[PATCH v3 9/9] HID: haptic: Remove stubs in favor of inlined dead code elimination

[Rong Zhang <i@rong.moe>]

All stubs in hid-haptic.h can be replaced by equivalent
!hid_plugin_enabled(HID_PLUGIN_HAPTIC) checks. The compiler will
eliminate calls to all methods when the plugin is disabled.

Signed-off-by: Rong Zhang <i@rong.moe>
---
Changes in v3:
- Fix the return value of hid_haptic_connected_to_input() when
  hid-haptic is disabled (thanks Sashiko)
---
 drivers/hid/hid-haptic.h | 83 +++++++++++++++++++-----------------------------
 1 file changed, 32 insertions(+), 51 deletions(-)

diff --git a/drivers/hid/hid-haptic.h b/drivers/hid/hid-haptic.h
index a71ccee569f3..8b18b06afa10 100644
--- a/drivers/hid/hid-haptic.h
+++ b/drivers/hid/hid-haptic.h
@@ -65,11 +65,18 @@ struct hid_plugin_haptic {
 		    struct input_dev *dev);
 };
 
-#if IS_ENABLED(CONFIG_HID_HAPTIC)
+static inline bool hid_haptic_enabled(void)
+{
+	return hid_plugin_enabled(HID_PLUGIN_HAPTIC);
+}
+
 static inline struct hid_haptic_device *hid_haptic_alloc(struct hid_device *hdev)
 {
 	struct hid_haptic_device *haptic;
 
+	if (!hid_haptic_enabled())
+		return ERR_PTR(-EOPNOTSUPP);
+
 	haptic = kzalloc_obj(struct hid_haptic_device);
 	if (haptic)
 		haptic->hdev = hdev;
@@ -80,6 +87,9 @@ static inline struct hid_haptic_device *hid_haptic_alloc(struct hid_device *hdev
 static inline bool hid_haptic_connected_to_input(struct hid_haptic_device *haptic,
 						 struct input_dev *input)
 {
+	if (!hid_haptic_enabled())
+		return false;
+
 	return haptic->input_dev == input;
 }
 
@@ -89,6 +99,9 @@ static inline void hid_haptic_feature_mapping(struct hid_device *hdev,
 {
 	u16 usage_hid;
 
+	if (!hid_haptic_enabled())
+		return;
+
 	if (usage->hid == HID_HP_AUTOTRIGGER) {
 		if (usage->usage_index >= field->report_count) {
 			dev_err(&hdev->dev, "HID_HP_AUTOTRIGGER out of range\n");
@@ -116,6 +129,9 @@ static inline void hid_haptic_feature_mapping(struct hid_device *hdev,
 static inline void hid_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
 						  struct hid_input *hi, struct hid_field *field)
 {
+	if (!hid_haptic_enabled())
+		return;
+
 	if (hi->application != HID_DG_TOUCHPAD)
 		return;
 
@@ -155,6 +171,9 @@ static inline int hid_haptic_input_mapping(struct hid_device *hdev,
 					   struct hid_field *field, struct hid_usage *usage,
 					   unsigned long **bit, int *max)
 {
+	if (!hid_haptic_enabled())
+		return 0;
+
 	if (usage->hid == HID_HP_MANUALTRIGGER) {
 		haptic->manual_trigger_report = field->report;
 		/* we don't really want to map these fields */
@@ -169,6 +188,9 @@ static inline int hid_haptic_init(struct hid_device *hdev, struct hid_haptic_dev
 	struct hid_plugin_haptic *self_plugin;
 	struct hid_plugin *plugin;
 
+	if (!hid_haptic_enabled())
+		return 0;
+
 	plugin = hid_plugin_get(HID_PLUGIN_HAPTIC);
 	if (IS_ERR(plugin))
 		return PTR_ERR(plugin);
@@ -184,6 +206,9 @@ static inline bool hid_haptic_input_configured(struct hid_device *hdev,
 					       struct hid_haptic_device *haptic,
 					       struct hid_input *hi)
 {
+	if (!hid_haptic_enabled())
+		return false;
+
 	if (IS_ERR_OR_NULL(haptic->input_dev) || haptic->input_dev != hi->input ||
 	    !haptic->auto_trigger_report || !haptic->manual_trigger_report)
 		return false;
@@ -195,61 +220,17 @@ static inline bool hid_haptic_input_configured(struct hid_device *hdev,
 
 static inline void hid_haptic_pressure_reset(struct hid_haptic_device *haptic)
 {
+	if (!hid_haptic_enabled())
+		return;
+
 	haptic->pressure_sum = 0;
 }
 
 static inline void hid_haptic_pressure_increase(struct hid_haptic_device *haptic,
 						__s32 pressure)
 {
-	haptic->pressure_sum += pressure;
-}
-#else
-static inline struct hid_haptic_device *hid_haptic_alloc(struct hid_device *hdev)
-{
-	return ERR_PTR(-EOPNOTSUPP);
-}
-
-static inline bool hid_haptic_connected_to_input(struct hid_haptic_device *haptic,
-						 struct input_dev *input)
-{
-	return false;
-}
+	if (!hid_haptic_enabled())
+		return;
 
-static inline
-void hid_haptic_feature_mapping(struct hid_device *hdev,
-				struct hid_haptic_device *haptic,
-				struct hid_field *field, struct hid_usage
-				*usage)
-{}
-static inline
-void hid_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
-				    struct hid_input *hi, struct hid_field *field)
-{}
-static inline
-int hid_haptic_input_mapping(struct hid_device *hdev,
-			     struct hid_haptic_device *haptic,
-			     struct hid_input *hi,
-			     struct hid_field *field, struct hid_usage *usage,
-			     unsigned long **bit, int *max)
-{
-	return 0;
-}
-static inline
-bool hid_haptic_input_configured(struct hid_device *hdev,
-				 struct hid_haptic_device *haptic, struct hid_input *hi)
-{
-	return false;
-}
-static inline
-int hid_haptic_init(struct hid_device *hdev, struct hid_haptic_device *haptic,
-		    struct input_dev *dev)
-{
-	return 0;
+	haptic->pressure_sum += pressure;
 }
-static inline
-void hid_haptic_pressure_reset(struct hid_haptic_device *haptic) {}
-static inline
-void hid_haptic_pressure_increase(struct hid_haptic_device *haptic,
-				  __s32 pressure)
-{}
-#endif

-- 
2.55.0