[PATCH v13 06/10] drm: drm_display_mode: add signal polarity flags

Laurent Pinchart laurent.pinchart at ideasonboard.com
Thu Jun 12 16:46:17 PDT 2014


Hi Denis,

Thank you for the patch.

On Tuesday 10 June 2014 12:25:47 Denis Carikli wrote:
> We need a way to pass signal polarity informations
>   between DRM panels, and the display drivers.
> 
> To do that, a pol_flags field was added to drm_display_mode.
> 
> Signed-off-by: Denis Carikli <denis at eukrea.com>
> ---
> ChangeLog v12->v13:
> - Added Docbook documentation for pol_flags the struct field.
> - Removed the _PRESERVE	defines: it was used by patches
>   against the imx_drm driver. Now theses patches have been
>   adapted not to require that defines.
> ChangeLog v11->v12:
> - Rebased: This patch now applies against drm_modes.h
> - Rebased: It now uses the new DRM_MODE_FLAG_POL_DE flags defines names
> 
> ChangeLog v10->v11:
> - Since the imx-drm won't be able to retrive its regulators
>   from the device tree when using display-timings nodes,
>   and that I was told that the drm simple-panel driver
>   already supported that, I then, instead, added what was
>   lacking to make the eukrea displays work with the
>   drm-simple-panel driver.
> 
>   That required a way to get back the display polarity
>   informations from the imx-drm driver without affecting
>   userspace.
> ---
>  Documentation/DocBook/drm.tmpl |   30 ++++++++++++++++++++++++++++++
>  include/drm/drm_modes.h        |    6 ++++++
>  2 files changed, 36 insertions(+)
> 
> diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl
> index c526d81..29c0e5a 100644
> --- a/Documentation/DocBook/drm.tmpl
> +++ b/Documentation/DocBook/drm.tmpl
> @@ -2292,6 +2292,36 @@ void intel_crt_init(struct drm_device *dev)
>              and <structfield>height_mm</structfield> fields are only used
> internally during EDID parsing and should not be set when creating modes
> manually. </para>
> +          <para>
> +            The <structfield>pol_flags</structfield> value represents the
> display
> +            signal polarity flags, it can be a combination of
> +            <variablelist>
> +              <varlistentry>
> +                <term>DRM_MODE_FLAG_POL_PIXDATA_NEGEDGE</term>
> +                 <listitem><para>
> +                     drive pixel data on falling edge, sample data on
> rising edge.
> +                 </para></listitem>
> +              </varlistentry>
> +              <varlistentry>
> +                <term>DRM_MODE_FLAG_POL_PIXDATA_POSEDGE</term>
> +                <listitem><para>
> +                  Drive pixel data on rising edge, sample data on falling
> edge.
> +                </para></listitem>
> +              </varlistentry>
> +              <varlistentry>
> +                <term>DRM_MODE_FLAG_POL_DE_LOW</term>
> +                <listitem><para>
> +                  data-enable pulse is active low
> +                </para></listitem>
> +              </varlistentry>
> +              <varlistentry>
> +                <term>DRM_MODE_FLAG_POL_DE_HIGH</term>
> +                <listitem><para>
> +                  data-enable pulse is active low

I assume you mean active high here.

> +                </para></listitem>
> +              </varlistentry>
> +            </variablelist>
> +          </para>
>          </listitem>
>          <listitem>
>            <synopsis>int (*mode_valid)(struct drm_connector *connector,
> diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h
> index 91d0582..c5cbe31 100644
> --- a/include/drm/drm_modes.h
> +++ b/include/drm/drm_modes.h
> @@ -93,6 +93,11 @@ enum drm_mode_status {
> 
>  #define DRM_MODE_FLAG_3D_MAX	DRM_MODE_FLAG_3D_SIDE_BY_SIDE_HALF
> 
> +#define DRM_MODE_FLAG_POL_PIXDATA_NEGEDGE	BIT(1)
> +#define DRM_MODE_FLAG_POL_PIXDATA_POSEDGE	BIT(2)
> +#define DRM_MODE_FLAG_POL_DE_LOW		BIT(3)
> +#define DRM_MODE_FLAG_POL_DE_HIGH		BIT(4)
> +
>  struct drm_display_mode {
>  	/* Header */
>  	struct list_head head;
> @@ -144,6 +149,7 @@ struct drm_display_mode {
>  	int vrefresh;		/* in Hz */
>  	int hsync;		/* in kHz */
>  	enum hdmi_picture_aspect picture_aspect_ratio;
> +	unsigned int pol_flags;
>  };
> 
>  /* mode specified on the command line */

-- 
Regards,

Laurent Pinchart




More information about the linux-arm-kernel mailing list