app-accessibility/brltty/files/brltty-4.5-hims.patch

Backport from svn trunk: autodetect Braille Sense U2 and correctly
detect cell count on HIMS displays.
--- a/Drivers/Braille/HIMS/braille.c
+++ b/Drivers/Braille/HIMS/braille.c
@@ -146,10 +146,10 @@
   unsigned char previousCells[MAXIMUM_CELL_COUNT];
 };
 
-static int
+static size_t
 readPacket (BrailleDisplay *brl, InputPacket *packet) {
-  const int length = 10;
-  int offset = 0;
+  const size_t length = 10;
+  size_t offset = 0;
 
   while (1) {
     unsigned char byte;
@@ -176,7 +176,7 @@
           int checksum = -packet->data.checksum;
 
           {
-            int i;
+            size_t i;
             for (i=0; i<offset; i+=1) checksum += packet->bytes[i];
           }
 
@@ -200,7 +200,17 @@
   }
 }
 
+static size_t
+readBytes (BrailleDisplay *brl, void *packet, size_t size) {
+  return readPacket(brl, packet);
+}
+
 static int
+writeBytes (BrailleDisplay *brl, const unsigned char *bytes, size_t count) {
+  return writeBraillePacket(brl, brl->data->gioEndpoint, bytes, count);
+}
+
+static int
 writePacket (
   BrailleDisplay *brl,
   unsigned char type, unsigned char mode,
@@ -264,7 +274,7 @@
     *checksum = sum;
   }
 
-  return writeBraillePacket(brl, brl->data->gioEndpoint, packet, byte - packet);
+  return writeBytes(brl, packet, byte - packet);
 }
 
 
@@ -282,24 +292,6 @@
 
 static int
 getSyncBrailleCellCount (BrailleDisplay *brl, unsigned int *count) {
-  static const unsigned char data[] = {
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
-  };
-
-  if (writePacket(brl, 0XFB, 0X01, data, sizeof(data), NULL, 0)) {
-    InputPacket packet;
-
-    while (gioAwaitInput(brl->data->gioEndpoint, 1000)) {
-      if (readPacket(brl, &packet)) {
-        if (packet.data.type == IPT_CELLS) {
-          *count = packet.data.data;
-          return 1;
-        }
-      }
-    }
-  }
-
   return 0;
 }
 
@@ -337,6 +329,38 @@
 }
 
 static int
+writeCellCountRequest (BrailleDisplay *brl) {
+  static const unsigned char data[] = {
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+  };
+
+  return writePacket(brl, 0XFB, 0X01, data, sizeof(data), NULL, 0);
+}
+
+static BrailleResponseResult
+isCellCountResponse (BrailleDisplay *brl, const void *packet, size_t size) {
+  const InputPacket *response = packet;
+
+  return (response->data.type == IPT_CELLS)? BRL_RSP_DONE: BRL_RSP_UNEXPECTED;
+}
+
+static int
+getCellCount (BrailleDisplay *brl, unsigned int *count) {
+  InputPacket response;
+
+  if (probeBrailleDisplay(brl, 2, brl->data->gioEndpoint, 1000,
+                          writeCellCountRequest,
+                          readBytes, &response, sizeof(response.bytes),
+                          isCellCountResponse)) {
+    *count = response.data.data;
+    return 1;
+  }
+
+  return brl->data->protocol->getCellCount(brl, count);
+}
+
+static int
 connectResource (BrailleDisplay *brl, const char *identifier) {
   static const SerialParameters serialParameters = {
     SERIAL_DEFAULT_PARAMETERS,
@@ -362,6 +386,15 @@
       .data=&brailleSenseOperations
     },
 
+    { /* Braille Sense U2 (USB 2.0) */
+      .version = UsbSpecificationVersion_2_0,
+      .vendor=0X045E, .product=0X930A,
+      .configuration=1, .interface=0, .alternative=0,
+      .inputEndpoint=1, .outputEndpoint=2,
+      .disableAutosuspend=1,
+      .data=&brailleSenseOperations
+    },
+
     { /* Sync Braille */
       .vendor=0X0403, .product=0X6001,
       .configuration=1, .interface=0, .alternative=0,
@@ -408,8 +441,7 @@
       brl->data->protocol = gioGetApplicationData(brl->data->gioEndpoint);
       logMessage(LOG_INFO, "detected: %s", brl->data->protocol->modelName);
 
-      if (brl->data->protocol->getCellCount(brl, &brl->textColumns) ||
-          brl->data->protocol->getCellCount(brl, &brl->textColumns)) {
+      if (getCellCount(brl, &brl->textColumns)) {
         brl->textRows = 1;
         brl->keyBindings = brl->data->protocol->keyTableDefinition->bindings;
         brl->keyNameTables = brl->data->protocol->keyTableDefinition->names;