[Linux-kernel-mentees] [PATCH v2 3/3] skd: use generic power management

[Vaibhav Gupta]

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(), pci_enable/disable_device(),
pci_request/release_regions(), pci_set_power_state() and
pci_set_master() to do required operations. In generic mode, they are no
longer needed.

Change function parameter in both .suspend() and .resume() to
"struct device*" type. Use to_pci_dev() to get "struct pci_dev*" variable.

Compile-tested only.

Signed-off-by: Vaibhav Gupta <vaibhavgupta40 at gmail.com>
---
 drivers/block/skd_main.c | 30 ++++++++----------------------
 1 file changed, 8 insertions(+), 22 deletions(-)

diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c
index 51569c199a6c..7f2d42900b38 100644
--- a/drivers/block/skd_main.c
+++ b/drivers/block/skd_main.c
@@ -3315,10 +3315,11 @@ static void skd_pci_remove(struct pci_dev *pdev)
 	return;
 }
 
-static int skd_pci_suspend(struct pci_dev *pdev, pm_message_t state)
+static int __maybe_unused skd_pci_suspend(struct device *dev)
 {
 	int i;
 	struct skd_device *skdev;
+	struct pci_dev *pdev = to_pci_dev(dev);
 
 	skdev = pci_get_drvdata(pdev);
 	if (!skdev) {
@@ -3337,18 +3338,15 @@ static int skd_pci_suspend(struct pci_dev *pdev, pm_message_t state)
 	if (skdev->pcie_error_reporting_is_enabled)
 		pci_disable_pcie_error_reporting(pdev);
 
-	pci_release_regions(pdev);
-	pci_save_state(pdev);
-	pci_disable_device(pdev);
-	pci_set_power_state(pdev, pci_choose_state(pdev, state));
 	return 0;
 }
 
-static int skd_pci_resume(struct pci_dev *pdev)
+static int __maybe_unused skd_pci_resume(struct device *dev)
 {
 	int i;
 	int rc = 0;
 	struct skd_device *skdev;
+	struct pci_dev *pdev = to_pci_dev(dev);
 
 	skdev = pci_get_drvdata(pdev);
 	if (!skdev) {
@@ -3356,16 +3354,8 @@ static int skd_pci_resume(struct pci_dev *pdev)
 		return -1;
 	}
 
-	pci_set_power_state(pdev, PCI_D0);
-	pci_enable_wake(pdev, PCI_D0, 0);
-	pci_restore_state(pdev);
+	device_wakeup_disable(dev);
 
-	rc = pci_enable_device(pdev);
-	if (rc)
-		return rc;
-	rc = pci_request_regions(pdev, DRV_NAME);
-	if (rc)
-		goto err_out;
 	rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
 	if (rc)
 		rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
@@ -3374,7 +3364,6 @@ static int skd_pci_resume(struct pci_dev *pdev)
 		goto err_out_regions;
 	}
 
-	pci_set_master(pdev);
 	rc = pci_enable_pcie_error_reporting(pdev);
 	if (rc) {
 		dev_err(&pdev->dev,
@@ -3427,10 +3416,6 @@ static int skd_pci_resume(struct pci_dev *pdev)
 		pci_disable_pcie_error_reporting(pdev);
 
 err_out_regions:
-	pci_release_regions(pdev);
-
-err_out:
-	pci_disable_device(pdev);
 	return rc;
 }
 
@@ -3450,13 +3435,14 @@ static void skd_pci_shutdown(struct pci_dev *pdev)
 	skd_stop_device(skdev);
 }
 
+static SIMPLE_DEV_PM_OPS(skd_pci_pm_ops, skd_pci_suspend, skd_pci_resume);
+
 static struct pci_driver skd_driver = {
 	.name		= DRV_NAME,
 	.id_table	= skd_pci_tbl,
 	.probe		= skd_pci_probe,
 	.remove		= skd_pci_remove,
-	.suspend	= skd_pci_suspend,
-	.resume		= skd_pci_resume,
+	.driver.pm	= &skd_pci_pm_ops,
 	.shutdown	= skd_pci_shutdown,
 };
 
-- 
2.27.0