gpu: nvgpu: enable runtime pm for pci

Enable runtime power management ops for PCIe devices, and
move gk20a_pm_finalize_poweron call into the resume routine.
This change only implements suspend as a stub, as suspend/resume
has not yet been verified for dGPU

Bug 1785512
Bug 200187507

Change-Id: I076bafc03c6b4ba10dce874804ed3fd0b9c7b0d8
Signed-off-by: Sachit Kadle <skadle@nvidia.com>
Reviewed-on: http://git-master/r/1179860
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-by: Thomas Fleury <tfleury@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Richard Zhao <rizhao@nvidia.com>
Reviewed-by: Vijayakumar Subbu <vsubbu@nvidia.com>

1 files changed, 50 insertions, 12 deletions

diff --git a/drivers/gpu/nvgpu/pci.c b/drivers/gpu/nvgpu/pci.c
index 01c7a2dc..90a54570 100644
--- a/drivers/gpu/nvgpu/pci.c
+++ b/drivers/gpu/nvgpu/pci.c
@@ -38,25 +38,15 @@ static bool nvgpu_pci_tegra_is_railgated(struct device *pdev)
         return false;
 }
 
-static int nvgpu_pci_busy(struct device *dev)
-{
-        struct gk20a *g = get_gk20a(dev);
-        int err = 0;
-
-        if (!g->power_on)
-                err = gk20a_pm_finalize_poweron(dev);
-
-        return err;
-}
-
 static struct gk20a_platform nvgpu_pci_device = {
         /* ptimer src frequency in hz */
         .ptimer_src_freq        = 31250000,
 
         .probe = nvgpu_pci_tegra_probe,
         .remove = nvgpu_pci_tegra_remove,
-        .busy = nvgpu_pci_busy,
 
+        /* power management configuration */
+        .railgate_delay         = 500,
         .can_elpg = false,
 
         /* power management callbacks */
@@ -148,6 +138,45 @@ static struct class nvgpu_pci_class = {
         .devnode = nvgpu_pci_devnode,
 };
 
+#ifdef CONFIG_PM
+static int nvgpu_pci_pm_runtime_resume(struct device *dev)
+{
+        return gk20a_pm_finalize_poweron(dev);
+}
+
+static int nvgpu_pci_pm_runtime_suspend(struct device *dev)
+{
+        return 0;
+}
+
+static const struct dev_pm_ops nvgpu_pci_pm_ops = {
+        .runtime_resume = nvgpu_pci_pm_runtime_resume,
+        .runtime_suspend = nvgpu_pci_pm_runtime_suspend,
+        .resume = nvgpu_pci_pm_runtime_resume,
+        .suspend = nvgpu_pci_pm_runtime_suspend,
+};
+#endif
+
+int nvgpu_pci_pm_init(struct device *dev)
+{
+#ifdef CONFIG_PM
+        struct gk20a_platform *platform = gk20a_get_platform(dev);
+
+        if (platform->railgate_delay)
+                pm_runtime_set_autosuspend_delay(dev,
+                        platform->railgate_delay);
+
+        /*
+         * Runtime PM for PCI devices is disabled by default,
+         * so we need to enable it first
+         */
+        pm_runtime_use_autosuspend(dev);
+        pm_runtime_put_noidle(dev);
+        pm_runtime_allow(dev);
+#endif
+        return 0;
+}
+
 static int nvgpu_pci_probe(struct pci_dev *pdev,
                            const struct pci_device_id *pent)
 {
@@ -252,6 +281,12 @@ static int nvgpu_pci_probe(struct pci_dev *pdev,
 
         gk20a_init_gr(g);
 
+        err = nvgpu_pci_pm_init(&pdev->dev);
+        if (err) {
+                gk20a_err(&pdev->dev, "pm init failed");
+                return err;
+        }
+
         return 0;
 }
 
@@ -281,6 +316,9 @@ static struct pci_driver nvgpu_pci_driver = {
         .id_table = nvgpu_pci_table,
         .probe = nvgpu_pci_probe,
         .remove = nvgpu_pci_remove,
+#ifdef CONFIG_PM
+        .driver.pm = &nvgpu_pci_pm_ops,
+#endif
 };
 
 int __init nvgpu_pci_init(void)