When OP-TEE driver is built as a module, OP-TEE client devices
registered on TEE bus during probe should be unregistered during
optee_remove. So implement optee_unregister_devices() accordingly.

Fixes: c3fa24af9244 ("tee: optee: add TEE bus device enumeration support")
Reported-by: Sudeep Holla <redacted>
Signed-off-by: Sumit Garg <redacted>
---
 drivers/tee/optee/core.c          |  3 +++
 drivers/tee/optee/device.c        | 22 ++++++++++++++++++++++
 drivers/tee/optee/optee_private.h |  1 +
 3 files changed, 26 insertions(+)

diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
index ccad3c7c8f6d..3915dc574503 100644
--- a/drivers/tee/optee/core.c
+++ b/drivers/tee/optee/core.c

@@ -586,6 +586,9 @@ static int optee_remove(struct platform_device *pdev)
 {
        struct optee *optee = platform_get_drvdata(pdev);

+       /* Unregister OP-TEE specific client devices on TEE bus */
+       optee_unregister_devices();
+
        /*
         * Ask OP-TEE to free all cached shared memory objects to decrease
         * reference counters and also avoid wild pointers in secure world

diff --git a/drivers/tee/optee/device.c b/drivers/tee/optee/device.c
index ec1d24693eba..128a2d2a50a1 100644
--- a/drivers/tee/optee/device.c
+++ b/drivers/tee/optee/device.c

@@ -53,6 +53,13 @@ static int get_devices(struct tee_context *ctx, u32 session,
        return 0;
 }

+static void optee_release_device(struct device *dev)
+{
+       struct tee_client_device *optee_device = to_tee_client_device(dev);
+
+       kfree(optee_device);
+}
+
 static int optee_register_device(const uuid_t *device_uuid)
 {
        struct tee_client_device *optee_device = NULL;

@@ -63,6 +70,7 @@ static int optee_register_device(const uuid_t *device_uuid)
                return -ENOMEM;

        optee_device->dev.bus = &tee_bus_type;
+       optee_device->dev.release = optee_release_device;
        if (dev_set_name(&optee_device->dev, "optee-ta-%pUb", device_uuid)) {
                kfree(optee_device);
                return -ENOMEM;

@@ -154,3 +162,17 @@ int optee_enumerate_devices(u32 func)
 {
        return  __optee_enumerate_devices(func);
 }
+
+static int __optee_unregister_device(struct device *dev, void *data)
+{
+       if (!strncmp(dev_name(dev), "optee-ta", strlen("optee-ta")))
+               device_unregister(dev);
+
+       return 0;
+}
+
+void optee_unregister_devices(void)
+{
+       bus_for_each_dev(&tee_bus_type, NULL, NULL,
+                        __optee_unregister_device);