sb_firmware: write PID to lockfile for powerd

Add logic to write PID to /var/lock/battery_tool_powerd.lock
while performing destructive battery firmware update actions.

BUG=chrome-os-partner:36310
BRANCH=none
CQ-DEPEND=CL:261318
TEST=Verified on glimmer.

Change-Id: I47f34a3a2cb890e66591ef16ac5cf7186d662900
Signed-off-by: Sheng-Liang Song <ssl@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/260868
Reviewed-by: Shawn N <shawnn@chromium.org>

3 files changed, 110 insertions, 0 deletions

diff --git a/util/build.mk b/util/build.mk
index b389324ffa..58410941a3 100644
--- a/util/build.mk
+++ b/util/build.mk
@@ -21,4 +21,5 @@ comm-objs+=comm-i2c.o
 
 ectool-objs=ectool.o ectool_keyscan.o misc_util.o ec_flash.o $(comm-objs)
 ec_sb_firmware_update-objs=ec_sb_firmware_update.o $(comm-objs) misc_util.o
+ec_sb_firmware_update-objs+=powerd_lock.o
 lbplay-objs=lbplay.o $(comm-objs)
diff --git a/util/powerd_lock.c b/util/powerd_lock.c
new file mode 100644
index 0000000000..632bae069a
--- /dev/null
+++ b/util/powerd_lock.c
@@ -0,0 +1,76 @@
+/*
+ * This file is ported from the flashrom project.
+ *
+ * Copyright 2015 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.
+ *
+ * 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; version 2 of the License.
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ *
+ * powerd_lock.c: power management routines
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "powerd_lock.h"
+
+/*
+ * Path to a file containing flashrom's PID. While present, powerd avoids
+ * suspending or shutting down the system.
+ */
+static const char lock_file_path[] = "/var/lock/battery_tool_powerd.lock";
+
+int disable_power_management()
+{
+	FILE *lock_file;
+	int rc = 0;
+
+	lock_file = fopen(lock_file_path, "w");
+	if (!lock_file) {
+		printf("%s: Failed to open %s for writing: %s\n",
+			__func__, lock_file_path, strerror(errno));
+		return 1;
+	}
+
+	if (fprintf(lock_file, "%ld", (long)getpid()) < 0) {
+		printf("%s: Failed to write PID to %s: %s\n",
+			__func__, lock_file_path, strerror(errno));
+		rc = 1;
+	}
+
+	if (fclose(lock_file) != 0) {
+		printf("%s: Failed to close %s: %s\n",
+			__func__, lock_file_path, strerror(errno));
+	}
+	return rc;
+
+}
+
+int restore_power_management()
+{
+	int result = 0;
+
+	result = unlink(lock_file_path);
+	if (result != 0 && errno != ENOENT)  {
+		printf("%s: Failed to unlink %s: %s\n",
+			__func__, lock_file_path, strerror(errno));
+		return 1;
+	}
+	return 0;
+}
diff --git a/util/powerd_lock.h b/util/powerd_lock.h
new file mode 100644
index 0000000000..c486047035
--- /dev/null
+++ b/util/powerd_lock.h
@@ -0,0 +1,33 @@
+/*
+ * This file is ported from the flashrom project.
+ *
+ * Copyright 2015 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.
+ *
+ * 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; version 2 of the License.
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ *
+ * powerd_lock.h: header file for power management routines
+ */
+
+#ifndef __POWER_H__
+#define __POWER_H__ 1
+
+/* Disable power management. */
+int disable_power_management(void);
+
+/* Re-enable power management. */
+int restore_power_management(void);
+
+#endif	/* __POWER_H__ */