Re: [PATCH v6 4/4] tpm: tpm_tis_spi: Support cr50 devices

[Heiko Stübner]

Hi Jarkko,

Am Samstag, 7. September 2019, 19:04:15 CEST schrieb Jarkko Sakkinen:
> On Tue, 2019-09-03 at 09:52 -0700, Stephen Boyd wrote:
> > 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?
> 
> Not sure I understood the question correctly but how I think
> this should be deployed is:
> 
> - A boolean CONFIG_TCG_TIS_SPI_CR50.
> - tpm_tis_spi_cr50.c that gets compiled in as part of tpm_tis_spi
>   when the config option is selected.
> 
> I think this would best follow the conventions that are in place
> already. Please tell if I got something wrong or if there is some
> bottleneck in this framework but this is anyway what I would prefer
> with the knowledge I have...

There is an implementation detail to iron out:

Doing

	obj-$(CONFIG_TCG_TIS_SPI) += tpm_tis_spi.o cr50_spi.o

as in this patch results in it failing to build as a module, due to them
getting compiled to separate modules, yt sharing code. So I guess doing

	obj-$(CONFIG_TCG_TIS_SPI) += tpm_tis_spi.o
	obj-$(CONFIG_TCG_TIS_SPI_CR50) += cr50_spi.o

will result in the same error, hence the question of doing something like

	obj-$(CONFIG_TCG_TIS_SPI) += tpm_tis_spi_mod.o
	tpm_tis_spi_mod-y := tpm_tis_spi.o
	tpm_tis_spi_mod-$(CONFIG_TCG_TIS_SPI_CR50) += cr50_spi.o

so that sources get compiled and the module getting build from the result.


Heiko