[PATCH v1 11/12] fbdev: s3fb: use generic power management

[Vaibhav Gupta]

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 at gmail.com>
---
 drivers/video/fbdev/s3fb.c | 39 ++++++++++++++++----------------------
 1 file changed, 16 insertions(+), 23 deletions(-)

diff --git a/drivers/video/fbdev/s3fb.c b/drivers/video/fbdev/s3fb.c
index 60c424fae988..5c74253e7b2c 100644
--- a/drivers/video/fbdev/s3fb.c
+++ b/drivers/video/fbdev/s3fb.c
@@ -1410,9 +1410,9 @@ static void s3_pci_remove(struct pci_dev *dev)
 
 /* PCI suspend */
 
-static int s3_pci_suspend(struct pci_dev* dev, pm_message_t state)
+static int __maybe_unused s3_pci_suspend(struct device *dev)
 {
-	struct fb_info *info = pci_get_drvdata(dev);
+	struct fb_info *info = dev_get_drvdata(dev);
 	struct s3fb_info *par = info->par;
 
 	dev_info(info->device, "suspend\n");
@@ -1420,7 +1420,7 @@ static int s3_pci_suspend(struct pci_dev* dev, pm_message_t state)
 	console_lock();
 	mutex_lock(&(par->open_lock));
 
-	if ((state.event == PM_EVENT_FREEZE) || (par->ref_count == 0)) {
+	if (par->ref_count == 0) {
 		mutex_unlock(&(par->open_lock));
 		console_unlock();
 		return 0;
@@ -1428,10 +1428,6 @@ static int s3_pci_suspend(struct pci_dev* dev, pm_message_t state)
 
 	fb_set_suspend(info, 1);
 
-	pci_save_state(dev);
-	pci_disable_device(dev);
-	pci_set_power_state(dev, pci_choose_state(dev, state));
-
 	mutex_unlock(&(par->open_lock));
 	console_unlock();
 
@@ -1441,11 +1437,10 @@ static int s3_pci_suspend(struct pci_dev* dev, pm_message_t state)
 
 /* PCI resume */
 
-static int s3_pci_resume(struct pci_dev* dev)
+static int __maybe_unused s3_pci_resume(struct device *dev)
 {
-	struct fb_info *info = pci_get_drvdata(dev);
+	struct fb_info *info = dev_get_drvdata(dev);
 	struct s3fb_info *par = info->par;
-	int err;
 
 	dev_info(info->device, "resume\n");
 
@@ -1458,17 +1453,6 @@ static int s3_pci_resume(struct pci_dev* dev)
 		return 0;
 	}
 
-	pci_set_power_state(dev, PCI_D0);
-	pci_restore_state(dev);
-	err = pci_enable_device(dev);
-	if (err) {
-		mutex_unlock(&(par->open_lock));
-		console_unlock();
-		dev_err(info->device, "error %d enabling device for resume\n", err);
-		return err;
-	}
-	pci_set_master(dev);
-
 	s3fb_set_par(info);
 	fb_set_suspend(info, 0);
 
@@ -1478,6 +1462,16 @@ static int s3_pci_resume(struct pci_dev* dev)
 	return 0;
 }
 
+static const struct dev_pm_ops s3_pci_pm_ops = {
+#ifdef CONFIG_PM_SLEEP
+	.suspend	= s3_pci_suspend,
+	.resume		= s3_pci_resume,
+	.freeze		= NULL,
+	.thaw		= s3_pci_resume,
+	.poweroff	= s3_pci_suspend,
+	.restore	= s3_pci_resume,
+#endif
+};
 
 /* List of boards that we are trying to support */
 
@@ -1510,8 +1504,7 @@ static struct pci_driver s3fb_pci_driver = {
 	.id_table	= s3_devices,
 	.probe		= s3_pci_probe,
 	.remove		= s3_pci_remove,
-	.suspend	= s3_pci_suspend,
-	.resume		= s3_pci_resume,
+	.driver.pm	= &s3_pci_pm_ops,
 };
 
 /* Parse user specified options */
-- 
2.27.0