[PATCH 12/18] HID: haptic: add functions handling events

[Angela Czubak <acz@semihalf.com>]

Implement hid_haptic_handle_press_release() which generates haptic feedback
as well as saves the pressed state of the haptic device.
Function hid_haptic_handle_input() inserts BTN_LEFT and ABS_PRESSURE events
if the device is in kernel mode.
Add functions to increase and reset the state of the pressure detected by
the device.

Signed-off-by: Angela Czubak <acz@semihalf.com>
---
 drivers/hid/hid-haptic.c | 72 +++++++++++++++++++++++++++++++++++++++-
 drivers/hid/hid-haptic.h | 20 +++++++++++
 2 files changed, 91 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-haptic.c b/drivers/hid/hid-haptic.c
index ad458bc7d4c5..85c4711f685e 100644
--- a/drivers/hid/hid-haptic.c
+++ b/drivers/hid/hid-haptic.c
@@ -51,8 +51,13 @@ bool hid_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
 				    struct hid_input *hi, struct hid_field *field)
 {
 	/* Accepted units are either grams or newtons. */
-	if (field->unit == 0x0101 || field->unit == 0xe111)
+	if (field->unit == 0x0101 || field->unit == 0xe111) {
+		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;
+	}
 	return false;
 }
 EXPORT_SYMBOL_GPL(hid_haptic_check_pressure_unit);
@@ -352,6 +357,13 @@ static void hid_haptic_destroy(struct ff_device *ff)
 	module_put(THIS_MODULE);
 }
 
+static __u32 convert_force_to_logical(struct hid_haptic_device *haptic,
+					 __u32 value)
+{
+	return (value - haptic->force_physical_minimum) *
+		haptic->force_resolution + haptic->force_logical_minimum;
+}
+
 int hid_haptic_init(struct hid_device *hdev,
 		    struct hid_haptic_device **haptic_ptr)
 {
@@ -459,6 +471,13 @@ int hid_haptic_init(struct hid_device *hdev,
 	fill_effect_buf(haptic, &stop_effect, &haptic->stop_effect,
 			HID_HAPTIC_ORDINAL_WAVEFORMSTOP);
 
+	haptic->mode = HID_HAPTIC_MODE_DEVICE;
+	haptic->press_threshold = convert_force_to_logical(haptic,
+							   HID_HAPTIC_PRESS_THRESH);
+	haptic->release_threshold = convert_force_to_logical(haptic,
+							     HID_HAPTIC_RELEASE_THRESH);
+
+
 	input_set_capability(dev, EV_FF, FF_HID);
 
 	flush = dev->flush;
@@ -550,3 +569,54 @@ int hid_haptic_init(struct hid_device *hdev,
 	return ret;
 }
 EXPORT_SYMBOL_GPL(hid_haptic_init);
+
+void hid_haptic_handle_press_release(struct hid_haptic_device *haptic)
+{
+	int prev_pressed_state = haptic->pressed_state;
+	struct input_dev *input = haptic->input_dev;
+	unsigned long flags;
+
+	if (haptic->pressure_sum > haptic->press_threshold)
+		haptic->pressed_state = 1;
+	else if (haptic->pressure_sum < haptic->release_threshold)
+		haptic->pressed_state = 0;
+	if (!prev_pressed_state && haptic->pressed_state &&
+	    haptic->mode == HID_HAPTIC_MODE_KERNEL) {
+		spin_lock_irqsave(&input->event_lock, flags);
+		input->ff->playback(input, PRESS_HID_EFFECT_ID, 1);
+		spin_unlock_irqrestore(&input->event_lock, flags);
+	}
+	if (prev_pressed_state && !haptic->pressed_state &&
+	    haptic->mode == HID_HAPTIC_MODE_KERNEL) {
+		spin_lock_irqsave(&input->event_lock, flags);
+		input->ff->playback(input, RELEASE_HID_EFFECT_ID, 1);
+		spin_unlock_irqrestore(&input->event_lock, flags);
+	}
+}
+EXPORT_SYMBOL_GPL(hid_haptic_handle_press_release);
+
+bool hid_haptic_handle_input(struct hid_haptic_device *haptic)
+{
+	if (haptic->mode == HID_HAPTIC_MODE_KERNEL) {
+		input_event(haptic->input_dev, EV_KEY, BTN_LEFT,
+			    haptic->pressed_state);
+		input_event(haptic->input_dev, EV_ABS, ABS_PRESSURE,
+			    haptic->pressure_sum);
+		return true;
+	}
+	return false;
+}
+EXPORT_SYMBOL_GPL(hid_haptic_handle_input);
+
+void hid_haptic_pressure_reset(struct hid_haptic_device *haptic)
+{
+	haptic->pressure_sum = 0;
+}
+EXPORT_SYMBOL_GPL(hid_haptic_pressure_reset);
+
+void hid_haptic_pressure_increase(struct hid_haptic_device *haptic,
+				 __s32 pressure)
+{
+	haptic->pressure_sum += pressure;
+}
+EXPORT_SYMBOL_GPL(hid_haptic_pressure_increase);
diff --git a/drivers/hid/hid-haptic.h b/drivers/hid/hid-haptic.h
index 2581833125dd..27ae1ed576c4 100644
--- a/drivers/hid/hid-haptic.h
+++ b/drivers/hid/hid-haptic.h
@@ -83,6 +83,11 @@ int 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_ptr);
+void hid_haptic_handle_press_release(struct hid_haptic_device *haptic);
+bool hid_haptic_handle_input(struct hid_haptic_device *haptic);
+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
 void hid_haptic_feature_mapping(struct hid_device *hdev,
@@ -117,4 +122,19 @@ int hid_haptic_init(struct hid_device *hdev, struct hid_haptic_device **haptic_p
 {
 	return 0;
 }
+static inline
+void hid_haptic_handle_press_release(struct hid_haptic_device *haptic)
+{}
+static inline
+bool hid_haptic_handle_input(struct hid_haptic_device *haptic)
+{
+	return false;
+}
+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
-- 
2.34.1.307.g9b7440fafd-goog