firmware: turris-mox-rwtm: Simplify debugfs code

Simplify debugfs code: do not check for errors, as debugfs errors should
be ignored, and use devm action for dropping the debugfs directory.

Signed-off-by: Marek Behún <kabel@kernel.org>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Link: https://lore.kernel.org/r/20240831092050.23093-9-kabel@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/drivers/firmware/turris-mox-rwtm.c b/drivers/firmware/turris-mox-rwtm.c
index 97b40982a3e7ba9f1000848a183a6280d95a4516..0462c345778cc7f4290a6c551a578335ad6402a0 100644 (file)
--- a/drivers/firmware/turris-mox-rwtm.c
+++ b/drivers/firmware/turris-mox-rwtm.c
@@ -91,7 +91,6 @@ struct mox_rwtm {
         * It should be rewritten via crypto API once akcipher API is available
         * from userspace.
         */
-       struct dentry *debugfs_root;
        u32 last_sig[MOX_ECC_SIGNATURE_WORDS];
        bool last_sig_done;
 #endif
@@ -404,39 +403,23 @@ static const struct file_operations do_sign_fops = {
        .llseek = no_llseek,
 };
 
-static int rwtm_register_debugfs(struct mox_rwtm *rwtm)
+static void rwtm_debugfs_release(void *root)
 {
-       struct dentry *root, *entry;
-
-       root = debugfs_create_dir("turris-mox-rwtm", NULL);
-
-       if (IS_ERR(root))
-               return PTR_ERR(root);
-
-       entry = debugfs_create_file_unsafe("do_sign", 0600, root, rwtm,
-                                          &do_sign_fops);
-       if (IS_ERR(entry))
-               goto err_remove;
-
-       rwtm->debugfs_root = root;
-
-       return 0;
-err_remove:
        debugfs_remove_recursive(root);
-       return PTR_ERR(entry);
 }
 
-static void rwtm_unregister_debugfs(struct mox_rwtm *rwtm)
+static void rwtm_register_debugfs(struct mox_rwtm *rwtm)
 {
-       debugfs_remove_recursive(rwtm->debugfs_root);
+       struct dentry *root;
+
+       root = debugfs_create_dir("turris-mox-rwtm", NULL);
+
+       debugfs_create_file_unsafe("do_sign", 0600, root, rwtm, &do_sign_fops);
+
+       devm_add_action_or_reset(rwtm->dev, rwtm_debugfs_release, root);
 }
 #else
-static inline int rwtm_register_debugfs(struct mox_rwtm *rwtm)
-{
-       return 0;
-}
-
-static inline void rwtm_unregister_debugfs(struct mox_rwtm *rwtm)
+static inline void rwtm_register_debugfs(struct mox_rwtm *rwtm)
 {
 }
 #endif
@@ -500,11 +483,7 @@ static int turris_mox_rwtm_probe(struct platform_device *pdev)
                goto free_channel;
        }
 
-       ret = rwtm_register_debugfs(rwtm);
-       if (ret < 0) {
-               dev_err(dev, "Failed creating debugfs entries: %i\n", ret);
-               goto free_channel;
-       }
+       rwtm_register_debugfs(rwtm);
 
        dev_info(dev, "HWRNG successfully registered\n");
 
@@ -528,7 +507,6 @@ static void turris_mox_rwtm_remove(struct platform_device *pdev)
 {
        struct mox_rwtm *rwtm = platform_get_drvdata(pdev);
 
-       rwtm_unregister_debugfs(rwtm);
        mbox_free_channel(rwtm->mbox);
 }