[PATCH V6 6/6] drm: bridge: samsung-dsim: Support non-burst mode

Jagan Teki jagan at amarulasolutions.com
Thu May 18 12:07:09 UTC 2023


On Tue, May 16, 2023 at 5:27 AM Adam Ford <aford173 at gmail.com> wrote:
>
> The high-speed clock is hard-coded to the burst-clock
> frequency specified in the device tree.  However, when
> using devices like certain bridge chips without burst mode
> and varying resolutions and refresh rates, it may be
> necessary to set the high-speed clock dynamically based
> on the desired pixel clock for the connected device.
>
> This also removes the need to set a clock speed from
> the device tree for non-burst mode operation, since the
> pixel clock rate is the rate requested from the attached
> device like a bridge chip.  This should have no impact
> for people using burst-mode and setting the burst clock
> rate is still required for those users.  If the burst
> clock is not present, change the error message to
> dev_info indicating the clock use the pixel clock.
>
> Signed-off-by: Adam Ford <aford173 at gmail.com>
> Tested-by: Chen-Yu Tsai <wenst at chromium.org>
> Tested-by: Frieder Schrempf <frieder.schrempf at kontron.de>
> Reviewed-by: Frieder Schrempf <frieder.schrempf at kontron.de>
> ---
>  drivers/gpu/drm/bridge/samsung-dsim.c | 27 +++++++++++++++++++++------
>  1 file changed, 21 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
> index 3944b7cfbbdf..03b21d13f067 100644
> --- a/drivers/gpu/drm/bridge/samsung-dsim.c
> +++ b/drivers/gpu/drm/bridge/samsung-dsim.c
> @@ -655,16 +655,28 @@ static unsigned long samsung_dsim_set_pll(struct samsung_dsim *dsi,
>
>         dsi->hs_clock = fout;
>
> +       dsi->hs_clock = fout;

I dropped this and tested it.

Reviewed-by: Jagan Teki <jagan at amarulasolutions.com>
Tested-by: Jagan Teki <jagan at amarulasolutions.com> # imx8mm-icore


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