linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Heiko Stuebner <heiko@sntech.de>
To: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Frank Wang <frank.wang@rock-chips.com>,
	dianders@chromium.org, linux@roeck-us.net, groeck@chromium.org,
	jwerner@chromium.org, robh+dt@kernel.org, pawel.moll@arm.com,
	mark.rutland@arm.com, ijc+devicetree@hellion.org.uk,
	galak@codeaurora.org, linux-kernel@vger.kernel.org,
	devicetree@vger.kernel.org, linux-usb@vger.kernel.org,
	linux-rockchip@lists.infradead.org, xzy.xu@rock-chips.com,
	kever.yang@rock-chips.com, huangtao@rock-chips.com,
	william.wu@rock-chips.com
Subject: Re: [PATCH v5 2/2] phy: rockchip-inno-usb2: add a new driver for Rockchip usb2phy
Date: Wed, 29 Jun 2016 16:27:19 +0200	[thread overview]
Message-ID: <2624359.mbyKrcyvqy@phil> (raw)
In-Reply-To: <5773D7DC.9050902@ti.com>

Hi Kishon,

Am Mittwoch, 29. Juni 2016, 19:44:52 schrieb Kishon Vijay Abraham I:
> On Friday 17 June 2016 10:16 PM, Heiko Stübner wrote:
> > Am Freitag, 17. Juni 2016, 17:24:46 schrieb Kishon Vijay Abraham I:
> > [...]
> > 
> >>> +	/* find out a proper config which can be matched with dt. */
> >>> +	index = 0;
> >>> +	while (phy_cfgs[index].reg) {
> >>> +		if (phy_cfgs[index].reg == reg) {
> >> 
> >> Why not pass these config values from dt? Moreover finding the config
> >> using register offset is bound to break.
> > 
> > As you have probably seen, this phy block is no stand-alone
> > (mmio-)device, but gets controlled through special register/bits in the
> > so called "General Register Files" syscon.
> > 
> > The values stored and accessed here, are the location and layout of
> > those
> > control registers. Bits in those phy control registers at times move
> > between phy-versions in different socs (rk3036, rk3228, rk3366, rk3368,
> > rk3399) and some are even missing. So I don't really see a nice way to
> > describe that in dt without describing the register and offset of each
> > of those 22 used bits individually.
> > 
> > 
> > I'm also not sure where you expect it to break? The reg-offset is the
> > offset of the phy inside the GRF and the Designware-phy also already
> > does something similar to select some appropriate values.
> 
> I'm concerned the phy can be placed in the different reg-offset within GRF
> (like in the next silicon revision) and this driver can't be used.

That is something that has not happened with all Rockchip SoCs I have had in 
my hands so far.

While the GRF is some sort-of wild-west area with settings for vastly 
different blocks in there and always changes between different socs (rk3288 
[4-core A17] <-> rk3366 <-> rk3368 [8-core A53] <-> rk3399 etc) there 
haven't been such changes (different register offsets) between soc-revisions 
of the same soc that I know off.

The GRF also includes such important things like the whole pinctrl handling, 
so if there were such offset changes in the GRF a lot of drivers (and 
maintainers) would get very unhappy - me included :-) .


Heiko

      reply	other threads:[~2016-06-29 14:52 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-13  2:10 [PATCH v5 0/2] Add a new Rockchip usb2 phy driver Frank Wang
2016-06-13  2:10 ` [PATCH v5 1/2] Documentation: bindings: add DT documentation for Rockchip USB2PHY Frank Wang
2016-06-13  8:38   ` Heiko Stübner
2016-06-14 13:28     ` Heiko Stübner
2016-06-15  1:24       ` Frank Wang
2016-06-14 22:26   ` Rob Herring
2016-06-13  2:10 ` [PATCH v5 2/2] phy: rockchip-inno-usb2: add a new driver for Rockchip usb2phy Frank Wang
2016-06-14 13:27   ` Heiko Stübner
2016-06-14 13:50     ` Guenter Roeck
2016-06-14 14:00       ` Heiko Stübner
2016-06-15  1:14         ` Frank Wang
2016-06-15 15:47           ` Guenter Roeck
2016-06-16  1:47             ` Frank Wang
2016-06-16 13:12               ` Guenter Roeck
2016-06-17  0:57                 ` Frank Wang
2016-06-15  3:23     ` Frank Wang
2016-06-15  9:04       ` Heiko Stübner
2016-06-15 10:58         ` Frank Wang
2016-06-15 18:49           ` Heiko Stübner
2016-06-14 14:52   ` Guenter Roeck
2016-06-14 15:20     ` Heiko Stübner
2016-06-17 11:54   ` Kishon Vijay Abraham I
2016-06-17 16:46     ` Heiko Stübner
2016-06-29 14:14       ` Kishon Vijay Abraham I
2016-06-29 14:27         ` Heiko Stuebner [this message]

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=2624359.mbyKrcyvqy@phil \
    --to=heiko@sntech.de \
    --cc=devicetree@vger.kernel.org \
    --cc=dianders@chromium.org \
    --cc=frank.wang@rock-chips.com \
    --cc=galak@codeaurora.org \
    --cc=groeck@chromium.org \
    --cc=huangtao@rock-chips.com \
    --cc=ijc+devicetree@hellion.org.uk \
    --cc=jwerner@chromium.org \
    --cc=kever.yang@rock-chips.com \
    --cc=kishon@ti.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-rockchip@lists.infradead.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=linux@roeck-us.net \
    --cc=mark.rutland@arm.com \
    --cc=pawel.moll@arm.com \
    --cc=robh+dt@kernel.org \
    --cc=william.wu@rock-chips.com \
    --cc=xzy.xu@rock-chips.com \
    --subject='Re: [PATCH v5 2/2] phy: rockchip-inno-usb2: add a new driver for Rockchip usb2phy' \
    /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

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).