Re: [PATCH v8 2/3] media: rockchip: Add a driver for Rockhip's camera interface

From: Paul Kocialkowski
Date: Wed Oct 25 2023 - 05:48:20 EST


Michael,

On Wed 25 Oct 23, 11:38, Michael Riesch wrote:
> Hi Paul,
>
> On 10/25/23 10:49, Paul Kocialkowski wrote:
> > Hi,
> >
> > On Mon 23 Oct 23, 15:28, Michael Riesch wrote:
> >> Typo in the subject: "Rockhip's" -> "Rockchip's"
> >> I think this typo has been in there for a while now ;-)
> >
> > Great hips make for great dancing!
>
> ...to rock music, obviously.

:)

> > [...]
> >>> +#define write_vip_reg(base, addr, val) writel(val, (addr) + (base))
> >>> +#define read_vip_reg(base, addr) readl((addr) + (base))
> >>
> >> Please provide those helpers as proper inline functions. As to the
> >> naming, the "_reg" suffix seems unnecessary.
> >>
> >> Alternatively, you could consider converting the driver to use regmap.
> >
> > Come to think of it, I feel like it would make more sense to have an inline
> > function which is given a struct rk_vip_device instead of having to dereference
> > it every time in the caller to access the base address.
>
> Indeed. Either using regmap, e.g.,
>
> int regmap_write(struct regmap *map, unsigned int reg, unsigned int val);
>
> or something equivalant
>
> static inline int cif_write(struct cif_device *device, unsigned int reg,
> unsigned int val);

Looks good to me!

> Not sure what you agreed on in terms of a method prefix. The Rockchip
> RGA driver uses "rga_something", the Rockchip ISP driver uses
> "rkisp1_something". This would mean either "cif_something" or
> "rkcif_something", right?

Yeah I don't really have strong opinions on this so I'll let Mehdi decide
(as long as it's consistent everywhere in the code).

I guess there is a slight readability advantage in using "cif_" instead of
"rkcif_".

> > [...]
> >>> + struct rk_vip_sensor_info sensor;
> >>
> >> Using "sensor" as name does not seem correct. As pointed out above it
> >> could be a video decoder just as well. Something with "subdevice" maybe?
> >
> > Agreed. I suggest renaming the struct "rk_vip_sensor_info" -> "rk_cif_remote"
> > and just calling the member "remote".
>
> "remote" sounds reasonable. Prefix to be bikeshedded, see comment above.
>
> In the future, we may add an array with mipi_remotes that represents the
> subdevices attached wia MIPI CSI-2.

Sounds good!

Thanks,

Paul

--
Paul Kocialkowski, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com

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