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Diffstat (limited to 'drivers/char/tpm/tpm_tis.c')
-rw-r--r--drivers/char/tpm/tpm_tis.c21
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index ae91c115c438..6c69ad72f82f 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -98,6 +98,22 @@ static inline int is_itpm(struct pnp_dev *dev)
}
#endif
+/* Before we attempt to access the TPM we must see that the valid bit is set.
+ * The specification says that this bit is 0 at reset and remains 0 until the
+ * 'TPM has gone through its self test and initialization and has established
+ * correct values in the other bits.' */
+static int wait_startup(struct tpm_chip *chip, int l)
+{
+ unsigned long stop = jiffies + chip->vendor.timeout_a;
+ do {
+ if (ioread8(chip->vendor.iobase + TPM_ACCESS(l)) &
+ TPM_ACCESS_VALID)
+ return 0;
+ msleep(TPM_TIMEOUT);
+ } while (time_before(jiffies, stop));
+ return -1;
+}
+
static int check_locality(struct tpm_chip *chip, int l)
{
if ((ioread8(chip->vendor.iobase + TPM_ACCESS(l)) &
@@ -541,6 +557,11 @@ static int tpm_tis_init(struct device *dev, resource_size_t start,
chip->vendor.timeout_c = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
chip->vendor.timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
+ if (wait_startup(chip, 0) != 0) {
+ rc = -ENODEV;
+ goto out_err;
+ }
+
if (request_locality(chip, 0) != 0) {
rc = -ENODEV;
goto out_err;