public inbox for linux-mmc@vger.kernel.org
 help / color / mirror / Atom feed
From: Wolfram Sang <wsa@the-dreams.de>
To: Chris Brandt <Chris.Brandt@renesas.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>,
	Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Simon Horman <horms@verge.net.au>,
	Wolfram Sang <wsa+renesas@sang-engineering.com>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
	"linux-renesas-soc@vger.kernel.org"
	<linux-renesas-soc@vger.kernel.org>
Subject: Re: [PATCH v4 2/3] mmc: sh_mobile_sdhi: explain clock bindings
Date: Fri, 20 Jan 2017 23:41:39 +0100	[thread overview]
Message-ID: <20170120224137.GD1438@katana> (raw)
In-Reply-To: <SG2PR06MB1165035F107F504185B525658A710@SG2PR06MB1165.apcprd06.prod.outlook.com>

[-- Attachment #1: Type: text/plain, Size: 1238 bytes --]


> It sounds like your suggestion is to just put the HW description in
> the DT bindings, but move the dirty details into the driver.
> 
> Keep in DT:
> 
> +- clocks: Most controllers only have 1 clock source per channel. However, on
> +	  some variations of this controller, the internal card detection
> +	  logic that exists in this controller is sectioned off to be run by a
> +	  separate second clock source to allow the main core clock to be turned
> +	  off to save power.
> +	  If 2 clocks are specified by the hardware, you must name them as
> +	  "core" and "cd".
> +	  If the controller only has 1 clock, naming is not required.
> 
> 
> 
> Move somewhere in the driver (maybe where the 2nd clock is detected):
> 
> +	  Unfortunately, the existing driver architecture
> +	  does not support such a separation of clocks.

"such" is not explained. Maybe "does not support a seperation of clocks.
It doesn't work with Runtime PM because ..."?

> +	  Additionally, it is prohibited to supply a clock to the core but not
> +	  to the card detect circuit. That leaves you with if separate clocks
> +	  are presented, you must treat them both as 1.
> 
> 
> Is this what you were thinking?

Exactly.


[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 819 bytes --]

  reply	other threads:[~2017-01-20 22:41 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-01-20 19:43 [PATCH v4 0/3] mmc: sh_mobile_sdhi: fix missing r7s72100 clocks Chris Brandt
2017-01-20 19:43 ` [PATCH v4 1/3] mmc: sh_mobile_sdhi: add support for 2 clocks Chris Brandt
2017-01-20 19:43 ` [PATCH v4 2/3] mmc: sh_mobile_sdhi: explain clock bindings Chris Brandt
2017-01-20 21:39   ` Wolfram Sang
2017-01-20 22:35     ` Chris Brandt
2017-01-20 22:41       ` Wolfram Sang [this message]
     [not found] ` <20170120194332.1683-1-chris.brandt-zM6kxYcvzFBBDgjK7y7TUQ@public.gmane.org>
2017-01-20 19:43   ` [PATCH v4 3/3] ARM: dts: r7s72100: update sdhi " Chris Brandt

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=20170120224137.GD1438@katana \
    --to=wsa@the-dreams.de \
    --cc=Chris.Brandt@renesas.com \
    --cc=devicetree@vger.kernel.org \
    --cc=geert@linux-m68k.org \
    --cc=horms@verge.net.au \
    --cc=linux-mmc@vger.kernel.org \
    --cc=linux-renesas-soc@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=robh+dt@kernel.org \
    --cc=ulf.hansson@linaro.org \
    --cc=wsa+renesas@sang-engineering.com \
    /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