[PATCH] tee: optee: rework TA bus scanning code

Ilias Apalodimas
2022-08-23T08:11:52Z

Late versions of OP-TEE support a pseudo bus. TAs that behave as
hardware blocks (e.g TPM, RNG etc) present themselves on a bus which we can
scan. Unfortunately U-Boot doesn't support that yet. It's worth noting
that we already have a workaround for RNG. The details are in
commit 70812bb83da6 ("tee: optee: bind rng optee driver")

So let's add a list of devices based on U-Boot Kconfig options that we will
scan until we properly implement the tee-bus functionality.

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
---
drivers/tee/optee/core.c | 22 +++++++++++++++++++---
1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
index a89d62aaf0b3..48a9b59171cb 100644
--- a/drivers/tee/optee/core.c
+++ b/drivers/tee/optee/core.c
@@ -31,6 +31,20 @@ struct optee_pdata {
optee_invoke_fn *invoke_fn;
};

+static const struct {
+ const char *drv_name;
+ const char *dev_name;
+} optee_bus_probe[] = {
+#ifdef CONFIG_RNG_OPTEE
+ { "optee-rng", "optee-rng" },
+#endif
+#ifdef CONFIG_TPM2_FTPM_TEE
+ { "ftpm-tee", "ftpm-tee" },
+#endif
+};
+
+#define MAX_TEE_BUS_DEV_COUNT ARRAY_SIZE(optee_bus_probe)
+
struct rpc_param {
u32 a0;
u32 a1;
@@ -643,7 +657,7 @@ static int optee_probe(struct udevice *dev)
struct optee_pdata *pdata = dev_get_plat(dev);
u32 sec_caps;
struct udevice *child;
- int ret;
+ int ret, i;

if (!is_optee_api(pdata->invoke_fn)) {
dev_err(dev, "OP-TEE api uid mismatch\n");
@@ -672,8 +686,10 @@ static int optee_probe(struct udevice *dev)
* in U-Boot, the discovery of TA on the TEE bus is not supported:
* only bind the drivers associated to the supported OP-TEE TA
*/
- if (IS_ENABLED(CONFIG_RNG_OPTEE)) {
- ret = device_bind_driver(dev, "optee-rng", "optee-rng", &child);
+
+ for (i = 0; i < MAX_TEE_BUS_DEV_COUNT; i++) {
+ ret = device_bind_driver(dev, optee_bus_probe[i].drv_name,
+ optee_bus_probe[i].dev_name, &child);
if (ret)
return ret;
}
--
2.34.1