This is based on wait_startup() from the Linux tpm_tis driver.
Signed-off-by: Stephen Douthit stephend@silicom-usa.com Tested-by: Stephen Douthit stephend@silicom-usa.com --- src/hw/tpm_drivers.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/src/hw/tpm_drivers.c b/src/hw/tpm_drivers.c index 13ad821..da8bb63 100644 --- a/src/hw/tpm_drivers.c +++ b/src/hw/tpm_drivers.c @@ -86,6 +86,11 @@ static u32 wait_reg8(u8* reg, u32 time, u8 mask, u8 expect) return rc; }
+static u32 tis_wait_access(u8 locty, u32 time, u8 mask, u8 expect) +{ + return wait_reg8(TIS_REG(locty, TIS_REG_ACCESS), time, mask, expect); +} + static u32 tis_wait_sts(u8 locty, u32 time, u8 mask, u8 expect) { return wait_reg8(TIS_REG(locty, TIS_REG_STS), time, mask, expect); @@ -102,7 +107,13 @@ static u32 tis_probe(void) if (!CONFIG_TCGBIOS) return 0;
- u32 rc = 0; + /* Wait for the interface to report it's ready */ + u32 rc = tis_wait_access(0, TIS_DEFAULT_TIMEOUT_A, + TIS_ACCESS_TPM_REG_VALID_STS, + TIS_ACCESS_TPM_REG_VALID_STS); + if (rc) + return 0; + u32 didvid = readl(TIS_REG(0, TIS_REG_DID_VID));
if ((didvid != 0) && (didvid != 0xffffffff))