driver core / ACPI: Represent ACPI companions using fwnode_handle

Now that we have struct fwnode_handle, we can use that to point to
ACPI companions from struct device objects instead of pointing to
struct acpi_device directly.

There are two benefits from that.  First, the somewhat ugly and
hackish struct acpi_dev_node can be dropped and, second, the same
struct fwnode_handle pointer can be used in the future to point
to other (non-ACPI) firmware device node types.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Grant Likely <grant.likely@linaro.org>
diff --git a/drivers/acpi/acpi_platform.c b/drivers/acpi/acpi_platform.c
index 1284138..4bf7559 100644
--- a/drivers/acpi/acpi_platform.c
+++ b/drivers/acpi/acpi_platform.c
@@ -102,7 +102,7 @@
 	pdevinfo.id = -1;
 	pdevinfo.res = resources;
 	pdevinfo.num_res = count;
-	pdevinfo.acpi_node.companion = adev;
+	pdevinfo.fwnode = acpi_fwnode_handle(adev);
 	pdevinfo.dma_mask = DMA_BIT_MASK(32);
 	pdev = platform_device_register_full(&pdevinfo);
 	if (IS_ERR(pdev))
diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index d9339b4..a688aa2 100644
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -615,7 +615,7 @@
 	memset(&pdevinfo, 0, sizeof(pdevinfo));
 	pdevinfo.name = "dock";
 	pdevinfo.id = dock_station_count;
-	pdevinfo.acpi_node.companion = adev;
+	pdevinfo.fwnode = acpi_fwnode_handle(adev);
 	pdevinfo.data = &ds;
 	pdevinfo.size_data = sizeof(ds);
 	dd = platform_device_register_full(&pdevinfo);
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 9421fed..17f0204 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -454,7 +454,7 @@
 		goto err_alloc;
 
 	pdev->dev.parent = pdevinfo->parent;
-	ACPI_COMPANION_SET(&pdev->dev, pdevinfo->acpi_node.companion);
+	pdev->dev.fwnode = pdevinfo->fwnode;
 
 	if (pdevinfo->dma_mask) {
 		/*
diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
index 550a5ea..ab892be 100644
--- a/drivers/gpio/gpiolib.h
+++ b/drivers/gpio/gpiolib.h
@@ -17,6 +17,8 @@
 
 enum of_gpio_flags;
 
+struct acpi_device;
+
 /**
  * struct acpi_gpio_info - ACPI GPIO specific information
  * @gpioint: if %true this GPIO is of type GpioInt otherwise type is GpioIo
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index edf274c..c87c313 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -133,7 +133,7 @@
 		return AE_OK;
 
 	memset(&info, 0, sizeof(info));
-	info.acpi_node.companion = adev;
+	info.fwnode = acpi_fwnode_handle(adev);
 	info.irq = -1;
 
 	INIT_LIST_HEAD(&resource_list);
@@ -971,7 +971,7 @@
 	client->dev.bus = &i2c_bus_type;
 	client->dev.type = &i2c_client_type;
 	client->dev.of_node = info->of_node;
-	ACPI_COMPANION_SET(&client->dev, info->acpi_node.companion);
+	client->dev.fwnode = info->fwnode;
 
 	i2c_dev_set_name(adap, client);
 	status = device_register(&client->dev);