVAL(i)     ((i) << 16) /* segment interval in 125 us units (isoc only) */
 
-#define QH_INFO3_TX_RATE_53_3    (0 << 24)
-#define QH_INFO3_TX_RATE_80      (1 << 24)
-#define QH_INFO3_TX_RATE_106_7   (2 << 24)
-#define QH_INFO3_TX_RATE_160     (3 << 24)
-#define QH_INFO3_TX_RATE_200     (4 << 24)
-#define QH_INFO3_TX_RATE_320     (5 << 24)
-#define QH_INFO3_TX_RATE_400     (6 << 24)
-#define QH_INFO3_TX_RATE_480     (7 << 24)
+#define QH_INFO3_TX_RATE(r)      ((r) << 24) /* PHY rate (see [ECMA-368] section 10.3.1.1) */
 #define QH_INFO3_TX_PWR(p)       ((p) << 29) /* transmit power (see [WUSB] section 5.2.1.2) */
 
 #define QH_STATUS_FLOW_CTRL      (1 << 15)

drivers/usb/wusbcore/wusbhc.c

···
 }
 static DEVICE_ATTR(wusb_chid, 0644, wusb_chid_show, wusb_chid_store);
 
+
+static ssize_t wusb_phy_rate_show(struct device *dev,
+				  struct device_attribute *attr,
+				  char *buf)
+{
+	struct wusbhc *wusbhc = usbhc_dev_to_wusbhc(dev);
+
+	return sprintf(buf, "%d\n", wusbhc->phy_rate);
+}
+
+static ssize_t wusb_phy_rate_store(struct device *dev,
+				   struct device_attribute *attr,
+				   const char *buf, size_t size)
+{
+	struct wusbhc *wusbhc = usbhc_dev_to_wusbhc(dev);
+	uint8_t phy_rate;
+	ssize_t result;
+
+	result = sscanf(buf, "%hhu", &phy_rate);
+	if (result != 1)
+		return -EINVAL;
+	if (phy_rate >= UWB_PHY_RATE_INVALID)
+		return -EINVAL;
+
+	wusbhc->phy_rate = phy_rate;
+	return size;
+}
+static DEVICE_ATTR(wusb_phy_rate, 0644, wusb_phy_rate_show, wusb_phy_rate_store);
+
 /* Group all the WUSBHC attributes */
 static struct attribute *wusbhc_attrs[] = {
 		&dev_attr_wusb_trust_timeout.attr,
 		&dev_attr_wusb_chid.attr,
+		&dev_attr_wusb_phy_rate.attr,
 		NULL,
 };
 
···
 	int result = 0;
 
 	wusbhc->trust_timeout = WUSB_TRUST_TIMEOUT_MS;
+	wusbhc->phy_rate = UWB_PHY_RATE_INVALID - 1;
+
 	mutex_init(&wusbhc->mutex);
 	result = wusbhc_mmcie_create(wusbhc);
 	if (result < 0)

drivers/usb/wusbcore/wusbhc.h

···
 
 	unsigned trust_timeout;			/* in jiffies */
 	struct wusb_ckhdid chid;
+	uint8_t phy_rate;
 	struct wuie_host_info *wuie_host_info;
 
 	struct mutex mutex;			/* locks everything else */