diff options
Diffstat (limited to 'drivers/char/tpm/tpm_tis.c')
| -rw-r--r-- | drivers/char/tpm/tpm_tis.c | 21 |
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; |