fbdev: lxfb: use generic power management

Switch to the new generic framework by updating function signatures and
define a "struct dev_pm_ops" variable to bind PM callbacks. This way we can
remove the legacy .suspend & .resume bindings from "lxfb_driver".

The lxfb_suspend() is designed to function only in the case of Suspend.
Thus, the code was kept inside "if (state.event == PM_EVENT_SUSPEND)"
container. This is because, in the legacy framework, this callback was
invoked even in the event of Freeze and Hibernate. Hence, added the load of
unnecessary function-calls.

The goal can be achieved by binding the callback with only
"lxfb_pm_ops.suspend" in the new framework. This also avoids the step of
checking "if (state.event == PM_EVENT_SUSPEND)" every time the callback is
invoked.
Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Cc: Bjorn Helgaas <helgaas@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Bjorn Helgaas <bjorn@helgaas.com>
Cc: Vaibhav Gupta <vaibhav.varodek@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Andres Salomon <dilinger@queued.net>
CC: Antonino Daplas <adaplas@gmail.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200819185654.151170-3-vaibhavgupta40@gmail.com

drivers/video/fbdev/geode/lxfb.h

@@ -29,7 +29,6 @@ struct lxfb_par {
 	void __iomem *gp_regs;
 	void __iomem *dc_regs;
 	void __iomem *vp_regs;
-#ifdef CONFIG_PM
 	int powered_down;
 
 	/* register state, for power mgmt functionality */
@@ -50,7 +49,6 @@ struct lxfb_par {
 	uint32_t hcoeff[DC_HFILT_COUNT * 2];
 	uint32_t vcoeff[DC_VFILT_COUNT];
 	uint32_t vp_coeff[VP_COEFF_SIZE / 4];
-#endif
 };
 
 static inline unsigned int lx_get_pitch(unsigned int xres, int bpp)
@@ -64,11 +62,8 @@ int lx_blank_display(struct fb_info *, int);
 void lx_set_palette_reg(struct fb_info *, unsigned int, unsigned int,
 			unsigned int, unsigned int);
 
-#ifdef CONFIG_PM
 int lx_powerdown(struct fb_info *info);
 int lx_powerup(struct fb_info *info);
-#endif
-
 
 /* Graphics Processor registers (table 6-29 from the data book) */
 enum gp_registers {

drivers/video/fbdev/geode/lxfb_core.c

@@ -443,17 +443,14 @@ static struct fb_info *lxfb_init_fbinfo(struct device *dev)
 	return info;
 }
 
-#ifdef CONFIG_PM
-static int lxfb_suspend(struct pci_dev *pdev, pm_message_t state)
+static int __maybe_unused lxfb_suspend(struct device *dev)
 {
-	struct fb_info *info = pci_get_drvdata(pdev);
+	struct fb_info *info = dev_get_drvdata(dev);
 
-	if (state.event == PM_EVENT_SUSPEND) {
 	console_lock();
 	lx_powerdown(info);
 	fb_set_suspend(info, 1);
 	console_unlock();
-	}
 
 	/* there's no point in setting PCI states; we emulate PCI, so
 	 * we don't end up getting power savings anyways */
@@ -461,9 +458,9 @@ static int lxfb_suspend(struct pci_dev *pdev, pm_message_t state)
 	return 0;
 }
 
-static int lxfb_resume(struct pci_dev *pdev)
+static int __maybe_unused lxfb_resume(struct device *dev)
 {
-	struct fb_info *info = pci_get_drvdata(pdev);
+	struct fb_info *info = dev_get_drvdata(dev);
 	int ret;
 
 	console_lock();
@@ -477,10 +474,6 @@ static int lxfb_resume(struct pci_dev *pdev)
 	console_unlock();
 	return 0;
 }
-#else
-#define lxfb_suspend NULL
-#define lxfb_resume NULL
-#endif
 
 static int lxfb_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
@@ -600,13 +593,23 @@ static struct pci_device_id lxfb_id_table[] = {
 
 MODULE_DEVICE_TABLE(pci, lxfb_id_table);
 
+static const struct dev_pm_ops lxfb_pm_ops = {
+#ifdef CONFIG_PM_SLEEP
+	.suspend	= lxfb_suspend,
+	.resume		= lxfb_resume,
+	.freeze		= NULL,
+	.thaw		= lxfb_resume,
+	.poweroff	= NULL,
+	.restore	= lxfb_resume,
+#endif
+};
+
 static struct pci_driver lxfb_driver = {
 	.name		= "lxfb",
 	.id_table	= lxfb_id_table,
 	.probe		= lxfb_probe,
 	.remove		= lxfb_remove,
-	.suspend	= lxfb_suspend,
-	.resume		= lxfb_resume,
+	.driver.pm	= &lxfb_pm_ops,
 };
 
 #ifndef MODULE

drivers/video/fbdev/geode/lxfb_ops.c

@@ -580,8 +580,6 @@ int lx_blank_display(struct fb_info *info, int blank_mode)
 	return 0;
 }
 
-#ifdef CONFIG_PM
-
 static void lx_save_regs(struct lxfb_par *par)
 {
 	uint32_t filt;
@@ -837,5 +835,3 @@ int lx_powerup(struct fb_info *info)
 	par->powered_down = 0;
 	return 0;
 }
-
-#endif