pata_sl82c105: add Power Management support

Fixes IDE -> libata regression.

There shouldn't be any problems with it as corresponding IDE's host
driver (sl82c105) has been supporting PCI Power Management since
Oct 10 2008 (commit feb22b7f "ide: add proper PCI PM support (v2)")
and IDE PM since Jun 14 2003 (patch v2.5.73 "ide: Power Management").
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/ata/pata_sl82c105.c

 /*
  * pata_sl82c105.c 	- SL82C105 PATA for new ATA layer
  *			  (C) 2005 Red Hat Inc
+ *			  (C) 2011 Bartlomiej Zolnierkiewicz
  *
  * Based in part on linux/drivers/ide/pci/sl82c105.c
  * 		SL82C105/Winbond 553 IDE driver
@@ -289,6 +290,14 @@ static int sl82c105_bridge_revision(struct pci_dev *pdev)
 	return bridge->revision;
 }
 
+static void sl82c105_fixup(struct pci_dev *pdev)
+{
+	u32 val;
+
+	pci_read_config_dword(pdev, 0x40, &val);
+	val |= CTRL_P0EN | CTRL_P0F16 | CTRL_P1F16;
+	pci_write_config_dword(pdev, 0x40, val);
+}
 
 static int sl82c105_init_one(struct pci_dev *dev, const struct pci_device_id *id)
 {
@@ -306,7 +315,6 @@ static int sl82c105_init_one(struct pci_dev *dev, const struct pci_device_id *id
 	/* for now use only the first port */
 	const struct ata_port_info *ppi[] = { &info_early,
 					       NULL };
-	u32 val;
 	int rev;
 	int rc;
 
@@ -325,13 +333,28 @@ static int sl82c105_init_one(struct pci_dev *dev, const struct pci_device_id *id
 	else
 		ppi[0] = &info_dma;
 
-	pci_read_config_dword(dev, 0x40, &val);
-	val |= CTRL_P0EN | CTRL_P0F16 | CTRL_P1F16;
-	pci_write_config_dword(dev, 0x40, val);
+	sl82c105_fixup(dev);
 
 	return ata_pci_bmdma_init_one(dev, ppi, &sl82c105_sht, NULL, 0);
 }
 
+#ifdef CONFIG_PM
+static int sl82c105_reinit_one(struct pci_dev *pdev)
+{
+	struct ata_host *host = dev_get_drvdata(&pdev->dev);
+	int rc;
+
+	rc = ata_pci_device_do_resume(pdev);
+	if (rc)
+		return rc;
+
+	sl82c105_fixup(pdev);
+
+	ata_host_resume(host);
+	return 0;
+}
+#endif
+
 static const struct pci_device_id sl82c105[] = {
 	{ PCI_VDEVICE(WINBOND, PCI_DEVICE_ID_WINBOND_82C105), },
 
@@ -342,7 +365,11 @@ static struct pci_driver sl82c105_pci_driver = {
 	.name 		= DRV_NAME,
 	.id_table	= sl82c105,
 	.probe 		= sl82c105_init_one,
-	.remove		= ata_pci_remove_one
+	.remove		= ata_pci_remove_one,
+#ifdef CONFIG_PM
+	.suspend	= ata_pci_device_suspend,
+	.resume		= sl82c105_reinit_one,
+#endif
 };
 
 static int __init sl82c105_init(void)