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authorAlexander Steffen <Alexander.Steffen@infineon.com>2022-06-08 19:31:13 +0200
committerJarkko Sakkinen <jarkko@kernel.org>2022-08-03 23:56:20 +0300
commitbbc23a07b0728c820d665d0054b2e2a6d01f0a98 (patch)
tree21faa692d92b1cd57b297aa6fc01231287d08077 /crypto
parentf25534a68b8e1ed8266d23b464a3b512364b124d (diff)
tpm: Add tpm_tis_i2c backend for tpm_tis_core
Implement the TCG I2C Interface driver, as specified in the TCG PC Client Platform TPM Profile (PTP) specification for TPM 2.0 v1.04 revision 14, section 8, I2C Interface Definition. This driver supports Guard Times. That is, if required by the TPM, the driver has to wait by a vendor-specific time after each I2C read/write. The specific time is read from the TPM_I2C_INTERFACE_CAPABILITY register. Unfortunately, the TCG specified almost but not quite compatible register addresses. Therefore, the TIS register addresses need to be mapped to I2C ones. The locality is stripped because for now, only locality 0 is supported. Add a sanity check to I2C reads of e.g. TPM_ACCESS and TPM_STS. This is to detect communication errors and issues due to non-standard behaviour (E.g. the clock stretching quirk in the BCM2835, see 4dbfb5f4401f). In case the sanity check fails, attempt a retry. Co-developed-by: Johannes Holland <johannes.holland@infineon.com> Signed-off-by: Johannes Holland <johannes.holland@infineon.com> Co-developed-by: Amir Mizinski <amirmizi6@gmail.com> Signed-off-by: Amir Mizinski <amirmizi6@gmail.com> Signed-off-by: Alexander Steffen <Alexander.Steffen@infineon.com> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Diffstat (limited to 'crypto')
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