Re: [PATCH 28/57] media: Add ovxxxx_16bit_addr_reg_helpers.h

Mauro Carvalho Chehab
2023-02-08T14:33:41Z

Em Wed, 8 Feb 2023 13:31:17 +0200
Sakari Ailus <sakari.ailus@linux.intel.com> escreveu:

> Hi Hans,
>
> On Mon, Jan 23, 2023 at 01:51:36PM +0100, Hans de Goede wrote:
> > The following drivers under drivers/media/i2c: ov08x40.c, ov13858.c,
> > ov13b10.c, ov2680.c, ov2685.c, ov2740.c, ov4689.c, ov5670.c,
> > ov5675.c, ov5695.c, ov8856.c, ov9282.c and ov9734.c,
> >
> > as well as various "atomisp" sensor drivers in drivers/staging, *all*
> > use register access helpers with the following function prototypes:
> >
> > int ovxxxx_read_reg(struct ovxxxx_dev *sensor, u16 reg,
> > unsigned int len, u32 *val);
> >
> > int ovxxxx_write_reg(struct ovxxxx_dev *sensor, u16 reg,
> > unsigned int len, u32 val);
> >
> > To read/write registers on Omnivision OVxxxx image sensors wich expect
> > a 16 bit register address in big-endian format and which have 1-3 byte
> > wide registers, in big-endian format (for the higher width registers).
> >
> > Add a new ovxxxx_16bit_addr_reg_helpers.h header file with static inline
> > versions of these register access helpers, so that this code duplication
> > can be removed.
>
> Ideally we'd have helpers for CCI, of which this is a subset. And on top of
> regmap. I don't object adding these either though.

Well, ideally, when the atomisp-specific sensor ioctls go away, we can
merge the atomisp-specific sensor drivers for not-yet-uptreamed sensors
or modify the existing sensor drivers to accept the atomisp resolutions [1].

So, for now, I wouldn't convert those to use regmap. This can be done
later with the remaining drivers.

[1] atomisp usually requires 16 extra lines/columns for it to work, so
the current sensor drivers there allow setting resolutions like
1616x1216 at the sensor, while offering 1600x1200 resolution to
userspace.

Thanks,
Mauro