Re: mcp251xfd on RPi 5.4 downstream

From: Drew Fustini <drew@beagleboard.org>
To: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Patrick Menschel <menschel.p@posteo.de>,
	Oliver Hartkopp <socketcan@hartkopp.net>,
	linux-can@vger.kernel.org, Josh S <josh@macchina.cc>
Subject: Re: mcp251xfd on RPi 5.4 downstream
Date: Sat, 31 Oct 2020 13:27:46 +0100	[thread overview]
Message-ID: <CAPgEAj6qZxfsyuarVgvnXkHd3ZUAP-3fgD-nONCcn-C5xY44+Q@mail.gmail.com> (raw)
In-Reply-To: <3d19330b-860b-7d76-bc6d-768a7b00ed4b@pengutronix.de>

On Wed, Oct 28, 2020 at 8:58 AM Marc Kleine-Budde <mkl@pengutronix.de> wrote:
>
> On 10/28/20 4:47 AM, Drew Fustini wrote:
> >> I assumed the Waveshare instructions work but that is error on my part
> >> for not actually reproducing.  That is what I will do first.
> >> Ultimately, I want the freshly upstreamed driver working but I should
> >> check if their driver tarball works.
> >
> > The Waveshare installer uses the 4.19 kernel with the mcp25xxfd
> > driver.  However, it also fails, sio I think I need to dig deeper:
> >
> > pi@raspberrypi:~ $ dmesg | grep -Ei spi\|can
> > [    4.263765] CAN device driver interface
> > [    4.286258] mcp25xxfd_can: loading out-of-tree module taints kernel.
> > [    5.477511] mcp25xxfd spi1.0: Cannot initialize MCP2517. Wrong
> > wiring? (oscilator register reads as 00000000)
>
> It reads the osc as 0x0, too. This is the same error as you've seen with my driver.
>
> Marc
>
> --
> Pengutronix e.K.                 | Marc Kleine-Budde           |
> Embedded Linux                   | https://www.pengutronix.de  |
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Alright, it looks like I had faulty hardware!  I got a Waveshare CAN
FD hat and both the old waveshare-provided driver and the new
mcp251xfd driver work.

Well, at least for can0 with mcp251xfd-spi0-0:

[   14.530587] CAN device driver interface
[   14.548941] mcp251xfd spi0.0: DEBUG mcp251xfd mcp251xfd_probe():
devm_clk_get()
[   14.548977] mcp251xfd spi0.0: DEBUG mcp251xfd mcp251xfd_probe(): feq=40000000
[   14.549045] spi_master spi0: will run message pump with realtime priority
[   14.562946] mcp251xfd spi0.0 can0: MCP2517FD rev0.0 (-RX_INT
+MAB_NO_WARN +CRC_REG +CRC_RX +CRC_TX +ECC -HD c:40.00MHz m:20.00MHz
r:17.00MHz e:0.00MHz) successfully initialized.

However, I am still trying to figure out can1.  I tried
mcp251xfd-spi0-1 and mcp251xfd-spi1-0 but neither was able to
initialize the device.  I am using:

commit 9e02abd4fe591b2d7f369cdaaaf8f1269b7c8693 (HEAD ->
v5.4-rpi/mcp251xfd-20201022-54, marc/v5.4-rpi/mcp251xfd-20201022-54)
Author: Marc Kleine-Budde <mkl@pengutronix.de>
Date:   Fri Nov 15 00:54:07 2019 +0100

    mcp251xfd-spi0-0, mcp251xfd-spi0-1, mcp251xfd-spi1-0: add overlays

    Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

I'll try tweaking it a bit and see if I get any further.

Thanks,
Drew