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From:   =?UTF-8?B?QsO2cmdlIFN0csO8bXBmZWw=?= <boerge.struempfel@gmail.com>
Date:   Wed, 24 May 2023 13:42:04 +0200
Message-ID: <CAEktqctAZzMifTpba5cgFoAVF_r0LmG-9kNM0mM1PhA764R-ww@mail.gmail.com>
Subject: Re: [PATCH v6 2/5] spi: spi-imx: add support for SPI_MOSI_IDLE_LOW
 mode bit
To:     Frieder Schrempf <frieder.schrempf@kontron.de>
Cc:     bstruempfel@ultratronik.de, andy.shevchenko@gmail.com,
        festevam@gmail.com, amit.kumar-mahapatra@amd.com,
        broonie@kernel.org, Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        NXP Linux Team <linux-imx@nxp.com>,
        linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org, gch981213@gmail.com
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Am Mi., 24. Mai 2023 um 11:47 Uhr schrieb Frieder Schrempf
<frieder.schrempf@kontron.de>:
>
> On 24.05.23 11:19, Boerge Struempfel wrote:
> > By default, the spi-imx controller pulls the mosi line high, whenever i=
t
> > is idle. This behaviour can be inverted per CS by setting the
> > corresponding DATA_CTL bit in the config register of the controller.
> >
> > Also, since the controller mode-bits have to be touched anyways, the
> > SPI_CPOL and SPI_CPHA are replaced by the combined SPI_MODE_X_MASK flag=
.
> >
> > Signed-off-by: Boerge Struempfel <boerge.struempfel@gmail.com>
>
> Thanks for working on this! We used a similar downstream patch for
> driving NeoPixels with i.MX. I'm happy to see a proper upstream solution.
>

Thanks for your reply. I'm glad to see that there is an interest for this
and I'm not the only one, who is working with this.

> I also have this Python module [1] around for using spidev to drive the
> LEDs. It would be nice to see support for SPI_MOSI_IDLE_LOW in py-spidev
> [2] so we could use it there. Though the latter looks a bit like it is
> not properly maintained anymore.

The python modules looks interesting.

FYI: there is already another patch by Chuanhong Guo on the mailing
list, which implements a proper driver for neopixel leds. It also allows
to add them via DT and access them via sys-fs. It might be an
interesting upstream alternative for your python module if it gets
accepted.

https://lore.kernel.org/lkml/20221212045558.69602-1-gch981213@gmail.com/

>
> [1] https://github.com/fschrempf/py-neopixel-spidev
> [2] https://github.com/doceme/py-spidev
>
> Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>

--
Kind Regards,
B=C3=B6rge Str=C3=BCmpfel