optee: add bidirectional communication support

So far, barebox support for OP-TEE was restricted to loading it either
early in PBL or via bootm and to not step over it when allocating
memory. This was guarded behind CONFIG_HAVE_OPTEE.

This commit imports from Linux the driver behind CONFIG_OPTEE, which
brings actual bidirectional communication with OP-TEE in barebox.
This is useful as trusted applications running in OP-TEE can provide
various services to the normal world, like filtered OTP access, RNG
seeded from normally inaccessible entropy sources, firmware TPM and
management of resources like clocks, resets, power domains and voltage
regulators in the form of SCMI.

We already have SCMI support, but only via the SMC calling convention
for communication with TF-A. For integration with publicly available
STM32MP13 firmware, we need to do SCMI over OP-TEE and this is likewise
interesting for STM32MP1 trusted boot setups.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.barebox.org/20231127063559.2205776-7-a.fatoum@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/Makefile b/drivers/Makefile
index 3f60e1b9c7..42a71f73c2 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -47,5 +47,5 @@ obj-y	+= ddr/
 obj-y	+= power/
 obj-$(CONFIG_SOUND) += sound/
 obj-y	+= virtio/
-obj-$(CONFIG_HAVE_OPTEE)	+= tee/optee/of.o
 obj-y	+= mailbox/
+obj-y	+= tee/