[U-Boot] [PATCH v2 1/5] tpm: Add a delay on start-up

Some TPMs hang on startup without a short delay after getting the lock. Add a small delay to cope with this.

Signed-off-by: Simon Glass sjg@chromium.org ---

Changes in v2: - Split out from main TPM patch

drivers/tpm/tpm_tis_lpc.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/drivers/tpm/tpm_tis_lpc.c b/drivers/tpm/tpm_tis_lpc.c index e993fd9f833..79e952146c2 100644 --- a/drivers/tpm/tpm_tis_lpc.c +++ b/drivers/tpm/tpm_tis_lpc.c @@ -408,6 +408,9 @@ static int tpm_tis_lpc_open(struct udevice *dev) return ret; }

+ /* Certain TPMs need some delay here or they hang */ + udelay(10); + tpm_write_word(priv, TIS_STS_COMMAND_READY, &regs[locality].tpm_status); return 0;