media: camera: Fix build for Linux v6.8

In Linux v6.8, the 'g_frame_interval' function pointer was removed from
the 'v4l2_subdev_video_ops' structure and replaced by
'get_frame_interval' that was added to the 'v4l2_subdev_pad_ops'
structure. Add a test to conftest to detect if 'get_frame_interval' is
supported and update the camera CSI driver accordingly to populate the
appropriate function pointer.

Note that the new 'get_frame_interval' function pointer has an
additional 'state' argument but is otherwise the same as the previous
'g_frame_interval' function pointer.

Bug 4448428

Change-Id: Iff049c3bffda11c677ac879b2b91e10deb78060c
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/3053901
Reviewed-by: Laxman Dewangan <ldewangan@nvidia.com>
GVS: Gerrit_Virtual_Submit <buildbot_gerritrpt@nvidia.com>

drivers/media/platform/tegra/camera/csi/csi.c

@@ -2,9 +2,11 @@
 /*
  * NVIDIA Tegra CSI Device
  *
- * Copyright (c) 2015-2022, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2015-2024, NVIDIA CORPORATION.  All rights reserved.
  */
 
+#include <nvidia/conftest.h>
+
 #include <linux/clk.h>
 #include <linux/device.h>
 #include <linux/gpio/consumer.h>
@@ -685,6 +687,9 @@ static int tegra_csi_set_format(struct v4l2_subdev *subdev,
 }
 
 static int tegra_csi_g_frame_interval(struct v4l2_subdev *sd,
+#if defined(NV_V4L2_SUBDEV_PAD_OPS_STRUCT_HAS_GET_FRAME_INTERVAL)
+			struct v4l2_subdev_state *sd_state,
+#endif
 			struct v4l2_subdev_frame_interval *vfi)
 {
 	struct tegra_csi_channel *chan = to_csi_chan(sd);
@@ -716,10 +721,15 @@ static int tegra_csi_enum_mbus_code(struct v4l2_subdev *sd,
 static struct v4l2_subdev_video_ops tegra_csi_video_ops = {
 	.s_stream	= tegra_csi_s_stream,
 	.g_input_status = tegra_csi_g_input_status,
+#if !defined(NV_V4L2_SUBDEV_PAD_OPS_STRUCT_HAS_GET_FRAME_INTERVAL)
 	.g_frame_interval = tegra_csi_g_frame_interval,
+#endif
 };
 
 static struct v4l2_subdev_pad_ops tegra_csi_pad_ops = {
+#if defined(NV_V4L2_SUBDEV_PAD_OPS_STRUCT_HAS_GET_FRAME_INTERVAL)
+	.get_frame_interval = tegra_csi_g_frame_interval,
+#endif
 	.get_fmt	= tegra_csi_get_format,
 	.set_fmt	= tegra_csi_set_format,
 	.enum_mbus_code = tegra_csi_enum_mbus_code,

scripts/conftest/Makefile

@@ -167,6 +167,7 @@ NV_CONFTEST_FUNCTION_COMPILE_TESTS += v4l2_async_subdev_nf_init
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += v4l2_async_notifier_init
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += v4l2_async_nf_init_has_v4l2_dev_arg
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += __v4l2_async_nf_add_subdev
+NV_CONFTEST_FUNCTION_COMPILE_TESTS += v4l2_subdev_pad_ops_struct_has_get_frame_interval
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += vm_area_struct_has_const_vm_flags
 NV_CONFTEST_GENERIC_COMPILE_TESTS += is_export_symbol_present_drm_gem_prime_fd_to_handle
 NV_CONFTEST_GENERIC_COMPILE_TESTS += is_export_symbol_present_drm_gem_prime_handle_to_fd

scripts/conftest/conftest.sh

@@ -7757,6 +7757,25 @@ compile_test() {
             compile_check_conftest "$CODE" "NV_V4L2_ASYNC_NF_ADD_SUBDEV_PRESENT" "" "functions"
         ;;
 
+        v4l2_subdev_pad_ops_struct_has_get_frame_interval)
+            #
+            # Determine if struct v4l2_subdev_pad_ops has the 'get_frame_interval'
+            # function pointer.
+            #
+            # Added by commit 287fe160834a ("media: v4l2-subdev: Turn
+            # .[gs]_frame_interval into pad operations") in Linux v6.8.
+            #
+            CODE="
+            #define _LINUX_EFI_H
+            #include <media/v4l2-subdev.h>
+            int conftest_v4l2_subdev_pad_ops_struct_has_get_set_frame_interval(void) {
+                return offsetof(struct v4l2_subdev_pad_ops, get_frame_interval);
+            }
+            "
+            compile_check_conftest "$CODE" \
+                    "NV_V4L2_SUBDEV_PAD_OPS_STRUCT_HAS_GET_FRAME_INTERVAL" "" "types"
+        ;;
+
         crypto_engine_ctx_struct_removed_test)
             #
             # Determine if struct 'crypto_engine_ctx' is removed in linux kernel.