Hi, On Wednesday 17 July 2013 10:55 PM, Greg KH wrote: > On Wed, Jul 17, 2013 at 03:02:59PM +0530, Kishon Vijay Abraham I wrote: >> 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 > > No, switch it around the other way. How would I even _know_ that I need > to enable the generic PHY subsystem in the first place? How can I > determine that I need this for my hardware? You need to give hints to > someone who doesn't even know what a PHY is, otherwise they will always > disable it and move on. > >>>> --- /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@xxxxxx> >>>> + * >>>> + * 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 > > So, is that what you really mean to have for this code? indeed. > >>>> + * 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 > > Ok, but what does the class usage get you? hmm.. actually I use class only to iterate through the list of devices in *phy* class which could very well be implemented using list. Just that I wont have a /sys/class/phy/ entry to find the list of phys added in the system. I dont think I want to add any other stuff to expose to the user space at this point of time. > >>> 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? > > If you are not creating anything in sysfs at all, why use the driver > model? (hint, I think you need to do something here to justify it...) Well.. it helps me to use pm_runtime to enable clocks utilizing the parent-child relationship. Thanks Kishon -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
