On 11.01.2019 04:51, Laurent Pinchart wrote:
> From: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
>
> The DRM_BUS_FLAG_PIXDATA_POSEDGE and DRM_BUS_FLAG_PIXDATA_NEGEDGE macros
> and their DRM_BUS_FLAG_SYNC_* counterparts define on which pixel clock
> edge data and sync signals are driven. They are however used in some
> drivers to define on which pixel clock edge data and sync signals are
> sampled, which should usually (but not always) be the opposite edge of
> the driving edge. This creates confusion.
>
> Create four new macros for both PIXDATA and SYNC that explicitly state
> the driving and sampling edge in their name to remove the confusion. The
> driving macros are defined as the opposite of the sampling macros to
> made code simpler based on the assumption that the driving and sampling
> edges are opposite.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
> Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Reviewed-by: Stefan Agner <stefan@xxxxxxxx>
--
Stefan
> ---
> Changes since v1:
>
> - Address the DRM_BUS_FLAG_SYNC_* flags
> - Rebase on top of drm-next
> ---
> include/drm/drm_connector.h | 36 ++++++++++++++++++++++++++++++++----
> 1 file changed, 32 insertions(+), 4 deletions(-)
>
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index 9be2181b3ed7..00bb7a74962b 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -330,19 +330,47 @@ struct drm_display_info {
>
> #define DRM_BUS_FLAG_DE_LOW (1<<0)
> #define DRM_BUS_FLAG_DE_HIGH (1<<1)
> -/* drive data on pos. edge */
> +
> +/*
> + * Don't use those two flags directly, use the DRM_BUS_FLAG_PIXDATA_DRIVE_*
> + * and DRM_BUS_FLAG_PIXDATA_SAMPLE_* variants to qualify the flags explicitly.
> + * The DRM_BUS_FLAG_PIXDATA_SAMPLE_* flags are defined as the opposite of the
> + * DRM_BUS_FLAG_PIXDATA_DRIVE_* flags to make code simpler, as signals are
> + * usually to be sampled on the opposite edge of the driving edge.
> + */
> #define DRM_BUS_FLAG_PIXDATA_POSEDGE (1<<2)
> -/* drive data on neg. edge */
> #define DRM_BUS_FLAG_PIXDATA_NEGEDGE (1<<3)
> +
> +/* Drive data on rising edge */
> +#define DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE DRM_BUS_FLAG_PIXDATA_POSEDGE
> +/* Drive data on falling edge */
> +#define DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE DRM_BUS_FLAG_PIXDATA_NEGEDGE
> +/* Sample data on rising edge */
> +#define DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE DRM_BUS_FLAG_PIXDATA_NEGEDGE
> +/* Sample data on falling edge */
> +#define DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE DRM_BUS_FLAG_PIXDATA_POSEDGE
> +
> /* data is transmitted MSB to LSB on the bus */
> #define DRM_BUS_FLAG_DATA_MSB_TO_LSB (1<<4)
> /* data is transmitted LSB to MSB on the bus */
> #define DRM_BUS_FLAG_DATA_LSB_TO_MSB (1<<5)
> -/* drive sync on pos. edge */
> +
> +/*
> + * Similarly to the DRM_BUS_FLAG_PIXDATA_* flags, don't use these two flags
> + * directly, use one of the DRM_BUS_FLAG_SYNC_(DRIVE|SAMPLE)_* instead.
> + */
> #define DRM_BUS_FLAG_SYNC_POSEDGE (1<<6)
> -/* drive sync on neg. edge */
> #define DRM_BUS_FLAG_SYNC_NEGEDGE (1<<7)
>
> +/* Drive sync on rising edge */
> +#define DRM_BUS_FLAG_SYNC_DRIVE_POSEDGE DRM_BUS_FLAG_SYNC_POSEDGE
> +/* Drive sync on falling edge */
> +#define DRM_BUS_FLAG_SYNC_DRIVE_NEGEDGE DRM_BUS_FLAG_SYNC_NEGEDGE
> +/* Sample sync on rising edge */
> +#define DRM_BUS_FLAG_SYNC_SAMPLE_POSEDGE DRM_BUS_FLAG_SYNC_NEGEDGE
> +/* Sample sync on falling edge */
> +#define DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE DRM_BUS_FLAG_SYNC_POSEDGE
> +
> /**
> * @bus_flags: Additional information (like pixel signal polarity) for
> * the pixel data on the bus, using DRM_BUS_FLAGS\_ defines.
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