-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
于 2013年12月12日 20:22, Thierry Reding 写道:
> On Mon, Dec 09, 2013 at 09:06:37PM +0800, randy wrote:
>> -----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.
>
> Are you sure the function generator runs at the same frequency? Do
> you
Yes, I am sure.
> have the possibility to check the PWM output with a scope to see if
> it outputs anything?
I have used a oscillograph to capture, nothing(althought it show some
waves, but it is nosie single captured by autoset). I have a scope but
I don't think there is any different.
>
> Thierry
Ayaka
Thank you
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/
iQEcBAEBAgAGBQJSqce4AAoJEPb4VsMIzTzikV4H/3NF4D2kcHYYt6axhgdnlDaI
rHUVYBDHcWR0gDUY6rHN7eyStCKWdGzant0pR8AcPOSTYStwXJbFnoqPHPb9sI2J
KU/EmhA+YOCzIlxeagovpFmlGopVQEWPbKM99txzljsIvjOD4xKZ2kSQv4L/QHLc
CHyi1p9NzL1uSz4h5N5XcpMiMWHSNbCBXWgjqejseTjli9n1A0o0ehY5Ip9507un
rYfJETB+imHOck9TH9Rol1QdS7PjIpInFMZiqkzxWKnjFXrlNQJujzPlgoJCTrv3
XIci86cnK9F2DEqkl3tJ1XsxMp0LlfEn45ZCKySeuZ2muyYpBSAHPo0uOj0DcEM=
=L3au
-----END PGP SIGNATURE-----
--
To unsubscribe from this list: send the line "unsubscribe linux-pwm" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
