gpu: nvgpu: Get host1x device from DTS

Currently the gpu driver assumes that the GPU is a child of host1x.
This is an invalid assumption and therefore we need to get the host1x
device from device tree based on nvidia,host1x property.

Bug 1311528
Bug 1434573

Change-Id: I097e39369aaa15ab6652cd23f353f88f7c2b9c48
Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Reviewed-on: http://git-master/r/395664
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Tested-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 23 insertions, 1 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c b/drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c
index 05aec1a7..7af801f8 100644
--- a/drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c
+++ b/drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c
@@ -15,6 +15,7 @@
  * more details.
  */
 
+#include <linux/of_platform.h>
 #include <linux/debugfs.h>
 #include <linux/tegra-powergate.h>
 #include <linux/platform_data/tegra_edp.h>
@@ -403,12 +404,33 @@ static void gk20a_tegra_debug_dump(struct platform_device *pdev)
 {
         struct gk20a_platform *platform = gk20a_get_platform(pdev);
         struct gk20a *g = platform->g;
-        nvhost_debug_dump_device(g->dev);
+        nvhost_debug_dump_device(g->host1x_dev);
 }
 
 static int gk20a_tegra_probe(struct platform_device *dev)
 {
         struct gk20a_platform *platform = gk20a_get_platform(dev);
+        struct device_node *np = dev->dev.of_node;
+        const __be32 *host1x_ptr;
+        struct platform_device *host1x_pdev = NULL;
+
+        host1x_ptr = of_get_property(np, "nvidia,host1x", NULL);
+        if (host1x_ptr) {
+                struct device_node *host1x_node =
+                        of_find_node_by_phandle(be32_to_cpup(host1x_ptr));
+
+                host1x_pdev = of_find_device_by_node(host1x_node);
+                if (!host1x_pdev) {
+                        dev_warn(&dev->dev, "host1x device not available");
+                        return -EPROBE_DEFER;
+                }
+
+        } else {
+                host1x_pdev = to_platform_device(dev->dev.parent);
+                dev_warn(&dev->dev, "host1x reference not found. assuming host1x to be parent");
+        }
+
+        platform->g->host1x_dev = host1x_pdev;
 
         if (tegra_get_chipid() == TEGRA_CHIPID_TEGRA13) {
                 t132_gk20a_tegra_platform.g = platform->g;