[ADV7393] DRM Encoder Slave or DRM Bridge

[Vikas Patil]

Hi Tomi,


Now with the adv7393 driver in place, I was getting following error.
After debugging found out that this is due to the “.interlace= true”
in display timings
“drivers\gpu\drm\omapdrm\displays\connector-analog-tv.c”.


[   14.564872] [drm:drm_helper_probe_single_connector_modes_merge_bits]
[CONNECTOR:32:Unknown-1]
[   14.564882] [drm:omap_connector_get_modes] cvbs_out
[   14.564898] ------>adv7393_check_timings: start
[   14.569646] [drm:omap_connector_mode_valid] connector: mode
invalid: 45:"720x480i" 120 27000 720 739 801 858 480 490 493 527 0x48
0x2a000015
[   14.569659] [drm:drm_mode_debug_printmodeline] Modeline
45:"720x480i" 120 27000 720 739 801 858 480 490 493 527 0x48
0x2a000015
[   14.569668] [drm:drm_mode_prune_invalid] Not using 720x480i mode: BAD

After setting “.interlace= false”  in display timings
“\displays\connector-analog-tv.c” mode seems to be valid but still
nothing on display probably because connector still doesn’t seem to be
enabled from the below drm log.

[   14.787200] [drm:drm_setup_crtcs]
[   14.787211] [drm:drm_enable_connectors] connector 32 enabled? no
[   14.787220] [drm:drm_enable_connectors] connector 36 enabled? Yes

Could you help me to understand if I could use “interlace=false”?
ADV7393 seems to be supporting non-interlaced mode. From datasheet:
“The ADV7390/ADV7391/ADV7392/ADV7393 support an SD noninterlaced mode.
Using this mode, progressive inputs at twice the frame rate of NTSC
and PAL (240p/59.94 Hz and 288p/50 Hz, respectively) can be input into
the ADV7390/ ADV7391/ADV7392/ADV7393. The SD noninterlaced mode can be
enabled using Subaddress 0x88, Bit 1.”

What/Where should I need to look for enabling the above connector and
attached to the correct encoder/crtc?

Also looking at function dispc_mgr_timings_ok () in
drivers/gpu/drm/omapdrm/dss/dispc.c, it seems driver of DSS doesn’t
support interlace out as comment suggests below. Would this be a
problem for me for driving ADV7393? What does this means?


if (dss_mgr_is_lcd(channel)) {
                /* TODO: OMAP4+ supports interlace for LCD outputs */
                if (timings->interlace)
                {
                        DSSWARN("vikas----->: interlace failed\n");
                        return false;
                }

                if (!_dispc_lcd_timings_ok(timings->hsw, timings->hfp,
                                timings->hbp, timings->vsw, timings->vfp,
                               timings->vbp))
                {
                        return false;
                }
        }


Thanks & Regards,
Vikash



On Thu, Sep 15, 2016 at 3:23 PM, Tomi Valkeinen <tomi.valkeinen at ti.com> wrote:
>
>
> On 15/09/16 12:44, Vikas Patil wrote:
>> On Wed, Sep 14, 2016 at 3:04 PM, Tomi Valkeinen <tomi.valkeinen at ti.com> wrote:
>>>
>>>
>>> On 13/09/16 16:13, Vikas Patil wrote:
>>>> Thanks Tomi for quick comment.
>>>>
>>>> I am thinking to base adv7393 driver on
>>>> "drivers\gpu\drm\omapdrm\displays\encoder-tc358768.c" as I don't think
>>>> any similar to adv7393 chip driver available. Could you please comment
>>>> if this will help to get adv chip running?
>>>
>>> I presume you're not using mainline kernel, as that driver is not there.
>>> I'm not familiar with adv7393, but yes, I think you can use that as an
>>> example.
>>>
>>
>> Thanks a lot for your comments. I am using latest (i.e. 3.00.00.03 )
>> Processor SDK Linux Automotive which is based on linux 4.4.14.
>>
>> As my display panel is connected as follows. I am little confused over
>> the values I need to set for following properties in probe function.
>>
>> DPI1/VOUT1 -----16bit DRGB---> ADV7393 (Digital to Analog video
>> encoder) ------> CVBS Out ------> Display Panel
>>
>>
>>      dssdev->ops.dpi = &adv7393_dpi_ops; (atv?)
>>     dssdev->type = OMAP_DISPLAY_TYPE_DPI;
>>     dssdev->output_type = OMAP_DISPLAY_TYPE_DPI; (Do I need to use
>> OMAP_DISPLAY_TYPE_VENC, but DRA74x do not have VENC Encoder I think)
>>     dssdev->phy.dpi.data_lines = ddata->dpi_ndl;
>>     dssdev->port_num = 1;
>>
>>
>> As adv7393 takes 16-bit DRGB as input and gives composite as output,
>> does above configuration looks correct? or Do I need to change to
>> something else (e.g. dpi,sdi,dvi, hdmi, atv, dsi)?
>
> The API is quite messy (full of legacy)...
>
> But the "ops" there are for the "downstream" direction, i.e. towards the
> connector. So here you should have atv ops. You should then have
> connector-analog-tv as a device after adv7393, and that connector driver
> will be calling those atv ops.
>
> adv7393 itself will be calling dpi ops, offered by the DSS.
>
> You should set dssdev->type to DPI (that's the input).
> dssdev->output_type to OMAP_DISPLAY_TYPE_VENC (output, although "venc"
> is not quite correct here, but closest match we have). DRA74x doesn't
> have VENC, but this is what the adv7393 outputs.
>
>  Tomi
>