rt2x00: pci: use generic power management

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.

The callbacks make use of PCI helper functions like
pci_save/restore_state(), pci_enable/disable_device() and
pci_set_power_state() 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 dev_get_drvdata() to get drv data.

The .suspend() callback is invoking rt2x00lib_suspend() which needs to be
modified as generic rt2x00pci_suspend() has no pm_message_t type argument,
passed to it, which is required by it according to its declaration.
Although this variable remained unused in the function body. Hence, remove
it from the function definition & declaration.

rt2x00lib_suspend() is also invoked by rt2x00usb_suspend() and
rt2x00soc_suspend(). Thus, modify the functional call accordingly in their
function body.

Earlier, .suspend() & .resume() were exported and were used by the
following drivers:
    - drivers/net/wireless/ralink/rt2x00/rt2400pci.c
    - drivers/net/wireless/ralink/rt2x00/rt2500pci.c
    - drivers/net/wireless/ralink/rt2x00/rt2800pci.c
    - drivers/net/wireless/ralink/rt2x00/rt61pci.c

Now, we only need to bind "struct dev_pm_ops" variable to
"struct pci_driver". Thus, make the callbacks static. Declare an
"extern const struct dev_pm_ops" variable and bind PM callbacks to it. Now,
export the variable instead and use it in respective drivers.

Compile-tested only.
Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200717110928.454867-1-vaibhavgupta40@gmail.com

drivers/net/wireless/ralink/rt2x00/rt2400pci.c

@@ -1834,8 +1834,7 @@ static struct pci_driver rt2400pci_driver = {
 	.id_table	= rt2400pci_device_table,
 	.probe		= rt2400pci_probe,
 	.remove		= rt2x00pci_remove,
-	.suspend	= rt2x00pci_suspend,
-	.resume		= rt2x00pci_resume,
+	.driver.pm	= &rt2x00pci_pm_ops,
 };
 
 module_pci_driver(rt2400pci_driver);

drivers/net/wireless/ralink/rt2x00/rt2500pci.c

@@ -2132,8 +2132,7 @@ static struct pci_driver rt2500pci_driver = {
 	.id_table	= rt2500pci_device_table,
 	.probe		= rt2500pci_probe,
 	.remove		= rt2x00pci_remove,
-	.suspend	= rt2x00pci_suspend,
-	.resume		= rt2x00pci_resume,
+	.driver.pm	= &rt2x00pci_pm_ops,
 };
 
 module_pci_driver(rt2500pci_driver);

drivers/net/wireless/ralink/rt2x00/rt2800pci.c

@@ -455,8 +455,7 @@ static struct pci_driver rt2800pci_driver = {
 	.id_table	= rt2800pci_device_table,
 	.probe		= rt2800pci_probe,
 	.remove		= rt2x00pci_remove,
-	.suspend	= rt2x00pci_suspend,
-	.resume		= rt2x00pci_resume,
+	.driver.pm	= &rt2x00pci_pm_ops,
 };
 
 module_pci_driver(rt2800pci_driver);

drivers/net/wireless/ralink/rt2x00/rt2x00.h

@@ -1487,9 +1487,8 @@ bool rt2x00mac_tx_frames_pending(struct ieee80211_hw *hw);
  */
 int rt2x00lib_probe_dev(struct rt2x00_dev *rt2x00dev);
 void rt2x00lib_remove_dev(struct rt2x00_dev *rt2x00dev);
-#ifdef CONFIG_PM
-int rt2x00lib_suspend(struct rt2x00_dev *rt2x00dev, pm_message_t state);
+
+int rt2x00lib_suspend(struct rt2x00_dev *rt2x00dev);
 int rt2x00lib_resume(struct rt2x00_dev *rt2x00dev);
-#endif /* CONFIG_PM */
 
 #endif /* RT2X00_H */

drivers/net/wireless/ralink/rt2x00/rt2x00dev.c

@@ -1556,8 +1556,7 @@ EXPORT_SYMBOL_GPL(rt2x00lib_remove_dev);
 /*
  * Device state handlers
  */
-#ifdef CONFIG_PM
-int rt2x00lib_suspend(struct rt2x00_dev *rt2x00dev, pm_message_t state)
+int rt2x00lib_suspend(struct rt2x00_dev *rt2x00dev)
 {
 	rt2x00_dbg(rt2x00dev, "Going to sleep\n");
 
@@ -1614,7 +1613,6 @@ int rt2x00lib_resume(struct rt2x00_dev *rt2x00dev)
 	return 0;
 }
 EXPORT_SYMBOL_GPL(rt2x00lib_resume);
-#endif /* CONFIG_PM */
 
 /*
  * rt2x00lib module information.

drivers/net/wireless/ralink/rt2x00/rt2x00pci.c

@@ -169,39 +169,24 @@ void rt2x00pci_remove(struct pci_dev *pci_dev)
 }
 EXPORT_SYMBOL_GPL(rt2x00pci_remove);
 
-#ifdef CONFIG_PM
-int rt2x00pci_suspend(struct pci_dev *pci_dev, pm_message_t state)
+static int __maybe_unused rt2x00pci_suspend(struct device *dev)
 {
-	struct ieee80211_hw *hw = pci_get_drvdata(pci_dev);
+	struct ieee80211_hw *hw = dev_get_drvdata(dev);
 	struct rt2x00_dev *rt2x00dev = hw->priv;
-	int retval;
-
-	retval = rt2x00lib_suspend(rt2x00dev, state);
-	if (retval)
-		return retval;
 
-	pci_save_state(pci_dev);
-	pci_disable_device(pci_dev);
-	return pci_set_power_state(pci_dev, pci_choose_state(pci_dev, state));
+	return rt2x00lib_suspend(rt2x00dev);
 }
-EXPORT_SYMBOL_GPL(rt2x00pci_suspend);
 
-int rt2x00pci_resume(struct pci_dev *pci_dev)
+static int __maybe_unused rt2x00pci_resume(struct device *dev)
 {
-	struct ieee80211_hw *hw = pci_get_drvdata(pci_dev);
+	struct ieee80211_hw *hw = dev_get_drvdata(dev);
 	struct rt2x00_dev *rt2x00dev = hw->priv;
 
-	if (pci_set_power_state(pci_dev, PCI_D0) ||
-	    pci_enable_device(pci_dev)) {
-		rt2x00_err(rt2x00dev, "Failed to resume device\n");
-		return -EIO;
-	}
-
-	pci_restore_state(pci_dev);
 	return rt2x00lib_resume(rt2x00dev);
 }
-EXPORT_SYMBOL_GPL(rt2x00pci_resume);
-#endif /* CONFIG_PM */
+
+SIMPLE_DEV_PM_OPS(rt2x00pci_pm_ops, rt2x00pci_suspend, rt2x00pci_resume);
+EXPORT_SYMBOL_GPL(rt2x00pci_pm_ops);
 
 /*
  * rt2x00pci module information.

drivers/net/wireless/ralink/rt2x00/rt2x00pci.h

@@ -21,12 +21,7 @@
  */
 int rt2x00pci_probe(struct pci_dev *pci_dev, const struct rt2x00_ops *ops);
 void rt2x00pci_remove(struct pci_dev *pci_dev);
-#ifdef CONFIG_PM
-int rt2x00pci_suspend(struct pci_dev *pci_dev, pm_message_t state);
-int rt2x00pci_resume(struct pci_dev *pci_dev);
-#else
-#define rt2x00pci_suspend	NULL
-#define rt2x00pci_resume	NULL
-#endif /* CONFIG_PM */
+
+extern const struct dev_pm_ops rt2x00pci_pm_ops;
 
 #endif /* RT2X00PCI_H */

drivers/net/wireless/ralink/rt2x00/rt2x00soc.c

@@ -130,7 +130,7 @@ int rt2x00soc_suspend(struct platform_device *pdev, pm_message_t state)
 	struct ieee80211_hw *hw = platform_get_drvdata(pdev);
 	struct rt2x00_dev *rt2x00dev = hw->priv;
 
-	return rt2x00lib_suspend(rt2x00dev, state);
+	return rt2x00lib_suspend(rt2x00dev);
 }
 EXPORT_SYMBOL_GPL(rt2x00soc_suspend);
 

drivers/net/wireless/ralink/rt2x00/rt2x00usb.c

@@ -886,7 +886,7 @@ int rt2x00usb_suspend(struct usb_interface *usb_intf, pm_message_t state)
 	struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
 	struct rt2x00_dev *rt2x00dev = hw->priv;
 
-	return rt2x00lib_suspend(rt2x00dev, state);
+	return rt2x00lib_suspend(rt2x00dev);
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_suspend);
 

drivers/net/wireless/ralink/rt2x00/rt61pci.c

@@ -3009,8 +3009,7 @@ static struct pci_driver rt61pci_driver = {
 	.id_table	= rt61pci_device_table,
 	.probe		= rt61pci_probe,
 	.remove		= rt2x00pci_remove,
-	.suspend	= rt2x00pci_suspend,
-	.resume		= rt2x00pci_resume,
+	.driver.pm	= &rt2x00pci_pm_ops,
 };
 
 module_pci_driver(rt61pci_driver);