spi: spi-topcliff-pch: 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.

This driver makes use of PCI helper functions like
pci_save/restore_state(), pci_enable/disable_device(), pci_enable_wake()
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.

Compile-tested only.

Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Link: https://lore.kernel.org/r/20200720155714.714114-1-vaibhavgupta40@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-topcliff-pch.c

@@ -1635,64 +1635,39 @@ static void pch_spi_remove(struct pci_dev *pdev)
 	kfree(pd_dev_save);
 }
 
-#ifdef CONFIG_PM
-static int pch_spi_suspend(struct pci_dev *pdev, pm_message_t state)
+static int __maybe_unused pch_spi_suspend(struct device *dev)
 {
-	int retval;
-	struct pch_pd_dev_save *pd_dev_save = pci_get_drvdata(pdev);
+	struct pch_pd_dev_save *pd_dev_save = dev_get_drvdata(dev);
 
-	dev_dbg(&pdev->dev, "%s ENTRY\n", __func__);
+	dev_dbg(dev, "%s ENTRY\n", __func__);
 
 	pd_dev_save->board_dat->suspend_sts = true;
 
-	/* save config space */
-	retval = pci_save_state(pdev);
-	if (retval == 0) {
-		pci_enable_wake(pdev, PCI_D3hot, 0);
-		pci_disable_device(pdev);
-		pci_set_power_state(pdev, PCI_D3hot);
-	} else {
-		dev_err(&pdev->dev, "%s pci_save_state failed\n", __func__);
-	}
-
-	return retval;
+	return 0;
 }
 
-static int pch_spi_resume(struct pci_dev *pdev)
+static int __maybe_unused pch_spi_resume(struct device *dev)
 {
-	int retval;
-	struct pch_pd_dev_save *pd_dev_save = pci_get_drvdata(pdev);
-	dev_dbg(&pdev->dev, "%s ENTRY\n", __func__);
+	struct pch_pd_dev_save *pd_dev_save = dev_get_drvdata(dev);
 
-	pci_set_power_state(pdev, PCI_D0);
-	pci_restore_state(pdev);
+	dev_dbg(dev, "%s ENTRY\n", __func__);
 
-	retval = pci_enable_device(pdev);
-	if (retval < 0) {
-		dev_err(&pdev->dev,
-			"%s pci_enable_device failed\n", __func__);
-	} else {
-		pci_enable_wake(pdev, PCI_D3hot, 0);
+	device_wakeup_disable(dev);
 
-		/* set suspend status to false */
-		pd_dev_save->board_dat->suspend_sts = false;
-	}
+	/* set suspend status to false */
+	pd_dev_save->board_dat->suspend_sts = false;
 
-	return retval;
+	return 0;
 }
-#else
-#define pch_spi_suspend NULL
-#define pch_spi_resume NULL
 
-#endif
+static SIMPLE_DEV_PM_OPS(pch_spi_pm_ops, pch_spi_suspend, pch_spi_resume);
 
 static struct pci_driver pch_spi_pcidev_driver = {
 	.name = "pch_spi",
 	.id_table = pch_spi_pcidev_id,
 	.probe = pch_spi_probe,
 	.remove = pch_spi_remove,
-	.suspend = pch_spi_suspend,
-	.resume = pch_spi_resume,
+	.driver.pm = &pch_spi_pm_ops,
 };
 
 static int __init pch_spi_init(void)