gpu: nvgpu: add is_railgated() callback

Add is_railgated() platform callback to check status
of gk20a power rail

Bug 1376916
Bug 1487804

Change-Id: Ia0d909210dc409ab684eb6f20528b81500aecd5c
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>

2 files changed, 16 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/platform_gk20a.h b/drivers/gpu/nvgpu/gk20a/platform_gk20a.h
index d9d86b63..49f386d8 100644
--- a/drivers/gpu/nvgpu/gk20a/platform_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/platform_gk20a.h
@@ -88,6 +88,9 @@ struct gk20a_platform {
         /* Called to turn on the device */
         int (*unrailgate)(struct platform_device *dev);
 
+        /* Called to check state of device */
+        bool (*is_railgated)(struct platform_device *dev);
+
         /* Postscale callback is called after frequency change */
         void (*postscale)(struct platform_device *pdev,
                           unsigned long freq);
diff --git a/drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c b/drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c
index 3a739cb6..813053e0 100644
--- a/drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c
+++ b/drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c
@@ -305,6 +305,17 @@ void gk20a_tegra_calibrate_emc(struct gk20a_emc_params *emc_params,
 }
 
 /*
+ * gk20a_tegra_is_railgated()
+ *
+ * Check status of gk20a power rail
+ */
+
+static bool gk20a_tegra_is_railgated(struct platform_device *pdev)
+{
+        return !tegra_powergate_is_powered(TEGRA_POWERGATE_GPU);
+}
+
+/*
  * gk20a_tegra_railgate()
  *
  * Gate (disable) gk20a power rail
@@ -504,6 +515,7 @@ struct gk20a_platform t132_gk20a_tegra_platform = {
         .suspend = gk20a_tegra_suspend,
         .railgate = gk20a_tegra_railgate,
         .unrailgate = gk20a_tegra_unrailgate,
+        .is_railgated = gk20a_tegra_is_railgated,
 
         /* frequency scaling configuration */
         .prescale = gk20a_tegra_prescale,
@@ -530,6 +542,7 @@ struct gk20a_platform gk20a_tegra_platform = {
         .suspend = gk20a_tegra_suspend,
         .railgate = gk20a_tegra_railgate,
         .unrailgate = gk20a_tegra_unrailgate,
+        .is_railgated = gk20a_tegra_is_railgated,
 
         /* frequency scaling configuration */
         .prescale = gk20a_tegra_prescale,