tpm: Autodetect itpm devices

Some Lenovos have TPMs that require a quirk to function correctly. This can
be autodetected by checking whether the device has a _HID of INTC0102. This
is an invalid PNPid, and as such is discarded by the pnp layer - however
it's still present in the ACPI code, so we can pull it out that way. This
means that the quirk won't be automatically applied on non-ACPI systems,
but without ACPI we don't have any way to identify the chip anyway so I
don't think that's a great concern.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Acked-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Tested-by: Andy Isaacson <adi@hexapodia.org>
Signed-off-by: James Morris <jmorris@namei.org>
This commit is contained in:
Matthew Garrett 2010-10-21 17:42:40 -04:00 committed by James Morris
parent 7208364652
commit 3f0d3d016d

View file

@ -25,6 +25,7 @@
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/wait.h>
#include <linux/acpi.h>
#include "tpm.h"
#define TPM_HEADER_SIZE 10
@ -78,6 +79,26 @@ enum tis_defaults {
static LIST_HEAD(tis_chips);
static DEFINE_SPINLOCK(tis_lock);
#ifdef CONFIG_ACPI
static int is_itpm(struct pnp_dev *dev)
{
struct acpi_device *acpi = pnp_acpi_device(dev);
struct acpi_hardware_id *id;
list_for_each_entry(id, &acpi->pnp.ids, list) {
if (!strcmp("INTC0102", id->id))
return 1;
}
return 0;
}
#else
static int is_itpm(struct pnp_dev *dev)
{
return 0;
}
#endif
static int check_locality(struct tpm_chip *chip, int l)
{
if ((ioread8(chip->vendor.iobase + TPM_ACCESS(l)) &
@ -472,6 +493,9 @@ static int tpm_tis_init(struct device *dev, resource_size_t start,
"1.2 TPM (device-id 0x%X, rev-id %d)\n",
vendor >> 16, ioread8(chip->vendor.iobase + TPM_RID(0)));
if (is_itpm(to_pnp_dev(dev)))
itpm = 1;
if (itpm)
dev_info(dev, "Intel iTPM workaround enabled\n");