[PATCH v2 3/9] HID: haptic, multitouch: Check haptic prerequisite properly

@@ -48,17 +48,40 @@ void hid_haptic_feature_mapping(struct hid_device *hdev,
 }
 EXPORT_SYMBOL_GPL(hid_haptic_feature_mapping);
 
-bool hid_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
+void hid_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
 				    struct hid_input *hi, struct hid_field *field)
 {
-	if (field->unit == HID_UNIT_GRAM || field->unit == HID_UNIT_NEWTON) {
-		haptic->force_logical_minimum = field->logical_minimum;
-		haptic->force_physical_minimum = field->physical_minimum;
-		haptic->force_resolution = input_abs_get_res(hi->input,
-							     ABS_MT_PRESSURE);
-		return true;
+	if (hi->application != HID_DG_TOUCHPAD)
+		return;
+
+	if (IS_ERR(haptic->input_dev))
+		return;
+
+	if (field->unit != HID_UNIT_GRAM && field->unit != HID_UNIT_NEWTON)
+		goto reject;
+
+	if (!haptic->input_dev) {
+		haptic->input_dev = hi->input;
+		haptic->pressure_field = field;
+		haptic->force_resolution = input_abs_get_res(hi->input, ABS_MT_PRESSURE);
+		return;
 	}
-	return false;
+
+	if (hid_haptic_connected_to_input(haptic, hi->input) &&
+	    haptic->pressure_field->unit == field->unit &&
+	    haptic->pressure_field->logical_minimum == field->logical_minimum &&
+	    haptic->pressure_field->physical_minimum == field->physical_minimum &&
+	    haptic->force_resolution == input_abs_get_res(hi->input, ABS_MT_PRESSURE))
+		return;
+
+reject:
+	/*
+	 * Reject if:
+	 * - there are multiple input devices with pressure sensors
+	 * - there is any touchpad application with a non-force unit
+	 * - pressure annotations mismatch among HID_DG_TIPPRESSURE usages
+	 */
+	haptic->input_dev = ERR_PTR(-EPROTO);
 }
 EXPORT_SYMBOL_GPL(hid_haptic_check_pressure_unit);
 

@@ -78,28 +101,16 @@ int hid_haptic_input_mapping(struct hid_device *hdev,
 }
 EXPORT_SYMBOL_GPL(hid_haptic_input_mapping);
 
-int hid_haptic_input_configured(struct hid_device *hdev,
-				struct hid_haptic_device *haptic,
-				struct hid_input *hi)
+bool hid_haptic_input_configured(struct hid_device *hdev,
+				 struct hid_haptic_device *haptic, struct hid_input *hi)
 {
-	int error;
-
-	if (hi->application != HID_DG_TOUCHPAD)
-		return -1;
-
-	if (!haptic->auto_trigger_report || !haptic->manual_trigger_report)
-		return 0;
+	if (IS_ERR_OR_NULL(haptic->input_dev) || haptic->input_dev != hi->input ||
+	    !haptic->auto_trigger_report || !haptic->manual_trigger_report)
+		return false;
 
 	__set_bit(INPUT_PROP_PRESSUREPAD, hi->input->propbit);
 
-	error = hid_haptic_init(hdev, haptic, hi->input);
-	if (error) {
-		dev_warn(&hdev->dev, "Cannot allocate haptic for %s\n",
-			 hdev->name);
-		return 0;
-	}
-
-	return 1;
+	return hid_haptic_init(hdev, haptic, hi->input) == 0;
 }
 EXPORT_SYMBOL_GPL(hid_haptic_input_configured);
 

@@ -537,6 +548,7 @@ int hid_haptic_init(struct hid_device *hdev,
 put_device:
 	put_device(&hdev->dev);
 exit:
+	dev_warn(&hdev->dev, "Cannot allocate haptic for %s: %d\n", hdev->name, ret);
 	module_put(THIS_MODULE);
 	return ret;
 }

@@ -33,12 +33,11 @@ struct hid_haptic_device {
 	struct mutex auto_trigger_mutex;
 	struct workqueue_struct *wq;
 	struct hid_report *manual_trigger_report;
+	struct hid_field *pressure_field;
 	struct mutex manual_trigger_mutex;
 	size_t manual_trigger_report_len;
 	int pressed_state;
 	s32 pressure_sum;
-	s32 force_logical_minimum;
-	s32 force_physical_minimum;
 	s32 force_resolution;
 	u32 mode;
 	u32 default_auto_trigger;

@@ -55,20 +54,25 @@ struct hid_haptic_device {
 };
 
 #if IS_ENABLED(CONFIG_HID_HAPTIC)
+static inline bool hid_haptic_connected_to_input(struct hid_haptic_device *haptic,
+						 struct input_dev *input)
+{
+	return haptic->input_dev == input;
+}
+
 void hid_haptic_feature_mapping(struct hid_device *hdev,
 				struct hid_haptic_device *haptic,
 				struct hid_field *field, struct hid_usage
 				*usage);
-bool hid_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
+void hid_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
 				    struct hid_input *hi, struct hid_field *field);
 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);
-int hid_haptic_input_configured(struct hid_device *hdev,
-				struct hid_haptic_device *haptic,
-				struct hid_input *hi);
+bool hid_haptic_input_configured(struct hid_device *hdev,
+				 struct hid_haptic_device *haptic, struct hid_input *hi);
 int hid_haptic_init(struct hid_device *hdev, struct hid_haptic_device *haptic,
 		    struct input_dev *dev);
 void hid_haptic_handle_press_release(struct hid_haptic_device *haptic);

@@ -76,6 +80,12 @@ void hid_haptic_pressure_reset(struct hid_haptic_device *haptic);
 void hid_haptic_pressure_increase(struct hid_haptic_device *haptic,
 				  __s32 pressure);
 #else
+static inline bool hid_haptic_connected_to_input(struct hid_haptic_device *haptic,
+						 struct input_dev *input)
+{
+	return false;
+}
+
 static inline
 void hid_haptic_feature_mapping(struct hid_device *hdev,
 				struct hid_haptic_device *haptic,

@@ -83,11 +93,9 @@ void hid_haptic_feature_mapping(struct hid_device *hdev,
 				*usage)
 {}
 static inline
-bool hid_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
+void hid_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
 				    struct hid_input *hi, struct hid_field *field)
-{
-	return false;
-}
+{}
 static inline
 int hid_haptic_input_mapping(struct hid_device *hdev,
 			     struct hid_haptic_device *haptic,

@@ -98,11 +106,10 @@ int hid_haptic_input_mapping(struct hid_device *hdev,
 	return 0;
 }
 static inline
-int hid_haptic_input_configured(struct hid_device *hdev,
-				struct hid_haptic_device *haptic,
-				struct hid_input *hi)
+bool hid_haptic_input_configured(struct hid_device *hdev,
+				 struct hid_haptic_device *haptic, struct hid_input *hi)
 {
-	return 0;
+	return false;
 }
 static inline
 void hid_haptic_reset(struct hid_device *hdev, struct hid_haptic_device *haptic)

@@ -605,7 +605,8 @@ static void mt_feature_mapping(struct hid_device *hdev,
 		break;
 	}
 
-	hid_haptic_feature_mapping(hdev, td->haptic, field, usage);
+	if (td->haptic)
+		hid_haptic_feature_mapping(hdev, td->haptic, field, usage);
 }
 
 static void set_abs(struct input_dev *input, unsigned int code,

@@ -961,9 +962,8 @@ static int mt_touch_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 		case HID_DG_TIPPRESSURE:
 			set_abs(hi->input, ABS_MT_PRESSURE, field,
 				cls->sn_pressure);
-			td->is_haptic_touchpad =
-				hid_haptic_check_pressure_unit(td->haptic,
-							       hi, field);
+			if (td->haptic)
+				hid_haptic_check_pressure_unit(td->haptic, hi, field);
 			MT_STORE_FIELD(p);
 			return 1;
 		case HID_DG_SCANTIME:

@@ -1085,7 +1085,7 @@ static void mt_sync_frame(struct mt_device *td, struct mt_application *app,
 
 	app->num_received = 0;
 	app->left_button_state = 0;
-	if (td->is_haptic_touchpad)
+	if (td->is_haptic_touchpad && hid_haptic_connected_to_input(td->haptic, input))
 		hid_haptic_pressure_reset(td->haptic);
 }
 

@@ -1238,7 +1238,7 @@ static int mt_process_slot(struct mt_device *td, struct input_dev *input,
 			minor = minor >> 1;
 		}
 
-		if (td->is_haptic_touchpad)
+		if (td->is_haptic_touchpad && hid_haptic_connected_to_input(td->haptic, input))
 			hid_haptic_pressure_increase(td->haptic, *slot->p);
 
 		x = hdev->quirks & HID_QUIRK_X_INVERT ?

@@ -1441,7 +1441,7 @@ static int mt_touch_input_configured(struct hid_device *hdev,
 	if (cls->is_indirect)
 		app->mt_flags |= INPUT_MT_POINTER;
 
-	if (td->is_haptic_touchpad)
+	if (td->is_haptic_touchpad && hid_haptic_connected_to_input(td->haptic, input))
 		app->mt_flags |= INPUT_MT_TOTAL_FORCE;
 
 	if (app->quirks & MT_QUIRK_NOT_SEEN_MEANS_UP)

@@ -1553,10 +1553,11 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 	if (field->physical == HID_DG_STYLUS)
 		hi->application = HID_DG_STYLUS;
 
-	ret = hid_haptic_input_mapping(hdev, td->haptic, hi, field, usage, bit,
-				       max);
-	if (ret != 0)
-		return ret;
+	if (td->haptic) {
+		ret = hid_haptic_input_mapping(hdev, td->haptic, hi, field, usage, bit, max);
+		if (ret)
+			return ret;
+	}
 
 	/* let hid-core decide for the others */
 	return 0;

@@ -1954,14 +1955,11 @@ static int mt_input_configured(struct hid_device *hdev, struct hid_input *hi)
 	struct hid_report *report;
 	int ret;
 
-	if (td->is_haptic_touchpad && (td->mtclass.name == MT_CLS_WIN_8 ||
-	    td->mtclass.name == MT_CLS_WIN_8_FORCE_MULTI_INPUT ||
-	    td->mtclass.name == MT_CLS_WIN_8_KEEP_LATENCY_ON_CLOSE)) {
-		if (hid_haptic_input_configured(hdev, td->haptic, hi) == 0)
-			td->is_haptic_touchpad = false;
-	} else {
-		td->is_haptic_touchpad = false;
-	}
+	if (td->haptic && !td->is_haptic_touchpad &&
+	    (td->mtclass.name == MT_CLS_WIN_8 ||
+	     td->mtclass.name == MT_CLS_WIN_8_FORCE_MULTI_INPUT ||
+	     td->mtclass.name == MT_CLS_WIN_8_KEEP_LATENCY_ON_CLOSE))
+		td->is_haptic_touchpad = hid_haptic_input_configured(hdev, td->haptic, hi);
 
 	list_for_each_entry(report, &hi->reports, hidinput_list) {
 		rdata = mt_find_report_data(td, report);