From: Tomasz Duszynski <tduszyns@gmail.com>
To: Johan Hovold <johan@kernel.org>
Cc: Tomasz Duszynski <tduszyns@gmail.com>,
linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org,
devicetree@vger.kernel.org
Subject: Re: [PATCH 1/3] iio: chemical: add support for Plantower PMS7003 sensor
Date: Tue, 8 Jan 2019 20:07:57 +0100 [thread overview]
Message-ID: <20190108190756.GA25862@arch> (raw)
In-Reply-To: <20190107153542.GD14782@localhost>
On Mon, Jan 07, 2019 at 04:35:42PM +0100, Johan Hovold wrote:
> On Sun, Jan 06, 2019 at 06:16:12PM +0100, Tomasz Duszynski wrote:
> > Add support for Plantower PMS7003 particulate matter sensor.
> >
> > Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
>
> > +static int pms7003_do_cmd(struct pms7003_state *state, u8 cmd)
> > +{
> > + /*
> > + * commands have following format:
> > + *
> > + * +------+------+-----+------+-----+-----------+-----------+
> > + * | 0x42 | 0x4d | cmd | 0x00 | arg | cksum msb | cksum lsb |
> > + * +------+------+-----+------+-----+-----------+-----------+
> > + */
> > + u8 tmp[PMS7003_CMD_LENGTH] = { PMS7003_MAGIC_MSB, PMS7003_MAGIC_LSB };
> > + int ret, n = 2;
> > + u16 checksum;
> > +
> > + switch (cmd) {
> > + case CMD_WAKEUP:
> > + tmp[n++] = 0xe4;
> > + tmp[n++] = 0x00;
> > + tmp[n++] = 0x01;
> > + break;
> > + case CMD_ENTER_PASSIVE_MODE:
> > + tmp[n++] = 0xe1;
> > + tmp[n++] = 0x00;
> > + tmp[n++] = 0x00;
> > + break;
> > + case CMD_READ_PASSIVE:
> > + tmp[n++] = 0xe2;
> > + tmp[n++] = 0x00;
> > + tmp[n++] = 0x00;
> > + break;
> > + case CMD_SLEEP:
> > + tmp[n++] = 0xe4;
> > + tmp[n++] = 0x00;
> > + tmp[n++] = 0x00;
> > + break;
> > + }
> > +
> > + checksum = pms7003_calc_checksum(tmp, n);
> > + put_unaligned_be16(checksum, tmp + n);
> > + n += PMS7003_CHECKSUM_LENGTH;
> > +
> > + ret = serdev_device_write(state->serdev, tmp, n, PMS7003_TIMEOUT);
> > + if (ret)
> > + return ret;
>
> Beginning with 5.0, serdev_device_write() returns the number of bytes
> written before timeout (or being interrupted) so you need to check
> against < n here.
>
Right, on the second though that can be simplified by just ignoring
return value I guess. Anyway, thanks for pointing this out.
> Johan
next prev parent reply other threads:[~2019-01-08 19:07 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-06 17:16 [PATCH 0/3] add support for PMS7003 PM sensor Tomasz Duszynski
2019-01-06 17:16 ` [PATCH 1/3] iio: chemical: add support for Plantower PMS7003 sensor Tomasz Duszynski
2019-01-07 15:35 ` Johan Hovold
2019-01-08 19:07 ` Tomasz Duszynski [this message]
2019-01-12 17:48 ` Jonathan Cameron
2019-01-23 21:08 ` Tomasz Duszynski
2019-01-06 17:16 ` [PATCH 2/3] dt-bindings: add Plantower to the vendor prefixes Tomasz Duszynski
2019-01-11 22:12 ` Rob Herring
2019-01-06 17:16 ` [PATCH 3/3] dt-bindings: iio: chemical: pms7003: add device tree support Tomasz Duszynski
2019-01-11 22:15 ` Rob Herring
2019-01-27 13:45 ` Tomasz Duszynski
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=20190108190756.GA25862@arch \
--to=tduszyns@gmail.com \
--cc=devicetree@vger.kernel.org \
--cc=johan@kernel.org \
--cc=linux-iio@vger.kernel.org \
--cc=linux-kernel@vger.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).