[PATCH 1/5] drm: drm_bridge: add cec_init/exit bridge ops

[Hans Verkuil]

On 19/02/2021 13:02, Laurent Pinchart wrote:
> Hi Hans,
> 
> Thank you for the patch.
> 
> On Thu, Feb 11, 2021 at 11:36:59AM +0100, Hans Verkuil wrote:
>> Add bridge cec_init/exit ops. These ops will be responsible for
>> creating and destroying the CEC adapter for the bridge that supports
>> CEC.
>>
>> Signed-off-by: Hans Verkuil <hverkuil-cisco at xs4all.nl>
>> ---
>>  drivers/gpu/drm/drm_bridge_connector.c | 23 +++++++++++++++++++
>>  include/drm/drm_bridge.h               | 31 ++++++++++++++++++++++++++
>>  2 files changed, 54 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_bridge_connector.c b/drivers/gpu/drm/drm_bridge_connector.c
>> index 791379816837..2ff90f5e468c 100644
>> --- a/drivers/gpu/drm/drm_bridge_connector.c
>> +++ b/drivers/gpu/drm/drm_bridge_connector.c
>> @@ -84,6 +84,13 @@ struct drm_bridge_connector {
>>  	 * connector modes detection, if any (see &DRM_BRIDGE_OP_MODES).
>>  	 */
>>  	struct drm_bridge *bridge_modes;
>> +	/**
>> +	 * @bridge_cec:
>> +	 *
>> +	 * The last bridge in the chain (closest to the connector) that provides
>> +	 * cec adapter support, if any (see &DRM_BRIDGE_OP_CEC).
>> +	 */
>> +	struct drm_bridge *bridge_cec;
>>  };
>>  
>>  #define to_drm_bridge_connector(x) \
>> @@ -204,6 +211,11 @@ static void drm_bridge_connector_destroy(struct drm_connector *connector)
>>  	struct drm_bridge_connector *bridge_connector =
>>  		to_drm_bridge_connector(connector);
>>  
>> +	if (bridge_connector->bridge_cec) {
>> +		struct drm_bridge *cec = bridge_connector->bridge_cec;
>> +
>> +		cec->funcs->cec_exit(cec);
>> +	}
>>  	if (bridge_connector->bridge_hpd) {
>>  		struct drm_bridge *hpd = bridge_connector->bridge_hpd;
>>  
>> @@ -352,6 +364,8 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm,
>>  			bridge_connector->bridge_detect = bridge;
>>  		if (bridge->ops & DRM_BRIDGE_OP_MODES)
>>  			bridge_connector->bridge_modes = bridge;
>> +		if (bridge->ops & DRM_BRIDGE_OP_CEC)
>> +			bridge_connector->bridge_cec = bridge;
>>  
>>  		if (!drm_bridge_get_next_bridge(bridge))
>>  			connector_type = bridge->type;
>> @@ -374,6 +388,15 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm,
>>  	else if (bridge_connector->bridge_detect)
>>  		connector->polled = DRM_CONNECTOR_POLL_CONNECT
>>  				  | DRM_CONNECTOR_POLL_DISCONNECT;
>> +	if (bridge_connector->bridge_cec) {
>> +		struct drm_bridge *bridge = bridge_connector->bridge_cec;
>> +		int ret = bridge->funcs->cec_init(bridge, connector);
>> +
>> +		if (ret) {
>> +			drm_bridge_connector_destroy(connector);
>> +			return ERR_PTR(ret);
>> +		}
>> +	}
>>  
>>  	return connector;
>>  }
>> diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
>> index 2195daa289d2..4c83c2657e87 100644
>> --- a/include/drm/drm_bridge.h
>> +++ b/include/drm/drm_bridge.h
>> @@ -629,6 +629,30 @@ struct drm_bridge_funcs {
>>  	 * the DRM_BRIDGE_OP_HPD flag in their &drm_bridge->ops.
>>  	 */
>>  	void (*hpd_disable)(struct drm_bridge *bridge);
>> +
>> +	/**
>> +	 * @cec_init:
>> +	 *
>> +	 * Initialize the CEC adapter.
>> +	 *
>> +	 * This callback is optional and shall only be implemented by bridges
>> +	 * that support a CEC adapter. Bridges that implement it shall also
>> +	 * implement the @cec_exit callback and set the DRM_BRIDGE_OP_CEC flag
>> +	 * in their &drm_bridge->ops.
>> +	 */
>> +	int (*cec_init)(struct drm_bridge *bridge, struct drm_connector *conn);
>> +
>> +	/**
>> +	 * @cec_exit:
>> +	 *
>> +	 * Terminate the CEC adapter.
>> +	 *
>> +	 * This callback is optional and shall only be implemented by bridges
>> +	 * that support a CEC adapter. Bridges that implement it shall also
>> +	 * implement the @cec_init callback and set the DRM_BRIDGE_OP_CEC flag
>> +	 * in their &drm_bridge->ops.
>> +	 */
>> +	void (*cec_exit)(struct drm_bridge *bridge);
> 
> These are very ad-hoc operations. Would it make sense to have something
> that could also be reused for other type of intiialization and cleanup
> that require access to the drm_connector ?

I do not have a very strong opinion, to be honest.

How about this:

	/**
	 * @DRM_BRIDGE_OP_CONN: The bridge can do additional work when
	 * a drm_connector is created or destroyed, such as creating or
	 * removing a CEC adapter.
	 * &drm_bridge_funcs->conn_init and &drm_bridge_funcs->conn_exit
	 * callbacks.
	 */
	DRM_BRIDGE_OP_CONN = BIT(4),

Would that work better for you?

Regards,

	Hans

> 
>>  };
>>  
>>  /**
>> @@ -698,6 +722,13 @@ enum drm_bridge_ops {
>>  	 * this flag shall implement the &drm_bridge_funcs->get_modes callback.
>>  	 */
>>  	DRM_BRIDGE_OP_MODES = BIT(3),
>> +	/**
>> +	 * @DRM_BRIDGE_OP_CEC: The bridge supports a CEC adapter.
>> +	 * Bridges that set this flag shall implement the
>> +	 * &drm_bridge_funcs->cec_init and &drm_bridge_funcs->cec_exit
>> +	 * callbacks.
>> +	 */
>> +	DRM_BRIDGE_OP_CEC = BIT(4),
>>  };
>>  
>>  /**
>