driver: add PPI support in tpm driver

The Physical Presence Interface enables the OS and the BIOS to cooperate and provides a simple and straightforward platform user experience for administering the TPM without sacrificing security. V2: separate the patch out in a separate source file, add #ifdef CONFIG_ACPI so it compiles out on ppc, use standard error instead of ACPI error as return code of show/store fns. V3: move #ifdef CONFIG_ACPI from .c file to .h file. V4: move tpm_ppi code from tpm module to tpm_bios module. V5: modify sys_add_ppi() so that ppi_attr_grp doesn't need to be exported Signed-off-by: Xiaoyan Zhang <[email protected]> Signed-off-by: Kent Yoder <[email protected]>
akvadrako · Aug 22, 2012 · f84fdff · f84fdff
1 parent 1f862f0
commit f84fdff
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Showing 4 changed files with 475 additions and 1 deletion.
diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
@@ -4,7 +4,7 @@
 obj-$(CONFIG_TCG_TPM) += tpm.o
 ifdef CONFIG_ACPI
 	obj-$(CONFIG_TCG_TPM) += tpm_bios.o
-	tpm_bios-objs += tpm_eventlog.o tpm_acpi.o
+	tpm_bios-objs += tpm_eventlog.o tpm_acpi.o tpm_ppi.o
 else
 ifdef CONFIG_TCG_IBMVTPM
 	obj-$(CONFIG_TCG_TPM) += tpm_bios.o

diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
@@ -1476,6 +1476,11 @@ struct tpm_chip *tpm_register_hardware(struct device *dev,
 		goto put_device;
 	}
 
+	if (sys_add_ppi(&dev->kobj)) {
+		misc_deregister(&chip->vendor.miscdev);
+		goto put_device;
+	}
+
 	chip->bios_dir = tpm_bios_log_setup(devname);
 
 	/* Make chip available */

diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
@@ -327,3 +327,12 @@ extern int tpm_pm_suspend(struct device *);
 extern int tpm_pm_resume(struct device *);
 extern int wait_for_tpm_stat(struct tpm_chip *, u8, unsigned long,
 			     wait_queue_head_t *);
+
+#ifdef CONFIG_ACPI
+extern ssize_t sys_add_ppi(struct kobject *parent);
+#else
+static inline ssize_t sys_add_ppi(struct kobject *parent)
+{
+	return 0;
+}
+#endif