From: Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>
To: Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
Cc: Mike Turquette
<mturquette-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>,
"linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org"
<linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org>,
"devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
<devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
"linux-rpi-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org"
<linux-rpi-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org>
Subject: Re: [PATCH 1/2] clk: fixed-rate: use full DT node name
Date: Tue, 18 Feb 2014 11:23:24 +0000 [thread overview]
Message-ID: <20140218112323.GB6051@e106331-lin.cambridge.arm.com> (raw)
In-Reply-To: <52FE4798.3010605-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
On Fri, Feb 14, 2014 at 04:43:04PM +0000, Stephen Warren wrote:
> On 02/14/2014 03:35 AM, Mark Rutland wrote:
> > On Fri, Feb 14, 2014 at 06:16:52AM +0000, Stephen Warren wrote:
> >> clk-fixed-rate currently names clocks according to a node's name without
> >> the unit address. When faced with the legal and technically correct DT
> >> structure below, this causes rgistration attempts for 3 clocks with the
> >> same name, 2 of which fail.
> >>
> >> clocks {
> >> compatible = "simple-bus";
> >> #address-cells = <1>;
> >> #size-cells = <0>;
> >>
> >> clk_mmc: clock@0 {
> >> compatible = "fixed-clock";
> >> reg = <0>;
> >> ...
> >> clk_i2c: clock@1 {
> >> compatible = "fixed-clock";
> >> reg = <1>;
> >> ...
> >> clk_spi: clock@2 {
> >> compatible = "fixed-clock";
> >> reg = <2>;
> >> ...
> >
> > I'd argue that this case isn't valid.
>
> Well, it's very widely used, and was the result of numerous discussions
> of how this kind of thing should be represented:-/
Maybe we have to live with it then. :/
>
> > The fixed-clock binding doesn't define a reg, yet simple bus binding
> > implies that the reg property of child nodes should be interpretted as
> > the same address space as their parent (MMIO in this case?). The
> > fixed-clock nodes reg proeprties clearly aren't MMIO addresses.
> >
> > Additionally, the _requred_ ranges property is missing.
>
> Perhaps we need to invent a simple-container instead then?
As you mention in your other reply, it makes some sense to omit ranges
if the address space is disjoint. My concern is that the address space
is meaningless and arbitrary. If we had a real disjoint address space
we'd have another kind of bus node as the container.
>
> > It's just nonsensical; rename them to clock_{0,1,..} instead and get rid
> > of the reg properties. Then they're named uniquely.
>
> That's not legal either. DT node names are supposed to represent the
> type of device/object (i.e. just "clock"), not the identity of the
> device/object (i.e. not include IDs etc.). Hence, the node name needs to
> be "clock" for all of them, and the unit address must be used to
> differentiate them.
As far as I can see from ePAPR, the only requriement is:
The node-name shall start with a lower or uppercase character and
should describe the general class of device.
IMO clock_1 describes the general class of device as well as clock@1,
while also not filling a unexpected property with a meaningless value.
Thanks,
Mark.
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2014-02-18 11:23 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-14 6:16 [PATCH 1/2] clk: fixed-rate: use full DT node name Stephen Warren
[not found] ` <1392358613-19962-1-git-send-email-swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
2014-02-14 6:16 ` [PATCH 2/2] ARM: bcm2835: fix clock DT node names Stephen Warren
[not found] ` <1392358613-19962-2-git-send-email-swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
2014-02-14 10:39 ` Mark Rutland
2014-02-14 10:35 ` [PATCH 1/2] clk: fixed-rate: use full DT node name Mark Rutland
[not found] ` <20140214103556.GC9907-NuALmloUBlrZROr8t4l/smS4ubULX0JqMm0uRHvK7Nw@public.gmane.org>
2014-02-14 16:43 ` Stephen Warren
[not found] ` <52FE4798.3010605-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
2014-02-18 11:23 ` Mark Rutland [this message]
[not found] ` <20140218112323.GB6051-NuALmloUBlrZROr8t4l/smS4ubULX0JqMm0uRHvK7Nw@public.gmane.org>
2014-02-18 17:34 ` Stephen Warren
2014-02-14 16:43 ` Stephen Warren
2014-02-15 15:18 ` Emilio López
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20140218112323.GB6051@e106331-lin.cambridge.arm.com \
--to=mark.rutland-5wv7dgnigg8@public.gmane.org \
--cc=devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org \
--cc=linux-rpi-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org \
--cc=mturquette-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org \
--cc=swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).