Re: [PATCH v9 1/8] drivers: phy: add generic PHY framework

[Kishon Vijay Abraham I <kishon@ti.com>]

Hi,

On Wednesday 17 July 2013 11:59 AM, Greg KH wrote:
> On Wed, Jun 26, 2013 at 05:17:29PM +0530, Kishon Vijay Abraham I wrote:
>> +menuconfig GENERIC_PHY
>> +	tristate "PHY Subsystem"
>> +	help
>> +	  Generic PHY support.
>> +
>> +	  This framework is designed to provide a generic interface for PHY
>> +	  devices present in the kernel. This layer will have the generic
>> +	  API by which phy drivers can create PHY using the phy framework and
>> +	  phy users can obtain reference to the PHY.
> 
> Shouldn't this be something that other drivers select?  How will anyone
> know if they need this or not?

All the PHY drivers should go here. So only if *GENERIC_PHY* is enabled those
PHY drivers can be selected like in [1].
The PHY consumer driver should ideally use *depends on* in their Kconfig.

[1] ->
http://archive.arm.linux.org.uk/lurker/message/20130628.134308.4a8f7668.ca.html
> 
>> --- /dev/null
>> +++ b/drivers/phy/phy-core.c
>> @@ -0,0 +1,544 @@
>> +/*
>> + * phy-core.c  --  Generic Phy framework.
>> + *
>> + * Copyright (C) 2013 Texas Instruments
>> + *
>> + * Author: Kishon Vijay Abraham I <kishon@ti.com>
>> + *
>> + * This program is free software; you can redistribute  it and/or modify it
>> + * under  the terms of  the GNU General  Public License as published by the
>> + * Free Software Foundation;  either version 2 of the  License, or (at your
>> + * option) any later version.
> 
> You really mean "any later version" (I have to ask)?

That was copied from somewhere :-s
> 
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU General Public License
>> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
> 
> Are these two paragraphs needed?  This isn't a "program", and they got a
> copy of the GPL already with the kernel.

hmm.. I can remove that.
> 
>> +static struct class *phy_class;
> 
> Why do you need a class?

Wanted to group all the PHY drivers to be used by different subsystems
(SATA/USB/PCIE/HDMI/VIDEO) into a single entity. There were some comments in my
initial version [3] on using a bus_type instead of class but then it was
decided to go with class itself.

[3] -> http://lkml.indiana.edu/hypermail/linux/kernel/1302.2/01389.html
> 
> When modifying/adding new sysfs stuff, you need a Documentation/ABI/
> entry as well.

I'm not actually adding any new sysfs entry other than what a *class_create*
must have created. Do I need to add one for that?

Thanks
Kishon