gpu: nvgpu: fix reset clock in gm20b

To assert reset on GPU, we store "gpu_ref" clock in
platform->clk[0] and use it to assert/deassert reset

But for gm20b, "gpu_ref" is no longer resettable.

To fix this, add two callbacks in gk20a_platform :
.reset_assert and .reset_deassert
Also, add a pointer "clk_reset" to store the clock
which needs to be reset

For gk20a specific implementation, we continue to
reset platform->clk[0]

For gm20b specific implementation, we first request
"gpu_gate" clock, store it and use it to assert reset

Bug 1513685
Bug 1517584

Change-Id: I15a583a4a07eb663b442084be8b8c7d0c7c7a142
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/gk20a.c b/drivers/gpu/nvgpu/gk20a/gk20a.c
index d411d011..c7d40fcd 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/gk20a.c
@@ -1671,10 +1671,14 @@ int __gk20a_do_idle(struct platform_device *pdev)
                 else
                         goto fail_timeout;
         } else {
+                if (!platform->reset_assert || !platform->reset_deassert)
+                        goto fail_timeout;
+
                 pm_runtime_get_sync(&pdev->dev);
                 gk20a_pm_prepare_poweroff(&pdev->dev);
 
-                tegra_periph_reset_assert(platform->clk[0]);
+                platform->reset_assert(pdev);
+
                 udelay(10);
 
                 g->forced_reset = true;
@@ -1717,7 +1721,7 @@ int __gk20a_do_unidle(struct platform_device *pdev)
         struct gk20a_platform *platform = dev_get_drvdata(&pdev->dev);
 
         if (g->forced_reset) {
-                tegra_periph_reset_deassert(platform->clk[0]);
+                platform->reset_deassert(pdev);
 
                 gk20a_pm_finalize_poweron(&pdev->dev);
                 pm_runtime_put_sync(&pdev->dev);