[PATCH v3 2/3] mach-snapdragon: of_fixup: Add OP-TEE DT fixup support

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

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 OP-TEE support is detected via
checking for OP-TEE message UID.

Signed-off-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
---
 arch/arm/mach-snapdragon/of_fixup.c | 35 +++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/arch/arm/mach-snapdragon/of_fixup.c b/arch/arm/mach-snapdragon/of_fixup.c
index 5b6076ea8e5..644afc22d88 100644
--- a/arch/arm/mach-snapdragon/of_fixup.c
+++ b/arch/arm/mach-snapdragon/of_fixup.c
@@ -25,6 +25,7 @@
 #include <fdt_support.h>
 #include <linux/errno.h>
 #include <stdlib.h>
+#include <tee/optee.h>
 #include <time.h>
 
 /* U-Boot only supports USB high-speed mode on Qualcomm platforms with DWC3
@@ -164,6 +165,37 @@ 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 'optee' subnode: %d\n", ret);
+		return;
+	}
+
+	ret = of_write_prop(optee, "compatible", strlen("linaro,optee-tz") + 1,
+			    "linaro,optee-tz");
+	if (ret) {
+		log_err("Failed to add optee 'compatible' property: %d\n", ret);
+		return;
+	}
+
+	ret = of_write_prop(optee, "method", strlen("smc") + 1, "smc");
+	if (ret) {
+		log_err("Failed to add optee 'method' property: %d\n", ret);
+		return;
+	}
+}
+
 #define time_call(func, ...) \
 	do { \
 		u64 start = timer_get_us(); \
@@ -178,6 +210,9 @@ 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) && is_optee_smc_api())
+		time_call(add_optee_node, root);
+
 	return 0;
 }
 
-- 
2.51.0