drm/radeon: Add support for the ATIF ACPI method to the radeon driver

By calling the ATIF method in the radeon driver we can make sure
that hotkeys such as the video switch key emit ACPI events when
pressed.

agd5f: fix warning

Signed-off-by: Alberto Milone <alberto.milone@canonical.com>
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/Makefile

@@ -69,5 +69,6 @@ radeon-y += radeon_device.o radeon_asic.o radeon_kms.o \
 
 radeon-$(CONFIG_COMPAT) += radeon_ioc32.o
 radeon-$(CONFIG_VGA_SWITCHEROO) += radeon_atpx_handler.o
+radeon-$(CONFIG_ACPI) += radeon_acpi.o
 
 obj-$(CONFIG_DRM_RADEON)+= radeon.o

drivers/gpu/drm/radeon/radeon.h

@@ -1414,6 +1414,13 @@ extern void r700_cp_fini(struct radeon_device *rdev);
 extern void evergreen_disable_interrupt_state(struct radeon_device *rdev);
 extern int evergreen_irq_set(struct radeon_device *rdev);
 
+/* radeon_acpi.c */ 
+#if defined(CONFIG_ACPI) 
+extern int radeon_acpi_init(struct radeon_device *rdev); 
+#else 
+static inline int radeon_acpi_init(struct radeon_device *rdev) { return 0; } 
+#endif 
+
 /* evergreen */
 struct evergreen_mc_save {
 	u32 vga_control[6];

drivers/gpu/drm/radeon/radeon_acpi.c

@@ -0,0 +1,67 @@
+#include <linux/pci.h>
+#include <linux/acpi.h>
+#include <linux/slab.h>
+#include <acpi/acpi_drivers.h>
+#include <acpi/acpi_bus.h>
+
+#include "drmP.h"
+#include "drm.h"
+#include "drm_sarea.h"
+#include "drm_crtc_helper.h"
+#include "radeon.h"
+
+#include <linux/vga_switcheroo.h>
+
+/* Call the ATIF method
+ *
+ * Note: currently we discard the output
+ */
+static int radeon_atif_call(acpi_handle handle)
+{
+	acpi_status status;
+	union acpi_object atif_arg_elements[2];
+	struct acpi_object_list atif_arg;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL};
+
+	atif_arg.count = 2;
+	atif_arg.pointer = &atif_arg_elements[0];
+
+	atif_arg_elements[0].type = ACPI_TYPE_INTEGER;
+	atif_arg_elements[0].integer.value = 0;
+	atif_arg_elements[1].type = ACPI_TYPE_INTEGER;
+	atif_arg_elements[1].integer.value = 0;
+
+	status = acpi_evaluate_object(handle, "ATIF", &atif_arg, &buffer);
+
+	/* Fail only if calling the method fails and ATIF is supported */
+	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
+		printk(KERN_INFO "failed to evaluate ATIF got %s\n", acpi_format_exception(status));
+		kfree(buffer.pointer);
+		return 1;
+	}
+
+	kfree(buffer.pointer);
+	return 0;
+}
+
+/* Call all ACPI methods here */
+int radeon_acpi_init(struct radeon_device *rdev)
+{
+	acpi_handle handle;
+	int ret;
+
+	/* No need to proceed if we're sure that ATIF is not supported */
+	if (!ASIC_IS_AVIVO(rdev) || !rdev->bios)
+		return 0;
+
+	/* Get the device handle */
+	handle = DEVICE_ACPI_HANDLE(&rdev->pdev->dev);
+
+	/* Call the ATIF method */
+	ret = radeon_atif_call(handle);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+

drivers/gpu/drm/radeon/radeon_kms.c

@@ -49,7 +49,7 @@ int radeon_driver_unload_kms(struct drm_device *dev)
 int radeon_driver_load_kms(struct drm_device *dev, unsigned long flags)
 {
 	struct radeon_device *rdev;
-	int r;
+	int r, acpi_status;
 
 	rdev = kzalloc(sizeof(struct radeon_device), GFP_KERNEL);
 	if (rdev == NULL) {
@@ -77,6 +77,12 @@ int radeon_driver_load_kms(struct drm_device *dev, unsigned long flags)
 		dev_err(&dev->pdev->dev, "Fatal error during GPU init\n");
 		goto out;
 	}
+
+	/* Call ACPI methods */
+	acpi_status = radeon_acpi_init(rdev);
+	if (acpi_status)
+		dev_err(&dev->pdev->dev, "Error during ACPI methods call\n");
+
 	/* Again modeset_init should fail only on fatal error
 	 * otherwise it should provide enough functionalities
 	 * for shadowfb to run