[PATCH v2 8/9] HID: haptic: Convert into a loadable plugin module

@@ -11909,6 +11909,7 @@ HID PLUGINS
 M:	Rong Zhang <i@rong.moe>
 L:	linux-input@vger.kernel.org
 S:	Maintained
+F:	drivers/hid/hid-haptic.*
 F:	drivers/hid/hid-plugin.*
 
 HID PULSAR DRIVER

@@ -106,9 +106,10 @@ menuconfig HID_PLUGIN
 
 	If unsure, say N.
 
+if HID_PLUGIN
+
 config HID_HAPTIC
-	bool "Haptic touchpad support"
-	default n
+	tristate "Haptic touchpad support"
 	help
 	Support for touchpads with force sensors and haptic actuators instead of a
 	traditional button.

@@ -117,6 +118,8 @@ config HID_HAPTIC
 
 	If unsure, say N.
 
+endif # HID_PLUGIN
+
 menu "Special HID drivers"
 
 config HID_A4TECH

@@ -6,7 +6,7 @@ hid-y			:= hid-core.o hid-input.o hid-quirks.o
 hid-$(CONFIG_DEBUG_FS)		+= hid-debug.o
 hid-$(CONFIG_HID_PLUGIN)	+= hid-plugin.o
 
-hid-$(CONFIG_HID_HAPTIC)	+= hid-haptic.o
+obj-$(CONFIG_HID_HAPTIC)	+= hid-haptic.o
 
 obj-$(CONFIG_HID_BPF)		+= bpf/
 

@@ -315,12 +315,11 @@ static void hid_haptic_destroy(struct ff_device *ff)
 	if (hdev)
 		put_device(&hdev->dev);
 
-	module_put(THIS_MODULE);
+	hid_plugin_put(HID_PLUGIN_HAPTIC, &haptic->self_plugin->hp);
 }
 
-int hid_haptic_init(struct hid_device *hdev,
-		    struct hid_haptic_device *haptic,
-		    struct input_dev *dev)
+static int __hid_haptic_init(struct hid_device *hdev, struct hid_haptic_device *haptic,
+			     struct input_dev *dev)
 {
 	struct ff_device *ff;
 	int ret = 0, r;

@@ -328,10 +327,6 @@ int hid_haptic_init(struct hid_device *hdev,
 		.hid_usage = HID_HP_WAVEFORMSTOP & HID_USAGE,
 	};
 
-	if (!try_module_get(THIS_MODULE)) {
-		dev_err(&hdev->dev, "Failed to increase module count.\n");
-		return -ENXIO;
-	}
 	if (!get_device(&hdev->dev)) {
 		dev_err(&hdev->dev, "Failed to get hdev device.\n");
 		ret = -ENXIO;

@@ -454,7 +449,20 @@ int hid_haptic_init(struct hid_device *hdev,
 	put_device(&hdev->dev);
 exit:
 	dev_warn(&hdev->dev, "Cannot allocate haptic for %s: %d\n", hdev->name, ret);
-	module_put(THIS_MODULE);
+	hid_plugin_put(HID_PLUGIN_HAPTIC, &haptic->self_plugin->hp);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(hid_haptic_init);
+
+static struct hid_plugin_haptic hid_plugin_haptic = {
+	.hp = {
+		.owner = THIS_MODULE,
+	},
+	.init = __hid_haptic_init,
+};
+module_hid_plugin(haptic, HID_PLUGIN_HAPTIC, &hid_plugin_haptic.hp);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Angela Czubak <aczubak@google.com>");
+MODULE_AUTHOR("Jonathan Denose <jdenose@google.com>");
+MODULE_AUTHOR("Rong Zhang <i@rong.moe>");
+MODULE_DESCRIPTION("HID helpers for Haptics Page");

@@ -5,9 +5,12 @@
  *  Copyright (c) 2021 Angela Czubak <acz@semihalf.com>
  */
 
+#include <linux/container_of.h>
 #include <linux/err.h>
 #include <linux/hid.h>
 
+#include "hid-plugin.h"
+
 #define HID_HAPTIC_ORDINAL_WAVEFORMNONE 1
 #define HID_HAPTIC_ORDINAL_WAVEFORMSTOP 2
 

@@ -52,6 +55,14 @@ struct hid_haptic_device {
 	u16 release_ordinal;
 	struct hid_haptic_effect *effect;
 	struct hid_haptic_effect stop_effect;
+
+	struct hid_plugin_haptic *self_plugin;
+};
+
+struct hid_plugin_haptic {
+	struct hid_plugin hp;
+	int (*init)(struct hid_device *hdev, struct hid_haptic_device *haptic,
+		    struct input_dev *dev);
 };
 
 #if IS_ENABLED(CONFIG_HID_HAPTIC)

@@ -152,8 +163,22 @@ static inline int hid_haptic_input_mapping(struct hid_device *hdev,
 	return 0;
 }
 
-int hid_haptic_init(struct hid_device *hdev, struct hid_haptic_device *haptic,
-		    struct input_dev *dev);
+static inline int hid_haptic_init(struct hid_device *hdev, struct hid_haptic_device *haptic,
+				  struct input_dev *dev)
+{
+	struct hid_plugin_haptic *self_plugin;
+	struct hid_plugin *plugin;
+
+	plugin = hid_plugin_get(HID_PLUGIN_HAPTIC);
+	if (IS_ERR(plugin))
+		return PTR_ERR(plugin);
+
+	self_plugin = container_of(plugin, struct hid_plugin_haptic, hp);
+
+	haptic->self_plugin = self_plugin;
+
+	return self_plugin->init(hdev, haptic, dev);
+}
 
 static inline bool hid_haptic_input_configured(struct hid_device *hdev,
 					       struct hid_haptic_device *haptic,

@@ -18,6 +18,9 @@
 #include "hid-plugin.h"
 
 static const char * const hid_plugin_mod_names[NR_HID_PLUGINS] = {
+#if IS_MODULE(CONFIG_HID_HAPTIC)
+	[HID_PLUGIN_HAPTIC] = "hid-haptic",
+#endif
 };
 
 static struct hid_plugin __rcu *hid_plugins[NR_HID_PLUGINS];

@@ -19,6 +19,12 @@
 enum hid_plugin_id {
 	HID_PLUGIN_DISABLED	= -1,
 
+#if IS_ENABLED(CONFIG_HID_HAPTIC)
+	HID_PLUGIN_HAPTIC,
+#else
+#define HID_PLUGIN_HAPTIC	HID_PLUGIN_DISABLED
+#endif
+
 	NR_HID_PLUGINS,
 };