[Linux-kernel-mentees] [PATCH v2 01/12] fbdev: gxfb: use generic power management

[Vaibhav Gupta <vaibhavgupta40@gmail.com>]

Drivers should do only device-specific jobs. But in general, drivers using
legacy PCI PM framework for .suspend()/.resume() have to manage many PCI
PM-related tasks themselves which can be done by PCI Core itself. This
brings extra load on the driver and it directly calls PCI helper functions
to handle them.

Although the gxfb driver does not have that extra load, we should switch to
the new generic framework by updating function signatures and define a
"struct dev_pm_ops" variable to bind PM callbacks so that we can remove
the legacy .suspend & .resume bindings. Additionally, this helps us to
remove the unnecessary call to gxfb_suspend() in the event of Freeze and
Hibernate, as the function does nothing in their case.

Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
---
 drivers/video/fbdev/geode/gxfb.h       |  5 ----
 drivers/video/fbdev/geode/gxfb_core.c  | 36 ++++++++++++++------------
 drivers/video/fbdev/geode/suspend_gx.c |  4 ---
 3 files changed, 20 insertions(+), 25 deletions(-)

diff --git a/drivers/video/fbdev/geode/gxfb.h b/drivers/video/fbdev/geode/gxfb.h
index d2e9c5c8e294..792c111c21e4 100644
--- a/drivers/video/fbdev/geode/gxfb.h
+++ b/drivers/video/fbdev/geode/gxfb.h
@@ -21,7 +21,6 @@ struct gxfb_par {
 	void __iomem *dc_regs;
 	void __iomem *vid_regs;
 	void __iomem *gp_regs;
-#ifdef CONFIG_PM
 	int powered_down;
 
 	/* register state, for power management functionality */
@@ -36,7 +35,6 @@ struct gxfb_par {
 	uint64_t fp[FP_REG_COUNT];
 
 	uint32_t pal[DC_PAL_COUNT];
-#endif
 };
 
 unsigned int gx_frame_buffer_size(void);
@@ -49,11 +47,8 @@ void gx_set_dclk_frequency(struct fb_info *info);
 void gx_configure_display(struct fb_info *info);
 int gx_blank_display(struct fb_info *info, int blank_mode);
 
-#ifdef CONFIG_PM
 int gx_powerdown(struct fb_info *info);
 int gx_powerup(struct fb_info *info);
-#endif
-
 
 /* Graphics Processor registers (table 6-23 from the data book) */
 enum gp_registers {
diff --git a/drivers/video/fbdev/geode/gxfb_core.c b/drivers/video/fbdev/geode/gxfb_core.c
index d38a148d4746..44089b331f91 100644
--- a/drivers/video/fbdev/geode/gxfb_core.c
+++ b/drivers/video/fbdev/geode/gxfb_core.c
@@ -322,17 +322,14 @@ static struct fb_info *gxfb_init_fbinfo(struct device *dev)
 	return info;
 }
 
-#ifdef CONFIG_PM
-static int gxfb_suspend(struct pci_dev *pdev, pm_message_t state)
+static int __maybe_unused gxfb_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();
-		gx_powerdown(info);
-		fb_set_suspend(info, 1);
-		console_unlock();
-	}
+	console_lock();
+	gx_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 */
@@ -340,9 +337,9 @@ static int gxfb_suspend(struct pci_dev *pdev, pm_message_t state)
 	return 0;
 }
 
-static int gxfb_resume(struct pci_dev *pdev)
+static int __maybe_unused gxfb_resume(struct device *dev)
 {
-	struct fb_info *info = pci_get_drvdata(pdev);
+	struct fb_info *info = dev_get_drvdata(dev);
 	int ret;
 
 	console_lock();
@@ -356,7 +353,6 @@ static int gxfb_resume(struct pci_dev *pdev)
 	console_unlock();
 	return 0;
 }
-#endif
 
 static int gxfb_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
@@ -467,15 +463,23 @@ static const struct pci_device_id gxfb_id_table[] = {
 
 MODULE_DEVICE_TABLE(pci, gxfb_id_table);
 
+static const struct dev_pm_ops gxfb_pm_ops = {
+#ifdef CONFIG_PM_SLEEP
+	.suspend	= gxfb_suspend,
+	.resume		= gxfb_resume,
+	.freeze		= NULL,
+	.thaw		= gxfb_resume,
+	.poweroff	= NULL,
+	.restore	= gxfb_resume,
+#endif
+};
+
 static struct pci_driver gxfb_driver = {
 	.name		= "gxfb",
 	.id_table	= gxfb_id_table,
 	.probe		= gxfb_probe,
 	.remove		= gxfb_remove,
-#ifdef CONFIG_PM
-	.suspend	= gxfb_suspend,
-	.resume		= gxfb_resume,
-#endif
+	.driver.pm	= &gxfb_pm_ops,
 };
 
 #ifndef MODULE
diff --git a/drivers/video/fbdev/geode/suspend_gx.c b/drivers/video/fbdev/geode/suspend_gx.c
index 1110a527c35c..8c49d4e98772 100644
--- a/drivers/video/fbdev/geode/suspend_gx.c
+++ b/drivers/video/fbdev/geode/suspend_gx.c
@@ -11,8 +11,6 @@
 
 #include "gxfb.h"
 
-#ifdef CONFIG_PM
-
 static void gx_save_regs(struct gxfb_par *par)
 {
 	int i;
@@ -259,5 +257,3 @@ int gx_powerup(struct fb_info *info)
 	par->powered_down  = 0;
 	return 0;
 }
-
-#endif
-- 
2.27.0

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