linux-fbdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Rob Herring <robh@kernel.org>
To: Tomi Valkeinen <tomi.valkeinen-l0cyMroinI0@public.gmane.org>
Cc: Jyri Sarha <jsarha-l0cyMroinI0@public.gmane.org>,
	"linux-fbdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
	<linux-fbdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	"devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
	<devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	Bartlomiej Zolnierkiewicz
	<b.zolnierkie-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>,
	Maxime Ripard
	<maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>,
	Benoit Cousson <bcousson-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>
Subject: Re: [PATCH v2 4/5] fbdev/ssd1307fb: add support to enable VBAT
Date: Thu, 19 Jan 2017 16:22:54 +0000	[thread overview]
Message-ID: <CAL_JsqLnuni0UVy9bDY9Jw6knVozdNT68gFYYfPwqoT-8h2vQw@mail.gmail.com> (raw)
In-Reply-To: <c0372d48-b538-64ce-f187-0502a9a4a00e-l0cyMroinI0@public.gmane.org>

On Thu, Jan 19, 2017 at 9:08 AM, Tomi Valkeinen <tomi.valkeinen@ti.com> wrote:
> On 19/01/17 17:03, Rob Herring wrote:
>
>>>> According to the datasheet, SSD1307 has 2 supplies: Vdd and Vcc
>>>>
>>>> I don't see any mention of a charge pump, so that must be an external
>>>> component.
>>>
>>> VBAT is for SSD1306. Perhaps the DT doc should mention it.
>>
>> Datasheet says VBAT is reserved, connect to Vdd. I would just describe
>> Vdd and Vcc in that case.
>
> I'm no HW guy, but as far as I understand, you can wire it up two ways.
> One has VBAT connected to VDD. The other one has VBAT connected to
> external supply. See "Figure 1 : Application Example of SSD1306Z with
> charge bump".

I should have kept reading...

So either Vdd and Vbat supplies or Vdd and Vcc supplies are valid and
the former only applies to 1306.

Rob

  parent reply	other threads:[~2017-01-19 16:22 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20170113103601epcas4p38f03c4eb4147ff5a08e93af2cda635ba@epcas4p3.samsung.com>
2017-01-13 10:35 ` [PATCH v2 0/5] fbdev/ssd1307fb: Some changes and improvement Jyri Sarha
     [not found]   ` <cover.1484303628.git.jsarha-l0cyMroinI0@public.gmane.org>
2017-01-13 10:35     ` [PATCH v2 1/5] fbdev: ssd1307fb: Start to use gpiod API for reset gpio Jyri Sarha
2017-01-13 10:35     ` [PATCH v2 2/5] fbdev: ssd1307fb: Remove reset-active-low from the DT binding document Jyri Sarha
     [not found]       ` <b68e1b9b735543b9e1511cfeb8e5d9ceec6c7666.1484303628.git.jsarha-l0cyMroinI0@public.gmane.org>
2017-01-18 22:28         ` Rob Herring
2017-01-19  8:24           ` Jyri Sarha
2017-01-13 10:35     ` [PATCH v2 3/5] fbdev: ssd1307fb: Make reset gpio devicetree property optional Jyri Sarha
2017-01-13 10:35     ` [PATCH v2 4/5] fbdev/ssd1307fb: add support to enable VBAT Jyri Sarha
     [not found]       ` <214ae9ca86009148f233be71a3606917f3150dcd.1484303628.git.jsarha-l0cyMroinI0@public.gmane.org>
2017-01-18 22:33         ` Rob Herring
2017-01-19 13:15           ` Tomi Valkeinen
     [not found]             ` <754f3644-a157-bb90-1494-aba4fc1264f8-l0cyMroinI0@public.gmane.org>
2017-01-19 15:03               ` Rob Herring
     [not found]                 ` <CAL_JsqLjTa2SWP_cNU9AV4tRZLDcjJsUV7pUvy=4UhQix7ZjQQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-01-19 15:08                   ` Tomi Valkeinen
     [not found]                     ` <c0372d48-b538-64ce-f187-0502a9a4a00e-l0cyMroinI0@public.gmane.org>
2017-01-19 16:22                       ` Rob Herring [this message]
2017-01-13 10:35     ` [PATCH v2 5/5] fbdev/ssd1307fb: clear screen in probe Jyri Sarha
2017-02-08 15:15     ` [PATCH v2 0/5] fbdev/ssd1307fb: Some changes and improvement Bartlomiej Zolnierkiewicz

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=CAL_JsqLnuni0UVy9bDY9Jw6knVozdNT68gFYYfPwqoT-8h2vQw@mail.gmail.com \
    --to=robh@kernel.org \
    --cc=b.zolnierkie-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org \
    --cc=bcousson-rdvid1DuHRBWk0Htik3J/w@public.gmane.org \
    --cc=devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=jsarha-l0cyMroinI0@public.gmane.org \
    --cc=linux-fbdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org \
    --cc=tomi.valkeinen-l0cyMroinI0@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).