Quoting Heiko Stuebner (2019-08-30 08:33:48) > Am Freitag, 30. August 2019, 00:41:10 CEST schrieb Stephen Boyd: > > 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> > > [swboyd@xxxxxxxxxxxx: Replace boilerplate with SPDX tag, drop > > suspended bit and remove ifdef checks in cr50.h, migrate to functions > > exported in tpm_tis_spi.h, combine into one module instead of two] > > Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx> > > This variant breaks building the tpm as a module: > > > WARNING: modpost: missing MODULE_LICENSE() in drivers/char/tpm/cr50_spi.o > see include/linux/module.h for more information > ERROR: "tpm_tis_spi_write32" [drivers/char/tpm/cr50_spi.ko] undefined! > ERROR: "tpm_tis_spi_read32" [drivers/char/tpm/cr50_spi.ko] undefined! > ERROR: "tpm_tis_spi_read16" [drivers/char/tpm/cr50_spi.ko] undefined! > ERROR: "tpm_tis_spi_init" [drivers/char/tpm/cr50_spi.ko] undefined! > ERROR: "tpm_tis_spi_transfer" [drivers/char/tpm/cr50_spi.ko] undefined! > ERROR: "tpm_tis_spi_resume" [drivers/char/tpm/tpm_tis_spi.ko] undefined! > ERROR: "cr50_spi_probe" [drivers/char/tpm/tpm_tis_spi.ko] undefined! > make[2]: *** [../scripts/Makefile.modpost:103: modules-modpost] Fehler 1 > make[1]: *** [/home/devel/hstuebner/00_git-repos/linux-rockchip/Makefile:1302: modules] Fehler 2 > make[1]: Verzeichnis „/home/devel/hstuebner/00_git-repos/linux-rockchip/_build-arm64“ wird verlassen > make: *** [Makefile:179: sub-make] Fehler 2 > > > After adding a dummy MODULE_LICENSE I end up with: > > ERROR: "tpm_tis_spi_write32" [drivers/char/tpm/cr50_spi.ko] undefined! > ERROR: "tpm_tis_spi_read32" [drivers/char/tpm/cr50_spi.ko] undefined! > ERROR: "tpm_tis_spi_read16" [drivers/char/tpm/cr50_spi.ko] undefined! > ERROR: "tpm_tis_spi_init" [drivers/char/tpm/cr50_spi.ko] undefined! > ERROR: "tpm_tis_spi_transfer" [drivers/char/tpm/cr50_spi.ko] undefined! > ERROR: "tpm_tis_spi_resume" [drivers/char/tpm/tpm_tis_spi.ko] undefined! > ERROR: "cr50_spi_probe" [drivers/char/tpm/tpm_tis_spi.ko] undefined! > > > So building things as modules this way clearly is not working. Going back > to the previous approach makes the module happy again, aka: > > diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile > index 6ff135d6f008..477fcddbff8c 100644 > --- a/drivers/char/tpm/Makefile > +++ b/drivers/char/tpm/Makefile > @@ -21,7 +21,9 @@ tpm-$(CONFIG_EFI) += eventlog/efi.o > tpm-$(CONFIG_OF) += eventlog/of.o > obj-$(CONFIG_TCG_TIS_CORE) += tpm_tis_core.o > obj-$(CONFIG_TCG_TIS) += tpm_tis.o > -obj-$(CONFIG_TCG_TIS_SPI) += tpm_tis_spi.o cr50_spi.o > +obj-$(CONFIG_TCG_TIS_SPI) += tpm_tis_spi_mod.o > +tpm_tis_spi_mod-y := tpm_tis_spi.o > +tpm_tis_spi_mod-y += cr50_spi.o > obj-$(CONFIG_TCG_TIS_I2C_ATMEL) += tpm_i2c_atmel.o > obj-$(CONFIG_TCG_TIS_I2C_INFINEON) += tpm_i2c_infineon.o > obj-$(CONFIG_TCG_TIS_I2C_NUVOTON) += tpm_i2c_nuvoton.o > I wasn't happy that I had to make a tpm_tis_spi_mod target to get the .ko to build properly but I thought it was because of the extra Kconfig option. If two files can't be combined into one .ko and have it be named tpm_tis_spi.ko then we have to do the above workaround. Or we can #include the cr50_spi.c file into tpm_tis_spi.c file. Or we can rename tpm_tis_spi.c to tpm_tis_spi_base.c and then do the above change with a tpm_tis_spi-y. Maybe Masahiro has some hints.
