From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Alexandru Ardelean <alexandru.ardelean@analog.com>
Cc: linux-spi <linux-spi@vger.kernel.org>,
devicetree <devicetree@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Rob Herring <robh+dt@kernel.org>, Mark Brown <broonie@kernel.org>,
"Bogdan, Dragos" <dragos.bogdan@analog.com>
Subject: Re: [PATCH v3 2/3] spi: Add SPI_NO_TX/RX support
Date: Fri, 27 Nov 2020 16:22:51 +0200 [thread overview]
Message-ID: <CAHp75Vcd4t=RqC31S-b1PXMtd=8sypSLhTrSgRD9hbpSqOphoQ@mail.gmail.com> (raw)
In-Reply-To: <20201127130834.136348-2-alexandru.ardelean@analog.com>
On Fri, Nov 27, 2020 at 3:08 PM Alexandru Ardelean
<alexandru.ardelean@analog.com> wrote:
> Transmit/receive only is a valid SPI mode. For example, the MOSI/TX line
> might be missing from an ADC while for a DAC the MISO/RX line may be
> optional. This patch adds these two new modes: SPI_NO_TX and
> SPI_NO_RX. This way, the drivers will be able to identify if any of
> these two lines is missing and to adjust the transfers accordingly.
...
> + /*
> + * check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO
> + * are set at the same time
> */
Since you are here,
check -> Check
time -> time.
...
> + if ((hweight_long(spi->mode &
> + (SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) ||
> + (hweight_long(spi->mode &
> + (SPI_RX_DUAL | SPI_RX_QUAD | SPI_NO_RX)) > 1)) {
> dev_err(&spi->dev,
> - "setup: can not select dual and quad at the same time\n");
> + "setup: can not select any two of dual, quad and no-rx/tx "
> + "at the same time\n");
Don't split literals, and probably rephrase (If I can't set 2, can I set 3?)
"setup: can't select more than one out of dual, quad, and no-Rx /
no-Tx at the same time\n");
> --- a/include/uapi/linux/spi/spi.h
> +++ b/include/uapi/linux/spi/spi.h
> @@ -43,5 +43,7 @@
> #define SPI_TX_OCTAL 0x2000 /* transmit with 8 wires */
> #define SPI_RX_OCTAL 0x4000 /* receive with 8 wires */
> #define SPI_3WIRE_HIZ 0x8000 /* high impedance turnaround */
> +#define SPI_NO_TX 0x10000 /* no transmit wire */
> +#define SPI_NO_RX 0x20000 /* no receive wire */
Is it really material for uAPI?
Perhaps we may have something like
SPI_MODE_USER_MASK in uAPI and
in internal headers
SPI_MODE_KERNEL_MASK with
static_assert(_USER_MASK & _KERNEL_MASK); // check conditional
?
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2020-11-27 14:22 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-27 13:08 [PATCH v3 1/3] spi: uapi: unify SPI modes into a single spi.h header Alexandru Ardelean
2020-11-27 13:08 ` [PATCH v3 2/3] spi: Add SPI_NO_TX/RX support Alexandru Ardelean
2020-11-27 14:22 ` Andy Shevchenko [this message]
2020-11-27 14:23 ` Andy Shevchenko
2020-12-03 8:20 ` Ardelean, Alexandru
2020-12-03 9:47 ` Mark Brown
2020-11-27 13:08 ` [PATCH v3 3/3] spi: dt-bindings: document zero value for spi-{rx,tx}-bus-width properties Alexandru Ardelean
2020-11-27 14:26 ` Andy Shevchenko
2020-12-03 13:35 ` Ardelean, Alexandru
2020-11-27 14:12 ` [PATCH v3 1/3] spi: uapi: unify SPI modes into a single spi.h header Andy Shevchenko
2020-12-03 8:15 ` Ardelean, Alexandru
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='CAHp75Vcd4t=RqC31S-b1PXMtd=8sypSLhTrSgRD9hbpSqOphoQ@mail.gmail.com' \
--to=andy.shevchenko@gmail.com \
--cc=alexandru.ardelean@analog.com \
--cc=broonie@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=dragos.bogdan@analog.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-spi@vger.kernel.org \
--cc=robh+dt@kernel.org \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).