nvmem: core: fix cleanup after dev_set_name()

If dev_set_name() fails, we leak nvmem->wp_gpio as the cleanup does not
put this. While a minimal fix for this would be to add the gpiod_put()
call, we can do better if we split device_register(), and use the
tested nvmem_release() cleanup code by initialising the device early,
and putting the device.

This results in a slightly larger fix, but results in clear code.

Note: this patch depends on "nvmem: core: initialise nvmem->id early"
and "nvmem: core: remove nvmem_config wp_gpio".

Fixes: 5544e90 ("nvmem: core: add error handling for dev_set_name")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
[Srini: Fixed subject line and error code handing with wp_gpio while applying.]
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

drivers/nvmem/core.c

@@ -772,14 +772,18 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 
 	nvmem->id = rval;
 
+	nvmem->dev.type = &nvmem_provider_type;
+	nvmem->dev.bus = &nvmem_bus_type;
+	nvmem->dev.parent = config->dev;
+
+	device_initialize(&nvmem->dev);
+
 	if (!config->ignore_wp)
 		nvmem->wp_gpio = gpiod_get_optional(config->dev, "wp",
 						    GPIOD_OUT_HIGH);
 	if (IS_ERR(nvmem->wp_gpio)) {
-		ida_free(&nvmem_ida, nvmem->id);
 		rval = PTR_ERR(nvmem->wp_gpio);
-		kfree(nvmem);
-		return ERR_PTR(rval);
+		goto err_put_device;
 	}
 
 	kref_init(&nvmem->refcnt);
@@ -791,9 +795,6 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 	nvmem->stride = config->stride ?: 1;
 	nvmem->word_size = config->word_size ?: 1;
 	nvmem->size = config->size;
-	nvmem->dev.type = &nvmem_provider_type;
-	nvmem->dev.bus = &nvmem_bus_type;
-	nvmem->dev.parent = config->dev;
 	nvmem->root_only = config->root_only;
 	nvmem->priv = config->priv;
 	nvmem->type = config->type;
@@ -821,11 +822,8 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 		break;
 	}
 
-	if (rval) {
-		ida_free(&nvmem_ida, nvmem->id);
-		kfree(nvmem);
-		return ERR_PTR(rval);
-	}
+	if (rval)
+		goto err_put_device;
 
 	nvmem->read_only = device_property_present(config->dev, "read-only") ||
 			   config->read_only || !nvmem->reg_write;
@@ -836,7 +834,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 
 	dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name);
 
-	rval = device_register(&nvmem->dev);
+	rval = device_add(&nvmem->dev);
 	if (rval)
 		goto err_put_device;