Re: [RFC 1/7] dm: add get_dp_node() to struct uclass_driver

[Heinrich Schuchardt <heinrich.schuchardt@canonical.com>]

On 3/27/23 06:00, Simon Glass wrote:
> Hi Heinrich,
> 
> On Mon, 27 Mar 2023 at 06:27, Heinrich Schuchardt
> <heinrich.schuchardt@canonical.com> wrote:
>>
>> Currently the device paths don't match the dm tree.
>> We should create a device path node per dm tree node.
>>
>> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
>> ---
>>   include/dm/uclass.h | 5 +++++
>>   1 file changed, 5 insertions(+)
> 
> This affects very few uclasses but adds a field to all of them. I
> think an event might be best for this. We can add an event spy in each
> of the affected uclasses.

EVENT_SPY does not allow to return information to the emitter of the event.

event_notfify() does not allow to select a single recipient.

In struct uclass_driver there are many other fields that are rarely used:

         int (*post_bind)(struct udevice *dev);
         int (*pre_unbind)(struct udevice *dev);
         int (*pre_probe)(struct udevice *dev);
         int (*post_probe)(struct udevice *dev);
         int (*pre_remove)(struct udevice *dev);
         int (*child_post_bind)(struct udevice *dev);
         int (*child_pre_probe)(struct udevice *dev);
         int (*child_post_probe)(struct udevice *dev);

If we wanted to save memory in linker generated lists we would convert 
structures with pointers to variable size arrays e.g.

struct ops * =
{
{ POST_BIND, post_bind },
{ CHILD_POST_BIND, child_post_bind},
{ END, NULL },
}

Best regards

Heinrich

> 
> 
>>
>> diff --git a/include/dm/uclass.h b/include/dm/uclass.h
>> index ee15c92063..e11637ce4d 100644
>> --- a/include/dm/uclass.h
>> +++ b/include/dm/uclass.h
>> @@ -11,6 +11,7 @@
>>
>>   #include <dm/ofnode.h>
>>   #include <dm/uclass-id.h>
>> +#include <efi.h>
>>   #include <linker_lists.h>
>>   #include <linux/list.h>
>>
>> @@ -68,6 +69,7 @@ struct udevice;
>>    * @child_post_probe: Called after a child in this uclass is probed
>>    * @init: Called to set up the uclass
>>    * @destroy: Called to destroy the uclass
>> + * @get_dp_node: Get EFI device path node
>>    * @priv_auto: If non-zero this is the size of the private data
>>    * to be allocated in the uclass's ->priv pointer. If zero, then the uclass
>>    * driver is responsible for allocating any data required.
>> @@ -99,6 +101,9 @@ struct uclass_driver {
>>          int (*child_post_probe)(struct udevice *dev);
>>          int (*init)(struct uclass *class);
>>          int (*destroy)(struct uclass *class);
>> +#if CONFIG_IS_ENABLED(EFI_LOADER)
>> +       struct efi_device_path *(*get_dp_node)(struct udevice *dev);
>> +#endif
>>          int priv_auto;
>>          int per_device_auto;
>>          int per_device_plat_auto;
>> --
>> 2.39.2
>>