[U-Boot] [PATCH 00/25] dm: Convert TPM drivers to driver model

christophe.ricard
2015-08-11T21:50:25Z

Hi Simon,

I pretty much like the move to driver model for TPM.
However, i have some few remarks:

The current i2c driver stick to Infineon TPMs and will not support any
other vendors like ST(in my case).
The main reason for this is that there is no transport protocol over I2C
specification defined by the Trusted Computing Group for TPM1.2.
You can take a look at my release tentative here:
http://lists.denx.de/pipermail/u-boot/2015-August/222596.html

The tpm.c file was delivering a way to ajust best the waiting time for
command duration to receive a command answer from a TPM command. It was
ported from Linux to u-boot.
You can find in chapter 17 how the table tpm_protected_ordinal_duration,
tpm_ordinal_duration were build.
(https://www.trustedcomputinggroup.org/files/resource_files/E14876A3-1A4B-B294-D086297A1ED38F96/mainP2Structrev103.pdf)
This is defined by the TCG and followed by TPM vendors. In u-boot, this
is used only by Infineon i2c driver but it could/should(?) be used
by all other drivers (i2c and lpc).

In short, the idea is to keep the way TPM commands are transfered
giving the hands to drivers for handling the communication over a
specified or proprietary transport protocol.

I fear the current approach would lead to duplicated codes on may TPM
drivers and 2 very differents kind of drivers (Linux/u-boot) very far
from each other.

Would it be possible to have your comments on my proposal ?
http://lists.denx.de/pipermail/u-boot/2015-August/222596.html

Best Regards
Christophe

On 11/08/2015 16:47, Simon Glass wrote:
> This series adds driver model support for Trusted Platform Modules (TPMs).
> These have a very simple interface and are configured via the device tree.
>
> Two bus types are supported at present: I2C and LPC (Intel Low-Pin-Count).
>
> Most drivers and users are converted over to driver model. The exception is
> the Atmel TPM and its users.
>
> The I2C driver has been cleaned up and simplified. It was ported from Linux
> and was pretty hard to follow. This series includes patches to unify the
> code, remove duplicated data structures and drop unnecessary indirection.
>
> Also this series enables the TPM on all Chromebooks (snow, spring, nyan-big,
> pit, pi, link) since some did not have it fully enabled.
>
> As before, the 'tpm' command can be used to implement TPM functionality.
>
>
> Simon Glass (25):
> tpm: Remove old pre-driver-model I2C code
> tpm: Drop two unused options
> tpm: Add Kconfig options for TPMs
> tpm: Convert board config TPM options to Kconfig
> tpm: Convert drivers to use SPDX
> tpm: Move the I2C TPM code into one file
> tpm: tpm_tis_i2c: Drop unnecessary methods
> tpm: tpm_tis_i2c: Drop struct tpm_vendor_specific
> tpm: tpm_tis_i2c: Merge struct tpm_dev into tpm_chip
> tpm: tpm_tis_i2c: Merge struct tpm into tpm_chip
> tpm: tpm_tis_i2c: Move definitions into the header file
> tpm: tpm_tis_i2c: Simplify init code
> tpm: tpm_tis_i2c: Use a consistent tpm_tis_i2c_ prefix
> tpm: tpm_tis_i2c: Tidy up delays
> dm: tpm: Add a uclass for Trusted Platform Modules
> dm: tpm: Convert the TPM command and library to driver model
> dm: i2c: Add a command to adjust the offset length
> tpm: Report tpm errors on the command line
> dm: tpm: sandbox: Convert TPM driver to driver model
> tpm: Check that parse_byte_string() has data to parse
> exynos: x86: dts: Add tpm nodes to the device tree for Chrome OS
> devices
> dm: tpm: Convert I2C driver to driver model
> dm: tpm: Convert LPC driver to driver model
> tpm: Add a 'tpm info' command
> tegra: nyan: Enable TPM command and driver
>
> README | 6 -
> arch/arm/dts/exynos5250-snow.dts | 9 +
> arch/arm/dts/exynos5250-spring.dts | 8 +
> arch/arm/dts/exynos5420-peach-pit.dts | 6 +-
> arch/arm/dts/exynos5800-peach-pi.dts | 6 +-
> arch/sandbox/dts/sandbox.dts | 4 +
> arch/x86/dts/chromebook_link.dts | 5 +
> common/Kconfig | 12 +
> common/cmd_i2c.c | 33 +
> common/cmd_tpm.c | 100 ++-
> configs/chromebook_link_defconfig | 4 +
> configs/chromebox_panther_defconfig | 4 +
> .../controlcenterd_36BIT_SDCARD_DEVELOP_defconfig | 4 +
> configs/controlcenterd_36BIT_SDCARD_defconfig | 4 +
> .../controlcenterd_TRAILBLAZER_DEVELOP_defconfig | 4 +
> configs/controlcenterd_TRAILBLAZER_defconfig | 4 +
> configs/coreboot-x86_defconfig | 4 +
> configs/nyan-big_defconfig | 4 +
> configs/peach-pi_defconfig | 4 +
> configs/peach-pit_defconfig | 4 +
> configs/sandbox_defconfig | 3 +
> configs/snow_defconfig | 4 +
> configs/spring_defconfig | 4 +
> drivers/tpm/Kconfig | 61 ++
> drivers/tpm/Makefile | 4 +-
> drivers/tpm/tpm-uclass.c | 57 ++
> drivers/tpm/tpm.c | 694 ---------------------
> drivers/tpm/tpm_atmel_twi.c | 15 +-
> drivers/tpm/tpm_private.h | 140 -----
> drivers/tpm/tpm_tis_i2c.c | 594 ++++++++++--------
> drivers/tpm/tpm_tis_i2c.h | 446 +++++++++++++
> drivers/tpm/tpm_tis_lpc.c | 291 +++++----
> drivers/tpm/tpm_tis_sandbox.c | 48 +-
> include/configs/controlcenterd.h | 7 -
> include/configs/efi-x86.h | 2 -
> include/configs/exynos5-common.h | 7 -
> include/configs/x86-common.h | 2 -
> include/dm/uclass-id.h | 1 +
> include/fdtdec.h | 2 -
> include/tis.h | 97 +++
> include/tpm.h | 2 +-
> lib/Kconfig | 10 +
> lib/fdtdec.c | 2 -
> lib/tpm.c | 29 +-
> 44 files changed, 1404 insertions(+), 1347 deletions(-)
> create mode 100644 drivers/tpm/tpm-uclass.c
> delete mode 100644 drivers/tpm/tpm.c
> delete mode 100644 drivers/tpm/tpm_private.h
> create mode 100644 drivers/tpm/tpm_tis_i2c.h
>