hostap: 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 <[e-mail]>
Signed-off-by: Kalle Valo <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/net/wireless/intersil/hostap/hostap_hw.c

···
 }
 
 
-#if (defined(PRISM2_PCI) && defined(CONFIG_PM)) || defined(PRISM2_PCCARD)
-static void prism2_suspend(struct net_device *dev)
+#if defined(PRISM2_PCI) || defined(PRISM2_PCCARD)
+static void __maybe_unused prism2_suspend(struct net_device *dev)
 {
 	struct hostap_interface *iface;
 	struct local_info *local;
···
 	/* Disable hardware and firmware */
 	prism2_hw_shutdown(dev, 0);
 }
-#endif /* (PRISM2_PCI && CONFIG_PM) || PRISM2_PCCARD */
+#endif /* PRISM2_PCI || PRISM2_PCCARD */
 
 
 /* These might at some point be compiled separately and used as separate

drivers/net/wireless/intersil/hostap/hostap_pci.c

···
 	pci_disable_device(pdev);
 }
 
-
-#ifdef CONFIG_PM
-static int prism2_pci_suspend(struct pci_dev *pdev, pm_message_t state)
+static int __maybe_unused prism2_pci_suspend(struct device *dev_d)
 {
-	struct net_device *dev = pci_get_drvdata(pdev);
+	struct net_device *dev = dev_get_drvdata(dev_d);
 
 	if (netif_running(dev)) {
 		netif_stop_queue(dev);
 		netif_device_detach(dev);
 	}
 	prism2_suspend(dev);
-	pci_save_state(pdev);
-	pci_disable_device(pdev);
-	pci_set_power_state(pdev, PCI_D3hot);
 
 	return 0;
 }
 
-static int prism2_pci_resume(struct pci_dev *pdev)
+static int __maybe_unused prism2_pci_resume(struct device *dev_d)
 {
-	struct net_device *dev = pci_get_drvdata(pdev);
-	int err;
+	struct net_device *dev = dev_get_drvdata(dev_d);
 
-	err = pci_enable_device(pdev);
-	if (err) {
-		printk(KERN_ERR "%s: pci_enable_device failed on resume\n",
-		       dev->name);
-		return err;
-	}
-	pci_restore_state(pdev);
 	prism2_hw_config(dev, 0);
 	if (netif_running(dev)) {
 		netif_device_attach(dev);
···
 
 	return 0;
 }
-#endif /* CONFIG_PM */
-
 
 MODULE_DEVICE_TABLE(pci, prism2_pci_id_table);
+
+static SIMPLE_DEV_PM_OPS(prism2_pci_pm_ops,
+			 prism2_pci_suspend,
+			 prism2_pci_resume);
 
 static struct pci_driver prism2_pci_driver = {
 	.name		= "hostap_pci",
 	.id_table	= prism2_pci_id_table,
 	.probe		= prism2_pci_probe,
 	.remove		= prism2_pci_remove,
-#ifdef CONFIG_PM
-	.suspend	= prism2_pci_suspend,
-	.resume		= prism2_pci_resume,
-#endif /* CONFIG_PM */
+	.driver.pm	= &prism2_pci_pm_ops,
 };
 
 module_pci_driver(prism2_pci_driver);