[Linux-kernel-mentees] [PATCH v1] scsi: smartpqi: use generic power management

[Vaibhav Gupta <vaibhavgupta40@gmail.com>]

Drivers using legacy power management .suspen()/.resume() callbacks
have to manage PCI states and device's PM states themselves. They also
need to take care of standard configuration registers.

Switch to generic power management framework using a single
"struct dev_pm_ops" variable to take the unnecessary load from the driver.
This also avoids the need for the driver to directly call most of the PCI
helper functions and device power state control functions, as through
the generic framework PCI Core takes care of the necessary operations,
and drivers are required to do only device-specific jobs.

Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
---
 drivers/scsi/smartpqi/smartpqi_init.c | 42 ++++++++++++++++++---------
 1 file changed, 29 insertions(+), 13 deletions(-)

diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c
index cd157f11eb22..dc8567236a23 100644
--- a/drivers/scsi/smartpqi/smartpqi_init.c
+++ b/drivers/scsi/smartpqi/smartpqi_init.c
@@ -8059,11 +8059,11 @@ static void pqi_process_module_params(void)
 	pqi_process_lockup_action_param();
 }
 
-static __maybe_unused int pqi_suspend(struct pci_dev *pci_dev, pm_message_t state)
+static __maybe_unused int pqi_suspend_late(struct device *dev, pm_message_t state)
 {
 	struct pqi_ctrl_info *ctrl_info;
 
-	ctrl_info = pci_get_drvdata(pci_dev);
+	ctrl_info = dev_get_drvdata(dev);
 
 	pqi_disable_events(ctrl_info);
 	pqi_cancel_update_time_worker(ctrl_info);
@@ -8081,20 +8081,33 @@ static __maybe_unused int pqi_suspend(struct pci_dev *pci_dev, pm_message_t stat
 	if (state.event == PM_EVENT_FREEZE)
 		return 0;
 
-	pci_save_state(pci_dev);
-	pci_set_power_state(pci_dev, pci_choose_state(pci_dev, state));
-
 	ctrl_info->controller_online = false;
 	ctrl_info->pqi_mode_enabled = false;
 
 	return 0;
 }
 
-static __maybe_unused int pqi_resume(struct pci_dev *pci_dev)
+static __maybe_unused int pqi_suspend(struct device *dev)
+{
+	return pqi_suspend_late(dev, PMSG_SUSPEND);
+}
+
+static __maybe_unused int pqi_hibernate(struct device *dev)
+{
+	return pqi_suspend_late(dev, PMSG_HIBERNATE);
+}
+
+static __maybe_unused int pqi_freeze(struct device *dev)
+{
+	return pqi_suspend_late(dev, PMSG_FREEZE);
+}
+
+static __maybe_unused int pqi_resume(struct device *dev)
 {
 	int rc;
 	struct pqi_ctrl_info *ctrl_info;
 
+	struct pci_dev *pci_dev = to_pci_dev(dev);
 	ctrl_info = pci_get_drvdata(pci_dev);
 
 	if (pci_dev->current_state != PCI_D0) {
@@ -8115,9 +8128,6 @@ static __maybe_unused int pqi_resume(struct pci_dev *pci_dev)
 		return 0;
 	}
 
-	pci_set_power_state(pci_dev, PCI_D0);
-	pci_restore_state(pci_dev);
-
 	return pqi_ctrl_init_resume(ctrl_info);
 }
 
@@ -8480,16 +8490,22 @@ static const struct pci_device_id pqi_pci_id_table[] = {
 
 MODULE_DEVICE_TABLE(pci, pqi_pci_id_table);
 
+static const struct dev_pm_ops pqi_pm_ops = {
+	.suspend = pqi_suspend,
+	.resume = pqi_resume,
+	.freeze = pqi_freeze,
+	.thaw = pqi_resume,
+	.poweroff = pqi_hibernate,
+	.restore = pqi_resume,
+};
+
 static struct pci_driver pqi_pci_driver = {
 	.name = DRIVER_NAME_SHORT,
 	.id_table = pqi_pci_id_table,
 	.probe = pqi_pci_probe,
 	.remove = pqi_pci_remove,
 	.shutdown = pqi_shutdown,
-#if defined(CONFIG_PM)
-	.suspend = pqi_suspend,
-	.resume = pqi_resume,
-#endif
+	.driver.pm = &pqi_pm_ops
 };
 
 static int __init pqi_init(void)
-- 
2.27.0

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