platform/chrome: cros_ec: Separate initialization from cros_ec_register()

Move the initialization of the `struct cros_ec_device` from
cros_ec_register() into cros_ec_device_alloc().

This decouples device initialization from registration.  By doing so,
the per-device lock is now available immediately after allocation,
allowing it to be used safely even before the device is fully
registered.

Link: https://lore.kernel.org/r/20250828083601.856083-4-tzungbi@kernel.org
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c
index da049068b6e9e1c54b571c9ffe032a1821ca5287..61bcef8741db59c3b5dfdcae22342351751b369a 100644 (file)
--- a/drivers/platform/chrome/cros_ec.c
+++ b/drivers/platform/chrome/cros_ec.c
@@ -30,6 +30,14 @@ static struct cros_ec_platform pd_p = {
        .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX),
 };
 
+static void cros_ec_device_free(void *data)
+{
+       struct cros_ec_device *ec_dev = data;
+
+       mutex_destroy(&ec_dev->lock);
+       lockdep_unregister_key(&ec_dev->lockdep_key);
+}
+
 struct cros_ec_device *cros_ec_device_alloc(struct device *dev)
 {
        struct cros_ec_device *ec_dev;
@@ -45,7 +53,28 @@ struct cros_ec_device *cros_ec_device_alloc(struct device *dev)
                            sizeof(struct ec_params_rwsig_action) +
                            EC_MAX_REQUEST_OVERHEAD;
 
+       ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
+       if (!ec_dev->din)
+               return NULL;
+
+       ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
+       if (!ec_dev->dout)
+               return NULL;
+
        ec_dev->dev = dev;
+       ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
+       ec_dev->max_request = sizeof(struct ec_params_rwsig_action);
+       ec_dev->suspend_timeout_ms = EC_HOST_SLEEP_TIMEOUT_DEFAULT;
+
+       BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);
+       BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->panic_notifier);
+
+       lockdep_register_key(&ec_dev->lockdep_key);
+       mutex_init(&ec_dev->lock);
+       lockdep_set_class(&ec_dev->lock, &ec_dev->lockdep_key);
+
+       if (devm_add_action_or_reset(dev, cros_ec_device_free, ec_dev))
+               return NULL;
 
        return ec_dev;
 }
@@ -200,29 +229,7 @@ static int cros_ec_ready_event(struct notifier_block *nb,
 int cros_ec_register(struct cros_ec_device *ec_dev)
 {
        struct device *dev = ec_dev->dev;
-       int err = 0;
-
-       BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);
-       BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->panic_notifier);
-
-       ec_dev->max_request = sizeof(struct ec_params_hello);
-       ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
-       ec_dev->max_passthru = 0;
-       ec_dev->ec = NULL;
-       ec_dev->pd = NULL;
-       ec_dev->suspend_timeout_ms = EC_HOST_SLEEP_TIMEOUT_DEFAULT;
-
-       ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
-       if (!ec_dev->din)
-               return -ENOMEM;
-
-       ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
-       if (!ec_dev->dout)
-               return -ENOMEM;
-
-       lockdep_register_key(&ec_dev->lockdep_key);
-       mutex_init(&ec_dev->lock);
-       lockdep_set_class(&ec_dev->lock, &ec_dev->lockdep_key);
+       int err;
 
        /* Send RWSIG continue to jump to RW for devices using RWSIG. */
        err = cros_ec_rwsig_continue(ec_dev);
@@ -322,8 +329,6 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
 exit:
        platform_device_unregister(ec_dev->ec);
        platform_device_unregister(ec_dev->pd);
-       mutex_destroy(&ec_dev->lock);
-       lockdep_unregister_key(&ec_dev->lockdep_key);
        return err;
 }
 EXPORT_SYMBOL(cros_ec_register);
@@ -343,8 +348,6 @@ void cros_ec_unregister(struct cros_ec_device *ec_dev)
                                                   &ec_dev->notifier_ready);
        platform_device_unregister(ec_dev->pd);
        platform_device_unregister(ec_dev->ec);
-       mutex_destroy(&ec_dev->lock);
-       lockdep_unregister_key(&ec_dev->lockdep_key);
 }
 EXPORT_SYMBOL(cros_ec_unregister);