[usb_gadget p01] Functions for encoding HID descriptors.

tools/usb_gadget/hid_descriptors_test.py

Index: tools/usb_gadget/hid_descriptors_test.py
diff --git a/tools/usb_gadget/hid_descriptors_test.py b/tools/usb_gadget/hid_descriptors_test.py
new file mode 100755
index 0000000000000000000000000000000000000000..d2313cacf88280ae9a6c8cc54eebb321ce849e32
--- /dev/null
+++ b/tools/usb_gadget/hid_descriptors_test.py
@@ -0,0 +1,125 @@
+#!/usr/bin/python
+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import unittest
+
+import hid_constants
+import hid_descriptors
+
+
+class HidTest(unittest.TestCase):
+
+  def test_keyboard_example(self):
+    report_desc = hid_descriptors.ReportDescriptor(
+        hid_descriptors.UsagePage(0x01),  # Generic Desktop
+        hid_descriptors.Usage(0x06),  # Keyboard
+        hid_descriptors.Collection(
+            hid_constants.CollectionType.APPLICATION,
+            hid_descriptors.UsagePage(0x07),  # Key Codes
+            hid_descriptors.UsageMinimum(224),
+            hid_descriptors.UsageMaximum(231),
+            hid_descriptors.LogicalMinimum(0, force_length=1),
+            hid_descriptors.LogicalMaximum(1),
+            hid_descriptors.ReportSize(1),
+            hid_descriptors.ReportCount(8),
+            hid_descriptors.Input(hid_descriptors.Data,
+                                  hid_descriptors.Variable,
+                                  hid_descriptors.Absolute),
+            hid_descriptors.ReportCount(1),
+            hid_descriptors.ReportSize(8),
+            hid_descriptors.Input(hid_descriptors.Constant),
+            hid_descriptors.ReportCount(5),
+            hid_descriptors.ReportSize(1),
+            hid_descriptors.UsagePage(0x08),  # LEDs
+            hid_descriptors.UsageMinimum(1),
+            hid_descriptors.UsageMaximum(5),
+            hid_descriptors.Output(hid_descriptors.Data,
+                                   hid_descriptors.Variable,
+                                   hid_descriptors.Absolute),
+            hid_descriptors.ReportCount(1),
+            hid_descriptors.ReportSize(3),
+            hid_descriptors.Output(hid_descriptors.Constant),
+            hid_descriptors.ReportCount(6),
+            hid_descriptors.ReportSize(8),
+            hid_descriptors.LogicalMinimum(0, force_length=1),
+            hid_descriptors.LogicalMaximum(101),
+            hid_descriptors.UsagePage(0x07),  # Key Codes
+            hid_descriptors.UsageMinimum(0, force_length=1),
+            hid_descriptors.UsageMaximum(101),
+            hid_descriptors.Input(hid_descriptors.Data, hid_descriptors.Array)
+        )
+    )
+
+    expected = ''.join(chr(x) for x in [
+        0x05, 0x01, 0x09, 0x06, 0xA1, 0x01, 0x05, 0x07, 0x19, 0xE0, 0x29,
+        0xE7, 0x15, 0x00, 0x25, 0x01, 0x75, 0x01, 0x95, 0x08, 0x81, 0x02,
+        0x95, 0x01, 0x75, 0x08, 0x81, 0x01, 0x95, 0x05, 0x75, 0x01, 0x05,
+        0x08, 0x19, 0x01, 0x29, 0x05, 0x91, 0x02, 0x95, 0x01, 0x75, 0x03,
+        0x91, 0x01, 0x95, 0x06, 0x75, 0x08, 0x15, 0x00, 0x25, 0x65, 0x05,
+        0x07, 0x19, 0x00, 0x29, 0x65, 0x81, 0x00, 0xC0
+    ])
+    self.assertEquals(report_desc, expected)
+
+  def test_mouse_example(self):
+    report_desc = hid_descriptors.ReportDescriptor(
+        hid_descriptors.UsagePage(0x01),  # Generic Desktop
+        hid_descriptors.Usage(0x02),  # Mouse
+        hid_descriptors.Collection(
+            hid_constants.CollectionType.APPLICATION,
+            hid_descriptors.Usage(0x01),  # Pointer
+            hid_descriptors.Collection(
+                hid_constants.CollectionType.PHYSICAL,
+                hid_descriptors.UsagePage(0x09),  # Buttons
+                hid_descriptors.UsageMinimum(1),
+                hid_descriptors.UsageMaximum(3),
+                hid_descriptors.LogicalMinimum(0, force_length=1),
+                hid_descriptors.LogicalMaximum(1),
+                hid_descriptors.ReportCount(3),
+                hid_descriptors.ReportSize(1),
+                hid_descriptors.Input(hid_descriptors.Data,
+                                      hid_descriptors.Variable,
+                                      hid_descriptors.Absolute),
+                hid_descriptors.ReportCount(1),
+                hid_descriptors.ReportSize(5),
+                hid_descriptors.Input(hid_descriptors.Constant),
+                hid_descriptors.UsagePage(0x01),  # Generic Desktop
+                hid_descriptors.Usage(0x30),  # X
+                hid_descriptors.Usage(0x31),  # Y
+                hid_descriptors.LogicalMinimum(0x81),  # -127
+                hid_descriptors.LogicalMaximum(127),
+                hid_descriptors.ReportSize(8),
+                hid_descriptors.ReportCount(2),
+                hid_descriptors.Input(hid_descriptors.Data,
+                                      hid_descriptors.Variable,
+                                      hid_descriptors.Relative)
+            )
+        )
+    )
+
+    expected = ''.join(chr(x) for x in [
+        0x05, 0x01, 0x09, 0x02, 0xA1, 0x01, 0x09, 0x01, 0xA1, 0x00, 0x05, 0x09,
+        0x19, 0x01, 0x29, 0x03, 0x15, 0x00, 0x25, 0x01, 0x95, 0x03, 0x75, 0x01,
+        0x81, 0x02, 0x95, 0x01, 0x75, 0x05, 0x81, 0x01, 0x05, 0x01, 0x09, 0x30,
+        0x09, 0x31, 0x15, 0x81, 0x25, 0x7F, 0x75, 0x08, 0x95, 0x02, 0x81, 0x06,
+        0xC0, 0xC0
+    ])
+    self.assertEquals(report_desc, expected)
+
+  def test_tag(self):
+    self.assertEquals(hid_descriptors.Push(), '\xa4')
+
+  def test_2byte_tag(self):
+    self.assertEquals(hid_descriptors.LogicalMaximum(0xFF00), '\x26\x00\xFF')
+
+  def test_4byte_tag(self):
+    self.assertEquals(hid_descriptors.LogicalMaximum(0xFF884400),
+                      '\x27\x00\x44\x88\xFF')
+
+  def test_long_tag(self):
+    with self.assertRaises(NotImplementedError):
+      hid_descriptors.LogicalMaximum(0xFFFFFFFFFFFFFFFF)
+
+if __name__ == '__main__':
+  unittest.main()