[Linux-kernel-mentees] [PATCH v2 13/15] scsi: 3w-sas: use generic power management

[Vaibhav Gupta <vaibhavgupta40@gmail.com>]

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_enable/disable_device(),
pci_set_power_state() and pci_set_master() 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() and dev_get_drvdata() to get
"struct pci_dev*" variable and drv data.

Compile-tested only.

Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
---
 drivers/scsi/3w-sas.c | 31 ++++++++-----------------------
 1 file changed, 8 insertions(+), 23 deletions(-)

diff --git a/drivers/scsi/3w-sas.c b/drivers/scsi/3w-sas.c
index dda6fa857709..efaba30b0ca8 100644
--- a/drivers/scsi/3w-sas.c
+++ b/drivers/scsi/3w-sas.c
@@ -1756,11 +1756,10 @@ static void twl_remove(struct pci_dev *pdev)
 	twl_device_extension_count--;
 } /* End twl_remove() */
 
-#ifdef CONFIG_PM
 /* This function is called on PCI suspend */
-static int twl_suspend(struct pci_dev *pdev, pm_message_t state)
+static int __maybe_unused twl_suspend(struct device *dev)
 {
-	struct Scsi_Host *host = pci_get_drvdata(pdev);
+	struct Scsi_Host *host = dev_get_drvdata(dev);
 	TW_Device_Extension *tw_dev = (TW_Device_Extension *)host->hostdata;
 
 	printk(KERN_WARNING "3w-sas: Suspending host %d.\n", tw_dev->host->host_no);
@@ -1779,32 +1778,21 @@ static int twl_suspend(struct pci_dev *pdev, pm_message_t state)
 	/* Clear doorbell interrupt */
 	TWL_CLEAR_DB_INTERRUPT(tw_dev);
 
-	pci_save_state(pdev);
-	pci_disable_device(pdev);
-	pci_set_power_state(pdev, pci_choose_state(pdev, state));
-
 	return 0;
 } /* End twl_suspend() */
 
 /* This function is called on PCI resume */
-static int twl_resume(struct pci_dev *pdev)
+static int __maybe_unused twl_resume(struct device *dev)
 {
 	int retval = 0;
+	struct pci_dev *pdev = to_pci_dev(dev);
 	struct Scsi_Host *host = pci_get_drvdata(pdev);
 	TW_Device_Extension *tw_dev = (TW_Device_Extension *)host->hostdata;
 
 	printk(KERN_WARNING "3w-sas: Resuming host %d.\n", tw_dev->host->host_no);
-	pci_set_power_state(pdev, PCI_D0);
-	pci_enable_wake(pdev, PCI_D0, 0);
-	pci_restore_state(pdev);
 
-	retval = pci_enable_device(pdev);
-	if (retval) {
-		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x24, "Enable device failed during resume");
-		return retval;
-	}
+	device_wakeup_disable(dev);
 
-	pci_set_master(pdev);
 	pci_try_set_mwi(pdev);
 
 	retval = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
@@ -1842,11 +1830,9 @@ static int twl_resume(struct pci_dev *pdev)
 
 out_disable_device:
 	scsi_remove_host(host);
-	pci_disable_device(pdev);
 
 	return retval;
 } /* End twl_resume() */
-#endif
 
 /* PCI Devices supported by this driver */
 static struct pci_device_id twl_pci_tbl[] = {
@@ -1855,16 +1841,15 @@ static struct pci_device_id twl_pci_tbl[] = {
 };
 MODULE_DEVICE_TABLE(pci, twl_pci_tbl);
 
+static SIMPLE_DEV_PM_OPS(twl_pm_ops, twl_suspend, twl_resume);
+
 /* pci_driver initializer */
 static struct pci_driver twl_driver = {
 	.name		= "3w-sas",
 	.id_table	= twl_pci_tbl,
 	.probe		= twl_probe,
 	.remove		= twl_remove,
-#ifdef CONFIG_PM
-	.suspend	= twl_suspend,
-	.resume		= twl_resume,
-#endif
+	.driver.pm	= &twl_pm_ops,
 	.shutdown	= twl_shutdown
 };
 
-- 
2.27.0

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