prism54: islpci_hotplug: use generic power management

Drivers using legacy power management .suspen()/.resume() callbacks
have to manage PCI states and device's PM states themselves. They also
need to take care of standard configuration registers.

Switch to generic power management framework using a single
"struct dev_pm_ops" variable to take the unnecessary load from the driver.
This also avoids the need for the driver to directly call most of the PCI
helper functions and device power state control functions as through
the generic framework, PCI Core takes care of the necessary operations,
and drivers are required to do only device-specific jobs.
Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200721125514.145607-1-vaibhavgupta40@gmail.com

drivers/net/wireless/intersil/prism54/islpci_hotplug.c

@@ -63,16 +63,17 @@ MODULE_DEVICE_TABLE(pci, prism54_id_tbl);
 
 static int prism54_probe(struct pci_dev *, const struct pci_device_id *);
 static void prism54_remove(struct pci_dev *);
-static int prism54_suspend(struct pci_dev *, pm_message_t state);
-static int prism54_resume(struct pci_dev *);
+static int __maybe_unused prism54_suspend(struct device *);
+static int __maybe_unused prism54_resume(struct device *);
+
+static SIMPLE_DEV_PM_OPS(prism54_pm_ops, prism54_suspend, prism54_resume);
 
 static struct pci_driver prism54_driver = {
 	.name = DRV_NAME,
 	.id_table = prism54_id_tbl,
 	.probe = prism54_probe,
 	.remove = prism54_remove,
-	.suspend = prism54_suspend,
-	.resume = prism54_resume,
+	.driver.pm = &prism54_pm_ops,
 };
 
 /******************************************************************************
@@ -243,16 +244,13 @@ prism54_remove(struct pci_dev *pdev)
 	pci_disable_device(pdev);
 }
 
-static int
-prism54_suspend(struct pci_dev *pdev, pm_message_t state)
+static int __maybe_unused
+prism54_suspend(struct device *dev)
 {
-	struct net_device *ndev = pci_get_drvdata(pdev);
+	struct net_device *ndev = dev_get_drvdata(dev);
 	islpci_private *priv = ndev ? netdev_priv(ndev) : NULL;
 	BUG_ON(!priv);
 
-
-	pci_save_state(pdev);
-
 	/* tell the device not to trigger interrupts for now... */
 	isl38xx_disable_interrupts(priv->device_base);
 
@@ -266,26 +264,16 @@ prism54_suspend(struct pci_dev *pdev, pm_message_t state)
 	return 0;
 }
 
-static int
-prism54_resume(struct pci_dev *pdev)
+static int __maybe_unused
+prism54_resume(struct device *dev)
 {
-	struct net_device *ndev = pci_get_drvdata(pdev);
+	struct net_device *ndev = dev_get_drvdata(dev);
 	islpci_private *priv = ndev ? netdev_priv(ndev) : NULL;
-	int err;
 
 	BUG_ON(!priv);
 
 	printk(KERN_NOTICE "%s: got resume request\n", ndev->name);
 
-	err = pci_enable_device(pdev);
-	if (err) {
-		printk(KERN_ERR "%s: pci_enable_device failed on resume\n",
-		       ndev->name);
-		return err;
-	}
-
-	pci_restore_state(pdev);
-
 	/* alright let's go into the PREBOOT state */
 	islpci_reset(priv, 1);