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

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@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 */