[PATCH v5 3/4] mtip32xx: convert to generic power management

[Bjorn Helgaas <helgaas@kernel.org>]

From: Vaibhav Gupta <vaibhavgupta40@gmail.com>

Convert mtip32xx from legacy PCI power management to the generic power
management framework.

Previously, mtip32xx used legacy PCI power management, where
mtip_pci_suspend() and mtip_pci_resume() were responsible for both
device-specific things and generic PCI things:

  mtip_pci_suspend
    mtip_block_suspend(dd)              <-- device-specific
    pci_save_state(pdev)                <-- generic PCI
    pci_set_power_state(pdev, pci_choose_state(pdev, state))

  mtip_pci_resume
    pci_set_power_state(PCI_D0)         <-- generic PCI
    pci_restore_state(pdev)             <-- generic PCI
    pcim_enable_device(pdev)            <-- generic PCI
    pci_set_master(pdev)                <-- generic PCI
    mtip_block_resume(dd)               <-- device-specific

With generic power management, the PCI bus PM methods do the generic PCI
things, and the driver needs only the device-specific part, i.e.,

  suspend_devices_and_enter
    dpm_suspend_start(PMSG_SUSPEND)
      pci_pm_suspend                    # PCI bus .suspend() method
        mtip_pci_suspend                # dev->driver->pm->suspend
          mtip_block_suspend            <-- device-specific
    suspend_enter
      dpm_suspend_noirq(PMSG_SUSPEND)
        pci_pm_suspend_noirq            # PCI bus .suspend_noirq() method
          pci_save_state                <-- generic PCI
          pci_prepare_to_sleep          <-- generic PCI
            pci_set_power_state
    ...
    dpm_resume_end(PMSG_RESUME)
      pci_pm_resume                     # PCI bus .resume() method
        pci_restore_standard_config
          pci_set_power_state(PCI_D0)   <-- generic PCI
          pci_restore_state             <-- generic PCI
        mtip_pci_resume                 # dev->driver->pm->resume
          mtip_block_resume             <-- device-specific

[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20210114115423.52414-2-vaibhavgupta40@gmail.com
Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
 drivers/block/mtip32xx/mtip32xx.c | 48 +++++++------------------------
 1 file changed, 10 insertions(+), 38 deletions(-)

diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 894020aaaaeb..368b3c4e0744 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -4144,30 +4144,17 @@ static void mtip_pci_remove(struct pci_dev *pdev)
  *	0  Success
  *	<0 Error
  */
-static int mtip_pci_suspend(struct pci_dev *pdev, pm_message_t mesg)
+static int __maybe_unused mtip_pci_suspend(struct device *dev)
 {
 	int rv = 0;
-	struct driver_data *dd = pci_get_drvdata(pdev);
+	struct driver_data *dd = dev_get_drvdata(dev);
 
 	set_bit(MTIP_DDF_RESUME_BIT, &dd->dd_flag);
 
 	/* Disable ports & interrupts then send standby immediate */
 	rv = mtip_block_suspend(dd);
-	if (rv < 0) {
-		dev_err(&pdev->dev,
-			"Failed to suspend controller\n");
-		return rv;
-	}
-
-	/*
-	 * Save the pci config space to pdev structure &
-	 * disable the device
-	 */
-	pci_save_state(pdev);
-	pci_disable_device(pdev);
-
-	/* Move to Low power state*/
-	pci_set_power_state(pdev, PCI_D3hot);
+	if (rv < 0)
+		dev_err(dev, "Failed to suspend controller\n");
 
 	return rv;
 }
@@ -4179,25 +4166,10 @@ static int mtip_pci_suspend(struct pci_dev *pdev, pm_message_t mesg)
  *      0  Success
  *      <0 Error
  */
-static int mtip_pci_resume(struct pci_dev *pdev)
+static int __maybe_unused mtip_pci_resume(struct device *dev)
 {
 	int rv = 0;
-	struct driver_data *dd = pci_get_drvdata(pdev);
-
-	/* Move the device to active State */
-	pci_set_power_state(pdev, PCI_D0);
-
-	/* Restore PCI configuration space */
-	pci_restore_state(pdev);
-
-	/* Enable the PCI device*/
-	rv = pcim_enable_device(pdev);
-	if (rv < 0) {
-		dev_err(&pdev->dev,
-			"Failed to enable card during resume\n");
-		goto err;
-	}
-	pci_set_master(pdev);
+	struct driver_data *dd = dev_get_drvdata(dev);
 
 	/*
 	 * Calls hbaReset, initPort, & startPort function
@@ -4205,9 +4177,8 @@ static int mtip_pci_resume(struct pci_dev *pdev)
 	 */
 	rv = mtip_block_resume(dd);
 	if (rv < 0)
-		dev_err(&pdev->dev, "Unable to resume\n");
+		dev_err(dev, "Unable to resume\n");
 
-err:
 	clear_bit(MTIP_DDF_RESUME_BIT, &dd->dd_flag);
 
 	return rv;
@@ -4238,14 +4209,15 @@ static const struct pci_device_id mtip_pci_tbl[] = {
 	{ 0 }
 };
 
+static SIMPLE_DEV_PM_OPS(mtip_pci_pm_ops, mtip_pci_suspend, mtip_pci_resume);
+
 /* Structure that describes the PCI driver functions. */
 static struct pci_driver mtip_pci_driver = {
 	.name			= MTIP_DRV_NAME,
 	.id_table		= mtip_pci_tbl,
 	.probe			= mtip_pci_probe,
 	.remove			= mtip_pci_remove,
-	.suspend		= mtip_pci_suspend,
-	.resume			= mtip_pci_resume,
+	.driver.pm		= &mtip_pci_pm_ops,
 	.shutdown		= mtip_pci_shutdown,
 };
 
-- 
2.25.1