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Date:      Fri, 5 Jun 2015 19:59:15 +0300
From:      Daniel Braniss <danny@cs.huji.ac.il>
To:        Luiz Otavio O Souza <lists.br@gmail.com>
Cc:        freebsd-arm <freeBSD-arm@freebsd.org>
Subject:   Re: pwm for raspberry pi?
Message-ID:  <DC13576F-D968-492C-B6F5-0578339A021D@cs.huji.ac.il>
In-Reply-To: <CAB=2f8zuMhPkwuuh-yNeMK1_iv3%2Bg3%2BXtXLZ-FyOmudBifsh0w@mail.gmail.com>
References:  <1FD1336E-D99F-4114-AD33-FBA1DF844E93@cs.huji.ac.il> <CAB=2f8wigyRaP9fXr6V=-%2BM9YZTE=2nzdj-AngD6m15zZFu1gQ@mail.gmail.com> <DB799EA8-3401-46F6-A4F5-79E5BE9743E2@cs.huji.ac.il> <CAB=2f8zuMhPkwuuh-yNeMK1_iv3%2Bg3%2BXtXLZ-FyOmudBifsh0w@mail.gmail.com>

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> On May 26, 2015, at 9:51 PM, Luiz Otavio O Souza <lists.br@gmail.com> =
wrote:
>=20
> On 26 May 2015 at 03:13, Daniel Braniss wrote:
>>=20
>>> On May 26, 2015, at 1:14 AM, Luiz Otavio O Souza wrote:
>>>=20
>>> On 25 May 2015 at 07:52, Daniel Braniss wrote:
>>>> Hi,
>>>> Now that I=E2=80=99m rapping up my spi/rfid driver (available on =
demand :-),
>>>> I would like to use the pwm interface to power on/off a lock, but
>>>> have no idea how to go around it, so any clues would be mostly =
welcomed.
>>>>=20
>>>> cheers,
>>>>       danny
>>>=20
>>> The PWM module is quite simple and has only two outputs, they can be
>>> used only with recent 40 GPIO pins header (RPi-B+ or RPi2), in the
>>> older models only one output was wired.
>>>=20
>> I do have a B+
>>=20
>>> The bcm2835 peripherals datasheet describes the PWM module registers
>>=20
>> I=E2=80=99ve read it, hence I know it=E2=80=99s possible, what I=E2=80=99=
 missing is how to access it via
>> FreeBSD. There is a some mention for the BeagleBoneBlack, but it =
seems
>> broken, the FDT mentions the pins. Too many leads but not enough info
>> on how to tie them up :-)
>>=20
>> cheers,
>>        danny
>=20
> There is no defined API to access PWM settings ATM, on beaglebone this
> is done with sysctls:
>=20
> dev.am335x_pwm.2.dutyB: 0
> dev.am335x_pwm.2.dutyA: 0
> dev.am335x_pwm.2.period: 1000
> dev.am335x_pwm.2.freq: 100000
> dev.am335x_pwm.2.clkdiv: 1
> dev.am335x_pwm.2.%parent: simplebus0
> dev.am335x_pwm.2.%pnpinfo: name=3Dpwm@48304000 compat=3Dti,am335x-pwm
> dev.am335x_pwm.2.%location:
> dev.am335x_pwm.2.%driver: am335x_pwm
> dev.am335x_pwm.2.%desc: AM335x PWM
>=20
> There are 3 PWM modules, each one with two outputs controlled by dutyA
> and dutyB.
>=20
> Here is the PWM code for beaglebone:
> =
https://svnweb.freebsd.org/base/head/sys/arm/ti/am335x/am335x_ehrpwm.c?vie=
w=3Dmarkup =
<https://svnweb.freebsd.org/base/head/sys/arm/ti/am335x/am335x_ehrpwm.c?vi=
ew=3Dmarkup>
>=20

i see these under 10.1 but nothing under 11, what am I missing?
i tried with today=E2=80=99s current, and I see the modules being =
compile, the .dts seems ok
but no signes of am35x_pwm


> At some point I think I will expose PWM settings via gpioctl (and
> possibly add a gpiopwm for a software based pwm).
>=20
> Regards,
> Luiz




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