[PATCH] drm/bridge: ti-tfp410: Fall back to HPD polling if HPD irq is not available

[Peter Ujfalusi]

On 02/04/2019 14.21, Laurent Pinchart wrote:
> Hi Peter,
> 
> Thank you for the patch.
> 
> On Mon, Apr 01, 2019 at 03:33:42PM +0300, Peter Ujfalusi wrote:
>> In case either the HPD gpio is not specified or when the HPD gpio can not
>> be used as interrupt we should tell the core that the HPD needs to be
>> polled for detecting hotplug.
>>
>> Signed-off-by: Peter Ujfalusi <peter.ujfalusi at ti.com>
>> ---
>>  drivers/gpu/drm/bridge/ti-tfp410.c | 14 +++++++++++---
>>  1 file changed, 11 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/bridge/ti-tfp410.c b/drivers/gpu/drm/bridge/ti-tfp410.c
>> index 285be4a0f4bd..6fc831eb3804 100644
>> --- a/drivers/gpu/drm/bridge/ti-tfp410.c
>> +++ b/drivers/gpu/drm/bridge/ti-tfp410.c
>> @@ -31,6 +31,7 @@ struct tfp410 {
>>  
>>  	struct i2c_adapter	*ddc;
>>  	struct gpio_desc	*hpd;
>> +	int			hpd_irq;
>>  	struct delayed_work	hpd_work;
>>  	struct gpio_desc	*powerdown;
>>  
>> @@ -124,8 +125,10 @@ static int tfp410_attach(struct drm_bridge *bridge)
>>  		return -ENODEV;
>>  	}
>>  
>> -	if (dvi->hpd)
>> +	if (dvi->hpd_irq >= 0)
> 
> Do you need a new hpd_irq field ? Can't you just test dvi->hpd as done
> today, simply adding the else clause to this if ?

We can have hpd GPIO, but the GPIO might not be usable for interrupt.

> 
>>  		dvi->connector.polled = DRM_CONNECTOR_POLL_HPD;
>> +	else
>> +		dvi->connector.polled = DRM_CONNECTOR_POLL_CONNECT | DRM_CONNECTOR_POLL_DISCONNECT;
>>  
>>  	drm_connector_helper_add(&dvi->connector,
>>  				 &tfp410_con_helper_funcs);
>> @@ -324,10 +327,15 @@ static int tfp410_init(struct device *dev, bool i2c)
>>  		return PTR_ERR(dvi->powerdown);
>>  	}
>>  
>> -	if (dvi->hpd) {
>> +	if (dvi->hpd)
>> +		dvi->hpd_irq = gpiod_to_irq(dvi->hpd);
>> +	else
>> +		dvi->hpd_irq = -ENXIO;
>> +
>> +	if (dvi->hpd_irq >= 0) {
>>  		INIT_DELAYED_WORK(&dvi->hpd_work, tfp410_hpd_work_func);
>>  
>> -		ret = devm_request_threaded_irq(dev, gpiod_to_irq(dvi->hpd),
>> +		ret = devm_request_threaded_irq(dev, dvi->hpd_irq,
>>  			NULL, tfp410_hpd_irq_thread, IRQF_TRIGGER_RISING |
>>  			IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
>>  			"hdmi-hpd", dvi);
> 

- Péter

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