mbox series

[V3,0/3] Tegra TPM driver with HW flow control

Message ID 20230223162635.19747-1-kyarlagadda@nvidia.com
Headers
Series Tegra TPM driver with HW flow control |

Message

Krishna Yarlagadda Feb. 23, 2023, 4:26 p.m. UTC 
  TPM interface spec defines flow control where TPM device would drive
MISO at same cycle as last address bit sent by controller on MOSI. This
state of wait can be detected by software reading the MISO line or
by controller hardware. Support sending transfers to controller in
single message and handle flow control in hardware. Half duplex
controllers have to support flow control in hardware.

Tegra234 and Tegra241 chips have QSPI controller that supports TPM
Interface Specification (TIS) flow control.
Since the controller only supports half duplex, SW wait polling
(flow control using full duplex transfers) method implemented in
tpm_tis_spi_main.c will not work and have to us HW flow control.

Updates in this patchset 
 - Tegra QSPI identifies itself as half duplex.
 - TPM TIS SPI driver skips flow control for half duplex and send
   transfers in single message for controller to handle it.
 - TPM device identifies as TPM device for controller to detect and
   enable HW TPM wait poll feature.

Verified with a TPM device on Tegra241 ref board using TPM2 tools.

V3:
 - Use SPI device mode flag and SPI controller flags.
 - Drop usage of device tree flags.
 - Generic TPM half duplex controller handling.
 - HW & SW flow control for TPM. Drop additional driver.
V2:
 - Fix dt schema errors.


Krishna Yarlagadda (3):
  tpm_tis-spi: Support hardware wait polling
  spi: tegra210-quad: set half duplex flag
  spi: tegra210-quad: Enable TPM wait polling

 drivers/char/tpm/tpm_tis_spi_main.c | 90 ++++++++++++++++++++++++++++-
 drivers/spi/spi-tegra210-quad.c     | 22 +++++++
 include/linux/spi/spi.h             |  7 ++-
 3 files changed, 114 insertions(+), 5 deletions(-)

Comments

Mark Brown Feb. 23, 2023, 6:31 p.m. UTC | #1 
On Thu, 23 Feb 2023 21:56:32 +0530, Krishna Yarlagadda wrote:
> TPM interface spec defines flow control where TPM device would drive
> MISO at same cycle as last address bit sent by controller on MOSI. This
> state of wait can be detected by software reading the MISO line or
> by controller hardware. Support sending transfers to controller in
> single message and handle flow control in hardware. Half duplex
> controllers have to support flow control in hardware.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[2/3] spi: tegra210-quad: set half duplex flag
      commit: f7482d8285b638be87a594a30edaaf1341135c1a

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark