1 files changed, 49 insertions, 9 deletions

diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 942ef5e053bf..c3a61853cd13 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -148,6 +148,9 @@ struct usb_ep_ops {
  * @maxpacket:The maximum packet size used on this endpoint.  The initial
  *      value can sometimes be reduced (hardware allowing), according to
  *      the endpoint descriptor used to configure the endpoint.
+ * @maxpacket_limit:The maximum packet size value which can be handled by this
+ *      endpoint. It's set once by UDC driver when endpoint is initialized, and
+ *      should not be changed. Should not be confused with maxpacket.
  * @max_streams: The maximum number of streams supported
  *      by this EP (0 - 16, actual number is 2^n)
  * @mult: multiplier, 'mult' value for SS Isoc EPs
@@ -171,6 +174,7 @@ struct usb_ep {
         const struct usb_ep_ops *ops;
         struct list_head        ep_list;
         unsigned                maxpacket:16;
+        unsigned                maxpacket_limit:16;
         unsigned                max_streams:16;
         unsigned                mult:2;
         unsigned                maxburst:5;
@@ -182,6 +186,21 @@ struct usb_ep {
 /*-------------------------------------------------------------------------*/
 
 /**
+ * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
+ * @ep:the endpoint being configured
+ * @maxpacket_limit:value of maximum packet size limit
+ *
+ * This function shoud be used only in UDC drivers to initialize endpoint
+ * (usually in probe function).
+ */
+static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
+                                              unsigned maxpacket_limit)
+{
+        ep->maxpacket_limit = maxpacket_limit;
+        ep->maxpacket = maxpacket_limit;
+}
+
+/**
  * usb_ep_enable - configure endpoint, making it usable
  * @ep:the endpoint being configured.  may not be the endpoint named "ep0".
  *      drivers discover endpoints through the ep_list of a usb_gadget.
@@ -485,6 +504,11 @@ struct usb_gadget_ops {
  * @max_speed: Maximal speed the UDC can handle.  UDC must support this
  *      and all slower speeds.
  * @state: the state we are now (attached, suspended, configured, etc)
+ * @name: Identifies the controller hardware type.  Used in diagnostics
+ *      and sometimes configuration.
+ * @dev: Driver model state for this abstract device.
+ * @out_epnum: last used out ep number
+ * @in_epnum: last used in ep number
  * @sg_supported: true if we can handle scatter-gather
  * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
  *      gadget driver must provide a USB OTG descriptor.
@@ -497,11 +521,8 @@ struct usb_gadget_ops {
  *      only supports HNP on a different root port.
  * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
  *      enabled HNP support.
- * @name: Identifies the controller hardware type.  Used in diagnostics
- *      and sometimes configuration.
- * @dev: Driver model state for this abstract device.
- * @out_epnum: last used out ep number
- * @in_epnum: last used in ep number
+ * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
+ *      MaxPacketSize.
  *
  * Gadgets have a mostly-portable "gadget driver" implementing device
  * functions, handling all usb configurations and interfaces.  Gadget
@@ -530,16 +551,18 @@ struct usb_gadget {
         enum usb_device_speed           speed;
         enum usb_device_speed           max_speed;
         enum usb_device_state           state;
+        const char                      *name;
+        struct device                   dev;
+        unsigned                        out_epnum;
+        unsigned                        in_epnum;
+
         unsigned                        sg_supported:1;
         unsigned                        is_otg:1;
         unsigned                        is_a_peripheral:1;
         unsigned                        b_hnp_enable:1;
         unsigned                        a_hnp_support:1;
         unsigned                        a_alt_hnp_support:1;
-        const char                      *name;
-        struct device                   dev;
-        unsigned                        out_epnum;
-        unsigned                        in_epnum;
+        unsigned                        quirk_ep_out_aligned_size:1;
 };
 #define work_to_gadget(w)       (container_of((w), struct usb_gadget, work))
 
@@ -558,6 +581,23 @@ static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
 
 
 /**
+ * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget
+ *      requires quirk_ep_out_aligned_size, otherwise reguens len.
+ * @g: controller to check for quirk
+ * @ep: the endpoint whose maxpacketsize is used to align @len
+ * @len: buffer size's length to align to @ep's maxpacketsize
+ *
+ * This helper is used in case it's required for any reason to check and maybe
+ * align buffer's size to an ep's maxpacketsize.
+ */
+static inline size_t
+usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len)
+{
+        return !g->quirk_ep_out_aligned_size ? len :
+                        round_up(len, (size_t)ep->desc->wMaxPacketSize);
+}
+
+/**
  * gadget_is_dualspeed - return true iff the hardware handles high speed
  * @g: controller that might support both high and full speeds
  */