tpm: move the PPI attributes to character device directory.

Moved PPI attributes to the character device directory. This aligns with
the sysfs guidelines and makes them race free because they are created
atomically with the character device as part of device_register().The
character device and the sysfs attributes appear at the same time to the
user space.

As part of this change we enable PPI attributes also for TPM 2.0
devices. In order to retain backwards compatibility with TPM 1.x
devices, a symlink is created to the platform device directory.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jason.gunthorpe@obsidianresearch.com>
Tested-by: Mimi Zohar <zohar@linux.vnet.ibm.com> (on TPM 1.2)
Tested-by: Chris J Arges <chris.j.arges@canonical.com>
Tested-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
diff --git a/drivers/char/tpm/tpm_ppi.c b/drivers/char/tpm/tpm_ppi.c
index 6ca9b5d..692a2c6 100644
--- a/drivers/char/tpm/tpm_ppi.c
+++ b/drivers/char/tpm/tpm_ppi.c
@@ -53,7 +53,7 @@
 static ssize_t tpm_show_ppi_version(struct device *dev,
 				    struct device_attribute *attr, char *buf)
 {
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	return scnprintf(buf, PAGE_SIZE, "%s\n", chip->ppi_version);
 }
@@ -63,7 +63,7 @@
 {
 	ssize_t size = -EINVAL;
 	union acpi_object *obj;
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	obj = tpm_eval_dsm(chip->acpi_dev_handle, TPM_PPI_FN_GETREQ,
 			   ACPI_TYPE_PACKAGE, NULL);
@@ -100,7 +100,7 @@
 	int func = TPM_PPI_FN_SUBREQ;
 	union acpi_object *obj, tmp;
 	union acpi_object argv4 = ACPI_INIT_DSM_ARGV4(1, &tmp);
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	/*
 	 * the function to submit TPM operation request to pre-os environment
@@ -156,7 +156,7 @@
 		.buffer.length = 0,
 		.buffer.pointer = NULL
 	};
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	static char *info[] = {
 		"None",
@@ -197,7 +197,7 @@
 	acpi_status status = -EINVAL;
 	union acpi_object *obj, *ret_obj;
 	u64 req, res;
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	obj = tpm_eval_dsm(chip->acpi_dev_handle, TPM_PPI_FN_GETRSP,
 			   ACPI_TYPE_PACKAGE, NULL);
@@ -296,7 +296,7 @@
 					   struct device_attribute *attr,
 					   char *buf)
 {
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	return show_ppi_operations(chip->acpi_dev_handle, buf, 0,
 				   PPI_TPM_REQ_MAX);
@@ -306,7 +306,7 @@
 					  struct device_attribute *attr,
 					  char *buf)
 {
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	return show_ppi_operations(chip->acpi_dev_handle, buf, PPI_VS_REQ_START,
 				   PPI_VS_REQ_END);
@@ -334,17 +334,16 @@
 	.attrs = ppi_attrs
 };
 
-int tpm_add_ppi(struct tpm_chip *chip)
+void tpm_add_ppi(struct tpm_chip *chip)
 {
 	union acpi_object *obj;
-	int rc;
 
 	if (!chip->acpi_dev_handle)
-		return 0;
+		return;
 
 	if (!acpi_check_dsm(chip->acpi_dev_handle, tpm_ppi_uuid,
 			    TPM_PPI_REVISION_ID, 1 << TPM_PPI_FN_VERSION))
-		return 0;
+		return;
 
 	/* Cache PPI version string. */
 	obj = acpi_evaluate_dsm_typed(chip->acpi_dev_handle, tpm_ppi_uuid,
@@ -356,16 +355,5 @@
 		ACPI_FREE(obj);
 	}
 
-	rc = sysfs_create_group(&chip->pdev->kobj, &ppi_attr_grp);
-
-	if (!rc)
-		chip->flags |= TPM_CHIP_FLAG_PPI;
-
-	return rc;
-}
-
-void tpm_remove_ppi(struct tpm_chip *chip)
-{
-	if (chip->flags & TPM_CHIP_FLAG_PPI)
-		sysfs_remove_group(&chip->pdev->kobj, &ppi_attr_grp);
+	chip->groups[chip->groups_cnt++] = &ppi_attr_grp;
 }