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path: root/drivers/usb/gadget/config.c
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Diffstat (limited to 'drivers/usb/gadget/config.c')
-rw-r--r--drivers/usb/gadget/config.c76
1 files changed, 75 insertions, 1 deletions
diff --git a/drivers/usb/gadget/config.c b/drivers/usb/gadget/config.c
index a4e54b2743f0..1ca1c326392a 100644
--- a/drivers/usb/gadget/config.c
+++ b/drivers/usb/gadget/config.c
@@ -96,7 +96,7 @@ int usb_gadget_config_buf(
/* config descriptor first */
if (length < USB_DT_CONFIG_SIZE || !desc)
return -EINVAL;
- *cp = *config;
+ *cp = *config;
/* then interface/endpoint/class/vendor/... */
len = usb_descriptor_fillbuf(USB_DT_CONFIG_SIZE + (u8*)buf,
@@ -115,3 +115,77 @@ int usb_gadget_config_buf(
return len;
}
+/**
+ * usb_copy_descriptors - copy a vector of USB descriptors
+ * @src: null-terminated vector to copy
+ * Context: initialization code, which may sleep
+ *
+ * This makes a copy of a vector of USB descriptors. Its primary use
+ * is to support usb_function objects which can have multiple copies,
+ * each needing different descriptors. Functions may have static
+ * tables of descriptors, which are used as templates and customized
+ * with identifiers (for interfaces, strings, endpoints, and more)
+ * as needed by a given function instance.
+ */
+struct usb_descriptor_header **__init
+usb_copy_descriptors(struct usb_descriptor_header **src)
+{
+ struct usb_descriptor_header **tmp;
+ unsigned bytes;
+ unsigned n_desc;
+ void *mem;
+ struct usb_descriptor_header **ret;
+
+ /* count descriptors and their sizes; then add vector size */
+ for (bytes = 0, n_desc = 0, tmp = src; *tmp; tmp++, n_desc++)
+ bytes += (*tmp)->bLength;
+ bytes += (n_desc + 1) * sizeof(*tmp);
+
+ mem = kmalloc(bytes, GFP_KERNEL);
+ if (!mem)
+ return NULL;
+
+ /* fill in pointers starting at "tmp",
+ * to descriptors copied starting at "mem";
+ * and return "ret"
+ */
+ tmp = mem;
+ ret = mem;
+ mem += (n_desc + 1) * sizeof(*tmp);
+ while (*src) {
+ memcpy(mem, *src, (*src)->bLength);
+ *tmp = mem;
+ tmp++;
+ mem += (*src)->bLength;
+ src++;
+ }
+ *tmp = NULL;
+
+ return ret;
+}
+
+/**
+ * usb_find_endpoint - find a copy of an endpoint descriptor
+ * @src: original vector of descriptors
+ * @copy: copy of @src
+ * @ep: endpoint descriptor found in @src
+ *
+ * This returns the copy of the @match descriptor made for @copy. Its
+ * intended use is to help remembering the endpoint descriptor to use
+ * when enabling a given endpoint.
+ */
+struct usb_endpoint_descriptor *__init
+usb_find_endpoint(
+ struct usb_descriptor_header **src,
+ struct usb_descriptor_header **copy,
+ struct usb_endpoint_descriptor *match
+)
+{
+ while (*src) {
+ if (*src == (void *) match)
+ return (void *)*copy;
+ src++;
+ copy++;
+ }
+ return NULL;
+}