Hi Mehdi,
On Mon, Feb 24, 2025 at 08:59:34AM +0100, Mehdi Djait wrote:
> Hi Laurent,
>
> On Mon, Feb 24, 2025 at 01:06:49AM +0200, Laurent Pinchart wrote:
> > Hi Mehdi,
> >
> > Thank you for the patch.
> >
> > On Thu, Feb 20, 2025 at 04:49:09PM +0100, Mehdi Djait wrote:
> > > Make the clock producer reference lookup optional
> > >
> > > Add support for ACPI-based platforms by parsing the 'clock-frequency'
> > > property when no clock producer is available
> > >
> > > Signed-off-by: Mehdi Djait <mehdi.djait@xxxxxxxxxxxxxxx>
> > > ---
> > > drivers/media/i2c/imx219.c | 14 ++++++++++++--
> > > 1 file changed, 12 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/media/i2c/imx219.c b/drivers/media/i2c/imx219.c
> > > index 2d54cea113e1..a876a6d80a47 100644
> > > --- a/drivers/media/i2c/imx219.c
> > > +++ b/drivers/media/i2c/imx219.c
> > > @@ -1103,12 +1103,22 @@ static int imx219_probe(struct i2c_client *client)
> > > "failed to initialize CCI\n");
> > >
> > > /* Get system clock (xclk) */
> > > - imx219->xclk = devm_clk_get(dev, NULL);
> > > + imx219->xclk = devm_clk_get_optional(dev, NULL);
> > > if (IS_ERR(imx219->xclk))
> > > return dev_err_probe(dev, PTR_ERR(imx219->xclk),
> > > "failed to get xclk\n");
> > >
> > > - imx219->xclk_freq = clk_get_rate(imx219->xclk);
> > > + if (imx219->xclk) {
> > > + imx219->xclk_freq = clk_get_rate(imx219->xclk);
> > > + } else {
> > > + ret = fwnode_property_read_u32(dev_fwnode(dev),
> > > + "clock-frequency",
> > > + &imx219->xclk_freq);
> > > + if (ret)
> > > + return dev_err_probe(dev, ret,
> > > + "failed to get clock frequency");
> > > + }
> > > +
> >
> > This doesn't seem specific to the imx219 driver. Could you turn this
> > into a generic V4L2 sensor helper that would take a struct device and a
> > clock name, and return the frequency, either retrieved from the clock,
> > or from the clock-frequency property as a fallback ?
> >
> > Some drivers will also need to control the clock, so the clock should
> > probably be returned too.
> >
>
> Yes, I saw that many sensor drivers have the same issue.
>
> I will try to make it into a generic V4L2 helper and send the patches.
There are other such functions in drivers/media/v4l2-core/v4l2-common.c.
Perhaps this is where the new helper could be located as well?
--
Regards,
Sakari Ailus
