[PATCH] Input: i8042 - Add quirk for polling the KBD port

[Friedrich Vock <friedrich.vock@gmx.de>]

It seems like there are some devices in the ASUS TUF A16 laptops that
just don't send any keyboard interrupts until you read from the KBD port.

Signed-off-by: Friedrich Vock <friedrich.vock@gmx.de>
---
 drivers/input/serio/i8042-acpipnpio.h | 30 +++++++++++++++--
 drivers/input/serio/i8042.c           | 47 ++++++++++++++++++++++-----
 drivers/input/serio/i8042.h           |  2 +-
 3 files changed, 67 insertions(+), 12 deletions(-)

diff --git a/drivers/input/serio/i8042-acpipnpio.h b/drivers/input/serio/i8042-acpipnpio.h
index 028e45bd050b..be2e72aaa658 100644
--- a/drivers/input/serio/i8042-acpipnpio.h
+++ b/drivers/input/serio/i8042-acpipnpio.h
@@ -83,6 +83,7 @@ static inline void i8042_write_command(int val)
 #define SERIO_QUIRK_KBDRESET		BIT(12)
 #define SERIO_QUIRK_DRITEK		BIT(13)
 #define SERIO_QUIRK_NOPNP		BIT(14)
+#define SERIO_QUIRK_POLL_KBD            BIT(15)

 /* Quirk table for different mainboards. Options similar or identical to i8042
  * module parameters.
@@ -99,6 +100,26 @@ static const struct dmi_system_id i8042_dmi_quirk_table[] __initconst = {
 		},
 		.driver_data = (void *)(SERIO_QUIRK_NOMUX)
 	},
+	/* Some laptops seem to not trigger any keyboard interrupts at all,
+	 * even when there is data available. On these devices, manually
+	 * polling the keyboard port is required.
+	 */
+	{
+		/* ASUS TUF Gaming A16 with Ryzen 7 7735HS */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "FA617NS"),
+		},
+		.driver_data = (void *)(SERIO_QUIRK_POLL_KBD)
+	},
+	{
+		/* ASUS TUF Gaming A16 with Ryzen 9 7940HS */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "FA617XS"),
+		},
+		.driver_data = (void *)(SERIO_QUIRK_POLL_KBD)
+	},
 	{
 		.matches = {
 			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
@@ -1634,6 +1655,8 @@ static void __init i8042_check_quirks(void)
 	if (quirks & SERIO_QUIRK_NOPNP)
 		i8042_nopnp = true;
 #endif
+	if (quirks & SERIO_QUIRK_POLL_KBD)
+		i8042_poll_kbd = true;
 }
 #else
 static inline void i8042_check_quirks(void) {}
@@ -1667,7 +1690,7 @@ static int __init i8042_platform_init(void)

 	i8042_check_quirks();

-	pr_debug("Active quirks (empty means none):%s%s%s%s%s%s%s%s%s%s%s%s%s\n",
+	pr_debug("Active quirks (empty means none):%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n",
 		i8042_nokbd ? " nokbd" : "",
 		i8042_noaux ? " noaux" : "",
 		i8042_nomux ? " nomux" : "",
@@ -1687,10 +1710,11 @@ static int __init i8042_platform_init(void)
 		"",
 #endif
 #ifdef CONFIG_PNP
-		i8042_nopnp ? " nopnp" : "");
+		i8042_nopnp ? " nopnp" : "",
 #else
-		"");
+		"",
 #endif
+		i8042_poll_kbd ? "poll_kbd" : "");

 	retval = i8042_pnp_init();
 	if (retval)
diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
index 6dac7c1853a5..7212263d3a41 100644
--- a/drivers/input/serio/i8042.c
+++ b/drivers/input/serio/i8042.c
@@ -115,6 +115,10 @@ module_param_named(nopnp, i8042_nopnp, bool, 0);
 MODULE_PARM_DESC(nopnp, "Do not use PNP to detect controller settings");
 #endif

+static bool i8042_poll_kbd;
+module_param_named(poll_kbd, i8042_poll_kbd, bool, 0);
+MODULE_PARM_DESC(poll_kbd, "Continuously poll the KBD port instead of relying on interrupts");
+
 #define DEBUG
 #ifdef DEBUG
 static bool i8042_debug;
@@ -178,6 +182,24 @@ static irqreturn_t i8042_interrupt(int irq, void *dev_id);
 static bool (*i8042_platform_filter)(unsigned char data, unsigned char str,
 				     struct serio *serio);

+#define POLL_TIME 1
+static void i8042_poll_func(struct timer_list *timer)
+{
+	unsigned char status;
+	unsigned long flags;
+
+	do {
+		spin_lock_irqsave(&i8042_lock, flags);
+		status = i8042_read_status();
+		spin_unlock_irqrestore(&i8042_lock, flags);
+		if (status & I8042_STR_OBF)
+			i8042_interrupt(0, NULL);
+	} while (status & I8042_STR_OBF);
+	mod_timer(timer, jiffies + msecs_to_jiffies(POLL_TIME));
+}
+
+DEFINE_TIMER(poll_timer, i8042_poll_func);
+
 void i8042_lock_chip(void)
 {
 	mutex_lock(&i8042_mutex);
@@ -1437,13 +1459,15 @@ static void i8042_unregister_ports(void)
 	}
 }

+
 static void i8042_free_irqs(void)
 {
 	if (i8042_aux_irq_registered)
 		free_irq(I8042_AUX_IRQ, i8042_platform_device);
-	if (i8042_kbd_irq_registered)
+	if (i8042_poll_kbd)
+		del_timer(&poll_timer);
+	else if (i8042_kbd_irq_registered)
 		free_irq(I8042_KBD_IRQ, i8042_platform_device);
-
 	i8042_aux_irq_registered = i8042_kbd_irq_registered = false;
 }

@@ -1497,10 +1521,14 @@ static int i8042_setup_kbd(void)
 	if (error)
 		return error;

-	error = request_irq(I8042_KBD_IRQ, i8042_interrupt, IRQF_SHARED,
-			    "i8042", i8042_platform_device);
-	if (error)
-		goto err_free_port;
+	if (i8042_poll_kbd)
+		mod_timer(&poll_timer, msecs_to_jiffies(POLL_TIME));
+	else {
+		error = request_irq(I8042_KBD_IRQ, i8042_interrupt, IRQF_SHARED,
+				    "i8042", i8042_platform_device);
+		if (error)
+			goto err_free_port;
+	}

 	error = i8042_enable_kbd_port();
 	if (error)
@@ -1510,8 +1538,11 @@ static int i8042_setup_kbd(void)
 	return 0;

  err_free_irq:
-	free_irq(I8042_KBD_IRQ, i8042_platform_device);
- err_free_port:
+	if (i8042_poll_kbd)
+		del_timer(&poll_timer);
+	else
+		free_irq(I8042_KBD_IRQ, i8042_platform_device);
+err_free_port:
 	i8042_free_kbd_port();
 	return error;
 }
--
2.40.1