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From:   Vaibhav Gupta <vaibhavgupta40@gmail.com>
To:     Bjorn Helgaas <helgaas@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Bjorn Helgaas <bjorn@helgaas.com>,
        Vaibhav Gupta <vaibhav.varodek@gmail.com>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
        Paul Mackerras <paulus@samba.org>,
        Russell King <linux@armlinux.org.uk>,
        Andres Salomon <dilinger@queued.net>,
        Antonino Daplas <adaplas@gmail.com>,
        Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc:     Vaibhav Gupta <vaibhavgupta40@gmail.com>,
        dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-geode@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-kernel-mentees@lists.linuxfoundation.org,
        Shuah Khan <skhan@linuxfoundation.org>
Subject: [PATCH v1 06/12] fbdev: nvidia: use generic power management
Date:   Wed,  5 Aug 2020 23:37:16 +0530
Message-Id: <20200805180722.244008-7-vaibhavgupta40@gmail.com>
In-Reply-To: <20200805180722.244008-1-vaibhavgupta40@gmail.com>
References: <20200805180722.244008-1-vaibhavgupta40@gmail.com>
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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@gmail.com>
---
 drivers/video/fbdev/nvidia/nvidia.c | 64 ++++++++++++++++-------------
 1 file changed, 35 insertions(+), 29 deletions(-)

diff --git a/drivers/video/fbdev/nvidia/nvidia.c b/drivers/video/fbdev/nvidia/nvidia.c
index c24de9107958..3a1a4330e0d3 100644
--- a/drivers/video/fbdev/nvidia/nvidia.c
+++ b/drivers/video/fbdev/nvidia/nvidia.c
@@ -1041,10 +1041,9 @@ static struct fb_ops nvidia_fb_ops = {
 	.fb_sync        = nvidiafb_sync,
 };
 
-#ifdef CONFIG_PM
-static int nvidiafb_suspend(struct pci_dev *dev, pm_message_t mesg)
+static int nvidiafb_suspend_late(struct device *dev, pm_message_t mesg)
 {
-	struct fb_info *info = pci_get_drvdata(dev);
+	struct fb_info *info = dev_get_drvdata(dev);
 	struct nvidia_par *par = info->par;
 
 	if (mesg.event == PM_EVENT_PRETHAW)
@@ -1056,46 +1055,54 @@ static int nvidiafb_suspend(struct pci_dev *dev, pm_message_t mesg)
 		fb_set_suspend(info, 1);
 		nvidiafb_blank(FB_BLANK_POWERDOWN, info);
 		nvidia_write_regs(par, &par->SavedReg);
-		pci_save_state(dev);
-		pci_disable_device(dev);
-		pci_set_power_state(dev, pci_choose_state(dev, mesg));
 	}
-	dev->dev.power.power_state = mesg;
+	dev->power.power_state = mesg;
 
 	console_unlock();
 	return 0;
 }
 
-static int nvidiafb_resume(struct pci_dev *dev)
+static int __maybe_unused nvidiafb_suspend(struct device *dev)
 {
-	struct fb_info *info = pci_get_drvdata(dev);
-	struct nvidia_par *par = info->par;
+	return nvidiafb_suspend_late(dev, PMSG_SUSPEND);
+}
 
-	console_lock();
-	pci_set_power_state(dev, PCI_D0);
+static int __maybe_unused nvidiafb_hibernate(struct device *dev)
+{
+	return nvidiafb_suspend_late(dev, PMSG_HIBERNATE);
+}
 
-	if (par->pm_state != PM_EVENT_FREEZE) {
-		pci_restore_state(dev);
+static int __maybe_unused nvidiafb_freeze(struct device *dev)
+{
+	return nvidiafb_suspend_late(dev, PMSG_FREEZE);
+}
 
-		if (pci_enable_device(dev))
-			goto fail;
+static int __maybe_unused nvidiafb_resume(struct device *dev)
+{
+	struct fb_info *info = dev_get_drvdata(dev);
+	struct nvidia_par *par = info->par;
 
-		pci_set_master(dev);
-	}
+	console_lock();
 
 	par->pm_state = PM_EVENT_ON;
 	nvidiafb_set_par(info);
 	fb_set_suspend (info, 0);
 	nvidiafb_blank(FB_BLANK_UNBLANK, info);
 
-fail:
 	console_unlock();
 	return 0;
 }
-#else
-#define nvidiafb_suspend NULL
-#define nvidiafb_resume NULL
-#endif
+
+static const struct dev_pm_ops nvidiafb_pm_ops = {
+#ifdef CONFIG_PM_SLEEP
+	.suspend	= nvidiafb_suspend,
+	.resume		= nvidiafb_resume,
+	.freeze		= nvidiafb_freeze,
+	.thaw		= nvidiafb_resume,
+	.poweroff	= nvidiafb_hibernate,
+	.restore	= nvidiafb_resume,
+#endif /* CONFIG_PM_SLEEP */
+};
 
 static int nvidia_set_fbinfo(struct fb_info *info)
 {
@@ -1496,12 +1503,11 @@ static int nvidiafb_setup(char *options)
 #endif				/* !MODULE */
 
 static struct pci_driver nvidiafb_driver = {
-	.name = "nvidiafb",
-	.id_table = nvidiafb_pci_tbl,
-	.probe    = nvidiafb_probe,
-	.suspend  = nvidiafb_suspend,
-	.resume   = nvidiafb_resume,
-	.remove   = nvidiafb_remove,
+	.name      = "nvidiafb",
+	.id_table  = nvidiafb_pci_tbl,
+	.probe     = nvidiafb_probe,
+	.driver.pm = &nvidiafb_pm_ops,
+	.remove    = nvidiafb_remove,
 };
 
 /* ------------------------------------------------------------------------- *
-- 
2.27.0