From: kishon@ti•com (Kishon Vijay Abraham I)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v9 1/8] drivers: phy: add generic PHY framework
Date: Thu, 18 Jul 2013 11:33:17 +0530 [thread overview]
Message-ID: <51E78525.9000802@ti.com> (raw)
In-Reply-To: <20130717172510.GB17093@kroah.com>
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@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
>
> 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
next prev parent reply other threads:[~2013-07-18 6:03 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-26 11:47 [PATCH v9 0/8] Generic PHY Framework Kishon Vijay Abraham I
2013-06-26 11:47 ` [PATCH v9 1/8] drivers: phy: add generic PHY framework Kishon Vijay Abraham I
2013-06-26 12:10 ` Felipe Balbi
2013-07-17 6:29 ` Greg KH
2013-07-17 9:32 ` Kishon Vijay Abraham I
2013-07-17 17:25 ` Greg KH
2013-07-18 6:03 ` Kishon Vijay Abraham I [this message]
2013-07-18 6:24 ` Greg KH
2013-07-18 6:27 ` Kishon Vijay Abraham I
2013-06-26 11:47 ` [PATCH v9 2/8] usb: phy: omap-usb2: use the new " Kishon Vijay Abraham I
2013-06-26 11:47 ` [PATCH v9 3/8] usb: phy: twl4030: " Kishon Vijay Abraham I
2013-06-26 11:47 ` [PATCH v9 4/8] ARM: OMAP: USB: Add phy binding information Kishon Vijay Abraham I
2013-06-26 11:47 ` [PATCH v9 5/8] ARM: dts: omap: update usb_otg_hs data Kishon Vijay Abraham I
2013-06-26 11:47 ` [PATCH v9 6/8] usb: musb: omap2430: use the new generic PHY framework Kishon Vijay Abraham I
2013-06-26 11:47 ` [PATCH v9 7/8] usb: phy: omap-usb2: remove *set_suspend* callback from omap-usb2 Kishon Vijay Abraham I
2013-06-26 11:47 ` [PATCH v9 8/8] usb: phy: twl4030-usb: remove *set_suspend* and *phy_init* ops Kishon Vijay Abraham I
2013-07-03 9:32 ` [PATCH v9 0/8] Generic PHY Framework Patel, Satish
2013-07-03 10:05 ` Kishon Vijay Abraham I
2013-07-03 13:20 ` Felipe Balbi
2013-07-04 5:17 ` Kishon Vijay Abraham I
2013-07-04 9:21 ` Patel, Satish
2013-07-04 9:55 ` Kishon Vijay Abraham I
2013-07-04 9:58 ` Patel, Satish
2013-07-04 10:12 ` Felipe Balbi
2013-07-04 10:45 ` Patel, Satish
2013-07-08 11:24 ` Patel, Satish
2013-07-08 12:17 ` Kishon Vijay Abraham I
2013-07-09 2:23 ` Patel, Satish
2013-07-09 11:44 ` Felipe Balbi
2013-07-09 12:33 ` Patel, Satish
2013-07-09 17:34 ` Felipe Balbi
2013-07-30 6:25 ` Rahul Sharma
2013-07-08 13:26 ` Felipe Balbi
[not found] <000d01ce73af$62a95a60$27fc0f20$@samsung.com>
2013-06-28 5:15 ` [PATCH v9 1/8] drivers: phy: add generic PHY framework Kishon Vijay Abraham I
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