Hi Heiko,
> On 10.04.2019, at 16:50, Heiko Stübner <heiko@xxxxxxxxx> wrote:
>
> Hi Christoph,
>
> Am Mittwoch, 10. April 2019, 16:10:44 CEST schrieb Christoph Muellner:
>> On our RK3399-Q7 EVK base board we have the option to connect an arbitrary
>> monitor via DP cable. The actual monitor is therefore not known in advance.
>> This means, we don't have any panel information besides the EDID
>> data from the device itself.
>
> Just so I understand correctly, you have a real dp-connector wired to
> the Analogix dp-controller, and therefore want to connect actual
> monitors to it.
>
> So the problem you're trying to work around is probably that the
> rockchip-driver of the analogix controller explictly expects a bridge
> to be present during probe, right?
>
> I think hacking up the panel-driver is not an ideal approach:
> (1) bridges/panels do expect to stay connected all the time
> and are meant for devices with actual hard-wired displays with specific
> power-sequence requirements
> (2) devicetree is expected to describe the real hardware, therefore the
> dt should not describe one thing while the actual hardware is really
> different
>
> So, I guess a more ideal approach could perhaps be to:
> (1) define a "dp-connector" devicetree binding, see
> Documentation/devicetree/bindings/display/connector/hdmi-connector.txt
> for a similar one
> (2) steal an idea from drivers/gpu/drm/mediatek/mtk_hdmi.c and check
> for that new compatible:
> if (!of_device_is_compatible(remote, "hdmi-connector")) {
> //move bridge handling here
> }
>
> and modify both the rockchip-part and the generic analogix bridge code
> to work with the connector declared instead of a panel?
Thank's for you input on this.
Modelling the connector instead of the panel is indeed a better approach,
since we can then also react to connect/disconnect events (after probe).
Thanks,
Christoph
>
>> The functionality for a 'simple-panel' has been remove a couple
>> of years ago with 81cf32b. This patch brings this feature back.
>>
>> Signed-off-by: Christoph Muellner <christoph.muellner@xxxxxxxxxxxxxxxxxxxxx>
>> ---
>> drivers/gpu/drm/panel/panel-simple.c | 24 ++++++++++++++++--------
>> 1 file changed, 16 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
>> index 9e8218f6a3f2..1f69283f3e4b 100644
>> --- a/drivers/gpu/drm/panel/panel-simple.c
>> +++ b/drivers/gpu/drm/panel/panel-simple.c
>> @@ -176,7 +176,7 @@ static int panel_simple_disable(struct drm_panel *panel)
>> backlight_update_status(p->backlight);
>> }
>>
>> - if (p->desc->delay.disable)
>> + if (p->desc && p->desc->delay.disable)
>> msleep(p->desc->delay.disable);
>>
>> p->enabled = false;
>> @@ -195,7 +195,7 @@ static int panel_simple_unprepare(struct drm_panel *panel)
>>
>> regulator_disable(p->supply);
>>
>> - if (p->desc->delay.unprepare)
>> + if (p->desc && p->desc->delay.unprepare)
>> msleep(p->desc->delay.unprepare);
>>
>> p->prepared = false;
>> @@ -220,11 +220,13 @@ static int panel_simple_prepare(struct drm_panel *panel)
>>
>> gpiod_set_value_cansleep(p->enable_gpio, 1);
>>
>> - delay = p->desc->delay.prepare;
>> - if (p->no_hpd)
>> - delay += p->desc->delay.hpd_absent_delay;
>> - if (delay)
>> - msleep(delay);
>> + if (p->desc) {
>> + delay = p->desc->delay.prepare;
>> + if (p->no_hpd)
>> + delay += p->desc->delay.hpd_absent_delay;
>> + if (delay)
>> + msleep(delay);
>> + }
>>
>> p->prepared = true;
>>
>> @@ -238,7 +240,7 @@ static int panel_simple_enable(struct drm_panel *panel)
>> if (p->enabled)
>> return 0;
>>
>> - if (p->desc->delay.enable)
>> + if (p->desc && p->desc->delay.enable)
>> msleep(p->desc->delay.enable);
>>
>> if (p->backlight) {
>> @@ -280,6 +282,9 @@ static int panel_simple_get_timings(struct drm_panel *panel,
>> struct panel_simple *p = to_panel_simple(panel);
>> unsigned int i;
>>
>> + if (!p->desc)
>> + return 0;
>> +
>> if (p->desc->num_timings < num_timings)
>> num_timings = p->desc->num_timings;
>>
>> @@ -2536,6 +2541,9 @@ static const struct panel_desc arm_rtsm = {
>>
>> static const struct of_device_id platform_of_match[] = {
>> {
>> + .compatible = "simple-panel",
>> + .data = NULL,
>> + }, {
>> .compatible = "ampire,am-480272h3tmqw-t01h",
>> .data = &ire_am_480272h3tmqw_t01h,
>> }, {
>>
>
>
>
>
