On Fri, Mar 31, 2023 at 11:06:44AM +0200, Neil Armstrong wrote:
> Hi,
>
> On 30/03/2023 12:17, Francesco Dolcini wrote:
> > From: Francesco Dolcini <francesco.dolcini@xxxxxxxxxxx>
> >
> > Enable configuration of the DSI video mode instead of hard-coding
> > MIPI_DSI_MODE_VIDEO_BURST. The bridge support any of burst-mode,
> > non-burst with sync event or non-burst with sync pulse
> >
> > With this change is possible to use the bridge with host DSI
> > that do not support burst mode.
> >
> > Signed-off-by: Francesco Dolcini <francesco.dolcini@xxxxxxxxxxx>
> > ---
> > drivers/gpu/drm/bridge/ti-sn65dsi83.c | 24 +++++++++++++++++++++++-
> > 1 file changed, 23 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi83.c b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> > index 91ecfbe45bf9..144d0de0d278 100644
> > --- a/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> > +++ b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> > @@ -145,6 +145,7 @@ struct sn65dsi83 {
> > struct drm_bridge *panel_bridge;
> > struct gpio_desc *enable_gpio;
> > struct regulator *vcc;
> > + u32 dsi_video_mode;
> > bool lvds_dual_link;
> > bool lvds_dual_link_even_odd_swap;
> > };
> > @@ -603,6 +604,9 @@ static int sn65dsi83_parse_dt(struct sn65dsi83 *ctx, enum sn65dsi83_model model)
> > return dev_err_probe(dev, PTR_ERR(ctx->vcc),
> > "Failed to get supply 'vcc'\n");
> > + ctx->dsi_video_mode = 0;
> > + of_property_read_u32(dev->of_node, "dsi-video-mode", &ctx->dsi_video_mode);
> > +
> > return 0;
> > }
> > @@ -642,7 +646,25 @@ static int sn65dsi83_host_attach(struct sn65dsi83 *ctx)
> > dsi->lanes = dsi_lanes;
> > dsi->format = MIPI_DSI_FMT_RGB888;
> > - dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST;
> > + dsi->mode_flags = MIPI_DSI_MODE_VIDEO;
> > +
> > + switch (ctx->dsi_video_mode) {
> > + case 0:
> > + /* burst mode */
> > + dsi->mode_flags |= MIPI_DSI_MODE_VIDEO_BURST;
> > + break;
> > + case 1:
> > + /* non-burst mode with sync event */
> > + break;
> > + case 2:
> > + /* non-burst mode with sync pulse */
> > + dsi->mode_flags |= MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
> > + break;
> > + default:
> > + dev_warn(dev, "invalid video mode %d\n", ctx->dsi_video_mode);
> > + break;
> > + }
> > +
> > ret = devm_mipi_dsi_attach(dev, dsi);
> > if (ret < 0) {
>
> As I understand from DSI spec is that those are dynamic, so they are hardcoded in driver now
> but they shouldn't be hardcoded in DT.
>
> The problem is larger and we should add some sort of "supported features" we can get
> from the DSI controller and set the flags accordingly because the features support accross the
> DSI controllers isn't linear.
I need to change this since I do have a bridge that does not support
DSI video burst mode, while the ti-sn65 supports really any mode.
The change here is the same as what is done for the raydium,rm67191
panel, see Documentation/devicetree/bindings/display/panel/raydium,rm67191.yaml
and drivers/gpu/drm/panel/panel-raydium-rm67191.c.
What's wrong to have this in the dts so that a panel can explicitly tell
which DSI video mode it expects?
Francesco
