Re: [PATCH 1/2] mach-snapdragon: of_fixup: Add OP-TEE DT fixup support

[Sumit Garg <sumit.garg@kernel.org>]

On Thu, Jan 08, 2026 at 05:19:32PM +0100, neil.armstrong@linaro.org wrote:
> On 12/29/25 12:43, Sumit Garg wrote:
> > From: Sumit Garg <sumit.garg@oss.qualcomm.com>
> > 
> > Add support for OP-TEE live tree DT fixup support which enables U-Boot
> > OP-TEE driver to be probed. As well as the EFI DT fixup protocol allows
> > the live tree fixup to be carried over to the OS for the OP-TEE driver
> > in the OS to probe as well.
> > 
> > Note that this fixup only gets applied if CONFIG_OPTEE gets enabled.
> 
> Can't the presence of OP-TEE be detected dynamically via scm calls ?

SCM calls aren't present in case of TF-A/OP-TEE flow.

-Sumit

> 
> Thanks,
> Neil
> 
> > 
> > Signed-off-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
> > ---
> >   arch/arm/mach-snapdragon/of_fixup.c | 34 +++++++++++++++++++++++++++++
> >   1 file changed, 34 insertions(+)
> > 
> > diff --git a/arch/arm/mach-snapdragon/of_fixup.c b/arch/arm/mach-snapdragon/of_fixup.c
> > index eec2c0c757e..29a99f73cf3 100644
> > --- a/arch/arm/mach-snapdragon/of_fixup.c
> > +++ b/arch/arm/mach-snapdragon/of_fixup.c
> > @@ -146,6 +146,37 @@ static void fixup_power_domains(struct device_node *root)
> >   	}
> >   }
> > +static void add_optee_node(struct device_node *root)
> > +{
> > +	struct device_node *fw = NULL, *optee = NULL;
> > +	int ret;
> > +
> > +	fw = of_find_node_by_path("/firmware");
> > +	if (!fw) {
> > +		log_err("Failed to find /firmware node\n");
> > +		return;
> > +	}
> > +
> > +	ret = of_add_subnode(fw, "optee", strlen("optee") + 1, &optee);
> > +	if (ret) {
> > +		log_err("Failed to add 'maximum-speed' property: %d\n", ret);
> > +		return;
> > +	}
> > +
> > +	ret = of_write_prop(optee, "compatible", strlen("linaro,optee-tz") + 1,
> > +			    "linaro,optee-tz");
> > +	if (ret) {
> > +		log_err("Failed to optee 'compatible' property: %d\n", ret);
> > +		return;
> > +	}
> > +
> > +	ret = of_write_prop(optee, "method", strlen("smc") + 1, "smc");
> > +	if (ret) {
> > +		log_err("Failed to optee 'method' property: %d\n", ret);
> > +		return;
> > +	}
> > +}
> > +
> >   #define time_call(func, ...) \
> >   	do { \
> >   		u64 start = timer_get_us(); \
> > @@ -160,6 +191,9 @@ static int qcom_of_fixup_nodes(void * __maybe_unused ctx, struct event *event)
> >   	time_call(fixup_usb_nodes, root);
> >   	time_call(fixup_power_domains, root);
> > +	if (IS_ENABLED(CONFIG_OPTEE))
> > +		time_call(add_optee_node, root);
> > +
> >   	return 0;
> >   }
>