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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>,
        Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc:     Vaibhav Gupta <vaibhavgupta40@gmail.com>,
        linux1394-devel@lists.sourceforge.net,
        linux-kernel@vger.kernel.org,
        linux-kernel-mentees@lists.linuxfoundation.org,
        Shuah Khan <skhan@linuxfoundation.org>
Subject: [PATCH v1] firewire: ohci: use generic power management
Date:   Mon, 20 Jul 2020 20:37:16 +0530
Message-Id: <20200720150715.624520-1-vaibhavgupta40@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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_disable_device() 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 to_pci_dev() to get "struct pci_dev*" variable.

Compile-tested only.

Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
---
 drivers/firewire/ohci.c | 43 ++++++++++++-----------------------------
 1 file changed, 12 insertions(+), 31 deletions(-)

diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 54fdc39cd0bc..2d19db5e81a1 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -3169,8 +3169,7 @@ static int ohci_set_iso_channels(struct fw_iso_context *base, u64 *channels)
 	return ret;
 }
 
-#ifdef CONFIG_PM
-static void ohci_resume_iso_dma(struct fw_ohci *ohci)
+static void __maybe_unused ohci_resume_iso_dma(struct fw_ohci *ohci)
 {
 	int i;
 	struct iso_context *ctx;
@@ -3187,7 +3186,6 @@ static void ohci_resume_iso_dma(struct fw_ohci *ohci)
 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
 	}
 }
-#endif
 
 static int queue_iso_transmit(struct iso_context *ctx,
 			      struct fw_iso_packet *packet,
@@ -3793,39 +3791,24 @@ static void pci_remove(struct pci_dev *dev)
 	dev_notice(&dev->dev, "removed fw-ohci device\n");
 }
 
-#ifdef CONFIG_PM
-static int pci_suspend(struct pci_dev *dev, pm_message_t state)
+static int __maybe_unused pci_suspend(struct device *dev)
 {
-	struct fw_ohci *ohci = pci_get_drvdata(dev);
-	int err;
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct fw_ohci *ohci = pci_get_drvdata(pdev);
 
 	software_reset(ohci);
-	err = pci_save_state(dev);
-	if (err) {
-		ohci_err(ohci, "pci_save_state failed\n");
-		return err;
-	}
-	err = pci_set_power_state(dev, pci_choose_state(dev, state));
-	if (err)
-		ohci_err(ohci, "pci_set_power_state failed with %d\n", err);
-	pmac_ohci_off(dev);
+	pmac_ohci_off(pdev);
 
 	return 0;
 }
 
-static int pci_resume(struct pci_dev *dev)
+static int __maybe_unused pci_resume(struct device *dev)
 {
-	struct fw_ohci *ohci = pci_get_drvdata(dev);
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct fw_ohci *ohci = pci_get_drvdata(pdev);
 	int err;
 
-	pmac_ohci_on(dev);
-	pci_set_power_state(dev, PCI_D0);
-	pci_restore_state(dev);
-	err = pci_enable_device(dev);
-	if (err) {
-		ohci_err(ohci, "pci_enable_device failed\n");
-		return err;
-	}
+	pmac_ohci_on(pdev);
 
 	/* Some systems don't setup GUID register on resume from ram  */
 	if (!reg_read(ohci, OHCI1394_GUIDLo) &&
@@ -3842,7 +3825,6 @@ static int pci_resume(struct pci_dev *dev)
 
 	return 0;
 }
-#endif
 
 static const struct pci_device_id pci_table[] = {
 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_FIREWIRE_OHCI, ~0) },
@@ -3851,15 +3833,14 @@ static const struct pci_device_id pci_table[] = {
 
 MODULE_DEVICE_TABLE(pci, pci_table);
 
+static SIMPLE_DEV_PM_OPS(pci_pm_ops, pci_suspend, pci_resume);
+
 static struct pci_driver fw_ohci_pci_driver = {
 	.name		= ohci_driver_name,
 	.id_table	= pci_table,
 	.probe		= pci_probe,
 	.remove		= pci_remove,
-#ifdef CONFIG_PM
-	.resume		= pci_resume,
-	.suspend	= pci_suspend,
-#endif
+	.driver.pm	= &pci_pm_ops,
 };
 
 static int __init fw_ohci_init(void)
-- 
2.27.0