i2c: nvidia-gpu: add runtime pm support

[linux.git] / drivers / i2c / busses / i2c-nvidia-gpu.c

diff --git a/drivers/i2c/busses/i2c-nvidia-gpu.c b/drivers/i2c/busses/i2c-nvidia-gpu.c
index 7678a460bf9ae52a3fbd44b880b1dc68a25b5569..364244ffb5bf316ccccc70f495baed14249ea814 100644 (file)
--- a/drivers/i2c/busses/i2c-nvidia-gpu.c
+++ b/drivers/i2c/busses/i2c-nvidia-gpu.c
@@ -176,6 +176,7 @@ static int gpu_i2c_master_xfer(struct i2c_adapter *adap,
         * The controller supports maximum 4 byte read due to known
         * limitation of sending STOP after every read.
         */
+       pm_runtime_get_sync(i2cd->dev);
        for (i = 0; i < num; i++) {
                if (msgs[i].flags & I2C_M_RD) {
                        /* program client address before starting read */
@@ -217,6 +218,8 @@ static int gpu_i2c_master_xfer(struct i2c_adapter *adap,
                if (status2 < 0)
                        dev_err(i2cd->dev, "i2c stop failed %d\n", status2);
        }
+       pm_runtime_mark_last_busy(i2cd->dev);
+       pm_runtime_put_autosuspend(i2cd->dev);
        return status;
 }
 
@@ -336,6 +339,11 @@ static int gpu_i2c_probe(struct pci_dev *pdev, const struct pci_device_id *id)
                goto del_adapter;
        }
 
+       pm_runtime_set_autosuspend_delay(&pdev->dev, 3000);
+       pm_runtime_use_autosuspend(&pdev->dev);
+       pm_runtime_put_autosuspend(&pdev->dev);
+       pm_runtime_allow(&pdev->dev);
+
        return 0;
 
 del_adapter:
@@ -349,10 +357,21 @@ static void gpu_i2c_remove(struct pci_dev *pdev)
 {
        struct gpu_i2c_dev *i2cd = dev_get_drvdata(&pdev->dev);
 
+       pm_runtime_get_noresume(i2cd->dev);
        i2c_del_adapter(&i2cd->adapter);
        pci_free_irq_vectors(pdev);
 }
 
+/*
+ * We need gpu_i2c_suspend() even if it is stub, for runtime pm to work
+ * correctly. Without it, lspci shows runtime pm status as "D0" for the card.
+ * Documentation/power/pci.txt also insists for driver to provide this.
+ */
+static __maybe_unused int gpu_i2c_suspend(struct device *dev)
+{
+       return 0;
+}
+
 static __maybe_unused int gpu_i2c_resume(struct device *dev)
 {
        struct gpu_i2c_dev *i2cd = dev_get_drvdata(dev);
@@ -361,7 +380,8 @@ static __maybe_unused int gpu_i2c_resume(struct device *dev)
        return 0;
 }
 
-static UNIVERSAL_DEV_PM_OPS(gpu_i2c_driver_pm, NULL, gpu_i2c_resume, NULL);
+static UNIVERSAL_DEV_PM_OPS(gpu_i2c_driver_pm, gpu_i2c_suspend, gpu_i2c_resume,
+                           NULL);
 
 static struct pci_driver gpu_i2c_driver = {
        .name           = "nvidia-gpu",