[PATCH 07/12] drm: drm_display_mode: add signal polarity flags

Andrzej Hajda
2014-03-17T13:41:09Z

Hi Denis,

Thanks for the patch.

On 03/13/2014 06:17 PM, 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 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.
> ---
> include/drm/drm_crtc.h | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index f764654..61a4fe1 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -131,6 +131,13 @@ 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_PIXDATA_PRESERVE BIT(3)
> +#define DRM_MODE_FLAG_POL_DE_NEGEDGE BIT(4)
> +#define DRM_MODE_FLAG_POL_DE_POSEDGE BIT(5)
> +#define DRM_MODE_FLAG_POL_DE_PRESERVE BIT(6)

Could you add some description to these flags.
What are *_PRESERVE flags for?
Are those flags 1:1 compatible with respective 'videomode:flags'?
I guess DE flags should be rather DRM_MODE_FLAG_POL_DE_(LOW|HIGH), am I
right?

Regards
Andrzej

> +
> struct drm_display_mode {
> /* Header */
> struct list_head head;
> @@ -183,6 +190,7 @@ struct drm_display_mode {
> int vrefresh; /* in Hz */
> int hsync; /* in kHz */
> enum hdmi_picture_aspect picture_aspect_ratio;
> + unsigned int pol_flags;
> };
>
> static inline bool drm_mode_is_stereo(const struct drm_display_mode *mode)
>