Quoting Jarkko Sakkinen (2019-09-03 09:39:51) > On Thu, 2019-08-29 at 15:41 -0700, Stephen Boyd wrote: > > From: Andrey Pronin <apronin@xxxxxxxxxxxx> > > > > Add TPM2.0 PTP FIFO compatible SPI interface for chips with Cr50 > > firmware. The firmware running on the currently supported H1 Secure > > Microcontroller requires a special driver to handle its specifics: > > > > - need to ensure a certain delay between SPI transactions, or else > > the chip may miss some part of the next transaction > > - if there is no SPI activity for some time, it may go to sleep, > > and needs to be waken up before sending further commands > > - access to vendor-specific registers > > > > Cr50 firmware has a requirement to wait for the TPM to wakeup before > > sending commands over the SPI bus. Otherwise, the firmware could be in > > deep sleep and not respond. The method to wait for the device to wakeup > > is slightly different than the usual flow control mechanism described in > > the TCG SPI spec. Add a completion to tpm_tis_spi_transfer() before we > > start a SPI transfer so we can keep track of the last time the TPM > > driver accessed the SPI bus to support the flow control mechanism. > > > > Split the cr50 logic off into a different file to keep it out of the > > normal code flow of the existing SPI driver while making it all part of > > the same module when the code is optionally compiled into the same > > module. Export a new function, tpm_tis_spi_init(), and the associated > > read/write/transfer APIs so that we can do this. Make the cr50 code wrap > > the tpm_tis_spi_phy struct with its own struct to override the behavior > > of tpm_tis_spi_transfer() by supplying a custom flow control hook. This > > shares the most code between the core driver and the cr50 support > > without combining everything into the core driver or exporting module > > symbols. > > > > Signed-off-by: Andrey Pronin <apronin@xxxxxxxxxxxx> > > Cc: Andrey Pronin <apronin@xxxxxxxxxxxx> > > Cc: Duncan Laurie <dlaurie@xxxxxxxxxxxx> > > Cc: Jason Gunthorpe <jgg@xxxxxxxx> > > Cc: Arnd Bergmann <arnd@xxxxxxxx> > > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > > Cc: Guenter Roeck <groeck@xxxxxxxxxxxx> > > Cc: Alexander Steffen <Alexander.Steffen@xxxxxxxxxxxx> > > Cc: Heiko Stuebner <heiko@xxxxxxxxx> > > Had to time to look at this patch set after all before LPC. I just > realized that the kconfig has taken away. Not sure why is that > because there's been only request to not have a new LKM. There > still should be ability opt-out to have Cr50 support in vmlinux. > That's fair. I'll put the Kconfig option back. There's still the small issue of what to do about the module name. Should I rename the tpm_tis_spi.c file to something else so that the module can keep the same name? Or was the tpm_tis_spi_mod.ko trick from v5 good enough?
