[U-Boot] [PATCH v1 03/18] dm: Add a No-op uclass

[Jean-Jacques Hiblot]

On 29/04/2019 11:56, Marek Vasut wrote:
> On 4/5/19 2:55 PM, Jean-Jacques Hiblot wrote:
>> This uclass is intended for devices that do not need any features from the
>> uclass, including binding children.
>> This will typically be used by devices that are used to bind child devices
>> but do not use dm_scan_fdt_dev() to do it. That is for example the case of
>> several USB wrappers that have 2 child devices (1 for device and 1 for
>> host) but bind only one at a any given time.
>>
>> Signed-off-by: Jean-Jacques Hiblot <jjhiblot at ti.com>
> Could this be UCLASS_BUS or some sort of simple bus ?

The reason we need a new UCLASS is that MISC or SIMPLE_BUS bind all 
their child devices. The dwc3 wrapper and maybe others too, need to bind 
only one of its 2 children (host or device)


> Anyway, +CC Simon.
>
>> ---
>>
>>   drivers/core/uclass.c  | 5 +++++
>>   include/dm/uclass-id.h | 1 +
>>   2 files changed, 6 insertions(+)
>>
>> diff --git a/drivers/core/uclass.c b/drivers/core/uclass.c
>> index fc3157de39..dc9eb62893 100644
>> --- a/drivers/core/uclass.c
>> +++ b/drivers/core/uclass.c
>> @@ -757,3 +757,8 @@ int uclass_pre_remove_device(struct udevice *dev)
>>   	return 0;
>>   }
>>   #endif
>> +
>> +UCLASS_DRIVER(nop) = {
>> +	.id		= UCLASS_NOP,
>> +	.name		= "nop",
>> +};
>> diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
>> index 86e59781b0..3797cd48f6 100644
>> --- a/include/dm/uclass-id.h
>> +++ b/include/dm/uclass-id.h
>> @@ -61,6 +61,7 @@ enum uclass_id {
>>   	UCLASS_MMC,		/* SD / MMC card or chip */
>>   	UCLASS_MOD_EXP,		/* RSA Mod Exp device */
>>   	UCLASS_MTD,		/* Memory Technology Device (MTD) device */
>> +	UCLASS_NOP,		/* No-op devices */
>>   	UCLASS_NORTHBRIDGE,	/* Intel Northbridge / SDRAM controller */
>>   	UCLASS_NVME,		/* NVM Express device */
>>   	UCLASS_PANEL,		/* Display panel, such as an LCD */
>>
>