Re: [PATCH v5 2/2] mailbox: mediatek: Add mtk-vcp-mailbox driver

[Chen-Yu Tsai]

On Fri, Sep 19, 2025 at 7:50 AM Jassi Brar <jassisinghbrar@xxxxxxxxx> wrote:
>
> On Thu, Aug 21, 2025 at 9:12 PM Jjian Zhou <jjian.zhou@xxxxxxxxxxxx> wrote:
>
> .....
>
> > +#include <linux/module.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/slab.h>
> > +
> > +struct mtk_vcp_mbox_priv {
> Maybe 'mtk_vcp_mbox' is a more appropriate name ?
>
> > +       void __iomem *base;
> > +       struct device *dev;
> > +       struct mbox_controller mbox;
> > +       const struct mtk_vcp_mbox_cfg *cfg;
> > +       struct mtk_ipi_info ipi_recv;
>
> Maybe also have "struct mbox_chan chan[1]; " so that you don't have to
> allocate one during the probe.

> Also if you have  "struct mbox_controller mbox;" as the first member,
> you could simply typecast that to get this structure.
> Something like "struct mpfs_mbox" in mailbox-mpfs.c

I read somewhere that this way of subclassing is not recommended.
Instead the base class should explicitly not be the first member.
And then container_of() should be used.

I don't remember where I read this though. But I think the explicit
container_of() is easier for understanding the intent.

ChenYu

> ....
> > +
> > +static struct mbox_chan *mtk_vcp_mbox_xlate(struct mbox_controller *mbox,
> > +                                           const struct of_phandle_args *sp)
> > +{
> > +       if (sp->args_count)
> > +               return NULL;
> > +
> > +       return mbox->chans;
>
> return &mbox->chans[0]   seems better.
>
> thnx