Hi Maxime, On Thu, Mar 19, 2020 at 01:44:52PM +0100, Maxime Ripard wrote: > On Fri, Mar 13, 2020 at 09:12:31PM +0000, Lad Prabhakar wrote: > > Use assigned-clock-rates to specify the clock rate. Also mark > > clock-frequency property as deprecated. > > > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> > > --- > > Documentation/devicetree/bindings/media/i2c/ov5645.txt | 5 +++-- > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/Documentation/devicetree/bindings/media/i2c/ov5645.txt b/Documentation/devicetree/bindings/media/i2c/ov5645.txt > > index 72ad992..e62fe82 100644 > > --- a/Documentation/devicetree/bindings/media/i2c/ov5645.txt > > +++ b/Documentation/devicetree/bindings/media/i2c/ov5645.txt > > @@ -8,7 +8,7 @@ Required Properties: > > - compatible: Value should be "ovti,ov5645". > > - clocks: Reference to the xclk clock. > > - clock-names: Should be "xclk". > > -- clock-frequency: Frequency of the xclk clock. > > +- clock-frequency (deprecated): Frequency of the xclk clock. > > - enable-gpios: Chip enable GPIO. Polarity is GPIO_ACTIVE_HIGH. This corresponds > > to the hardware pin PWDNB which is physically active low. > > - reset-gpios: Chip reset GPIO. Polarity is GPIO_ACTIVE_LOW. This corresponds to > > @@ -37,7 +37,8 @@ Example: > > > > clocks = <&clks 200>; > > clock-names = "xclk"; > > - clock-frequency = <24000000>; > > + assigned-clocks = <&clks 200>; > > + assigned-clock-rates = <24000000>; > > > > vdddo-supply = <&camera_dovdd_1v8>; > > vdda-supply = <&camera_avdd_2v8>; > > clock-frequency is quite different from assigned-clock-rates though, > semantically speaking. clock-frequency is only about what the clock > frequency is, while assigned-clock-rates will change the rate as well, > and you have no idea how long it will last. The driver currently reads the clock-frequency property and then calls clk_set_rate(). I agree tht assigned-clock-rates isn't a panacea, but I think it's less of a hack than what we currently have. As discussed on IRC, maybe the best option in this specific case is to drop clock-frequency and assigned-clok-rates, and call clk_set_rate() with a hardcoded frequency of 24MHz in the driver, as that's the only frequency the driver supports. > If you want to retrieve that through the clock framework, then just > making clock-frequency optional is enough and falling back to > clk_get_rate on the clocks property already provided is enough. -- Regards, Laurent Pinchart
