From: randy <lxr1234@hotmail.com>
To: linux-pwm@vger.kernel.org
Cc: Thierry Reding <thierry.reding@gmail.com>
Subject: Re: [exynos4412]How to test a pwm device, is there a test program?
Date: Mon, 9 Dec 2013 21:06:37 +0800 [thread overview]
Message-ID: <BLU0-SMTP30A197FE32DA623BBA7713ADD30@phx.gbl> (raw)
In-Reply-To: <20131209115523.GA17693@ulmo.nvidia.com>
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
于 2013年12月09日 19:55, Thierry Reding 写道:
> On Mon, Dec 09, 2013 at 07:04:12PM +0800, randy wrote: [...]
>> Actually, I don't know whether the pwm works or not. In dmesg, I
>> saw: [ 853.690000] samsung-pwm 139d0000.pwm: tried to request
>> PWM channel 0 without output [ 876.930000] samsung-pwm
>> 139d0000.pwm: tried to request PWM channel 0 without output [
>> 879.615000] samsung-pwm 139d0000.pwm: tried to request PWM
>> channel 1 without output
>>
>> in my dts, I only add ================================
>> pwm@139D0000 { status = "okay";
I added
samsung,pwm-outputs = <0>;
>> }; ================================ is it enough to make pwm
>> work, if the driver in kernel has been correct.
>
> It seems like you're missing the samsung,pwm-outputs property (see
> Documentation/devicetree/bindings/pwm/pwm-samsung.txt).
>
> Thierry
Well I have make it output to channel 0 now. But it doesn't work with
the config below. As it is a buzzer, I change your config.
=============================================
root@mifu:~# cat /sys/class/pwm/pwmchip0/pwm0/enable
1
root@mifu:~# cat /sys/class/pwm/pwmchip0/pwm0/period
1000000
root@mifu:~# cat /sys/class/pwm/pwmchip0/pwm0/duty_cycle
500000
==============================================
I have used a function generator with Vpp=2.2, it works.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/
iQEcBAEBAgAGBQJSpcBdAAoJEPb4VsMIzTzir6kH/izw1ALJVXhEw3C28tj5grKk
zgJ5eTh4fiATR6nMg9539YTmkH65nmrK7C7QdrwAmsb9t/lnX5ulcZUZmrrRKE+j
03r+L45PH7Vqx7ZMt3UO74jMThs9+vHFY+Kj0dALoxZsnBS1aaheGaHuShrcTbpG
ZaKOZs7lSuxuZsWKr1njodYG3hL3z418JISII7DQ7J8RHYQF88JwIAMPw8Ybt1U8
7J2qA4DDKmQmL/kPQqTiPMfj64fcZ6E8jtLY5jZ0OLN78T8+juHrm+8l5xBm0AFa
3HNzLrmyAKPYD4yjPI8LYdNhk3EVVOaxA+lcDy26aYJ1PpIHxHuFgGdvqM47eq4=
=1SNZ
-----END PGP SIGNATURE-----
next prev parent reply other threads:[~2013-12-09 13:06 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-08 17:22 [exynos4412]How to test a pwm device, is there a test program? randy
2013-12-09 8:52 ` Thierry Reding
2013-12-09 11:04 ` randy
2013-12-09 11:55 ` Thierry Reding
2013-12-09 13:06 ` randy [this message]
2013-12-12 12:22 ` Thierry Reding
2013-12-12 14:27 ` randy
2013-12-14 12:44 ` Thierry Reding
2013-12-14 13:05 ` Tomasz Figa
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=BLU0-SMTP30A197FE32DA623BBA7713ADD30@phx.gbl \
--to=lxr1234@hotmail.com \
--cc=linux-pwm@vger.kernel.org \
--cc=thierry.reding@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