tpm: device class for tpm

Added own device class for TPM. Uses MISC_MAJOR:TPM_MINOR for the
first character device in order to retain backwards compatibility.
Added tpm_dev_release() back attached to the character device.

I've been running this code now for a while on my laptop (Lenovo
T430S) TrouSerS works perfectly without modifications. I don't
believe it breaks anything significantly.

The sysfs attributes that have been placed under the wrong place
and are against sysfs-rules.txt should be probably left to
stagnate under platform device directory and start defining
new sysfs attributes to the char device directory.

Guidelines for future TPM sysfs attributes should be probably
along the lines of

- Single flat set of mandatory sysfs attributes. For example,
  current PPI interface is way way too rich when you only want
  to use it to clear and activate the TPM.

- Define sysfs attribute if and only if there's no way to get
  the value from ring-3. No attributes for TPM properties. It's
  just unnecessary maintenance hurdle that we don't want.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jasob Gunthorpe <jason.gunthorpe@obsidianresearch.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Tested-by: Scot Doyle <lkml14@scotdoyle.com>
Tested-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>

1 files changed, 3 insertions, 33 deletions

diff --git a/drivers/char/tpm/tpm-dev.c b/drivers/char/tpm/tpm-dev.c
index 356832146788..de0337ebd658 100644
--- a/drivers/char/tpm/tpm-dev.c
+++ b/drivers/char/tpm/tpm-dev.c
@@ -17,7 +17,6 @@
  * License.
  *
  */
-#include <linux/miscdevice.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
 #include "tpm.h"
@@ -54,9 +53,8 @@ static void timeout_work(struct work_struct *work)
 
 static int tpm_open(struct inode *inode, struct file *file)
 {
-	struct miscdevice *misc = file->private_data;
-	struct tpm_chip *chip = container_of(misc, struct tpm_chip,
-					     vendor.miscdev);
+	struct tpm_chip *chip =
+		container_of(inode->i_cdev, struct tpm_chip, cdev);
 	struct file_priv *priv;
 
 	/* It's assured that the chip will be opened just once,
@@ -173,7 +171,7 @@ static int tpm_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
-static const struct file_operations tpm_fops = {
+const struct file_operations tpm_fops = {
 	.owner = THIS_MODULE,
 	.llseek = no_llseek,
 	.open = tpm_open,
@@ -182,32 +180,4 @@ static const struct file_operations tpm_fops = {
 	.release = tpm_release,
 };
 
-int tpm_dev_add_device(struct tpm_chip *chip)
-{
-	int rc;
 
-	chip->vendor.miscdev.fops = &tpm_fops;
-	if (chip->dev_num == 0)
-		chip->vendor.miscdev.minor = TPM_MINOR;
-	else
-		chip->vendor.miscdev.minor = MISC_DYNAMIC_MINOR;
-
-	chip->vendor.miscdev.name = chip->devname;
-	chip->vendor.miscdev.parent = chip->pdev;
-
-	rc = misc_register(&chip->vendor.miscdev);
-	if (rc) {
-		chip->vendor.miscdev.name = NULL;
-		dev_err(chip->pdev,
-			"unable to misc_register %s, minor %d err=%d\n",
-			chip->vendor.miscdev.name,
-			chip->vendor.miscdev.minor, rc);
-	}
-	return rc;
-}
-
-void tpm_dev_del_device(struct tpm_chip *chip)
-{
-	if (chip->vendor.miscdev.name)
-		misc_deregister(&chip->vendor.miscdev);
-}