Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / usb / gadget / usbstring.c

diff --git a/kernel/drivers/usb/gadget/usbstring.c b/kernel/drivers/usb/gadget/usbstring.c
new file mode 100644 (file)
index 0000000..73a4dfb
--- /dev/null
+++ b/kernel/drivers/usb/gadget/usbstring.c
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2003 David Brownell
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/string.h>
+#include <linux/device.h>
+#include <linux/nls.h>
+
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+
+
+/**
+ * usb_gadget_get_string - fill out a string descriptor 
+ * @table: of c strings encoded using UTF-8
+ * @id: string id, from low byte of wValue in get string descriptor
+ * @buf: at least 256 bytes, must be 16-bit aligned
+ *
+ * Finds the UTF-8 string matching the ID, and converts it into a
+ * string descriptor in utf16-le.
+ * Returns length of descriptor (always even) or negative errno
+ *
+ * If your driver needs stings in multiple languages, you'll probably
+ * "switch (wIndex) { ... }"  in your ep0 string descriptor logic,
+ * using this routine after choosing which set of UTF-8 strings to use.
+ * Note that US-ASCII is a strict subset of UTF-8; any string bytes with
+ * the eighth bit set will be multibyte UTF-8 characters, not ISO-8859/1
+ * characters (which are also widely used in C strings).
+ */
+int
+usb_gadget_get_string (struct usb_gadget_strings *table, int id, u8 *buf)
+{
+       struct usb_string       *s;
+       int                     len;
+
+       /* descriptor 0 has the language id */
+       if (id == 0) {
+               buf [0] = 4;
+               buf [1] = USB_DT_STRING;
+               buf [2] = (u8) table->language;
+               buf [3] = (u8) (table->language >> 8);
+               return 4;
+       }
+       for (s = table->strings; s && s->s; s++)
+               if (s->id == id)
+                       break;
+
+       /* unrecognized: stall. */
+       if (!s || !s->s)
+               return -EINVAL;
+
+       /* string descriptors have length, tag, then UTF16-LE text */
+       len = min ((size_t) 126, strlen (s->s));
+       len = utf8s_to_utf16s(s->s, len, UTF16_LITTLE_ENDIAN,
+                       (wchar_t *) &buf[2], 126);
+       if (len < 0)
+               return -EINVAL;
+       buf [0] = (len + 1) * 2;
+       buf [1] = USB_DT_STRING;
+       return buf [0];
+}
+EXPORT_SYMBOL_GPL(usb_gadget_get_string);