Date: Wed, 15 May 2013 09:46:01 -0400 From: Warner Losh <imp@bsdimp.com> To: Tom Everett <tom@khubla.com> Cc: Aleksandr Rybalko <ray@freebsd.org>, "freebsd-arm@freebsd.org" <freebsd-arm@freebsd.org> Subject: Re: RS-232 driver for GPIO Message-ID: <C37D5616-255B-45C5-A2E3-1257A73773CF@bsdimp.com> In-Reply-To: <CAB3ij4DrNMFD%2BKm0Cf=O_1TonXpYGnX67jfAVE0=8PbH=9OywQ@mail.gmail.com> References: <CAB3ij4AzL8B6nS1kFa%2BgjmAVEOE8qO7UwPv_vBzRPn1sUNYuDQ@mail.gmail.com> <CAJ-Vmo=ZzAOyy9hWzMDw7bt9=nxsEzyAJnScgL-3NFfzcf7RXA@mail.gmail.com> <20130514192448.7b48e095.ray@freebsd.org> <CAB3ij4DLEBe_R1ydVJ0T-V0-ufizMHERNnPuzO_DY8iOE=1kSQ@mail.gmail.com> <20130515021751.8848a996.ray@freebsd.org> <CAB3ij4Ctq9j0svwqeUJk32Ugy6NJ1W7PJ9rrTue%2BtyDnky5g_Q@mail.gmail.com> <20130515122955.4387631e9969ae460f6500c7@freebsd.org> <CAB3ij4DrNMFD%2BKm0Cf=O_1TonXpYGnX67jfAVE0=8PbH=9OywQ@mail.gmail.com>
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On May 15, 2013, at 9:40 AM, Tom Everett wrote:
> ok, just one further question. It was basically guess work that =
enabled me
> to decypher that /dev/ttyu0 (sio0) was bound to uart0. I presume =
there
> must be some simple way from the command line to query the OS and find =
out
> which hardware devices are bound to which /dev/ entries?
The unit numbers generally match the alias names in the FDT.
However, we don't note what the names for the nodes we're attaching to =
on FDT systems. We really should, but we don't...
Warner
> On Wed, May 15, 2013 at 3:29 AM, Aleksandr Rybalko <ray@freebsd.org> =
wrote:
>=20
>> On Tue, 14 May 2013 20:24:42 -0600
>> Tom Everett <tom@khubla.com> wrote:
>>=20
>>> Did you mean 14 &15, or 14 & 16?
>> Yeah, right.
>>=20
>>=20
>>> ok so given this, I've done some reading. I'm by no means a FreeBSD
>>> expert, so forgive me if I'm completely wrong. I see this in the =
FDT:
>>>=20
>>> /* UART0 */
>>> pins_uart0_a: uart0_a {
>>> broadcom,pins =3D <14>, <15>;
>>> broadcom,function =3D "ALT0";
>>> };
>>=20
>> If you satisfied by single UART, you no need change that.
>>=20
>>=20
>>>=20
>>>=20
>>> and this:
>>>=20
>>> chosen {
>>> bootargs =3D ""; /* Set by VideoCore =
*/
>>> stdin =3D "uart0";
>>> stdout =3D "uart0";
>>> };
>>>=20
>>=20
>> But that stdin and stdout direct kernel console messages to air by =
your
>> xbee :)
>> So you need comment it or set different in/out device.
>>=20
>>=20
>>>=20
>>> So I interpret that to mean that uart0 is bound to pins 14, 15, and
>>> furthermore that the serial device bound to uart0 is bound to stdin =
and
>>> stdout. In my /dev/ I see:
>>>=20
>>> crw------- 1 root wheel 0x1f Apr 27 13:42 ttyu0
>>> crw------- 1 root wheel 0x20 Apr 27 21:42 ttyu0.init
>>> crw------- 1 root wheel 0x21 Apr 27 21:42 ttyu0.lock
>>> crw-rw---- 1 uucp dialer 0x22 Apr 27 21:42 cuau0
>>> crw-rw---- 1 uucp dialer 0x23 Apr 27 21:42 cuau0.init
>>> crw-rw---- 1 uucp dialer 0x24 Apr 27 21:42 cuau0.lock
>>>=20
>>> So, that is telling me that sio0 is bound to uart0, which is a =
serial
>>> console?
>>=20
>> Yep.
>>=20
>>>=20
>>> If so, that means that I could use pins 14 & 15 for rs-232, but I =
would
>>> have to chose b/t using those pins to talk to another device (xbee), =
or a
>>> serial console?
>>=20
>> if you will disconnect serial console you will have to choose between
>> control over network (SSH/telnet/etc) or graphic console (Display =
with
>> HDMI + USB keyboard).
>>=20
>>>=20
>>>=20
>>>=20
>>>=20
>>>=20
>>> On Tue, May 14, 2013 at 5:17 PM, Aleksandr Rybalko <ray@freebsd.org>
>> wrote:
>>>=20
>>>> On Tue, 14 May 2013 12:20:08 -0600
>>>> Tom Everett <tom@khubla.com> wrote:
>>>>=20
>>>>> ok so the FDT definition would have to be added here?
>>>>>=20
>>>>>=20
>>>>=20
>> =
http://svnweb.freebsd.org/base/head/sys/boot/fdt/dts/bcm2835-rpi-b.dts?vie=
w=3Dmarkup
>>>>>=20
>>>>=20
>>>> Yeah, right.
>>>>=20
>>>> But I have bad news. Both UARTs can be connected to pairs(tx+rx) =
14+16,
>>>> 32+33, 40+41 and both UARTs can be connected to any of this pins.
>>>> But only 14, 16 and 40(PWM0) wired to ext.pin.
>>>>=20
>>>>>=20
>>>>>=20
>>>>> On Tue, May 14, 2013 at 10:24 AM, Aleksandr Rybalko =
<ray@freebsd.org
>>>=20
>>>>> wrote:
>>>>>=20
>>>>>> On Tue, 14 May 2013 09:06:44 -0700
>>>>>> Adrian Chadd <adrian@freebsd.org> wrote:
>>>>>>=20
>>>>>>> ... the r-pi actually has an RS232 port exposed via GPIO. It's
>>>>>>> only 3.3v but it's there.
>>>>>>>=20
>>>>>>> Someone just needs to write up an SIO driver for it and then put
>>>>>>> the GPIO pins in question into RS232 "mode".
>>>>>>=20
>>>>>> we have it already :) (console works on uart)
>>>>>> only FDT definition is required.
>>>>>> And maybe some fixes for boudrate setting and/or format setup
>>>>>> (bits/parity/stop bits/etc)
>>>>>>=20
>>>>>>>=20
>>>>>>> Yay multi-function GPIO pins!
>>>>>>>=20
>>>>>>>=20
>>>>>>>=20
>>>>>>> adrian
>>>>>>>=20
>>>>>>>=20
>>>>>>> On 14 May 2013 08:58, Tom Everett <tom@khubla.com> wrote:
>>>>>>>> Good morning ARM mailing list.
>>>>>>>>=20
>>>>>>>> I've been running FreeBSD on my Pi, and I've now got two XBee
>>>>>>>> Pros which I hope to connect. XBee's communicate over RS-232.
>>>>>>>>=20
>>>>>>>> https://www.sparkfun.com/products/8742
>>>>>>>>=20
>>>>>>>> I see from the source tree that it was possible to attach the
>>>>>>>> iic driver to GPIO pins in software:
>>>>>>>>=20
>>>>>>>>=20
>>>> =
http://svnweb.freebsd.org/base/head/sys/dev/gpio/gpioiic.c?view=3Dmarkup
>>>>>>>>=20
>>>>>>>> I'm wondering, it is possible to connect the FreeBSD serial
>>>>>>>> driver for RS-2332 to GPIO in a similar way to how iic was
>>>>>>>> connected?
>>>>>>>>=20
>>>>>>>>=20
>>>>>>>>=20
>>>>>>>> --
>>>>>>>> A better world shall emerge based on faith and understanding -
>>>>>>>> Douglas MacArthur
>>>>>>>> _______________________________________________
>>>>>>>> freebsd-arm@freebsd.org mailing list
>>>>>>>> http://lists.freebsd.org/mailman/listinfo/freebsd-arm
>>>>>>>> To unsubscribe, send any mail to
>>>>>>>> "freebsd-arm-unsubscribe@freebsd.org"
>>>>>>> _______________________________________________
>>>>>>> freebsd-arm@freebsd.org mailing list
>>>>>>> http://lists.freebsd.org/mailman/listinfo/freebsd-arm
>>>>>>> To unsubscribe, send any mail to
>>>>>>> "freebsd-arm-unsubscribe@freebsd.org"
>>>>>>=20
>>>>>>=20
>>>>>> --
>>>>>> Aleksandr Rybalko <ray@freebsd.org>
>>>>>>=20
>>>>>=20
>>>>>=20
>>>>>=20
>>>>> --
>>>>> A better world shall emerge based on faith and understanding -
>>>>> Douglas MacArthur
>>>>=20
>>>>=20
>>>> --
>>>> Aleksandr Rybalko <ray@freebsd.org>
>>>>=20
>>>=20
>>>=20
>>>=20
>>> --
>>> A better world shall emerge based on faith and understanding - =
Douglas
>>> MacArthur
>>=20
>> Good luck! And let us know how things is going :)
>>=20
>> WBW
>> --
>> Aleksandr Rybalko <ray@freebsd.org>
>>=20
>=20
>=20
>=20
> --=20
> A better world shall emerge based on faith and understanding - =
Douglas
> MacArthur
> _______________________________________________
> freebsd-arm@freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-arm
> To unsubscribe, send any mail to "freebsd-arm-unsubscribe@freebsd.org"
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