[Linux-kernel-mentees] [PATCH v2 3/4] ide: sc1200: use generic power management

[Vaibhav Gupta]

With the support of generic PM callbacks, drivers no longer need to use
legacy .suspend() and .resume() in which they had to maintain PCI states
changes and device's power state themselves. The required operations are
done by PCI core.

Compile-tested only.

Signed-off-by: Vaibhav Gupta <vaibhavgupta40 at gmail.com>
---
 drivers/ide/sc1200.c | 43 ++++++++++++++-----------------------------
 1 file changed, 14 insertions(+), 29 deletions(-)

diff --git a/drivers/ide/sc1200.c b/drivers/ide/sc1200.c
index a5b701818405..91a197832d1f 100644
--- a/drivers/ide/sc1200.c
+++ b/drivers/ide/sc1200.c
@@ -222,46 +222,33 @@ static void sc1200_set_pio_mode(ide_hwif_t *hwif, ide_drive_t *drive)
 	sc1200_tunepio(drive, pio);
 }
 
-#ifdef CONFIG_PM
 struct sc1200_saved_state {
 	u32 regs[8];
 };
 
-static int sc1200_suspend (struct pci_dev *dev, pm_message_t state)
+static int __maybe_unused sc1200_suspend(struct device *dev_d)
 {
-	printk("SC1200: suspend(%u)\n", state.event);
+	struct pci_dev *dev = to_pci_dev(dev_d);
+	struct ide_host *host = pci_get_drvdata(dev);
+	struct sc1200_saved_state *ss = host->host_priv;
+	unsigned int r;
 
 	/*
-	 * we only save state when going from full power to less
+	 * save timing registers
+	 * (this may be unnecessary if BIOS also does it)
 	 */
-	if (state.event == PM_EVENT_ON) {
-		struct ide_host *host = pci_get_drvdata(dev);
-		struct sc1200_saved_state *ss = host->host_priv;
-		unsigned int r;
-
-		/*
-		 * save timing registers
-		 * (this may be unnecessary if BIOS also does it)
-		 */
-		for (r = 0; r < 8; r++)
-			pci_read_config_dword(dev, 0x40 + r * 4, &ss->regs[r]);
-	}
+	for (r = 0; r < 8; r++)
+		pci_read_config_dword(dev, 0x40 + r * 4, &ss->regs[r]);
 
-	pci_disable_device(dev);
-	pci_set_power_state(dev, pci_choose_state(dev, state));
 	return 0;
 }
 
-static int sc1200_resume (struct pci_dev *dev)
+static int __maybe_unused sc1200_resume(struct device *dev_d)
 {
+	struct pci_dev *dev = to_pci_dev(dev_d);
 	struct ide_host *host = pci_get_drvdata(dev);
 	struct sc1200_saved_state *ss = host->host_priv;
 	unsigned int r;
-	int i;
-
-	i = pci_enable_device(dev);
-	if (i)
-		return i;
 
 	/*
 	 * restore timing registers
@@ -272,7 +259,6 @@ static int sc1200_resume (struct pci_dev *dev)
 
 	return 0;
 }
-#endif
 
 static const struct ide_port_ops sc1200_port_ops = {
 	.set_pio_mode		= sc1200_set_pio_mode,
@@ -326,15 +312,14 @@ static const struct pci_device_id sc1200_pci_tbl[] = {
 };
 MODULE_DEVICE_TABLE(pci, sc1200_pci_tbl);
 
+static SIMPLE_DEV_PM_OPS(sc1200_pm_ops, sc1200_suspend, sc1200_resume);
+
 static struct pci_driver sc1200_pci_driver = {
 	.name		= "SC1200_IDE",
 	.id_table	= sc1200_pci_tbl,
 	.probe		= sc1200_init_one,
 	.remove		= ide_pci_remove,
-#ifdef CONFIG_PM
-	.suspend	= sc1200_suspend,
-	.resume		= sc1200_resume,
-#endif
+	.driver.pm	= &sc1200_pm_ops,
 };
 
 static int __init sc1200_ide_init(void)
-- 
2.27.0