RE: [PATCH v3 net-next 04/15] ptp: netc: add NETC V4 Timer PTP driver support

Wei Fang
2025-08-13T02:21:12Z

> On Tue, Aug 12, 2025 at 05:46:23PM +0800, Wei Fang wrote:
> > +int netc_timer_get_phc_index(struct pci_dev *timer_pdev) {
> > + struct netc_timer *priv;
> > +
> > + if (!timer_pdev)
> > + return -ENODEV;
> > +
> > + priv = pci_get_drvdata(timer_pdev);
> > + if (!priv)
> > + return -EINVAL;
> > +
> > + return priv->phc_index;
> > +}
> > +EXPORT_SYMBOL_GPL(netc_timer_get_phc_index);
> ...
> > @@ -16,4 +17,13 @@ static inline void netc_write(void __iomem *reg, u32
> val)
> > iowrite32(val, reg);
> > }
> >
> > +#if IS_ENABLED(CONFIG_PTP_NETC_V4_TIMER)
> > +int netc_timer_get_phc_index(struct pci_dev *timer_pdev); #else
> > +static inline int netc_timer_get_phc_index(struct pci_dev
> > +*timer_pdev) {
> > + return -ENODEV;
> > +}
> > +#endif
> > +
>
> I was expecting that with the generic ptp-timer phandle you'd also offer
> a generic mechanism of retrieving the PHC index, instead of cooking up a
> custom API convention between the NETC MAC and the NETC timer.
>

Good advice, I did not realize that, I will try to apply your proposal,
many thanks.

> Something like below, completely untested:
>
> struct ptp_clock_fwnode_match {
> struct fwnode_handle *fwnode;
> struct ptp_clock *clock;
> };
>
> static int ptp_clock_fwnode_match(struct device *dev, void *data)
> {
> struct ptp_clock_fwnode_match *match = data;
>
> if (!dev->parent || dev_fwnode(dev->parent) != match->fwnode)
> return 0;
>
> match->clock = dev_get_drvdata(dev);
> return 1;
> }
>
> static struct ptp_clock *ptp_clock_find_by_fwnode(struct fwnode_handle
> *fwnode)
> {
> struct ptp_clock_fwnode_match match = { .fwnode = fwnode };
>
> class_for_each_device(&ptp_class, NULL, &match,
> ptp_clock_fwnode_match);
>
> return match.clock;
> }
>
> int ptp_clock_index_by_fwnode_handle(struct fwnode_handle *fwnode)
> {
> struct fwnode_handle *ptp_fwnode;
> struct ptp_clock *clock;
> int phc_index;
>
> ptp_fwnode = fwnode_find_reference(fwnode, "ptp-timer", 0);
> if (!ptp_fwnode)
> return -1;
>
> clock = ptp_clock_find_by_fwnode(ptp_fwnode);
> fwnode_handle_put(ptp_fwnode);
> if (!clock)
> return -1;
>
> phc_index = ptp_clock_index(clock);
> put_device(&clock->dev);
>
> return phc_index;
> }
> EXPORT_SYMBOL_GPL(ptp_clock_index_by_fwnode_handle);