Re: [PATCH v3 08/13] davinci: vpif: add support for clipping on output data

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Manjunath,

Thank you for the patch.

On Monday 25 June 2012 16:37:30 Manjunath Hadli wrote:
> add hardware clipping support for VPIF output data. This
> is needed as it is possible that the external encoder
> might get confused between the FF or 00 which are a part
> of the data and that of the SAV or EAV codes.
> 
> Signed-off-by: Manjunath Hadli <manjunath.hadli@ti.com>
> Signed-off-by: Lad, Prabhakar <prabhakar.lad@ti.com>
> ---
>  drivers/media/video/davinci/vpif.h         |   30 +++++++++++++++++++++++++
>  drivers/media/video/davinci/vpif_display.c |   10 +++++++++
>  include/media/davinci/vpif_types.h         |    2 +
>  3 files changed, 42 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/media/video/davinci/vpif.h
> b/drivers/media/video/davinci/vpif.h index a4d2141..c2ce4d9 100644
> --- a/drivers/media/video/davinci/vpif.h
> +++ b/drivers/media/video/davinci/vpif.h
> @@ -211,6 +211,12 @@ static inline void vpif_clr_bit(u32 reg, u32 bit)
>  #define VPIF_CH3_INT_CTRL_SHIFT	(6)
>  #define VPIF_CH_INT_CTRL_SHIFT	(6)
> 
> +#define VPIF_CH2_CLIP_ANC_EN	14
> +#define VPIF_CH2_CLIP_ACTIVE_EN	13
> +
> +#define VPIF_CH3_CLIP_ANC_EN	14
> +#define VPIF_CH3_CLIP_ACTIVE_EN	13
> +
>  /* enabled interrupt on both the fields on vpid_ch0_ctrl register */
>  #define channel0_intr_assert()	(regw((regr(VPIF_CH0_CTRL)|\
>  	(VPIF_INT_BOTH << VPIF_CH0_INT_CTRL_SHIFT)), VPIF_CH0_CTRL))
> @@ -515,6 +521,30 @@ static inline void channel3_raw_enable(int enable, u8
> index) vpif_clr_bit(VPIF_CH3_CTRL, mask);
>  }
> 
> +/* function to enable clipping (for both active and blanking regions) on ch
> 2 */ +static inline void channel2_clipping_enable(int enable)
> +{
> +	if (enable) {
> +		vpif_set_bit(VPIF_CH2_CTRL, VPIF_CH2_CLIP_ANC_EN);
> +		vpif_set_bit(VPIF_CH2_CTRL, VPIF_CH2_CLIP_ACTIVE_EN);
> +	} else {
> +		vpif_clr_bit(VPIF_CH2_CTRL, VPIF_CH2_CLIP_ANC_EN);
> +		vpif_clr_bit(VPIF_CH2_CTRL, VPIF_CH2_CLIP_ACTIVE_EN);
> +	}
> +}
> +
> +/* function to enable clipping (for both active and blanking regions) on ch
> 2 */ +static inline void channel3_clipping_enable(int enable)
> +{
> +	if (enable) {
> +		vpif_set_bit(VPIF_CH3_CTRL, VPIF_CH3_CLIP_ANC_EN);
> +		vpif_set_bit(VPIF_CH3_CTRL, VPIF_CH3_CLIP_ACTIVE_EN);
> +	} else {
> +		vpif_clr_bit(VPIF_CH3_CTRL, VPIF_CH3_CLIP_ANC_EN);
> +		vpif_clr_bit(VPIF_CH3_CTRL, VPIF_CH3_CLIP_ACTIVE_EN);
> +	}
> +}
> +
>  /* inline function to set buffer addresses in case of Y/C non mux mode */
>  static inline void ch2_set_videobuf_addr_yc_nmux(unsigned long
> top_strt_luma, unsigned long btm_strt_luma,
> diff --git a/drivers/media/video/davinci/vpif_display.c
> b/drivers/media/video/davinci/vpif_display.c index 61ea8bc..4436ef6 100644
> --- a/drivers/media/video/davinci/vpif_display.c
> +++ b/drivers/media/video/davinci/vpif_display.c
> @@ -1046,6 +1046,8 @@ static int vpif_streamon(struct file *file, void
> *priv, channel2_intr_assert();
>  			channel2_intr_enable(1);
>  			enable_channel2(1);
> +			if (vpif_config_data->ch2_clip_en)
> +				channel2_clipping_enable(1);
>  		}
> 
>  		if ((VPIF_CHANNEL3_VIDEO == ch->channel_id)
> @@ -1053,6 +1055,8 @@ static int vpif_streamon(struct file *file, void
> *priv, channel3_intr_assert();
>  			channel3_intr_enable(1);
>  			enable_channel3(1);
> +			if (vpif_config_data->ch3_clip_en)
> +				channel3_clipping_enable(1);
>  		}
>  		channel_first_int[VPIF_VIDEO_INDEX][ch->channel_id] = 1;
>  	}
> @@ -1065,6 +1069,8 @@ static int vpif_streamoff(struct file *file, void
> *priv, struct vpif_fh *fh = priv;
>  	struct channel_obj *ch = fh->channel;
>  	struct common_obj *common = &ch->common[VPIF_VIDEO_INDEX];
> +	struct vpif_display_config *vpif_config_data =
> +					vpif_dev->platform_data;
> 
>  	if (buftype != V4L2_BUF_TYPE_VIDEO_OUTPUT) {
>  		vpif_err("buffer type not supported\n");
> @@ -1084,11 +1090,15 @@ static int vpif_streamoff(struct file *file, void
> *priv, if (buftype == V4L2_BUF_TYPE_VIDEO_OUTPUT) {
>  		/* disable channel */
>  		if (VPIF_CHANNEL2_VIDEO == ch->channel_id) {
> +			if (vpif_config_data->ch2_clip_en)
> +				channel2_clipping_enable(0);
>  			enable_channel2(0);
>  			channel2_intr_enable(0);
>  		}
>  		if ((VPIF_CHANNEL3_VIDEO == ch->channel_id) ||
>  					(2 == common->started)) {
> +			if (vpif_config_data->ch3_clip_en)
> +				channel3_clipping_enable(0);
>  			enable_channel3(0);
>  			channel3_intr_enable(0);
>  		}
> diff --git a/include/media/davinci/vpif_types.h
> b/include/media/davinci/vpif_types.h index bd8217c..d8f6ab1 100644
> --- a/include/media/davinci/vpif_types.h
> +++ b/include/media/davinci/vpif_types.h
> @@ -50,6 +50,8 @@ struct vpif_display_config {
>  	const char **output;
>  	int output_count;
>  	const char *card_name;
> +	bool ch2_clip_en;
> +	bool ch3_clip_en;

Instead of hardcoding this in platform data, I think it would be better to 
make this runtime-configurable. One option is to use the value of the 
v4l2_pix_format::colorspace field configured by userspace. We already have 
V4L2_COLORSPACE_JPEG which maps to the full 0-255 range, but we're missing a 
colorspace for the clipped 1-254 range used by the VPIF and I'm not sure 
whether it would really make sense to add one. Another option is to use a V4L2 
control.

>  };
> 
>  struct vpif_input {

-- 
Regards,

Laurent Pinchart