[Linux-kernel-mentees] [PATCH v1] media: cafe-driver: use generic power management

Vaibhav Gupta vaibhavgupta40 at gmail.com
Mon Jul 20 17:45:46 UTC 2020


Drivers using legacy PM have to manage PCI states and device's PM states
themselves. They also need to take care of configuration registers.

With improved and powerful support of generic PM, PCI Core takes care of
above mentioned, device-independent, jobs.

This driver makes use of PCI helper functions like
pci_save/restore_state() and pci_enable/disable_device() to do required
operations. In generic mode, they are no longer needed.

Change function parameter in both .suspend() and .resume() to
"struct device*" type.

Compile-tested only.

Signed-off-by: Vaibhav Gupta <vaibhavgupta40 at gmail.com>
---
 .../media/platform/marvell-ccic/cafe-driver.c | 31 +++++--------------
 .../media/platform/marvell-ccic/mcam-core.c   |  3 --
 2 files changed, 7 insertions(+), 27 deletions(-)

diff --git a/drivers/media/platform/marvell-ccic/cafe-driver.c b/drivers/media/platform/marvell-ccic/cafe-driver.c
index 9a09a10a3631..58b9915ac7a4 100644
--- a/drivers/media/platform/marvell-ccic/cafe-driver.c
+++ b/drivers/media/platform/marvell-ccic/cafe-driver.c
@@ -604,44 +604,28 @@ static void cafe_pci_remove(struct pci_dev *pdev)
 }
 
 
-#ifdef CONFIG_PM
 /*
  * Basic power management.
  */
-static int cafe_pci_suspend(struct pci_dev *pdev, pm_message_t state)
+static int __maybe_unused cafe_pci_suspend(struct device *dev)
 {
-	struct v4l2_device *v4l2_dev = dev_get_drvdata(&pdev->dev);
+	struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
 	struct cafe_camera *cam = to_cam(v4l2_dev);
-	int ret;
 
-	ret = pci_save_state(pdev);
-	if (ret)
-		return ret;
 	mccic_suspend(&cam->mcam);
-	pci_disable_device(pdev);
 	return 0;
 }
 
 
-static int cafe_pci_resume(struct pci_dev *pdev)
+static int __maybe_unused cafe_pci_resume(struct device *dev)
 {
-	struct v4l2_device *v4l2_dev = dev_get_drvdata(&pdev->dev);
+	struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
 	struct cafe_camera *cam = to_cam(v4l2_dev);
-	int ret = 0;
 
-	pci_restore_state(pdev);
-	ret = pci_enable_device(pdev);
-
-	if (ret) {
-		cam_warn(cam, "Unable to re-enable device on resume!\n");
-		return ret;
-	}
 	cafe_ctlr_init(&cam->mcam);
 	return mccic_resume(&cam->mcam);
 }
 
-#endif  /* CONFIG_PM */
-
 static const struct pci_device_id cafe_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_MARVELL,
 		     PCI_DEVICE_ID_MARVELL_88ALP01_CCIC) },
@@ -650,15 +634,14 @@ static const struct pci_device_id cafe_ids[] = {
 
 MODULE_DEVICE_TABLE(pci, cafe_ids);
 
+static SIMPLE_DEV_PM_OPS(cafe_pci_pm_ops, cafe_pci_suspend, cafe_pci_resume);
+
 static struct pci_driver cafe_pci_driver = {
 	.name = "cafe1000-ccic",
 	.id_table = cafe_ids,
 	.probe = cafe_pci_probe,
 	.remove = cafe_pci_remove,
-#ifdef CONFIG_PM
-	.suspend = cafe_pci_suspend,
-	.resume = cafe_pci_resume,
-#endif
+	.driver.pm = &cafe_pci_pm_ops,
 };
 
 
diff --git a/drivers/media/platform/marvell-ccic/mcam-core.c b/drivers/media/platform/marvell-ccic/mcam-core.c
index 09775b6624c6..d81d0c130e3c 100644
--- a/drivers/media/platform/marvell-ccic/mcam-core.c
+++ b/drivers/media/platform/marvell-ccic/mcam-core.c
@@ -1967,8 +1967,6 @@ EXPORT_SYMBOL_GPL(mccic_shutdown);
 /*
  * Power management
  */
-#ifdef CONFIG_PM
-
 void mccic_suspend(struct mcam_camera *cam)
 {
 	mutex_lock(&cam->s_mutex);
@@ -2015,7 +2013,6 @@ int mccic_resume(struct mcam_camera *cam)
 	return ret;
 }
 EXPORT_SYMBOL_GPL(mccic_resume);
-#endif /* CONFIG_PM */
 
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Jonathan Corbet <corbet at lwn.net>");
-- 
2.27.0



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