diff --git a/src/kernel/linux/v4.19/tools/spi/.gitignore b/src/kernel/linux/v4.19/tools/spi/.gitignore
new file mode 100644
index 0000000..4280576
--- /dev/null
+++ b/src/kernel/linux/v4.19/tools/spi/.gitignore
@@ -0,0 +1,2 @@
+spidev_fdx
+spidev_test
diff --git a/src/kernel/linux/v4.19/tools/spi/Build b/src/kernel/linux/v4.19/tools/spi/Build
new file mode 100644
index 0000000..8e84660
--- /dev/null
+++ b/src/kernel/linux/v4.19/tools/spi/Build
@@ -0,0 +1,2 @@
+spidev_test-y += spidev_test.o
+spidev_fdx-y += spidev_fdx.o
diff --git a/src/kernel/linux/v4.19/tools/spi/Makefile b/src/kernel/linux/v4.19/tools/spi/Makefile
new file mode 100644
index 0000000..815d155
--- /dev/null
+++ b/src/kernel/linux/v4.19/tools/spi/Makefile
@@ -0,0 +1,64 @@
+include ../scripts/Makefile.include
+
+bindir ?= /usr/bin
+
+ifeq ($(srctree),)
+srctree := $(patsubst %/,%,$(dir $(CURDIR)))
+srctree := $(patsubst %/,%,$(dir $(srctree)))
+endif
+
+# Do not use make's built-in rules
+# (this improves performance and avoids hard-to-debug behaviour);
+MAKEFLAGS += -r
+
+CFLAGS += -O2 -Wall -g -D_GNU_SOURCE -I$(OUTPUT)include
+
+ALL_TARGETS := spidev_test spidev_fdx
+ALL_PROGRAMS := $(patsubst %,$(OUTPUT)%,$(ALL_TARGETS))
+
+all: $(ALL_PROGRAMS)
+
+export srctree OUTPUT CC LD CFLAGS
+include $(srctree)/tools/build/Makefile.include
+
+#
+# We need the following to be outside of kernel tree
+#
+$(OUTPUT)include/linux/spi/spidev.h: ../../include/uapi/linux/spi/spidev.h
+	mkdir -p $(OUTPUT)include/linux/spi 2>&1 || true
+	ln -sf $(CURDIR)/../../include/uapi/linux/spi/spidev.h $@
+
+prepare: $(OUTPUT)include/linux/spi/spidev.h
+
+#
+# spidev_test
+#
+SPIDEV_TEST_IN := $(OUTPUT)spidev_test-in.o
+$(SPIDEV_TEST_IN): prepare FORCE
+	$(Q)$(MAKE) $(build)=spidev_test
+$(OUTPUT)spidev_test: $(SPIDEV_TEST_IN)
+	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@
+
+#
+# spidev_fdx
+#
+SPIDEV_FDX_IN := $(OUTPUT)spidev_fdx-in.o
+$(SPIDEV_FDX_IN): prepare FORCE
+	$(Q)$(MAKE) $(build)=spidev_fdx
+$(OUTPUT)spidev_fdx: $(SPIDEV_FDX_IN)
+	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@
+
+clean:
+	rm -f $(ALL_PROGRAMS)
+	rm -f $(OUTPUT)include/linux/spi/spidev.h
+	find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete
+
+install: $(ALL_PROGRAMS)
+	install -d -m 755 $(DESTDIR)$(bindir);		\
+	for program in $(ALL_PROGRAMS); do		\
+		install $$program $(DESTDIR)$(bindir);	\
+	done
+
+FORCE:
+
+.PHONY: all install clean FORCE prepare
diff --git a/src/kernel/linux/v4.19/tools/spi/spidev_fdx.c b/src/kernel/linux/v4.19/tools/spi/spidev_fdx.c
new file mode 100644
index 0000000..7d2a867
--- /dev/null
+++ b/src/kernel/linux/v4.19/tools/spi/spidev_fdx.c
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <string.h>
+
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <linux/types.h>
+#include <linux/spi/spidev.h>
+
+
+static int verbose;
+
+static void do_read(int fd, int len)
+{
+	unsigned char	buf[32], *bp;
+	int		status;
+
+	/* read at least 2 bytes, no more than 32 */
+	if (len < 2)
+		len = 2;
+	else if (len > sizeof(buf))
+		len = sizeof(buf);
+	memset(buf, 0, sizeof buf);
+
+	status = read(fd, buf, len);
+	if (status < 0) {
+		perror("read");
+		return;
+	}
+	if (status != len) {
+		fprintf(stderr, "short read\n");
+		return;
+	}
+
+	printf("read(%2d, %2d): %02x %02x,", len, status,
+		buf[0], buf[1]);
+	status -= 2;
+	bp = buf + 2;
+	while (status-- > 0)
+		printf(" %02x", *bp++);
+	printf("\n");
+}
+
+static void do_msg(int fd, int len)
+{
+	struct spi_ioc_transfer	xfer[2];
+	unsigned char		buf[32], *bp;
+	int			status;
+
+	memset(xfer, 0, sizeof xfer);
+	memset(buf, 0, sizeof buf);
+
+	if (len > sizeof buf)
+		len = sizeof buf;
+
+	buf[0] = 0xaa;
+	xfer[0].tx_buf = (unsigned long)buf;
+	xfer[0].len = 1;
+
+	xfer[1].rx_buf = (unsigned long) buf;
+	xfer[1].len = len;
+
+	status = ioctl(fd, SPI_IOC_MESSAGE(2), xfer);
+	if (status < 0) {
+		perror("SPI_IOC_MESSAGE");
+		return;
+	}
+
+	printf("response(%2d, %2d): ", len, status);
+	for (bp = buf; len; len--)
+		printf(" %02x", *bp++);
+	printf("\n");
+}
+
+static void dumpstat(const char *name, int fd)
+{
+	__u8	lsb, bits;
+	__u32	mode, speed;
+
+	if (ioctl(fd, SPI_IOC_RD_MODE32, &mode) < 0) {
+		perror("SPI rd_mode");
+		return;
+	}
+	if (ioctl(fd, SPI_IOC_RD_LSB_FIRST, &lsb) < 0) {
+		perror("SPI rd_lsb_fist");
+		return;
+	}
+	if (ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits) < 0) {
+		perror("SPI bits_per_word");
+		return;
+	}
+	if (ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed) < 0) {
+		perror("SPI max_speed_hz");
+		return;
+	}
+
+	printf("%s: spi mode 0x%x, %d bits %sper word, %d Hz max\n",
+		name, mode, bits, lsb ? "(lsb first) " : "", speed);
+}
+
+int main(int argc, char **argv)
+{
+	int		c;
+	int		readcount = 0;
+	int		msglen = 0;
+	int		fd;
+	const char	*name;
+
+	while ((c = getopt(argc, argv, "hm:r:v")) != EOF) {
+		switch (c) {
+		case 'm':
+			msglen = atoi(optarg);
+			if (msglen < 0)
+				goto usage;
+			continue;
+		case 'r':
+			readcount = atoi(optarg);
+			if (readcount < 0)
+				goto usage;
+			continue;
+		case 'v':
+			verbose++;
+			continue;
+		case 'h':
+		case '?':
+usage:
+			fprintf(stderr,
+				"usage: %s [-h] [-m N] [-r N] /dev/spidevB.D\n",
+				argv[0]);
+			return 1;
+		}
+	}
+
+	if ((optind + 1) != argc)
+		goto usage;
+	name = argv[optind];
+
+	fd = open(name, O_RDWR);
+	if (fd < 0) {
+		perror("open");
+		return 1;
+	}
+
+	dumpstat(name, fd);
+
+	if (msglen)
+		do_msg(fd, msglen);
+
+	if (readcount)
+		do_read(fd, readcount);
+
+	close(fd);
+	return 0;
+}
diff --git a/src/kernel/linux/v4.19/tools/spi/spidev_test.c b/src/kernel/linux/v4.19/tools/spi/spidev_test.c
new file mode 100644
index 0000000..8c590cd
--- /dev/null
+++ b/src/kernel/linux/v4.19/tools/spi/spidev_test.c
@@ -0,0 +1,483 @@
+/*
+ * SPI testing utility (using spidev driver)
+ *
+ * Copyright (c) 2007  MontaVista Software, Inc.
+ * Copyright (c) 2007  Anton Vorontsov <avorontsov@ru.mvista.com>
+ *
+ * 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 2 of the License.
+ *
+ * Cross-compile with cross-gcc -I/path/to/cross-kernel/include
+ */
+
+#include <stdint.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <getopt.h>
+#include <fcntl.h>
+#include <time.h>
+#include <sys/ioctl.h>
+#include <linux/ioctl.h>
+#include <sys/stat.h>
+#include <linux/types.h>
+#include <linux/spi/spidev.h>
+
+#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
+
+static void pabort(const char *s)
+{
+	perror(s);
+	abort();
+}
+
+static const char *device = "/dev/spidev1.1";
+static uint32_t mode;
+static uint8_t bits = 8;
+static char *input_file;
+static char *output_file;
+static uint32_t speed = 500000;
+static uint16_t delay;
+static int verbose;
+static int transfer_size;
+static int iterations;
+static int interval = 5; /* interval in seconds for showing transfer rate */
+
+uint8_t default_tx[] = {
+	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+	0x40, 0x00, 0x00, 0x00, 0x00, 0x95,
+	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+	0xF0, 0x0D,
+};
+
+uint8_t default_rx[ARRAY_SIZE(default_tx)] = {0, };
+char *input_tx;
+
+static void hex_dump(const void *src, size_t length, size_t line_size,
+		     char *prefix)
+{
+	int i = 0;
+	const unsigned char *address = src;
+	const unsigned char *line = address;
+	unsigned char c;
+
+	printf("%s | ", prefix);
+	while (length-- > 0) {
+		printf("%02X ", *address++);
+		if (!(++i % line_size) || (length == 0 && i % line_size)) {
+			if (length == 0) {
+				while (i++ % line_size)
+					printf("__ ");
+			}
+			printf(" | ");  /* right close */
+			while (line < address) {
+				c = *line++;
+				printf("%c", (c < 33 || c == 255) ? 0x2E : c);
+			}
+			printf("\n");
+			if (length > 0)
+				printf("%s | ", prefix);
+		}
+	}
+}
+
+/*
+ *  Unescape - process hexadecimal escape character
+ *      converts shell input "\x23" -> 0x23
+ */
+static int unescape(char *_dst, char *_src, size_t len)
+{
+	int ret = 0;
+	int match;
+	char *src = _src;
+	char *dst = _dst;
+	unsigned int ch;
+
+	while (*src) {
+		if (*src == '\\' && *(src+1) == 'x') {
+			match = sscanf(src + 2, "%2x", &ch);
+			if (!match)
+				pabort("malformed input string");
+
+			src += 4;
+			*dst++ = (unsigned char)ch;
+		} else {
+			*dst++ = *src++;
+		}
+		ret++;
+	}
+	return ret;
+}
+
+static void transfer(int fd, uint8_t const *tx, uint8_t const *rx, size_t len)
+{
+	int ret;
+	int out_fd;
+	struct spi_ioc_transfer tr = {
+		.tx_buf = (unsigned long)tx,
+		.rx_buf = (unsigned long)rx,
+		.len = len,
+		.delay_usecs = delay,
+		.speed_hz = speed,
+		.bits_per_word = bits,
+	};
+
+	if (mode & SPI_TX_QUAD)
+		tr.tx_nbits = 4;
+	else if (mode & SPI_TX_DUAL)
+		tr.tx_nbits = 2;
+	if (mode & SPI_RX_QUAD)
+		tr.rx_nbits = 4;
+	else if (mode & SPI_RX_DUAL)
+		tr.rx_nbits = 2;
+	if (!(mode & SPI_LOOP)) {
+		if (mode & (SPI_TX_QUAD | SPI_TX_DUAL))
+			tr.rx_buf = 0;
+		else if (mode & (SPI_RX_QUAD | SPI_RX_DUAL))
+			tr.tx_buf = 0;
+	}
+
+	ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr);
+	if (ret < 1)
+		pabort("can't send spi message");
+
+	if (verbose)
+		hex_dump(tx, len, 32, "TX");
+
+	if (output_file) {
+		out_fd = open(output_file, O_WRONLY | O_CREAT | O_TRUNC, 0666);
+		if (out_fd < 0)
+			pabort("could not open output file");
+
+		ret = write(out_fd, rx, len);
+		if (ret != len)
+			pabort("not all bytes written to output file");
+
+		close(out_fd);
+	}
+
+	if (verbose)
+		hex_dump(rx, len, 32, "RX");
+}
+
+static void print_usage(const char *prog)
+{
+	printf("Usage: %s [-DsbdlHOLC3vpNR24SI]\n", prog);
+	puts("  -D --device   device to use (default /dev/spidev1.1)\n"
+	     "  -s --speed    max speed (Hz)\n"
+	     "  -d --delay    delay (usec)\n"
+	     "  -b --bpw      bits per word\n"
+	     "  -i --input    input data from a file (e.g. \"test.bin\")\n"
+	     "  -o --output   output data to a file (e.g. \"results.bin\")\n"
+	     "  -l --loop     loopback\n"
+	     "  -H --cpha     clock phase\n"
+	     "  -O --cpol     clock polarity\n"
+	     "  -L --lsb      least significant bit first\n"
+	     "  -C --cs-high  chip select active high\n"
+	     "  -3 --3wire    SI/SO signals shared\n"
+	     "  -v --verbose  Verbose (show tx buffer)\n"
+	     "  -p            Send data (e.g. \"1234\\xde\\xad\")\n"
+	     "  -N --no-cs    no chip select\n"
+	     "  -R --ready    slave pulls low to pause\n"
+	     "  -2 --dual     dual transfer\n"
+	     "  -4 --quad     quad transfer\n"
+	     "  -S --size     transfer size\n"
+	     "  -I --iter     iterations\n");
+	exit(1);
+}
+
+static void parse_opts(int argc, char *argv[])
+{
+	while (1) {
+		static const struct option lopts[] = {
+			{ "device",  1, 0, 'D' },
+			{ "speed",   1, 0, 's' },
+			{ "delay",   1, 0, 'd' },
+			{ "bpw",     1, 0, 'b' },
+			{ "input",   1, 0, 'i' },
+			{ "output",  1, 0, 'o' },
+			{ "loop",    0, 0, 'l' },
+			{ "cpha",    0, 0, 'H' },
+			{ "cpol",    0, 0, 'O' },
+			{ "lsb",     0, 0, 'L' },
+			{ "cs-high", 0, 0, 'C' },
+			{ "3wire",   0, 0, '3' },
+			{ "no-cs",   0, 0, 'N' },
+			{ "ready",   0, 0, 'R' },
+			{ "dual",    0, 0, '2' },
+			{ "verbose", 0, 0, 'v' },
+			{ "quad",    0, 0, '4' },
+			{ "size",    1, 0, 'S' },
+			{ "iter",    1, 0, 'I' },
+			{ NULL, 0, 0, 0 },
+		};
+		int c;
+
+		c = getopt_long(argc, argv, "D:s:d:b:i:o:lHOLC3NR24p:vS:I:",
+				lopts, NULL);
+
+		if (c == -1)
+			break;
+
+		switch (c) {
+		case 'D':
+			device = optarg;
+			break;
+		case 's':
+			speed = atoi(optarg);
+			break;
+		case 'd':
+			delay = atoi(optarg);
+			break;
+		case 'b':
+			bits = atoi(optarg);
+			break;
+		case 'i':
+			input_file = optarg;
+			break;
+		case 'o':
+			output_file = optarg;
+			break;
+		case 'l':
+			mode |= SPI_LOOP;
+			break;
+		case 'H':
+			mode |= SPI_CPHA;
+			break;
+		case 'O':
+			mode |= SPI_CPOL;
+			break;
+		case 'L':
+			mode |= SPI_LSB_FIRST;
+			break;
+		case 'C':
+			mode |= SPI_CS_HIGH;
+			break;
+		case '3':
+			mode |= SPI_3WIRE;
+			break;
+		case 'N':
+			mode |= SPI_NO_CS;
+			break;
+		case 'v':
+			verbose = 1;
+			break;
+		case 'R':
+			mode |= SPI_READY;
+			break;
+		case 'p':
+			input_tx = optarg;
+			break;
+		case '2':
+			mode |= SPI_TX_DUAL;
+			break;
+		case '4':
+			mode |= SPI_TX_QUAD;
+			break;
+		case 'S':
+			transfer_size = atoi(optarg);
+			break;
+		case 'I':
+			iterations = atoi(optarg);
+			break;
+		default:
+			print_usage(argv[0]);
+			break;
+		}
+	}
+	if (mode & SPI_LOOP) {
+		if (mode & SPI_TX_DUAL)
+			mode |= SPI_RX_DUAL;
+		if (mode & SPI_TX_QUAD)
+			mode |= SPI_RX_QUAD;
+	}
+}
+
+static void transfer_escaped_string(int fd, char *str)
+{
+	size_t size = strlen(str);
+	uint8_t *tx;
+	uint8_t *rx;
+
+	tx = malloc(size);
+	if (!tx)
+		pabort("can't allocate tx buffer");
+
+	rx = malloc(size);
+	if (!rx)
+		pabort("can't allocate rx buffer");
+
+	size = unescape((char *)tx, str, size);
+	transfer(fd, tx, rx, size);
+	free(rx);
+	free(tx);
+}
+
+static void transfer_file(int fd, char *filename)
+{
+	ssize_t bytes;
+	struct stat sb;
+	int tx_fd;
+	uint8_t *tx;
+	uint8_t *rx;
+
+	if (stat(filename, &sb) == -1)
+		pabort("can't stat input file");
+
+	tx_fd = open(filename, O_RDONLY);
+	if (tx_fd < 0)
+		pabort("can't open input file");
+
+	tx = malloc(sb.st_size);
+	if (!tx)
+		pabort("can't allocate tx buffer");
+
+	rx = malloc(sb.st_size);
+	if (!rx)
+		pabort("can't allocate rx buffer");
+
+	bytes = read(tx_fd, tx, sb.st_size);
+	if (bytes != sb.st_size)
+		pabort("failed to read input file");
+
+	transfer(fd, tx, rx, sb.st_size);
+	free(rx);
+	free(tx);
+	close(tx_fd);
+}
+
+static uint64_t _read_count;
+static uint64_t _write_count;
+
+static void show_transfer_rate(void)
+{
+	static uint64_t prev_read_count, prev_write_count;
+	double rx_rate, tx_rate;
+
+	rx_rate = ((_read_count - prev_read_count) * 8) / (interval*1000.0);
+	tx_rate = ((_write_count - prev_write_count) * 8) / (interval*1000.0);
+
+	printf("rate: tx %.1fkbps, rx %.1fkbps\n", rx_rate, tx_rate);
+
+	prev_read_count = _read_count;
+	prev_write_count = _write_count;
+}
+
+static void transfer_buf(int fd, int len)
+{
+	uint8_t *tx;
+	uint8_t *rx;
+	int i;
+
+	tx = malloc(len);
+	if (!tx)
+		pabort("can't allocate tx buffer");
+	for (i = 0; i < len; i++)
+		tx[i] = random();
+
+	rx = malloc(len);
+	if (!rx)
+		pabort("can't allocate rx buffer");
+
+	transfer(fd, tx, rx, len);
+
+	_write_count += len;
+	_read_count += len;
+
+	if (mode & SPI_LOOP) {
+		if (memcmp(tx, rx, len)) {
+			fprintf(stderr, "transfer error !\n");
+			hex_dump(tx, len, 32, "TX");
+			hex_dump(rx, len, 32, "RX");
+			exit(1);
+		}
+	}
+
+	free(rx);
+	free(tx);
+}
+
+int main(int argc, char *argv[])
+{
+	int ret = 0;
+	int fd;
+
+	parse_opts(argc, argv);
+
+	fd = open(device, O_RDWR);
+	if (fd < 0)
+		pabort("can't open device");
+
+	/*
+	 * spi mode
+	 */
+	ret = ioctl(fd, SPI_IOC_WR_MODE32, &mode);
+	if (ret == -1)
+		pabort("can't set spi mode");
+
+	ret = ioctl(fd, SPI_IOC_RD_MODE32, &mode);
+	if (ret == -1)
+		pabort("can't get spi mode");
+
+	/*
+	 * bits per word
+	 */
+	ret = ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bits);
+	if (ret == -1)
+		pabort("can't set bits per word");
+
+	ret = ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits);
+	if (ret == -1)
+		pabort("can't get bits per word");
+
+	/*
+	 * max speed hz
+	 */
+	ret = ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed);
+	if (ret == -1)
+		pabort("can't set max speed hz");
+
+	ret = ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed);
+	if (ret == -1)
+		pabort("can't get max speed hz");
+
+	printf("spi mode: 0x%x\n", mode);
+	printf("bits per word: %d\n", bits);
+	printf("max speed: %d Hz (%d KHz)\n", speed, speed/1000);
+
+	if (input_tx && input_file)
+		pabort("only one of -p and --input may be selected");
+
+	if (input_tx)
+		transfer_escaped_string(fd, input_tx);
+	else if (input_file)
+		transfer_file(fd, input_file);
+	else if (transfer_size) {
+		struct timespec last_stat;
+
+		clock_gettime(CLOCK_MONOTONIC, &last_stat);
+
+		while (iterations-- > 0) {
+			struct timespec current;
+
+			transfer_buf(fd, transfer_size);
+
+			clock_gettime(CLOCK_MONOTONIC, &current);
+			if (current.tv_sec - last_stat.tv_sec > interval) {
+				show_transfer_rate();
+				last_stat = current;
+			}
+		}
+		printf("total: tx %.1fKB, rx %.1fKB\n",
+		       _write_count/1024.0, _read_count/1024.0);
+	} else
+		transfer(fd, default_tx, default_rx, sizeof(default_tx));
+
+	close(fd);
+
+	return ret;
+}