[PATCH v2] HID: i2c-hid: Enable touchpad wakeup from Suspend-to-Idle

[Kai-Heng Feng <kai.heng.feng@canonical.com>]

Many laptops have the ability to be woken up from Suspend-to-Idle by
touchpad. This is also the default behavior on other OSes.

So let's enable the wakeup support if the system defaults to use
Suspend-to-Idle.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
v2:
 - Fix compile error when ACPI is not enabled.

 drivers/hid/i2c-hid/i2c-hid-core.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index 294c84e136d7..e6caef006cd3 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -931,6 +931,14 @@ static void i2c_hid_acpi_fix_up_power(struct device *dev)
 		acpi_device_fix_up_power(adev);
 }
 
+static void i2c_hid_acpi_enable_wakeup(struct device *dev)
+{
+	if (acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0) {
+		device_set_wakeup_capable(dev, true);
+		device_wakeup_enable(dev);
+	}
+}
+
 static const struct acpi_device_id i2c_hid_acpi_match[] = {
 	{"ACPI0C50", 0 },
 	{"PNP0C50", 0 },
@@ -945,6 +953,8 @@ static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
 }
 
 static inline void i2c_hid_acpi_fix_up_power(struct device *dev) {}
+
+static inline void i2c_hid_acpi_enable_wakeup(struct device *dev) {}
 #endif
 
 #ifdef CONFIG_OF
@@ -1072,6 +1082,8 @@ static int i2c_hid_probe(struct i2c_client *client,
 
 	i2c_hid_acpi_fix_up_power(&client->dev);
 
+	i2c_hid_acpi_enable_wakeup(&client->dev);
+
 	device_enable_async_suspend(&client->dev);
 
 	/* Make sure there is something at this address */
-- 
2.17.1