gpu: nvgpu: Add support for XPU rail split

Check if CPU/GPU rails are joint, disable railgating if they are.

Bug 1722942

Change-Id: I002488f6418805569b0ef0fc3032b58297adeafb
Signed-off-by: Anshul Jain <anshulj@nvidia.com>
Reviewed-on: http://git-master/r/937026
(cherry picked from commit 61617c558a379a2a0a0f034bf0ef65cbef33d913)
Reviewed-on: http://git-master/r/1122047
(cherry picked from commit 2fb891988fdec15141ae227623d5525833c78052)
Reviewed-on: http://git-master/r/1123747
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Tested-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c b/drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c
index 468c9257..f69e12df 100644
--- a/drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c
+++ b/drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c
@@ -726,6 +726,7 @@ static int gk20a_tegra_probe(struct device *dev)
         struct device_node *np = dev->of_node;
         const __be32 *host1x_ptr;
         struct platform_device *host1x_pdev = NULL;
+        bool joint_xpu_rail = false;
 
         host1x_ptr = of_get_property(np, "nvidia,host1x", NULL);
         if (host1x_ptr) {
@@ -748,6 +749,15 @@ static int gk20a_tegra_probe(struct device *dev)
         if (platform->g->host1x_dev)
                 nvhost_register_dump_device(platform->g->host1x_dev,
                                         gk20a_debug_dump_device);
+#ifdef CONFIG_OF
+        joint_xpu_rail = of_property_read_bool(of_chosen,
+                                "nvidia,tegra-joint_xpu_rail");
+#endif
+
+        if (joint_xpu_rail) {
+                gk20a_dbg_info("XPU rails are joint\n");
+                platform->can_railgate = false;
+        }
 
         /* WAR for bug 1547668: Disable railgating and scaling irrespective of
          * platform data if the rework has not been made. */