media: rc: self test for IR encoders and decoders

ir-loopback can transmit IR on one rc device and check the correct
scancode and protocol is decoded on a different rc device. This can be
used to check IR transmission between two rc devices. Using rc-loopback,
we use it to check the IR encoders and decoders themselves.

No hardware is required for this test.
Signed-off-by: Sean Young <sean@mess.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Shuah Khan <shuah@kernel.org>

tools/testing/selftests/Makefile

@@ -15,6 +15,7 @@ TARGETS += futex
 TARGETS += gpio
 TARGETS += intel_pstate
 TARGETS += ipc
+TARGETS += ir
 TARGETS += kcmp
 TARGETS += kvm
 TARGETS += lib

tools/testing/selftests/ir/.gitignore

+ir_loopback

tools/testing/selftests/ir/Makefile

+# SPDX-License-Identifier: GPL-2.0
+TEST_PROGS := ir_loopback.sh
+TEST_GEN_PROGS_EXTENDED := ir_loopback
+
+include ../lib.mk

tools/testing/selftests/ir/ir_loopback.c

+// SPDX-License-Identifier: GPL-2.0
+// test ir decoder
+//
+// Copyright (C) 2018 Sean Young <sean@mess.org>
+
+// When sending LIRC_MODE_SCANCODE, the IR will be encoded. rc-loopback
+// will send this IR to the receiver side, where we try to read the decoded
+// IR. Decoding happens in a separate kernel thread, so we will need to
+// wait until that is scheduled, hence we use poll to check for read
+// readiness.
+
+#include <linux/lirc.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <unistd.h>
+#include <poll.h>
+#include <time.h>
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <dirent.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include "../kselftest.h"
+
+#define TEST_SCANCODES	10
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
+static const struct {
+	enum rc_proto proto;
+	const char *name;
+	unsigned int mask;
+	const char *decoder;
+} protocols[] = {
+	{ RC_PROTO_RC5, "rc-5", 0x1f7f, "rc-5" },
+	{ RC_PROTO_RC5X_20, "rc-5x-20", 0x1f7f3f, "rc-5" },
+	{ RC_PROTO_RC5_SZ, "rc-5-sz", 0x2fff, "rc-5-sz" },
+	{ RC_PROTO_JVC, "jvc", 0xffff, "jvc" },
+	{ RC_PROTO_SONY12, "sony-12", 0x1f007f, "sony" },
+	{ RC_PROTO_SONY15, "sony-15", 0xff007f, "sony" },
+	{ RC_PROTO_SONY20, "sony-20", 0x1fff7f, "sony" },
+	{ RC_PROTO_NEC, "nec", 0xffff, "nec" },
+	{ RC_PROTO_NECX, "nec-x", 0xffffff, "nec" },
+	{ RC_PROTO_NEC32, "nec-32", 0xffffffff, "nec" },
+	{ RC_PROTO_SANYO, "sanyo", 0x1fffff, "sanyo" },
+	{ RC_PROTO_RC6_0, "rc-6-0", 0xffff, "rc-6" },
+	{ RC_PROTO_RC6_6A_20, "rc-6-6a-20", 0xfffff, "rc-6" },
+	{ RC_PROTO_RC6_6A_24, "rc-6-6a-24", 0xffffff, "rc-6" },
+	{ RC_PROTO_RC6_6A_32, "rc-6-6a-32", 0xffffffff, "rc-6" },
+	{ RC_PROTO_RC6_MCE, "rc-6-mce", 0x00007fff, "rc-6" },
+	{ RC_PROTO_SHARP, "sharp", 0x1fff, "sharp" },
+};
+
+int lirc_open(const char *rc)
+{
+	struct dirent *dent;
+	char buf[100];
+	DIR *d;
+	int fd;
+
+	snprintf(buf, sizeof(buf), "/sys/class/rc/%s", rc);
+
+	d = opendir(buf);
+	if (!d)
+		ksft_exit_fail_msg("cannot open %s: %m\n", buf);
+
+	while ((dent = readdir(d)) != NULL) {
+		if (!strncmp(dent->d_name, "lirc", 4)) {
+			snprintf(buf, sizeof(buf), "/dev/%s", dent->d_name);
+			break;
+		}
+	}
+
+	if (!dent)
+		ksft_exit_fail_msg("cannot find lirc device for %s\n", rc);
+
+	closedir(d);
+
+	fd = open(buf, O_RDWR | O_NONBLOCK);
+	if (fd == -1)
+		ksft_exit_fail_msg("cannot open: %s: %m\n", buf);
+
+	return fd;
+}
+
+int main(int argc, char **argv)
+{
+	unsigned int mode;
+	char buf[100];
+	int rlircfd, wlircfd, protocolfd, i, n;
+
+	srand(time(NULL));
+
+	if (argc != 3)
+		ksft_exit_fail_msg("Usage: %s <write rcN> <read rcN>\n",
+				   argv[0]);
+
+	rlircfd = lirc_open(argv[2]);
+	mode = LIRC_MODE_SCANCODE;
+	if (ioctl(rlircfd, LIRC_SET_REC_MODE, &mode))
+		ksft_exit_fail_msg("failed to set scancode rec mode %s: %m\n",
+				   argv[2]);
+
+	wlircfd = lirc_open(argv[1]);
+	if (ioctl(wlircfd, LIRC_SET_SEND_MODE, &mode))
+		ksft_exit_fail_msg("failed to set scancode send mode %s: %m\n",
+				   argv[1]);
+
+	snprintf(buf, sizeof(buf), "/sys/class/rc/%s/protocols", argv[2]);
+	protocolfd = open(buf, O_WRONLY);
+	if (protocolfd == -1)
+		ksft_exit_fail_msg("failed to open %s: %m\n", buf);
+
+	printf("Sending IR on %s and receiving IR on %s.\n", argv[1], argv[2]);
+
+	for (i = 0; i < ARRAY_SIZE(protocols); i++) {
+		if (write(protocolfd, protocols[i].decoder,
+			  strlen(protocols[i].decoder)) == -1)
+			ksft_exit_fail_msg("failed to set write decoder\n");
+
+		printf("Testing protocol %s for decoder %s (%d/%d)...\n",
+		       protocols[i].name, protocols[i].decoder,
+		       i + 1, (int)ARRAY_SIZE(protocols));
+
+		for (n = 0; n < TEST_SCANCODES; n++) {
+			unsigned int scancode = rand() & protocols[i].mask;
+			unsigned int rc_proto = protocols[i].proto;
+
+			if (rc_proto == RC_PROTO_RC6_MCE)
+				scancode |= 0x800f0000;
+
+			if (rc_proto == RC_PROTO_NECX &&
+			    (((scancode >> 16) ^ ~(scancode >> 8)) & 0xff) == 0)
+				continue;
+
+			if (rc_proto == RC_PROTO_NEC32 &&
+			    (((scancode >> 8) ^ ~scancode) & 0xff) == 0)
+				continue;
+
+			struct lirc_scancode lsc = {
+				.rc_proto = rc_proto,
+				.scancode = scancode
+			};
+
+			printf("Testing scancode:%x\n", scancode);
+
+			while (write(wlircfd, &lsc, sizeof(lsc)) < 0) {
+				if (errno == EINTR)
+					continue;
+
+				ksft_exit_fail_msg("failed to send ir: %m\n");
+			}
+
+			struct pollfd pfd = { .fd = rlircfd, .events = POLLIN };
+			struct lirc_scancode lsc2;
+
+			poll(&pfd, 1, 1000);
+
+			bool decoded = true;
+
+			while (read(rlircfd, &lsc2, sizeof(lsc2)) < 0) {
+				if (errno == EINTR)
+					continue;
+
+				ksft_test_result_error("no scancode decoded: %m\n");
+				decoded = false;
+				break;
+			}
+
+			if (!decoded)
+				continue;
+
+			if (lsc.rc_proto != lsc2.rc_proto)
+				ksft_test_result_error("decoded protocol is different: %d\n",
+						       lsc2.rc_proto);
+
+			else if (lsc.scancode != lsc2.scancode)
+				ksft_test_result_error("decoded scancode is different: %llx\n",
+						       lsc2.scancode);
+			else
+				ksft_inc_pass_cnt();
+		}
+
+		printf("OK\n");
+	}
+
+	close(rlircfd);
+	close(wlircfd);
+	close(protocolfd);
+
+	if (ksft_get_fail_cnt() > 0)
+		ksft_exit_fail();
+	else
+		ksft_exit_pass();
+
+	return 0;
+}

tools/testing/selftests/ir/ir_loopback.sh

+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+
+if ! /sbin/modprobe -q -n rc-loopback; then
+        echo "ir_loopback: module rc-loopback is not found [SKIP]"
+        exit $ksft_skip
+fi
+
+/sbin/modprobe rc-loopback
+if [ $? -ne 0 ]; then
+	exit
+fi
+
+RCDEV=$(grep -l DRV_NAME=rc-loopback /sys/class/rc/rc*/uevent | grep -o 'rc[0-9]\+')
+
+./ir_loopback $RCDEV $RCDEV
+exit