extcon: int3496: Add GPIO ACPI mapping table

In order to make GPIO ACPI library stricter prepare users of
gpiod_get_index() to correctly behave when there no mapping is
provided by firmware.

Here we add explicit mapping between _CRS GpioIo() resources and
their names used in the driver.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

Documentation/extcon/intel-int3496.txt

@@ -20,3 +20,8 @@ Index 1: The output gpio for enabling Vbus output from the device to the otg
 Index 2: The output gpio for muxing of the data pins between the USB host and
          the USB peripheral controller, write 1 to mux to the peripheral
          controller
+
+There is a mapping between indices and GPIO connection IDs as follows
+	id	index 0
+	vbus	index 1
+	mux	index 2

drivers/extcon/extcon-intel-int3496.c

@@ -45,6 +45,17 @@ static const unsigned int int3496_cable[] = {
 	EXTCON_NONE,
 };
 
+static const struct acpi_gpio_params id_gpios = { INT3496_GPIO_USB_ID, 0, false };
+static const struct acpi_gpio_params vbus_gpios = { INT3496_GPIO_VBUS_EN, 0, false };
+static const struct acpi_gpio_params mux_gpios = { INT3496_GPIO_USB_MUX, 0, false };
+
+static const struct acpi_gpio_mapping acpi_int3496_default_gpios[] = {
+	{ "id-gpios", &id_gpios, 1 },
+	{ "vbus-gpios", &vbus_gpios, 1 },
+	{ "mux-gpios", &mux_gpios, 1 },
+	{ },
+};
+
 static void int3496_do_usb_id(struct work_struct *work)
 {
 	struct int3496_data *data =
@@ -83,6 +94,13 @@ static int int3496_probe(struct platform_device *pdev)
 	struct int3496_data *data;
 	int ret;
 
+	ret = acpi_dev_add_driver_gpios(ACPI_COMPANION(dev),
+					acpi_int3496_default_gpios);
+	if (ret) {
+		dev_err(dev, "can't add GPIO ACPI mapping\n");
+		return ret;
+	}
+
 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;
@@ -154,6 +172,8 @@ static int int3496_remove(struct platform_device *pdev)
 	devm_free_irq(&pdev->dev, data->usb_id_irq, data);
 	cancel_delayed_work_sync(&data->work);
 
+	acpi_dev_remove_driver_gpios(ACPI_COMPANION(&pdev->dev));
+
 	return 0;
 }