From: Takashi Iwai <tiwai@suse.de>
Subject: [PATCH] Input: elan_i2c: Add deny list for Lenovo Yoga Slim 7
Date: Fri, 04 Feb 2022 17:57:14 +0100
Message-ID: <s5hleyqwowl.wl-tiwai@suse.de>
Patch-mainline: Submitted, linux-input ML
References: bsc#1193064

The touchpad on Lenovo Yoga Slim 7 doesn't work well with elan-i2c but
rather better with i2c-hid.  Add a deny list for avoiding to bind with
elan-i2c.

BugLink: https://bugzilla.opensuse.org/show_bug.cgi?id=1193064
Signed-off-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/input/mouse/elan_i2c_core.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

--- a/drivers/input/mouse/elan_i2c_core.c
+++ b/drivers/input/mouse/elan_i2c_core.c
@@ -18,6 +18,7 @@
 #include <linux/acpi.h>
 #include <linux/delay.h>
 #include <linux/device.h>
+#include <linux/dmi.h>
 #include <linux/firmware.h>
 #include <linux/i2c.h>
 #include <linux/init.h>
@@ -1187,6 +1188,20 @@ static void elan_disable_regulator(void *_data)
 	regulator_disable(data->vcc);
 }
 
+static const struct dmi_system_id elan_i2c_denylist[] = {
+#if IS_ENABLED(CONFIG_I2C_HID_ACPI)
+	{
+		/* Lenovo Yoga Slim 7 is better supported by i2c-hid */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "82A3"),
+			DMI_MATCH(DMI_PRODUCT_VERSION, "Yoga Slim 7 14ITL05"),
+		},
+	},
+#endif
+	{ }
+};
+
 static int elan_probe(struct i2c_client *client)
 {
 	const struct elan_transport_ops *transport_ops;
@@ -1197,6 +1212,10 @@ static int elan_probe(struct i2c_client *client)
 
 	if (IS_ENABLED(CONFIG_MOUSE_ELAN_I2C_I2C) &&
 	    i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		if (dmi_check_system(elan_i2c_denylist)) {
+			dev_info(dev, "Hits deny list, skipping\n");
+			return -ENODEV;
+		}
 		transport_ops = &elan_i2c_ops;
 	} else if (IS_ENABLED(CONFIG_MOUSE_ELAN_I2C_SMBUS) &&
 		   i2c_check_functionality(client->adapter,