From: <Thomas.Kopp@microchip.com>
To: <menschel.p@posteo.de>, <mkl@pengutronix.de>, <drew@beagleboard.org>
Cc: <socketcan@hartkopp.net>, <linux-can@vger.kernel.org>,
<josh@macchina.cc>
Subject: RE: mcp251xfd on RPi 5.4 downstream
Date: Mon, 2 Nov 2020 18:57:01 +0000 [thread overview]
Message-ID: <DM6PR11MB4283DF81AFCFEBB886559B5AFB100@DM6PR11MB4283.namprd11.prod.outlook.com> (raw)
In-Reply-To: <cd778ddb-eb0e-bff9-5c14-06731ffb35a0@posteo.de>
> It may be a blunt guess, but according to page 99
>
> https://www.raspberrypi.org/documentation/hardware/raspberrypi/bcm27
> 11/rpi_DATA_2711_1p0.pdf
>
> Pin 26 is pulldown. So it works if it remains unused because the pin is
> input with pulldown thus the chip is selected by default.
>
> I don't know if the CE pin can actually work if there is no matching alt
> function in pinselect register.
>
> --
> Patrick
Do you suggest that the communication works with a permanent low on CS/CE?
Without the CS/CE pin having edges you will not be able to send multiple
commands. The driver is writing/reading multiple times when bringing up the
chip. If you have a permanent low that will fail. So somehow the CS does
generate the right edges.
Thomas
next prev parent reply other threads:[~2020-11-02 18:57 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-22 3:10 mcp251xfd on RPi 5.4 downstream Drew Fustini
2020-10-22 6:00 ` Drew Fustini
2020-10-22 6:33 ` Marc Kleine-Budde
2020-10-22 18:42 ` Drew Fustini
2020-10-25 4:30 ` Drew Fustini
2020-10-25 8:49 ` Oliver Hartkopp
2020-10-25 10:58 ` Marc Kleine-Budde
2020-10-25 17:43 ` Patrick Menschel
2020-10-25 18:14 ` Marc Kleine-Budde
2020-10-25 18:42 ` Patrick Menschel
2020-10-26 1:59 ` Drew Fustini
2020-10-26 2:50 ` Drew Fustini
2020-10-26 5:16 ` Patrick Menschel
2020-10-26 7:45 ` Marc Kleine-Budde
2020-10-26 9:40 ` Marc Kleine-Budde
2020-10-26 16:51 ` Patrick Menschel
2020-10-26 17:00 ` Marc Kleine-Budde
2020-10-27 2:22 ` Drew Fustini
2020-10-27 6:35 ` Drew Fustini
2020-10-27 7:06 ` Marc Kleine-Budde
2020-10-27 18:18 ` Patrick Menschel
2020-10-27 18:22 ` Marc Kleine-Budde
2020-10-28 1:57 ` Drew Fustini
2020-10-28 3:47 ` Drew Fustini
2020-10-28 7:57 ` Marc Kleine-Budde
2020-10-31 12:27 ` Drew Fustini
2020-10-31 15:14 ` Patrick Menschel
2020-10-31 15:35 ` Patrick Menschel
2020-10-31 21:57 ` Drew Fustini
2020-11-01 22:49 ` Drew Fustini
2020-11-02 7:25 ` Marc Kleine-Budde
2020-11-02 8:18 ` Marc Kleine-Budde
[not found] ` <CAPgEAj7LcX3cb+syhtR1i3Uo1XkYYFQ_wDPV8GniaA-YwPk2Hg@mail.gmail.com>
2020-11-02 11:00 ` Marc Kleine-Budde
[not found] ` <CAPgEAj7BTJyiBg4QkKuekYH0zyrA-10dby3Lgb5qj2uiD4ZOYQ@mail.gmail.com>
2020-11-02 14:22 ` mcp251xfd: loopback test on waveshare canfd hat Marc Kleine-Budde
2020-11-02 14:35 ` Drew Fustini
2020-11-02 14:38 ` Marc Kleine-Budde
2020-11-02 17:34 ` mcp251xfd on RPi 5.4 downstream Patrick Menschel
2020-11-02 18:47 ` Patrick Menschel
2020-11-02 18:57 ` Thomas.Kopp [this message]
2020-11-02 19:32 ` Patrick Menschel
2020-11-04 18:48 ` Patrick Menschel
2020-11-05 7:15 ` Marc Kleine-Budde
2020-11-05 18:11 ` Patrick Menschel
2020-11-06 9:00 ` Marc Kleine-Budde
2020-11-06 11:31 ` Patrick Menschel
2020-11-06 11:36 ` Marc Kleine-Budde
2020-11-06 11:46 ` Patrick Menschel
2020-11-05 8:08 ` Marc Kleine-Budde
2020-11-05 8:07 ` Marc Kleine-Budde
2020-11-02 7:55 ` Marc Kleine-Budde
2020-11-02 7:26 ` Marc Kleine-Budde
2020-10-26 7:43 ` Marc Kleine-Budde
2020-11-20 12:32 ` Marc Kleine-Budde
[not found] ` <CAEf4M_B68X2T0rkaq0tqahBFPc+Gbvac7-+G0j5jd-g4j+j01g@mail.gmail.com>
2020-11-20 13:16 ` Marc Kleine-Budde
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=DM6PR11MB4283DF81AFCFEBB886559B5AFB100@DM6PR11MB4283.namprd11.prod.outlook.com \
--to=thomas.kopp@microchip.com \
--cc=drew@beagleboard.org \
--cc=josh@macchina.cc \
--cc=linux-can@vger.kernel.org \
--cc=menschel.p@posteo.de \
--cc=mkl@pengutronix.de \
--cc=socketcan@hartkopp.net \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.