Add ec_uartd build-side utility

This provides a pty for the EC UART channel on the BD-ICDI-B FTDI
daughtercard for EC debugging.

Signed-off-by: Randall Spangler <rspangler@chromium.org>

BUG=none
TEST=make && build/bds/util/ec_uartd (with EC attached to FTDI board)

Change-Id: I51fe50d0da6345962affb860b923425197a04fa1

4 files changed, 134 insertions, 3 deletions

diff --git a/Makefile.rules b/Makefile.rules
index 888425daa1..bd2472e22c 100644
--- a/Makefile.rules
+++ b/Makefile.rules
@@ -11,7 +11,8 @@ build-utils := $(foreach u,$(build-util-bin),$(out)/util/$(u))
 host-utils := $(foreach u,$(host-util-bin),$(out)/util/$(u))
 
 # Create output directories if necessary
-_dir_create := $(foreach d,$(dirs),$(shell [ -d $(out)/$(d) ] || mkdir -p $(out)/$(d)))
+_dir_create := $(foreach d,$(dirs),$(shell [ -d $(out)/$(d) ] || \
+	    mkdir -p $(out)/$(d)))
 
 section = $(subst .,,$(suffix $(1)))
 
@@ -29,9 +30,11 @@ cmd_elf_to_flat = $(OBJCOPY) -O binary $^ $@
 cmd_elf_to_dis = $(OBJDUMP) -D $< > $@
 cmd_elf = $(LD) $(LDFLAGS) $(objs) -o $@ -T $< -Map $(out)/$*.map
 cmd_c_to_o = $(CC) $(CFLAGS) -MMD -MF $@.d -c $< -o $@
-cmd_c_to_build = $(BUILDCC) $(BUILD_CFLAGS) -MMD -MF $@.d $< -o $@
+cmd_c_to_build = $(BUILDCC) $(BUILD_CFLAGS) $(BUILD_LDFLAGS) \
+	         -MMD -MF $@.d $< -o $@
 cmd_c_to_host = $(HOSTCC) $(HOST_CFLAGS) -MMD -MF $@.d $< -o $@
-cmd_qemu = ./util/run_qemu_test --image=build/$(BOARD)/$*/$*.bin test/$*.py $(silent)
+cmd_qemu = ./util/run_qemu_test --image=build/$(BOARD)/$*/$*.bin test/$*.py \
+	   $(silent)
 
 
 .PHONY: all tests utils
diff --git a/Makefile.toolchain b/Makefile.toolchain
index d52967edde..a7a961c4f8 100644
--- a/Makefile.toolchain
+++ b/Makefile.toolchain
@@ -30,3 +30,4 @@ CFLAGS=$(CPPFLAGS) $(CFLAGS_CPU) $(CFLAGS_DEBUG) $(CFLAGS_WARN)
 BUILD_CFLAGS=$(CPPFLAGS) -O3 $(CFLAGS_DEBUG) $(CFLAGS_WARN)
 HOST_CFLAGS=$(CPPFLAGS) -O3 $(CFLAGS_DEBUG) $(CFLAGS_WARN)
 LDFLAGS=-nostdlib -X
+BUILD_LDFLAGS=-lftdi
diff --git a/util/build.mk b/util/build.mk
index 6d44606562..024f2054cf 100644
--- a/util/build.mk
+++ b/util/build.mk
@@ -6,3 +6,4 @@
 #
 
 host-util-bin=ectool
+build-util-bin=ec_uartd
diff --git a/util/ec_uartd.c b/util/ec_uartd.c
new file mode 100644
index 0000000000..ae2e51a580
--- /dev/null
+++ b/util/ec_uartd.c
@@ -0,0 +1,126 @@
+/* Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+/* ec_uartd.c - UART daemon for BD-ICDI-B board for EC debugging
+ *
+ * based on chromeos_public/src/third_party/hdctools/src/ftdiuart.c
+ *
+ * compile with:
+ *    gcc -o ftdi_uartd ftdi_uartd.c -lftdi
+ */
+
+/* Force header files to define grantpt(), posix_openpt(), cfmakeraw() */
+#define _BSD_SOURCE
+#define _XOPEN_SOURCE 600
+
+#include <fcntl.h>
+#include <ftdi.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <termios.h>
+#include <unistd.h>
+
+int main(int argc, char **argv)
+{
+	struct ftdi_context fcontext;
+	struct termios tty_cfg;
+	char ptname[PATH_MAX];
+	char buf[1024];
+	int fd;
+	int rv;
+
+	/* Init */
+	if (ftdi_init(&fcontext) < 0) {
+		fprintf(stderr, "ftdi_init failed\n");
+		return 1;
+	}
+
+	/* Open interface B (UART) in the FTDI device and set 115kbaud */
+	ftdi_set_interface(&fcontext, INTERFACE_B);
+	rv = ftdi_usb_open(&fcontext, 0x0403, 0xbcda);
+	if (rv < 0) {
+		fprintf(stderr, "error opening ftdi device: %d (%s)\n",
+			rv, ftdi_get_error_string(&fcontext));
+		return 2;
+	}
+	rv = ftdi_set_baudrate(&fcontext, 115200);
+	if (rv < 0) {
+		fprintf(stderr, "error setting baudrate: %d (%s)\n",
+			rv, ftdi_get_error_string(&fcontext));
+		return 2;
+	}
+
+	/* Set DTR; this muxes RX on the ICDI board */
+	ftdi_setdtr(&fcontext, 1);
+
+	/* Open the pty */
+	fd = posix_openpt(O_RDWR | O_NOCTTY);
+	if (fd == -1) {
+		perror("opening pty master");
+		return 3;
+	}
+	if (grantpt(fd) == -1) {
+		perror("grantpt");
+		return 3;
+	}
+	if (unlockpt(fd) == -1) {
+		perror("unlockpt");
+		return 3;
+	}
+	if (fcntl(fd, F_SETFL, O_NONBLOCK) == -1) {
+		perror("fcntl setfl -> nonblock");
+		return 3;
+	}
+	if (ptsname_r(fd, ptname, PATH_MAX) != 0) {
+		perror("getting name of pty");
+		return 3;
+	}
+	fprintf(stderr, "pty name = %s\n", ptname);
+	if (!isatty(fd)) {
+		perror("not a TTY device\n");
+		return 3;
+	}
+	cfmakeraw(&tty_cfg);
+	tcsetattr(fd, TCSANOW, &tty_cfg);
+	if (chmod(ptname, 0666) == -1) {
+		perror("setting pty attributes");
+		return 3;
+	}
+
+	/* Read and write data forever */
+	while (1) {
+		int bytes = read(fd, buf, sizeof(buf));
+		if (bytes > 0) {
+			rv = ftdi_write_data(&fcontext, buf, bytes);
+			if (rv != bytes) {
+				perror("writing to uart");
+				break;
+			}
+		}
+
+		usleep(1000);
+
+		bytes = ftdi_read_data(&fcontext, buf, sizeof(buf));
+		if (bytes > 0) {
+			int bytes_remaining = bytes;
+			while ((bytes = write(fd, buf, bytes_remaining)) > 0)
+				bytes_remaining -= bytes;
+
+			if (bytes == -1)
+				perror("writing ftdi data to pty");
+
+		} else if (bytes < 0) {
+			perror("failed ftdi_read_data");
+			break;
+		}
+	}
+
+	/* Cleanup */
+	close(fd);
+	ftdi_usb_close(&fcontext);
+	ftdi_deinit(&fcontext);
+	return 0;
+}