From 904e75c28aa41e7c3967f0b9db3ad1a2a35a1224 Mon Sep 17 00:00:00 2001
From: Peter Wu <peter@lekensteyn.nl>
Date: Tue, 8 Apr 2014 00:27:43 +0200
Subject: lib/hidpp10: implement HID++ 1.0 protocol details

---
 lib/hidpp10.c | 108 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 108 insertions(+)
 create mode 100644 lib/hidpp10.c

diff --git a/lib/hidpp10.c b/lib/hidpp10.c
new file mode 100644
index 0000000..efd0bee
--- /dev/null
+++ b/lib/hidpp10.c
@@ -0,0 +1,108 @@
+/*
+ * HID++ 1.0 protocol details.
+ *
+ * Copyright (C) 2014 Peter Wu <peter@lekensteyn.nl>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdbool.h>
+#include <string.h>
+#include "hidpp10.h"
+#include "hidpp.h"
+
+#define READ_TIMEOUT 2000
+
+static bool hidpp10_msg_filter(HidppMessage *msg, void *userdata)
+{
+	bool ok;
+	struct {
+		hidpp_msg_cb_t *cb;
+		void *userdata;
+		HidppMessage *msg_out;
+	} *cd = userdata;
+	const HidppMessage *out = cd->msg_out;
+	const uint8_t out_addr = out->address;
+
+	ok = msg->device_index == out->device_index;
+
+	/* accept error responses matching the request, return as there are no
+	 * notifications to check for. */
+	if (ok && msg->report_id == HIDPP_SHORT && msg->sub_id == SUB_ERROR_MSG
+		&& msg->sub_id == out->sub_id && msg->params[0] == out_addr) {
+		return true;
+	}
+
+	ok = ok && msg->sub_id == out->sub_id && msg->address == out_addr;
+
+	switch (out->report_id) {
+	case SUB_SET_REGISTER:
+	case SUB_GET_REGISTER:
+	case SUB_SET_LONG_REGISTER:
+		return ok && msg->report_id == HIDPP_SHORT;
+	case SUB_GET_LONG_REGISTER:
+		return ok && msg->report_id == HIDPP_LONG;
+	case NOTIF_DEV_DISCONNECT:
+	case NOTIF_DEV_CONNECT:
+	case NOTIF_RECV_LOCK_CHANGE:
+		if (cd->cb) {
+			/* notify of ... well... notifications */
+			cd->cb(msg, cd->userdata);
+		}
+		/* fall-through */
+	default:
+		/* no idea whether the report IDs must match or not */
+		return ok;
+	}
+}
+
+int hidpp10_request(int fd, HidppMessage *msg, hidpp_msg_cb_t *cb, void *userdata)
+{
+	HidppMessage msg_in;
+	struct {
+		hidpp_msg_cb_t *cb;
+		void *userdata;
+		HidppMessage *msg_out;
+	} cd = { cb, userdata, msg };
+
+	if (!hidpp_write_report(fd, msg))
+		return -1;
+
+	/* find the HID++ response, passing notifications if needed */
+	if (!hidpp_read_msg(fd, READ_TIMEOUT, &msg_in, hidpp10_msg_filter, &cd))
+		return -1;
+
+	memcpy(msg, &msg_in, sizeof(msg_in));
+	return msg_in.sub_id == SUB_ERROR_MSG ? msg_in.params[1] : 0;
+}
+
+int hidpp10_enable_wireless_notifications(int fd, bool enabled)
+{
+	int r;
+	HidppMessage msg = {
+		.report_id = HIDPP_SHORT,
+		.device_index = 0xFF,
+		.sub_id = SUB_GET_REGISTER,
+		.address = REG_ENABLED_NOTIFS
+	};
+
+	/* get notifications state */
+	r = hidpp10_request(fd, &msg, NULL, NULL);
+	if (r == 0 && !(msg.params[1] & 1) != !enabled) {
+		msg.params[1] |= enabled ? 1 : 0;
+
+		r = hidpp10_request(fd, &msg, NULL, NULL);
+	}
+	return r;
+}
-- 
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