[21/21] drm/bridge: tc358767: implement naive HPD handling

[Tomi Valkeinen]

On 20/03/2019 07:55, Andrey Smirnov wrote:
> On Tue, Mar 19, 2019 at 11:18 AM Andrey Smirnov
> <andrew.smirnov at gmail.com> wrote:
>>
>>> tc358767 driver doesn't have any HPD handling at the moment, as it was
>>> originally developed to support only eDP.
>>
>>> This patch implements a naive, polling-based HPD handling, which is used
>>> when the driver is in DP mode.
>>
>>> Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ti.com>
>>> ---
>>>  drivers/gpu/drm/bridge/tc358767.c | 56 +++++++++++++++++++++----------
>>>  1 file changed, 38 insertions(+), 18 deletions(-)
>>
>>> diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
>>> index 8606de29c9b2..2b252f7ac070 100644
>>> --- a/drivers/gpu/drm/bridge/tc358767.c
>>> +++ b/drivers/gpu/drm/bridge/tc358767.c
>>> @@ -1095,6 +1095,12 @@ static void tc_bridge_enable(struct drm_bridge *bridge)
>>>       struct tc_data *tc = bridge_to_tc(bridge);
>>>       int ret;
>>
>>> +     ret = tc_get_display_props(tc);
>>> +     if (ret < 0) {
>>> +             dev_err(tc->dev, "failed to read display props: %d\n", ret);
>>> +             return;
>>> +     }
>>> +
>>>       ret = tc_main_link_enable(tc);
>>>       if (ret < 0) {
>>>               dev_err(tc->dev, "main link enable error: %d\n", ret);
>>> @@ -1200,19 +1206,35 @@ static int tc_connector_get_modes(struct drm_connector *connector)
>>>       return count;
>>>  }
>>
>>> -static void tc_connector_set_polling(struct tc_data *tc,
>>> -                                  struct drm_connector *connector)
>>> -{
>>> -     /* TODO: add support for HPD */
>>> -     connector->polled = DRM_CONNECTOR_POLL_CONNECT |
>>> -                         DRM_CONNECTOR_POLL_DISCONNECT;
>>> -}
>>> -
>>>  static const struct drm_connector_helper_funcs tc_connector_helper_funcs = {
>>>       .get_modes = tc_connector_get_modes,
>>>  };
>>
>>> +static enum drm_connector_status tc_connector_detect(struct drm_connector *connector, bool force)
>>> +{
>>> +     struct tc_data *tc = connector_to_tc(connector);
>>> +     u32 val;
>>> +     int ret;
>>> +     bool conn;
>>> +
>>> +     tc_read(GPIOI, &val);
>>> +
>>> +     conn = val & BIT(0);
> 
> Another thing I noticed when trying this patch is that
> tc_connector_detect() will get called via drm_helper_probe_detect()
> even if tc->panel is not NULL and tc->connector.polled is zero, which
> creates a problem for eDP use-case.

Ok, thanks for testing. So we need to return "connected" from the detect
function for eDP cases.

I think I need to create a fake setup where I can also run with an eDP
panel to test this series properly. Probably I can create a "panel"
driver for my DP monitor, so I would still get a picture.

 Tomi

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