HID: multitouch: make mt_set_mode() less cryptic

JIRA: https://issues.redhat.com/browse/RHEL-101770
Upstream Status: since v6.13
Tested: with the hid-tools test suite and some hardware

commit e8a0581
Author: Dmitry Torokhov <[email protected]>
Date:   Mon Oct 28 12:07:50 2024 -0700

    HID: multitouch: make mt_set_mode() less cryptic

    mt_set_mode() accepts 2 boolean switches indicating whether the device
    (if it follows Windows Precision Touchpad specification) should report
    hardware buttons and/or surface contacts. For a casual reader it is
    completely not clear, as they look at the call site, which exact mode
    is being requested.

    Define report_mode enum and change mt_set_mode() to accept is as
    an argument instead. This allows to write:

            mt_set_modes(hdev, HID_LATENCY_NORMAL, TOUCHPAD_REPORT_ALL);

    or

            mt_set_modes(hdev, HID_LATENCY_HIGH, TOUCHPAD_REPORT_BUTTONS);

    which makes intent much more clear.

    Reviewed-by: Benjamin Tissoires <[email protected]>
    Signed-off-by: Dmitry Torokhov <[email protected]>
    Link: https://patch.msgid.link/[email protected]
    Signed-off-by: Benjamin Tissoires <[email protected]>

Signed-off-by: Benjamin Tissoires <[email protected]>

Author: bentiss

drivers/hid/hid-multitouch.c

@@ -31,6 +31,7 @@
  * [1] https://gitlab.freedesktop.org/libevdev/hid-tools
  */
 
+#include <linux/bits.h>
 #include <linux/device.h>
 #include <linux/hid.h>
 #include <linux/module.h>
@@ -83,6 +84,13 @@ enum latency_mode {
 	HID_LATENCY_HIGH = 1,
 };
 
+enum report_mode {
+	TOUCHPAD_REPORT_NONE = 0,
+	TOUCHPAD_REPORT_BUTTONS = BIT(0),
+	TOUCHPAD_REPORT_CONTACTS = BIT(1),
+	TOUCHPAD_REPORT_ALL = TOUCHPAD_REPORT_BUTTONS | TOUCHPAD_REPORT_CONTACTS,
+};
+
 #define MT_IO_FLAGS_RUNNING		0
 #define MT_IO_FLAGS_ACTIVE_SLOTS	1
 #define MT_IO_FLAGS_PENDING_SLOTS	2
@@ -1493,8 +1501,7 @@ static bool mt_need_to_apply_feature(struct hid_device *hdev,
 				     struct hid_field *field,
 				     struct hid_usage *usage,
 				     enum latency_mode latency,
-				     bool surface_switch,
-				     bool button_switch,
+				     enum report_mode report_mode,
 				     bool *inputmode_found)
 {
 	struct mt_device *td = hid_get_drvdata(hdev);
@@ -1549,19 +1556,19 @@ static bool mt_need_to_apply_feature(struct hid_device *hdev,
 		return true;
 
 	case HID_DG_SURFACESWITCH:
-		field->value[index] = surface_switch;
+		field->value[index] = !!(report_mode & TOUCHPAD_REPORT_CONTACTS);
 		return true;
 
 	case HID_DG_BUTTONSWITCH:
-		field->value[index] = button_switch;
+		field->value[index] = !!(report_mode & TOUCHPAD_REPORT_BUTTONS);
 		return true;
 	}
 
 	return false; /* no need to update the report */
 }
 
 static void mt_set_modes(struct hid_device *hdev, enum latency_mode latency,
-			 bool surface_switch, bool button_switch)
+			 enum report_mode report_mode)
 {
 	struct hid_report_enum *rep_enum;
 	struct hid_report *rep;
@@ -1586,8 +1593,7 @@ static void mt_set_modes(struct hid_device *hdev, enum latency_mode latency,
 							     rep->field[i],
 							     usage,
 							     latency,
-							     surface_switch,
-							     button_switch,
+							     report_mode,
 							     &inputmode_found))
 					update_report = true;
 			}
@@ -1830,7 +1836,7 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
 		dev_warn(&hdev->dev, "Cannot allocate sysfs group for %s\n",
 				hdev->name);
 
-	mt_set_modes(hdev, HID_LATENCY_NORMAL, true, true);
+	mt_set_modes(hdev, HID_LATENCY_NORMAL, TOUCHPAD_REPORT_ALL);
 
 	return 0;
 }
@@ -1842,17 +1848,17 @@ static int mt_suspend(struct hid_device *hdev, pm_message_t state)
 	/* High latency is desirable for power savings during S3/S0ix */
 	if ((td->mtclass.quirks & MT_QUIRK_DISABLE_WAKEUP) ||
 	    !hid_hw_may_wakeup(hdev))
-		mt_set_modes(hdev, HID_LATENCY_HIGH, false, false);
+		mt_set_modes(hdev, HID_LATENCY_HIGH, TOUCHPAD_REPORT_NONE);
 	else
-		mt_set_modes(hdev, HID_LATENCY_HIGH, true, true);
+		mt_set_modes(hdev, HID_LATENCY_HIGH, TOUCHPAD_REPORT_ALL);
 
 	return 0;
 }
 
 static int mt_reset_resume(struct hid_device *hdev)
 {
 	mt_release_contacts(hdev);
-	mt_set_modes(hdev, HID_LATENCY_NORMAL, true, true);
+	mt_set_modes(hdev, HID_LATENCY_NORMAL, TOUCHPAD_REPORT_ALL);
 	return 0;
 }
 
@@ -1864,7 +1870,7 @@ static int mt_resume(struct hid_device *hdev)
 
 	hid_hw_idle(hdev, 0, 0, HID_REQ_SET_IDLE);
 
-	mt_set_modes(hdev, HID_LATENCY_NORMAL, true, true);
+	mt_set_modes(hdev, HID_LATENCY_NORMAL, TOUCHPAD_REPORT_ALL);
 
 	return 0;
 }