ACPI: Revert "ACPI: Remove CONFIG_ACPI_PROCFS_POWER and cm_sbsc.c"

The commit 1e2d9cd and 7d7ee95 remove ACPI Proc Battery
directory and breaks some old userspace tools. This patch
is to revert 7d7ee95.

Fixes: 7d7ee958867a (ACPI: Remove CONFIG_ACPI_PROCFS_POWER and cm_sbsc.c)
Cc: 3.13+ <stable@vger.kernel.org> # 3.13+
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/acpi/cm_sbs.c b/drivers/acpi/cm_sbs.c
new file mode 100644
index 0000000..6c9ee68
--- /dev/null
+++ b/drivers/acpi/cm_sbs.c
@@ -0,0 +1,105 @@
+/*
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  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, or (at
+ *  your option) any later version.
+ *
+ *  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.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/acpi.h>
+#include <linux/types.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+
+#define PREFIX "ACPI: "
+
+ACPI_MODULE_NAME("cm_sbs");
+#define ACPI_AC_CLASS		"ac_adapter"
+#define ACPI_BATTERY_CLASS	"battery"
+#define _COMPONENT		ACPI_SBS_COMPONENT
+static struct proc_dir_entry *acpi_ac_dir;
+static struct proc_dir_entry *acpi_battery_dir;
+
+static DEFINE_MUTEX(cm_sbs_mutex);
+
+static int lock_ac_dir_cnt;
+static int lock_battery_dir_cnt;
+
+struct proc_dir_entry *acpi_lock_ac_dir(void)
+{
+	mutex_lock(&cm_sbs_mutex);
+	if (!acpi_ac_dir)
+		acpi_ac_dir = proc_mkdir(ACPI_AC_CLASS, acpi_root_dir);
+	if (acpi_ac_dir) {
+		lock_ac_dir_cnt++;
+	} else {
+		printk(KERN_ERR PREFIX
+				  "Cannot create %s\n", ACPI_AC_CLASS);
+	}
+	mutex_unlock(&cm_sbs_mutex);
+	return acpi_ac_dir;
+}
+EXPORT_SYMBOL(acpi_lock_ac_dir);
+
+void acpi_unlock_ac_dir(struct proc_dir_entry *acpi_ac_dir_param)
+{
+	mutex_lock(&cm_sbs_mutex);
+	if (acpi_ac_dir_param)
+		lock_ac_dir_cnt--;
+	if (lock_ac_dir_cnt == 0 && acpi_ac_dir_param && acpi_ac_dir) {
+		remove_proc_entry(ACPI_AC_CLASS, acpi_root_dir);
+		acpi_ac_dir = NULL;
+	}
+	mutex_unlock(&cm_sbs_mutex);
+}
+EXPORT_SYMBOL(acpi_unlock_ac_dir);
+
+struct proc_dir_entry *acpi_lock_battery_dir(void)
+{
+	mutex_lock(&cm_sbs_mutex);
+	if (!acpi_battery_dir) {
+		acpi_battery_dir =
+		    proc_mkdir(ACPI_BATTERY_CLASS, acpi_root_dir);
+	}
+	if (acpi_battery_dir) {
+		lock_battery_dir_cnt++;
+	} else {
+		printk(KERN_ERR PREFIX
+				  "Cannot create %s\n", ACPI_BATTERY_CLASS);
+	}
+	mutex_unlock(&cm_sbs_mutex);
+	return acpi_battery_dir;
+}
+EXPORT_SYMBOL(acpi_lock_battery_dir);
+
+void acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir_param)
+{
+	mutex_lock(&cm_sbs_mutex);
+	if (acpi_battery_dir_param)
+		lock_battery_dir_cnt--;
+	if (lock_battery_dir_cnt == 0 && acpi_battery_dir_param
+	    && acpi_battery_dir) {
+		remove_proc_entry(ACPI_BATTERY_CLASS, acpi_root_dir);
+		acpi_battery_dir = NULL;
+	}
+	mutex_unlock(&cm_sbs_mutex);
+	return;
+}
+EXPORT_SYMBOL(acpi_unlock_battery_dir);