[patch 154/176] tpm: Autodetect itpm devices

From: Greg KH
Date: Tue Feb 15 2011 - 19:57:09 EST


2.6.36-stable review patch. If anyone has any objections, please let us know.

------------------

From: Matthew Garrett <mjg@xxxxxxxxxx>

commit 3f0d3d016d89a5efb8b926d4707eb21fa13f3d27 upstream.

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@xxxxxxxxxx>
Acked-by: Rajiv Andrade <srajiv@xxxxxxxxxxxxxxxxxx>
Tested-by: Jiri Kosina <jkosina@xxxxxxx>
Tested-by: Andy Isaacson <adi@xxxxxxxxxxxxx>
Signed-off-by: James Morris <jmorris@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
drivers/char/tpm/tpm_tis.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)

--- 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)) &
@@ -474,6 +495,9 @@ static int tpm_tis_init(struct device *d
"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");



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/