Re: [PATCH v2 6/9] drm/bridge: Add ITE IT6263 LVDS to HDMI converter

[Liu Ying]

On 10/14/2024, Dmitry Baryshkov wrote:
> On Mon, Oct 14, 2024 at 03:18:15PM +0800, Liu Ying wrote:
>> On 10/14/2024, Dmitry Baryshkov wrote:
>>> On Sat, Oct 12, 2024 at 03:35:40PM +0800, Liu Ying wrote:
>>>> Add basic HDMI video output support. Currently, only RGB888 output
>>>> pixel format is supported.  At the LVDS input side, the driver
>>>> supports single LVDS link and dual LVDS links with "jeida-24" LVDS
>>>> mapping.
>>>>
>>>> Product link:
>>>> https://www.ite.com.tw/en/product/cate1/IT6263
>>>>
>>>> Signed-off-by: Liu Ying <victor.liu@xxxxxxx>
>>>> ---
>>>> v2:
>>>> * Add AVI inforframe support.  (Maxime)
>>>> * Add DRM_MODE_CONNECTOR_HDMIA.  (Biju)
>>>> * Rename it6263_reset() to it6263_hw_reset().  (Biju)
>>>> * Check number of LVDS link data lanes.  (Biju)
>>>>
>>>>  drivers/gpu/drm/bridge/Kconfig      |   8 +
>>>>  drivers/gpu/drm/bridge/Makefile     |   1 +
>>>>  drivers/gpu/drm/bridge/ite-it6263.c | 919 ++++++++++++++++++++++++++++
>>>>  3 files changed, 928 insertions(+)
>>>>  create mode 100644 drivers/gpu/drm/bridge/ite-it6263.c
>>>>
>>>
>>> [...]
>>>
>>>> +static int it6263_parse_dt(struct it6263 *it)
>>>> +{
>>>> +	struct device *dev = it->dev;
>>>> +	struct device_node *port0, *port1;
>>>> +	int ret;
>>>> +
>>>> +	ret = of_property_read_u8(dev->of_node, "ite,lvds-link-num-data-lanes",
>>>> +				  &it->lvds_link_num_dlanes);
>>>> +	if (ret) {
>>>> +		dev_err(dev, "failed to get LVDS link number of data lanes: %d\n",
>>>> +			ret);
>>>> +		return ret;
>>>> +	}
>>>> +
>>>> +	it->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 2, 0);
>>>> +	if (IS_ERR(it->next_bridge))
>>>> +		return dev_err_probe(dev, PTR_ERR(it->next_bridge),
>>>> +				     "failed to get next bridge\n");
>>>> +
>>>> +	port0 = of_graph_get_port_by_id(dev->of_node, 0);
>>>> +	port1 = of_graph_get_port_by_id(dev->of_node, 1);
>>>> +	if (port0 && port1) {
>>>> +		if (of_property_read_bool(port0, "dual-lvds-even-pixels") &&
>>>> +		    of_property_read_bool(port1, "dual-lvds-odd-pixels")) {
>>>> +			it->lvds_dual_link = true;
>>>> +			it->lvds_link12_swap = true;
>>>> +		} else if (of_property_read_bool(port0, "dual-lvds-odd-pixels") &&
>>>> +			   of_property_read_bool(port1, "dual-lvds-even-pixels")) {
>>>> +			it->lvds_dual_link = true;
>>>> +		}
>>>> +
>>>> +		if (!it->lvds_dual_link) {
>>>> +			dev_err(dev,
>>>> +				"failed to get LVDS dual link pixel order\n");
>>>> +			ret = -EINVAL;
>>>> +		}
>>>
>>> Please use drm_of_lvds_get_dual_link_pixel_order(), it validates that
>>> the DT definition is sound: one port for odd pixels, one port for even
>>> pixels.
>>
>> It cannot be used, because it get the pixel order for the LVDS
>> source not sink. IT6263 is the LVDS sink.
> 
> Then you need a similar function for the sink side. Add it to the
> drm_of.c

How about getting remote LVDS source ports first and use
drm_of_lvds_get_dual_link_pixel_order() like the snippet below?
This way, no need to add a similar function or modify
drm_of_lvds_get_dual_link_pixel_order() implementation.

If you don't like this, can you please suggest a similar function
name or maybe an additional parameter(with type and name) for
drm_of_lvds_get_dual_link_pixel_order()?

---8<---
        port0_ep = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);           
        if (port0_ep) {                                                          
                remote_port0 = of_graph_get_remote_port(port0_ep);               
                of_node_put(port0_ep);                                           
        }                                                                        
        port1_ep = of_graph_get_endpoint_by_regs(dev->of_node, 1, -1);           
        if (port1_ep) {                                                          
                remote_port1 = of_graph_get_remote_port(port1_ep);               
                of_node_put(port1_ep);                                           
        }                                                                        
                                                                                 
        if (remote_port0 && remote_port1) {                                      
                order = drm_of_lvds_get_dual_link_pixel_order(remote_port0,      
                                                              remote_port1);     
                if (order < 0) {                                                 
                        dev_err(dev,                                             
                                "failed to get dual link pixel order: %d\n",     
                                order);                                          
                        ret = order;                                             
                } else if (order == DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS) {        
                        it->lvds_dual_link = true;                               
                } else if (order == DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS) {        
                        it->lvds_dual_link = true;                               
                        it->lvds_link12_swap = true;                             
                }                                                                
        } else if (remote_port1) {                                               
                ret = -EINVAL;                                                   
                dev_err(dev, "single input LVDS port1 is not supported\n");      
        } else if (!remote_port0) {                                              
                ret = -EINVAL;                                                   
                dev_err(dev, "no input LVDS port\n");                            
        }                                                                        
                                                                                 
        of_node_put(remote_port0);                                               
        of_node_put(remote_port1); 
---8<---

> 
>>
>>  * drm_of_lvds_get_dual_link_pixel_order - Get LVDS dual-link pixel order        
>>  * @port1: First DT port node of the Dual-link LVDS source                       
>>  * @port2: Second DT port node of the Dual-link LVDS source      
>>
>>>
>>>> +	} else if (port1) {
>>>> +		ret = -EINVAL;
>>>> +		dev_err(dev, "single input LVDS port1 is not supported\n");
>>>> +	} else if (!port0) {
>>>> +		ret = -EINVAL;
>>>> +		dev_err(dev, "no input LVDS port\n");
>>>> +	}
>>>> +
>>>> +	of_node_put(port0);
>>>> +	of_node_put(port1);
>>>> +
>>>> +	return ret;
>>>> +}
>>>> +
>>>
>>
>> -- 
>> Regards,
>> Liu Ying
>>
> 

-- 
Regards,
Liu Ying