usb: gadget: f_fs: handle control requests not directed to interface or endpoint

Introduces a new FunctionFS descriptor flag named
FUNCTIONFS_ALL_CTRL_RECIP. When this flag is enabled, control requests,
which are not explicitly directed to an interface or endpoint, can be
handled.

This allows FunctionFS userspace drivers to process non-standard
control requests.

Signed-off-by: Felix Hädicke <felixhaedicke@web.de>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

1 files changed, 30 insertions, 4 deletions

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 5c8429f23a89..d7acab873836 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -98,6 +98,8 @@ static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
 static void ffs_func_disable(struct usb_function *);
 static int ffs_func_setup(struct usb_function *,
                           const struct usb_ctrlrequest *);
+static bool ffs_func_req_match(struct usb_function *,
+                               const struct usb_ctrlrequest *);
 static void ffs_func_suspend(struct usb_function *);
 static void ffs_func_resume(struct usb_function *);
 
@@ -2243,7 +2245,8 @@ static int __ffs_data_got_descs(struct ffs_data *ffs,
                               FUNCTIONFS_HAS_SS_DESC |
                               FUNCTIONFS_HAS_MS_OS_DESC |
                               FUNCTIONFS_VIRTUAL_ADDR |
-                              FUNCTIONFS_EVENTFD)) {
+                              FUNCTIONFS_EVENTFD |
+                              FUNCTIONFS_ALL_CTRL_RECIP)) {
                         ret = -ENOSYS;
                         goto error;
                 }
@@ -3094,8 +3097,9 @@ static int ffs_func_setup(struct usb_function *f,
          * handle them.  All other either handled by composite or
          * passed to usb_configuration->setup() (if one is set).  No
          * matter, we will handle requests directed to endpoint here
-         * as well (as it's straightforward) but what to do with any
-         * other request?
+         * as well (as it's straightforward).  Other request recipient
+         * types are only handled when the user flag FUNCTIONFS_ALL_CTRL_RECIP
+         * is being used.
          */
         if (ffs->state != FFS_ACTIVE)
                 return -ENODEV;
@@ -3116,7 +3120,10 @@ static int ffs_func_setup(struct usb_function *f,
                 break;
 
         default:
-                return -EOPNOTSUPP;
+                if (func->ffs->user_flags & FUNCTIONFS_ALL_CTRL_RECIP)
+                        ret = le16_to_cpu(creq->wIndex);
+                else
+                        return -EOPNOTSUPP;
         }
 
         spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
@@ -3128,6 +3135,24 @@ static int ffs_func_setup(struct usb_function *f,
         return 0;
 }
 
+static bool ffs_func_req_match(struct usb_function *f,
+                               const struct usb_ctrlrequest *creq)
+{
+        struct ffs_function *func = ffs_func_from_usb(f);
+
+        switch (creq->bRequestType & USB_RECIP_MASK) {
+        case USB_RECIP_INTERFACE:
+                return ffs_func_revmap_intf(func,
+                                            le16_to_cpu(creq->wIndex) >= 0);
+        case USB_RECIP_ENDPOINT:
+                return ffs_func_revmap_ep(func,
+                                          le16_to_cpu(creq->wIndex) >= 0);
+        default:
+                return (bool) (func->ffs->user_flags &
+                               FUNCTIONFS_ALL_CTRL_RECIP);
+        }
+}
+
 static void ffs_func_suspend(struct usb_function *f)
 {
         ENTER();
@@ -3378,6 +3403,7 @@ static struct usb_function *ffs_alloc(struct usb_function_instance *fi)
         func->function.set_alt = ffs_func_set_alt;
         func->function.disable = ffs_func_disable;
         func->function.setup   = ffs_func_setup;
+        func->function.req_match = ffs_func_req_match;
         func->function.suspend = ffs_func_suspend;
         func->function.resume  = ffs_func_resume;
         func->function.free_func = ffs_free;