RE: [PATCH v3 2/4] media: i2c: ov5645: Switch to assigned-clock-rates

[Prabhakar Mahadev Lad]

Hi Laurent,

Thank you for the quick review.

> -----Original Message-----
> From: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> Sent: 13 March 2020 21:17
> To: Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>; Shawn Guo
> <shawnguo@xxxxxxxxxx>; Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>;
> Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>; Rob Herring
> <robh+dt@xxxxxxxxxx>; Mark Rutland <mark.rutland@xxxxxxx>; Sakari
> Ailus <sakari.ailus@xxxxxxxxxxxxxxx>; NXP Linux Team <linux-imx@xxxxxxx>;
> Magnus Damm <magnus.damm@xxxxxxxxx>; Ezequiel Garcia
> <ezequiel@xxxxxxxxxxxxx>; Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>;
> devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-renesas-
> soc@xxxxxxxxxxxxxxx; Fabio Estevam <festevam@xxxxxxxxx>; linux-
> media@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH v3 2/4] media: i2c: ov5645: Switch to assigned-clock-
> rates
>
> Hi Prabakhar,
>
> Thank you for the patch.
>
> On Fri, Mar 13, 2020 at 09:12:32PM +0000, Lad Prabhakar wrote:
> > This patch switches to assigned-clock-rates for specifying the clock rate.
> > The clk-conf.c internally handles setting the clock rate when
> > assigned-clock-rates is passed.
> >
> > The driver now sets the clock frequency only if the deprecated
> > property clock-frequency is defined instead assigned-clock-rates, this
> > is to avoid breakage with existing DT binaries.
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-
> lad.rj@xxxxxxxxxxxxxx>
> > ---
> >  drivers/media/i2c/ov5645.c | 21 +++++++++++----------
> >  1 file changed, 11 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/media/i2c/ov5645.c b/drivers/media/i2c/ov5645.c
> > index a6c17d1..4fbabf3 100644
> > --- a/drivers/media/i2c/ov5645.c
> > +++ b/drivers/media/i2c/ov5645.c
> > @@ -1055,6 +1055,7 @@ static int ov5645_probe(struct i2c_client *client)
> >  struct device_node *endpoint;
> >  struct ov5645 *ov5645;
> >  u8 chip_id_high, chip_id_low;
> > +bool set_clk = false;
>
> This isn't used.
>
Argh! missed it.

> >  unsigned int i;
> >  u32 xclk_freq;
> >  int ret;
> > @@ -1094,12 +1095,18 @@ static int ov5645_probe(struct i2c_client
> *client)
> >  return PTR_ERR(ov5645->xclk);
> >  }
> >
> > -ret = of_property_read_u32(dev->of_node, "clock-frequency",
> &xclk_freq);
> > -if (ret) {
> > -dev_err(dev, "could not get xclk frequency\n");
> > -return ret;
> > +/* check if deprecated property clock-frequency is defined */
> > +ret = of_property_read_u32(dev->of_node, "clock-frequency",
> > +   &xclk_freq);
> > +if (!ret) {
> > +ret = clk_set_rate(ov5645->xclk, xclk_freq);
> > +if (ret) {
> > +dev_err(dev, "could not set xclk frequency\n");
> > +return ret;
> > +}
> >  }
> >
> > +xclk_freq = clk_get_rate(ov5645->xclk);
>
> I would move this line below the comment.
>
Sure will do that.

Cheers,
--Prabhakar

> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
>
> >  /* external clock must be 24MHz, allow 1% tolerance */
> >  if (xclk_freq < 23760000 || xclk_freq > 24240000) {
> >  dev_err(dev, "external clock frequency %u is not
> supported\n", @@
> > -1107,12 +1114,6 @@ static int ov5645_probe(struct i2c_client *client)
> >  return -EINVAL;
> >  }
> >
> > -ret = clk_set_rate(ov5645->xclk, xclk_freq);
> > -if (ret) {
> > -dev_err(dev, "could not set xclk frequency\n");
> > -return ret;
> > -}
> > -
> >  for (i = 0; i < OV5645_NUM_SUPPLIES; i++)
> >  ov5645->supplies[i].supply = ov5645_supply_name[i];
> >
>
> --
> Regards,
>
> Laurent Pinchart


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