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Commit 3f0d3d01 authored by Matthew Garrett's avatar Matthew Garrett Committed by James Morris
Browse files

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: default avatarMatthew Garrett <mjg@redhat.com>
Acked-by: default avatarRajiv Andrade <srajiv@linux.vnet.ibm.com>
Tested-by: default avatarJiri Kosina <jkosina@suse.cz>
Tested-by: default avatarAndy Isaacson <adi@hexapodia.org>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
parent 72083646

drivers/char/tpm/tpm_tis.c

+24 −0
Original line number Diff line number Diff line
@@ -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");