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authorMatthew Garrett <mjg@redhat.com>2010-10-21 17:42:40 -0400
committerJames Morris <jmorris@namei.org>2010-11-30 09:18:01 +1100
commit3f0d3d016d89a5efb8b926d4707eb21fa13f3d27 (patch)
tree9cf5a19b80d8c935db98110f2ac822c74f9ec9b9
parent72083646528d4887b920deb71b37e09bc7d227bb (diff)
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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>
-rw-r--r--drivers/char/tpm/tpm_tis.c24
1 files changed, 24 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index 1030f842013..c17a305ecb2 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -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");