Re: Info Regarding how the Redeon driver access EDID info

Re: Info Regarding how the Redeon driver access EDID info

[Benjamin Herrenschmidt]

On Wed, 2005-04-06 at 13:46 -0700, karthik wrote:
> Hi,
> 
>           I am not able to understand how the radeon video card  
> driver access EDID info of Monitors attached to the cards.The 
> driver is calling one funtion 
> get_property(dp, propnames[i], NULL);

This is specific to PowerMacs where the EDID is stored there by the
firmware.

> But in this funtion its just return some value ie 
> dp->property->value; how this property->value field is 
> Initialized. Is this get_EDID is called only at boot time. how the value of 
> the device _node structure is initilized.
> 
> If any have any ideas regarding this please mail me.

This is all done by the firmware. radeonfb can also directly get the
EDID from the monitor though via DDC2 (i2c). Look at
drivers/video/aty/radeon_i2c.c and radeon_monitor.c

Ben.

Info Regarding how the Redeon driver access EDID info

[karthik]

Hi,

          I am not able to understand how the radeon video card  
driver access EDID info of Monitors attached to the cards.The 
driver is calling one funtion 
get_property(dp, propnames[i], NULL);

But in this funtion its just return some value ie 
dp->property->value; how this property->value field is 
Initialized. Is this get_EDID is called only at boot time. how the value of 
the device _node structure is initilized.

If any have any ideas regarding this please mail me.

Karthik