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.
--
Kind Regards
Mehdi Djait
