Re: [PATCH v3 6/6] mfd: cros_ec: Instantiate sub-devices from device tree

[Javier Martinez Canillas <javier.martinez@collabora.co.uk>]

Hello Lee,

On 09/18/2014 09:49 AM, Javier Martinez Canillas wrote:
>>>  int cros_ec_register(struct cros_ec_device *ec_dev)
>>>  {
>>>  	struct device *dev = ec_dev->dev;
>>> +	struct device_node *node = dev->of_node;
>>>  	int err = 0;
>>>  
>>>  	if (ec_dev->din_size) {
>>> @@ -140,12 +129,12 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
>>>  
>>>  	mutex_init(&ec_dev->lock);
>>>  
>>> -	err = mfd_add_devices(dev, 0, cros_devs,
>>> -			      ARRAY_SIZE(cros_devs),
>>> -			      NULL, ec_dev->irq, NULL);
>>> -	if (err) {
>>> -		dev_err(dev, "failed to add mfd devices\n");
>>> -		return err;
>> 
>> So these devices will only ever probe with DT now ...
>>
> 
> Well, these are preparatory patches to reduce the delta between upstream and
> the downstream so the missing functionality could be added. One of the missing
> drivers is the cros_ec_dev.c [0] which allows user-space to access the
> ChromeOS Embedded Controller using a virtual character device (/dev/cros_ec).
> 
> Since that is a virtual device, it does not fit on the DT which only describes
> hw and also is used on x86 machines so that subdevice is still probed using
> mfd_add_devices() and the mfd_cells array is not empty in the downstream
> cros_ec driver [1].
> 

I posted a new revision (v4) of the series but dropped this patch since this
change probably makes more sense once the cros_ec_dev driver lands. Since then
the mfd cells array will not be empty and not all subdevices will be probed
with of_platform_populate().

Best regards,
Javier