On Wed, May 30, 2018 at 11:44:39PM +0300, Jarkko Sakkinen wrote: > From: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx> > > commit b5d0ebc99bf5d0801a5ecbe958caa3d68b8eaee8 upstream > > The suspend/resume behavior of the TPM can be controlled by setting > "powered-while-suspended" in the DTS. This is useful for the cases > when hardware does not power-off the TPM. > > Signed-off-by: Sonny Rao <sonnyrao@xxxxxxxxxxxx> > Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx> > Reviewed-by: Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx> > Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx> > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx> > Signed-off-by: James Morris <james.l.morris@xxxxxxxxxx> > --- > drivers/char/tpm/tpm-chip.c | 12 ++++++++++++ > drivers/char/tpm/tpm-interface.c | 3 +++ > drivers/char/tpm/tpm.h | 1 + > 3 files changed, 16 insertions(+) > > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c > index a0d9ac6b6cc9..a8d7220f613c 100644 > --- a/drivers/char/tpm/tpm-chip.c > +++ b/drivers/char/tpm/tpm-chip.c > @@ -324,8 +324,20 @@ static void tpm1_chip_unregister(struct tpm_chip *chip) > */ > int tpm_chip_register(struct tpm_chip *chip) > { > +#ifdef CONFIG_TCG_IBMVTPM > + struct device_node *np; > +#endif > int rc; > > +#ifdef CONFIG_TCG_IBMVTPM > + np = of_find_node_by_name(NULL, "vtpm"); > + if (!np) > + return -ENODEV; > + if (of_property_read_bool(np, "powered-while-suspended")) > + chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED; > + of_node_put(np); > +#endif I'll have to revise this as more config flag should be CONFIG_OF and property should be conditionally read if the node is found. Then it can be relocated without interference. /Jarkko