tpm: Fix initialization of the cdev

When a cdev is contained in a dynamic structure the cdev parent kobj
should be set to the kobj that controls the lifetime of the enclosing
structure. In TPM's case this is the embedded struct device.

Also, cdev_init 0's the whole structure, so all sets must be after,
not before. This fixes module ref counting and cdev.

Cc: <[email protected]>
Fixes: 313d21e ("tpm: device class for tpm")
Signed-off-by: Jason Gunthorpe <[email protected]>
Reviewed-by: Dmitry Torokhov <[email protected]>
Reviewed-by: Jarkko Sakkinen <[email protected]>
Tested-by: Jarkko Sakkinen <[email protected]>
Signed-off-by: Peter Huewe <[email protected]>

Author: jgunthorpe

drivers/char/tpm/tpm-chip.c

@@ -129,8 +129,9 @@ struct tpm_chip *tpmm_chip_alloc(struct device *dev,
 
 	device_initialize(&chip->dev);
 
-	chip->cdev.owner = chip->pdev->driver->owner;
 	cdev_init(&chip->cdev, &tpm_fops);
+	chip->cdev.owner = chip->pdev->driver->owner;
+	chip->cdev.kobj.parent = &chip->dev.kobj;
 
 	return chip;
 }