[PATCH 5.4 03/86] platform/x86: ideapad-laptop: Disable touchpad_switch for ELAN0634

Greg Kroah-Hartman
2021-01-26T08:39:50Z

From: Jiaxun Yang <jiaxun.yang@flygoat.com>

commit f419e5940f1d9892ea6f45acdaca572b9e73ff39 upstream.

Newer ideapads (e.g.: Yoga 14s, 720S 14) come with ELAN0634 touchpad do not
use EC to switch touchpad.

Reading VPCCMD_R_TOUCHPAD will return zero thus touchpad may be blocked
unexpectedly.
Writing VPCCMD_W_TOUCHPAD may cause a spurious key press.

Add has_touchpad_switch to workaround these machines.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: stable@vger.kernel.org # 5.4+
--
v2: Specify touchpad to ELAN0634
v3: Stupid missing ! in v2
v4: Correct acpi_dev_present usage (Hans)
Link: https://lore.kernel.org/r/20210107144438.12605-1-jiaxun.yang@flygoat.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/platform/x86/ideapad-laptop.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)

--- a/drivers/platform/x86/ideapad-laptop.c
+++ b/drivers/platform/x86/ideapad-laptop.c
@@ -92,6 +92,7 @@ struct ideapad_private {
struct dentry *debug;
unsigned long cfg;
bool has_hw_rfkill_switch;
+ bool has_touchpad_switch;
const char *fnesc_guid;
};

@@ -535,7 +536,9 @@ static umode_t ideapad_is_visible(struct
} else if (attr == &dev_attr_fn_lock.attr) {
supported = acpi_has_method(priv->adev->handle, "HALS") &&
acpi_has_method(priv->adev->handle, "SALS");
- } else
+ } else if (attr == &dev_attr_touchpad.attr)
+ supported = priv->has_touchpad_switch;
+ else
supported = true;

return supported ? attr->mode : 0;
@@ -867,6 +870,9 @@ static void ideapad_sync_touchpad_state(
{
unsigned long value;

+ if (!priv->has_touchpad_switch)
+ return;
+
/* Without reading from EC touchpad LED doesn't switch state */
if (!read_ec_data(priv->adev->handle, VPCCMD_R_TOUCHPAD, &value)) {
/* Some IdeaPads don't really turn off touchpad - they only
@@ -989,6 +995,9 @@ static int ideapad_acpi_add(struct platf
priv->platform_device = pdev;
priv->has_hw_rfkill_switch = dmi_check_system(hw_rfkill_list);

+ /* Most ideapads with ELAN0634 touchpad don't use EC touchpad switch */
+ priv->has_touchpad_switch = !acpi_dev_present("ELAN0634", NULL, -1);
+
ret = ideapad_sysfs_init(priv);
if (ret)
return ret;
@@ -1006,6 +1015,10 @@ static int ideapad_acpi_add(struct platf
if (!priv->has_hw_rfkill_switch)
write_ec_cmd(priv->adev->handle, VPCCMD_W_RF, 1);

+ /* The same for Touchpad */
+ if (!priv->has_touchpad_switch)
+ write_ec_cmd(priv->adev->handle, VPCCMD_W_TOUCHPAD, 1);
+
for (i = 0; i < IDEAPAD_RFKILL_DEV_NUM; i++)
if (test_bit(ideapad_rfk_data[i].cfgbit, &priv->cfg))
ideapad_register_rfkill(priv, i);