usb: common: add function to get interval expressed in us unit

Add a new function to convert bInterval into the time expressed
in 1us unit.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/25c8a09b055f716c1e5bf11fea72c3418f844482.1615170625.git.chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/common/common.c b/drivers/usb/common/common.c
index fc21cf2d36f65ed86a9578930f6f9c269e6273c8..675e8a4e683a266c611e3542b198454ac5e1a270 100644 (file)
--- a/drivers/usb/common/common.c
+++ b/drivers/usb/common/common.c
@@ -165,6 +165,47 @@ enum usb_dr_mode usb_get_dr_mode(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(usb_get_dr_mode);
 
+/**
+ * usb_decode_interval - Decode bInterval into the time expressed in 1us unit
+ * @epd: The descriptor of the endpoint
+ * @speed: The speed that the endpoint works as
+ *
+ * Function returns the interval expressed in 1us unit for servicing
+ * endpoint for data transfers.
+ */
+unsigned int usb_decode_interval(const struct usb_endpoint_descriptor *epd,
+                                enum usb_device_speed speed)
+{
+       unsigned int interval = 0;
+
+       switch (usb_endpoint_type(epd)) {
+       case USB_ENDPOINT_XFER_CONTROL:
+               /* uframes per NAK */
+               if (speed == USB_SPEED_HIGH)
+                       interval = epd->bInterval;
+               break;
+       case USB_ENDPOINT_XFER_ISOC:
+               interval = 1 << (epd->bInterval - 1);
+               break;
+       case USB_ENDPOINT_XFER_BULK:
+               /* uframes per NAK */
+               if (speed == USB_SPEED_HIGH && usb_endpoint_dir_out(epd))
+                       interval = epd->bInterval;
+               break;
+       case USB_ENDPOINT_XFER_INT:
+               if (speed >= USB_SPEED_HIGH)
+                       interval = 1 << (epd->bInterval - 1);
+               else
+                       interval = epd->bInterval;
+               break;
+       }
+
+       interval *= (speed >= USB_SPEED_HIGH) ? 125 : 1000;
+
+       return interval;
+}
+EXPORT_SYMBOL_GPL(usb_decode_interval);
+
 #ifdef CONFIG_OF
 /**
  * of_usb_get_dr_mode_by_phy - Get dual role mode for the controller device

diff --git a/drivers/usb/core/devices.c b/drivers/usb/core/devices.c
index 1ef2de6e375ac84b80aa31540069088a8257983a..d8b0041de612ffc30a41aa5f09d4701f88b109b3 100644 (file)
--- a/drivers/usb/core/devices.c
+++ b/drivers/usb/core/devices.c
@@ -157,38 +157,25 @@ static char *usb_dump_endpoint_descriptor(int speed, char *start, char *end,
        switch (usb_endpoint_type(desc)) {
        case USB_ENDPOINT_XFER_CONTROL:
                type = "Ctrl";
-               if (speed == USB_SPEED_HIGH)    /* uframes per NAK */
-                       interval = desc->bInterval;
-               else
-                       interval = 0;
                dir = 'B';                      /* ctrl is bidirectional */
                break;
        case USB_ENDPOINT_XFER_ISOC:
                type = "Isoc";
-               interval = 1 << (desc->bInterval - 1);
                break;
        case USB_ENDPOINT_XFER_BULK:
                type = "Bulk";
-               if (speed == USB_SPEED_HIGH && dir == 'O') /* uframes per NAK */
-                       interval = desc->bInterval;
-               else
-                       interval = 0;
                break;
        case USB_ENDPOINT_XFER_INT:
                type = "Int.";
-               if (speed == USB_SPEED_HIGH || speed >= USB_SPEED_SUPER)
-                       interval = 1 << (desc->bInterval - 1);
-               else
-                       interval = desc->bInterval;
                break;
        default:        /* "can't happen" */
                return start;
        }
-       interval *= (speed == USB_SPEED_HIGH ||
-                    speed >= USB_SPEED_SUPER) ? 125 : 1000;
-       if (interval % 1000)
+
+       interval = usb_decode_interval(desc, speed);
+       if (interval % 1000) {
                unit = 'u';
-       else {
+       } else {
                unit = 'm';
                interval /= 1000;
        }

diff --git a/drivers/usb/core/endpoint.c b/drivers/usb/core/endpoint.c
index 903426b6d305c8f8fcb0eee03440f354570d3589..a2530811cf7ded0656556d35abcc43b302409ce8 100644 (file)
--- a/drivers/usb/core/endpoint.c
+++ b/drivers/usb/core/endpoint.c
@@ -84,40 +84,13 @@ static ssize_t interval_show(struct device *dev, struct device_attribute *attr,
                             char *buf)
 {
        struct ep_device *ep = to_ep_device(dev);
+       unsigned int interval;
        char unit;
-       unsigned interval = 0;
-       unsigned in;
 
-       in = (ep->desc->bEndpointAddress & USB_DIR_IN);
-
-       switch (usb_endpoint_type(ep->desc)) {
-       case USB_ENDPOINT_XFER_CONTROL:
-               if (ep->udev->speed == USB_SPEED_HIGH)
-                       /* uframes per NAK */
-                       interval = ep->desc->bInterval;
-               break;
-
-       case USB_ENDPOINT_XFER_ISOC:
-               interval = 1 << (ep->desc->bInterval - 1);
-               break;
-
-       case USB_ENDPOINT_XFER_BULK:
-               if (ep->udev->speed == USB_SPEED_HIGH && !in)
-                       /* uframes per NAK */
-                       interval = ep->desc->bInterval;
-               break;
-
-       case USB_ENDPOINT_XFER_INT:
-               if (ep->udev->speed == USB_SPEED_HIGH)
-                       interval = 1 << (ep->desc->bInterval - 1);
-               else
-                       interval = ep->desc->bInterval;
-               break;
-       }
-       interval *= (ep->udev->speed == USB_SPEED_HIGH) ? 125 : 1000;
-       if (interval % 1000)
+       interval = usb_decode_interval(ep->desc, ep->udev->speed);
+       if (interval % 1000) {
                unit = 'u';
-       else {
+       } else {
                unit = 'm';
                interval /= 1000;
        }

diff --git a/include/linux/usb/ch9.h b/include/linux/usb/ch9.h
index abdd310c77f053cd0a8e4143ad126fa591d9927a..74debc8246454e5120962485cc84e75fea0a43d7 100644 (file)
--- a/include/linux/usb/ch9.h
+++ b/include/linux/usb/ch9.h
@@ -90,6 +90,9 @@ extern enum usb_ssp_rate usb_get_maximum_ssp_rate(struct device *dev);
  */
 extern const char *usb_state_string(enum usb_device_state state);
 
+unsigned int usb_decode_interval(const struct usb_endpoint_descriptor *epd,
+                                enum usb_device_speed speed);
+
 #ifdef CONFIG_TRACING
 /**
  * usb_decode_ctrl - Returns human readable representation of control request.