Re: [PATCH 4/8] i2c: acpi: Use ACPI GPIO wake capability bit to set wake_irq

Device tree already has a mechanism to pass the wake_irq. It does this
by looking for the wakeup-source property and setting the
I2C_CLIENT_WAKE flag. This CL adds the ACPI equivalent. It uses at the
ACPI GpioInt wake flag to determine if the interrupt can be used to wake
the system. Previously the i2c drivers had to make assumptions and
blindly enable the wake IRQ. This can cause spurious wake events. e.g.,
If there is a device with an Active Low interrupt and the device gets
powered off while suspending, the interrupt line will go low since it's
no longer powered and wake the system. For this reason we should respect
the board designers wishes and honor the wake bit defined on the
GpioInt.

This change does not cover the ACPI Interrupt or IRQ resources.

Signed-off-by: Raul E Rangel <redacted>
---

 drivers/i2c/i2c-core-acpi.c |  8 ++++++--
 drivers/i2c/i2c-core-base.c | 17 +++++++++++------
 drivers/i2c/i2c-core.h      |  4 ++--
 3 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index c762a879c4cc6b..cfe82a6ba3ef28 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c

@@ -182,12 +182,13 @@ static int i2c_acpi_add_resource(struct acpi_resource *ares, void *data)
 /**
  * i2c_acpi_get_irq - get device IRQ number from ACPI
  * @client: Pointer to the I2C client device
+ * @wake_capable: Set to 1 if the IRQ is wake capable
  *
  * Find the IRQ number used by a specific client device.
  *
  * Return: The IRQ number or an error code.
  */
-int i2c_acpi_get_irq(struct i2c_client *client)
+int i2c_acpi_get_irq(struct i2c_client *client, int *wake_capable)
 {
 	struct acpi_device *adev = ACPI_COMPANION(&client->dev);
 	struct list_head resource_list;

@@ -196,6 +197,9 @@ int i2c_acpi_get_irq(struct i2c_client *client)
 
 	INIT_LIST_HEAD(&resource_list);
 
+	if (wake_capable)
+		*wake_capable = 0;
+
 	ret = acpi_dev_get_resources(adev, &resource_list,
 				     i2c_acpi_add_resource, &irq);