Add reverse engineered nqnfcinfo binary

Change-Id: I0fef4aff6f66570faf1e5680134f09b353e2205d
Co-authored-by: Alexander Koskovich <[email protected]>

Author: 2 people

nqnfcinfo/.clang-format

@@ -0,0 +1 @@
+../../../../build/soong/scripts/system-clang-format

nqnfcinfo/Android.bp

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+cc_binary {
+    name: "nqnfcinfo",
+    vendor: true,
+
+    cflags: [
+        "-Wall",
+        "-Werror",
+        "-Wextra",
+    ],
+
+    srcs: [
+        "main.cpp",
+    ],
+
+    header_libs: ["generated_kernel_headers"],
+
+    shared_libs: [
+        "libc",
+        "libbase"
+    ],
+}

nqnfcinfo/main.cpp

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+/*
+ * Copyright (C) 2022 The LineageOS Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "nqnfcinfo"
+
+#include <errno.h>
+#include <fcntl.h>
+
+#include <fmt/format.h>
+
+#include <android-base/logging.h>
+#include <android-base/properties.h>
+
+#include <linux/nfc/nfcinfo.h>
+
+using ::android::base::SetProperty;
+
+#define NQ_NCI_PATH "/dev/nq-nci"
+
+int main() {
+    // Open our fd
+    int fd = open(NQ_NCI_PATH, O_RDONLY);
+
+    // Make sure we could get the fd
+    if (fd < 0) {
+        LOG(ERROR) << "Could not open " << NQ_NCI_PATH << ": " << strerror(errno);
+        return fd;
+    }
+
+    // NXP's kernel driver returns a struct that is union'ed with an integer
+    // as the return value of the IOCTL call here. Presumably this is to avoid
+    // dealing with copying memory to/from userspace, but it's a little silly
+    // Since this is an unsigned type, I don't know how to check for errors...
+    nqx_uinfo info{};
+    info.i = ioctl(fd, NFCC_GET_INFO, 0);
+
+    // Close fd
+    close(fd);
+
+    // Set properties based on IOCTL return
+    SetProperty("vendor.qti.nfc.chipid", fmt::format("{:#02x}", info.info.chip_type));
+    SetProperty("vendor.qti.nfc.fwver", fmt::format("{:02x}.{:02x}.{:02x}", info.info.rom_version,
+                                                    info.info.fw_major, info.info.fw_minor));
+
+    return 0;
+}