linux-omap.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Nishanth Menon <nm@ti.com>
To: Joachim Eastwood <manabian@gmail.com>
Cc: linux-omap@vger.kernel.org
Subject: Re: omap4 and cpufreq
Date: Mon, 6 Jan 2014 16:02:08 -0600	[thread overview]
Message-ID: <52CB27E0.6080408@ti.com> (raw)
In-Reply-To: <CAGhQ9Vy1mja7-F0a4v9gBQ5naPmRoxNv6GZgjqZ30dhVfD7q8w@mail.gmail.com>

On 01/06/2014 03:51 PM, Joachim Eastwood wrote:
> On 6 January 2014 17:28, Nishanth Menon <nm@ti.com> wrote:
>> On 01/01/2014 04:37 PM, Joachim Eastwood wrote:
[...]
>>> I assume this would work but I don't have a 4430 board to test it on.
>>> Unsure about voltage range, but at least 1.0 to 1.4V covers the operation
>>> points for cpu in omap443xx.dtsi.
>> This will not work. 6030 does not allow voltage to be set over i2c1,
>> needs voltage controller/processor to work.
> 
> Well, it allows the LDO regulators to be changed over i2c, but I guess
> the SMPS regulators are different.

yes, they are different control paths. To give a relative history:

(OMAP3)TWL5030 -> we can control SMPS from either i2c1 OR i2c_SR by
flipping a control bit - but only one path at a time.
(OMAP4)TWL6030 -> only i2c_SR control allowed for SMPS
(OMAP5)Palmas family -> we can control using i2c1 or i2c_SR -> so no
real need for using voltage controller for SMPS.

that said, it is necessary to use SR path to ensure that AVS also
functions. which requires on OMAP4,3 to use i2c_SR.

> 
> 
> 
> Anyways, thanks for the information and bugzilla link with links to
> the patch postings on the mailing list.

Glad to be of help.

-- 
Regards,
Nishanth Menon

  reply	other threads:[~2014-01-06 22:02 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-01-01 22:37 omap4 and cpufreq Joachim Eastwood
2014-01-06 16:28 ` Nishanth Menon
2014-01-06 21:51   ` Joachim Eastwood
2014-01-06 22:02     ` Nishanth Menon [this message]
2014-01-06 22:24       ` Joachim Eastwood
2014-01-06 22:43         ` Nishanth Menon

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=52CB27E0.6080408@ti.com \
    --to=nm@ti.com \
    --cc=linux-omap@vger.kernel.org \
    --cc=manabian@gmail.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;
as well as URLs for NNTP newsgroup(s).