Re: [PATCH v3 07/13] drm/bridge: tc358762: Update comment about the number of lanes

[Andreas Kemnade <andreas@kemnade.info>]

On Wed, 13 May 2026 16:10:16 +0300
Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> wrote:

> Update comment about the number of lanes.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> ---
>  drivers/gpu/drm/bridge/tc358762.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/bridge/tc358762.c b/drivers/gpu/drm/bridge/tc358762.c
> index 7840ab3454f6..c5734c4df440 100644
> --- a/drivers/gpu/drm/bridge/tc358762.c
> +++ b/drivers/gpu/drm/bridge/tc358762.c
> @@ -306,7 +306,14 @@ static int tc358762_probe(struct mipi_dsi_device *dsi)
>  	ctx->dev = dev;
>  	ctx->pre_enabled = false;
>  
> -	/* TODO: Find out how to get dual-lane mode working */
> +	/*
> +	 * When using DSI clk for pixel clock (only mode supported in the driver),
> +	 * the pclk is derived directly from the DSI byteclk via simple divider,
> +	 * which is either 2 or 3.
> +	 * The required divider can be calculated with bitspp / 8 / nlanes. Thus,
> +	 * for RGB888, only nlanes = 1 works as nlanes = 2 would require divider
> +	 * of 1.5.
> +	 */
>  	dsi->lanes = 1;
>  	dsi->format = MIPI_DSI_FMT_RGB888;
>  	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
> 
wondering: I am using lanes = 2 and RGB888. But I need to write something to
SYSPLL3 register. Which somehow is sensitive to write to.... Do you have any
information about that register?

My dirty attic:
https://github.com/akemnade/linux/blob/epson-7.1rc-panel-experiments-part-upstr/drivers/gpu/drm/panel/panel-bt2.c

Regards,
Andreas