1 files changed, 78 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm-dev.c b/drivers/char/tpm/tpm-dev.c
new file mode 100644
index 000000000..ebd74ab5a
--- /dev/null
+++ b/drivers/char/tpm/tpm-dev.c
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2004 IBM Corporation
+ * Authors:
+ * Leendert van Doorn <leendert@watson.ibm.com>
+ * Dave Safford <safford@watson.ibm.com>
+ * Reiner Sailer <sailer@watson.ibm.com>
+ * Kylene Hall <kjhall@us.ibm.com>
+ *
+ * Copyright (C) 2013 Obsidian Research Corp
+ * Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
+ *
+ * Device file system interface to the TPM
+ *
+ * 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.
+ *
+ */
+#include <linux/slab.h>
+#include "tpm-dev.h"
+
+static int tpm_open(struct inode *inode, struct file *file)
+{
+	struct tpm_chip *chip;
+	struct file_priv *priv;
+
+	chip = container_of(inode->i_cdev, struct tpm_chip, cdev);
+
+	/* It's assured that the chip will be opened just once,
+	 * by the check of is_open variable, which is protected
+	 * by driver_lock. */
+	if (test_and_set_bit(0, &chip->is_open)) {
+		dev_dbg(&chip->dev, "Another process owns this TPM\n");
+		return -EBUSY;
+	}
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (priv == NULL)
+		goto out;
+
+	tpm_common_open(file, chip, priv);
+
+	return 0;
+
+ out:
+	clear_bit(0, &chip->is_open);
+	return -ENOMEM;
+}
+
+static ssize_t tpm_write(struct file *file, const char __user *buf,
+			 size_t size, loff_t *off)
+{
+	return tpm_common_write(file, buf, size, off, NULL);
+}
+
+/*
+ * Called on file close
+ */
+static int tpm_release(struct inode *inode, struct file *file)
+{
+	struct file_priv *priv = file->private_data;
+
+	tpm_common_release(file, priv);
+	clear_bit(0, &priv->chip->is_open);
+	kfree(priv);
+
+	return 0;
+}
+
+const struct file_operations tpm_fops = {
+	.owner = THIS_MODULE,
+	.llseek = no_llseek,
+	.open = tpm_open,
+	.read = tpm_common_read,
+	.write = tpm_write,
+	.release = tpm_release,
+};