[PATCH v2] firewire: ohci: Convert to generic power management

From: Bjorn Helgaas
Date: Tue Jun 07 2022 - 22:27:45 EST


From: Vaibhav Gupta <vaibhavgupta40@xxxxxxxxx>

Convert firewire-ohci from legacy PCI power management to the generic power
management framework.

Previously firewire-ohci used legacy PCI power management, and
pci_suspend() and pci_resume() were responsible for both device-specific
things and generic PCI things like saving and restoring config space and
managing power state:

pci_suspend
software_reset <-- device-specific
pci_save_state <-- generic PCI
pci_set_power_state <-- generic PCI
pmac_ohci_off <-- device-specific

pci_resume
pmac_ohci_on <-- device-specific
pci_set_power_state(PCI_D0) <-- generic PCI
pci_restore_state <-- generic PCI
pci_enable_device <-- generic PCI
ohci_enable <-- device-specific

Convert to generic power management where 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
pci_suspend # driver->pm->suspend
software_reset <-- device-specific
pmac_ohci_off <-- 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
pci_resume # driver->pm->resume
pmac_ohci_on <-- device-specific
ohci_enable <-- device-specific

[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20200720150715.624520-1-vaibhavgupta40@xxxxxxxxx
Signed-off-by: Vaibhav Gupta <vaibhavgupta40@xxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
drivers/firewire/ohci.c | 35 ++++++++---------------------------
1 file changed, 8 insertions(+), 27 deletions(-)

diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 17c9d825188b..aee705132330 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -3165,8 +3165,7 @@ static int ohci_set_iso_channels(struct fw_iso_context *base, u64 *channels)
return ret;
}

-#ifdef CONFIG_PM
-static void ohci_resume_iso_dma(struct fw_ohci *ohci)
+static void __maybe_unused ohci_resume_iso_dma(struct fw_ohci *ohci)
{
int i;
struct iso_context *ctx;
@@ -3183,7 +3182,6 @@ static void ohci_resume_iso_dma(struct fw_ohci *ohci)
ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
}
}
-#endif

static int queue_iso_transmit(struct iso_context *ctx,
struct fw_iso_packet *packet,
@@ -3789,39 +3787,24 @@ static void pci_remove(struct pci_dev *dev)
dev_notice(&dev->dev, "removed fw-ohci device\n");
}

-#ifdef CONFIG_PM
-static int pci_suspend(struct pci_dev *dev, pm_message_t state)
+static int __maybe_unused pci_suspend(struct device *devp)
{
+ struct pci_dev *dev = to_pci_dev(devp);
struct fw_ohci *ohci = pci_get_drvdata(dev);
- int err;

software_reset(ohci);
- err = pci_save_state(dev);
- if (err) {
- ohci_err(ohci, "pci_save_state failed\n");
- return err;
- }
- err = pci_set_power_state(dev, pci_choose_state(dev, state));
- if (err)
- ohci_err(ohci, "pci_set_power_state failed with %d\n", err);
pmac_ohci_off(dev);

return 0;
}

-static int pci_resume(struct pci_dev *dev)
+static int __maybe_unused pci_resume(struct device *devp)
{
+ struct pci_dev *dev = to_pci_dev(devp);
struct fw_ohci *ohci = pci_get_drvdata(dev);
int err;

pmac_ohci_on(dev);
- pci_set_power_state(dev, PCI_D0);
- pci_restore_state(dev);
- err = pci_enable_device(dev);
- if (err) {
- ohci_err(ohci, "pci_enable_device failed\n");
- return err;
- }

/* Some systems don't setup GUID register on resume from ram */
if (!reg_read(ohci, OHCI1394_GUIDLo) &&
@@ -3838,7 +3821,6 @@ static int pci_resume(struct pci_dev *dev)

return 0;
}
-#endif

static const struct pci_device_id pci_table[] = {
{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_FIREWIRE_OHCI, ~0) },
@@ -3847,15 +3829,14 @@ static const struct pci_device_id pci_table[] = {

MODULE_DEVICE_TABLE(pci, pci_table);

+static SIMPLE_DEV_PM_OPS(pci_pm_ops, pci_suspend, pci_resume);
+
static struct pci_driver fw_ohci_pci_driver = {
.name = ohci_driver_name,
.id_table = pci_table,
.probe = pci_probe,
.remove = pci_remove,
-#ifdef CONFIG_PM
- .resume = pci_resume,
- .suspend = pci_suspend,
-#endif
+ .driver.pm = &pci_pm_ops,
};

static int __init fw_ohci_init(void)
--
2.25.1