lkml.org 
[lkml]   [2018]   [Jan]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: [PATCH v3] drm/bridge/synopsys: dsi: add optional pixel clock
    Date
    Hi Brian,

    On 01/24/2018 07:09 PM, Brian Norris wrote:
    > On Wed, Jan 24, 2018 at 09:24:06AM +0000, Philippe CORNU wrote:
    >> On 01/23/2018 09:49 PM, Brian Norris wrote:
    >>> On Tue, Jan 23, 2018 at 06:08:06PM +0100, Philippe Cornu wrote:
    >>>> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
    >>>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
    >
    >>>> @@ -828,6 +833,14 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
    >>>> return ERR_PTR(ret);
    >>>> }
    >>>>
    >>>> + dsi->px_clk = devm_clk_get(dev, "px_clk");
    >>>
    >>> Did you write a device tree binding document update for this anywhere?
    >>
    >> Many thanks for your review,
    >>
    >> yes, "px_clk" is already documented, please have a look to
    >> Documentation/devicetree/bindings/display/bridge/dw_mipi_dsi.txt
    >
    > Ah, I see. Normally I expect that the binding document is sent around
    > when the first user of it shows up, but I guess that's not a
    > requirement. Sorry I missed that!
    >
    > Just a note: I don't think that Rockchip systems have an equivalent
    > clock from which to directly derive the pixel clock rate. I believe it's
    > controlled through additional dividers that are not part of the common
    > clock framework. So this isn't particularly useful for them.
    >
    > I don't think it's worth very much in this case, but:
    >
    > Reviewed-by: Brian Norris <briannorris@chromium.org>
    >

    Many thanks for the review and your comments.

    Looking more deeply into the rockchip vop driver (in order to understand
    how the px clock is used), I can see that adjusted_mode/mode_fixup is
    (now) used.

    I have already tried to use adjusted_mode/mode_fixup on stm32 but
    without success.

    Nevertheless, I will do more tests with adjusted_mode/mode_fixup as it
    could help to have a simpler patch than adding the px_clk.

    Many thanks,
    Philippe :-)
    \
     
     \ /
      Last update: 2018-01-25 12:36    [W:4.459 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site