platform/x86: asus-wmi: Change q500a_i8042_filter() into a generic i8042-filter

Change asus_q500a_i8042_filter() into a generic i8042-filter,
using a new filter_i8042_e1_extended_codes flag in the quirks struct
to decide if e1 extended codes should be filtered out or not.

This is a preparation patch for adding support for filtering volume key
events being reported twice through both the PS/2 keyboard and asus-wmi.

Note while modifying the code also drop the unnecessary unlikely()
annotations, this is not in a hot path so those are not necessary.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20231120154235.610808-3-hdegoede@redhat.comReviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

drivers/platform/x86/asus-nb-wmi.c

@@ -49,24 +49,26 @@ MODULE_PARM_DESC(tablet_mode_sw, "Tablet mode detect: -1:auto 0:disable 1:kbd-do
 
 static struct quirk_entry *quirks;
 
-static bool asus_q500a_i8042_filter(unsigned char data, unsigned char str,
-			      struct serio *port)
+static bool asus_i8042_filter(unsigned char data, unsigned char str, struct serio *port)
 {
-	static bool extended;
-	bool ret = false;
+	static bool extended_e1;
 
 	if (str & I8042_STR_AUXDATA)
 		return false;
 
-	if (unlikely(data == 0xe1)) {
-		extended = true;
-		ret = true;
-	} else if (unlikely(extended)) {
-		extended = false;
-		ret = true;
+	if (quirks->filter_i8042_e1_extended_codes) {
+		if (data == 0xe1) {
+			extended_e1 = true;
+			return true;
 		}
 
-	return ret;
+		if (extended_e1) {
+			extended_e1 = false;
+			return true;
+		}
+	}
+
+	return false;
 }
 
 static struct quirk_entry quirk_asus_unknown = {
@@ -75,7 +77,7 @@ static struct quirk_entry quirk_asus_unknown = {
 };
 
 static struct quirk_entry quirk_asus_q500a = {
-	.i8042_filter = asus_q500a_i8042_filter,
+	.filter_i8042_e1_extended_codes = true,
 	.wmi_backlight_set_devstate = true,
 };
 
@@ -619,6 +621,7 @@ static struct asus_wmi_driver asus_nb_wmi_driver = {
 	.input_phys = ASUS_NB_WMI_FILE "/input0",
 	.detect_quirks = asus_nb_wmi_quirks,
 	.key_filter = asus_nb_wmi_key_filter,
+	.i8042_filter = asus_i8042_filter,
 };
 
 

drivers/platform/x86/asus-wmi.c

@@ -4567,8 +4567,8 @@ static int asus_wmi_add(struct platform_device *pdev)
 		goto fail_wmi_handler;
 	}
 
-	if (asus->driver->quirks->i8042_filter) {
-		err = i8042_install_filter(asus->driver->quirks->i8042_filter);
+	if (asus->driver->i8042_filter) {
+		err = i8042_install_filter(asus->driver->i8042_filter);
 		if (err)
 			pr_warn("Unable to install key filter - %d\n", err);
 	}
@@ -4609,8 +4609,8 @@ static int asus_wmi_remove(struct platform_device *device)
 	struct asus_wmi *asus;
 
 	asus = platform_get_drvdata(device);
-	if (asus->driver->quirks->i8042_filter)
-		i8042_remove_filter(asus->driver->quirks->i8042_filter);
+	if (asus->driver->i8042_filter)
+		i8042_remove_filter(asus->driver->i8042_filter);
 	wmi_remove_notify_handler(asus->driver->event_guid);
 	asus_wmi_backlight_exit(asus);
 	asus_screenpad_exit(asus);

drivers/platform/x86/asus-wmi.h

@@ -39,6 +39,7 @@ struct quirk_entry {
 	bool wmi_backlight_set_devstate;
 	bool wmi_force_als_set;
 	bool wmi_ignore_fan;
+	bool filter_i8042_e1_extended_codes;
 	enum asus_wmi_tablet_switch_mode tablet_switch_mode;
 	int wapf;
 	/*
@@ -49,9 +50,6 @@ struct quirk_entry {
 	 */
 	int no_display_toggle;
 	u32 xusb2pr;
-
-	bool (*i8042_filter)(unsigned char data, unsigned char str,
-			     struct serio *serio);
 };
 
 struct asus_wmi_driver {
@@ -73,6 +71,9 @@ struct asus_wmi_driver {
 	 * Return ASUS_WMI_KEY_IGNORE in code if event should be ignored. */
 	void (*key_filter) (struct asus_wmi_driver *driver, int *code,
 			    unsigned int *value, bool *autorelease);
+	/* Optional standard i8042 filter */
+	bool (*i8042_filter)(unsigned char data, unsigned char str,
+			     struct serio *serio);
 
 	int (*probe) (struct platform_device *device);
 	void (*detect_quirks) (struct asus_wmi_driver *driver);