tpm: two-phase chip management functions

tpm_register_hardware() and tpm_remove_hardware() are called often
before initializing the device. The problem is that the device might
not be fully initialized when it comes visible to the user space.

This patch resolves the issue by diving initialization into two
parts:

- tpmm_chip_alloc() creates struct tpm_chip.

- tpm_chip_register() sets up the character device and sysfs
  attributes.

The framework takes care of freeing struct tpm_chip by using the devres
API. The broken release callback has been wiped. ACPI drivers do not
ever get this callback.

Regards to Jason Gunthorpe for carefully reviewing this part of the
code.

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>
[phuewe: update to upstream changes]
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>

1 files changed, 11 insertions, 5 deletions

diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index e638eb016b90..72ff18c872d3 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -94,9 +94,14 @@ struct tpm_vendor_specific {
 #define TPM_VID_WINBOND  0x1050
 #define TPM_VID_STM      0x104A
 
+enum tpm_chip_flags {
+	TPM_CHIP_FLAG_REGISTERED	= BIT(0),
+};
+
 struct tpm_chip {
 	struct device *dev;	/* Device stuff */
 	const struct tpm_class_ops *ops;
+	unsigned int flags;
 
 	int dev_num;		/* /dev/tpm# */
 	char devname[7];
@@ -110,7 +115,6 @@ struct tpm_chip {
 	struct dentry **bios_dir;
 
 	struct list_head list;
-	void (*release) (struct device *);
 };
 
 #define to_tpm_chip(n) container_of(n, struct tpm_chip, vendor)
@@ -322,15 +326,17 @@ extern int tpm_get_timeouts(struct tpm_chip *);
 extern void tpm_gen_interrupt(struct tpm_chip *);
 extern int tpm_do_selftest(struct tpm_chip *);
 extern unsigned long tpm_calc_ordinal_duration(struct tpm_chip *, u32);
-extern struct tpm_chip* tpm_register_hardware(struct device *,
-					      const struct tpm_class_ops *ops);
-extern void tpm_dev_vendor_release(struct tpm_chip *);
-extern void tpm_remove_hardware(struct device *);
 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 *, bool);
 
+struct tpm_chip *tpm_chip_find_get(int chip_num);
+extern struct tpm_chip *tpmm_chip_alloc(struct device *dev,
+				       const struct tpm_class_ops *ops);
+extern int tpm_chip_register(struct tpm_chip *chip);
+extern void tpm_chip_unregister(struct tpm_chip *chip);
+
 int tpm_dev_add_device(struct tpm_chip *chip);
 void tpm_dev_del_device(struct tpm_chip *chip);
 int tpm_sysfs_add_device(struct tpm_chip *chip);