tpm: fix raciness of PPI interface lookup

Traversal of the ACPI device tree was not done right. PPI interface
should be looked up only from the ACPI device that is the platform
device for the TPM. This could cause problems with systems with
two TPM chips such as 4th gen Intel systems.

In addition, added the missing license and copyright platter to
the tpm_ppi.c.

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>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 72ff18c..3409acf 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -27,6 +27,7 @@
 #include <linux/platform_device.h>
 #include <linux/io.h>
 #include <linux/tpm.h>
+#include <linux/acpi.h>
 
 enum tpm_const {
 	TPM_MINOR = 224,	/* officially assigned */
@@ -94,8 +95,11 @@
 #define TPM_VID_WINBOND  0x1050
 #define TPM_VID_STM      0x104A
 
+#define TPM_PPI_VERSION_LEN		3
+
 enum tpm_chip_flags {
 	TPM_CHIP_FLAG_REGISTERED	= BIT(0),
+	TPM_CHIP_FLAG_PPI		= BIT(1),
 };
 
 struct tpm_chip {
@@ -114,6 +118,11 @@
 
 	struct dentry **bios_dir;
 
+#ifdef CONFIG_ACPI
+	acpi_handle acpi_dev_handle;
+	char ppi_version[TPM_PPI_VERSION_LEN + 1];
+#endif /* CONFIG_ACPI */
+
 	struct list_head list;
 };
 
@@ -345,15 +354,15 @@
 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf);
 
 #ifdef CONFIG_ACPI
-extern int tpm_add_ppi(struct kobject *);
-extern void tpm_remove_ppi(struct kobject *);
+extern int tpm_add_ppi(struct tpm_chip *chip);
+extern void tpm_remove_ppi(struct tpm_chip *chip);
 #else
-static inline int tpm_add_ppi(struct kobject *parent)
+static inline int tpm_add_ppi(struct tpm_chip *chip)
 {
 	return 0;
 }
 
-static inline void tpm_remove_ppi(struct kobject *parent)
+static inline void tpm_remove_ppi(struct tpm_chip *chip)
 {
 }
 #endif