From: Lars-Peter Clausen <lars@metafoo.de>
To: Puranjay Mohan <puranjay12@gmail.com>,
alexandru.ardelean@analog.com, jic23@kernel.org,
devicetree@vger.kernel.org, knaack.h@gmx.de,
linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 2/2] iio: temperature: add driver support for ti tmp117
Date: Sun, 21 Mar 2021 06:07:31 +0100 [thread overview]
Message-ID: <760dccc2-b098-71ce-037b-b667dbc05f57@metafoo.de> (raw)
In-Reply-To: <20210320064509.119878-3-puranjay12@gmail.com>
On 3/20/21 7:45 AM, Puranjay Mohan wrote:
> TMP117 is a Digital temperature sensor with integrated NV memory.
>
> Add support for tmp117 driver in iio subsystem.
>
> Datasheet:-https://www.ti.com/lit/gpn/tmp117
>
> Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
This looks good to me. Just two small bits I overlooked during the first
review, sorry for that.
> +};
> +
> [...]
> +static int tmp117_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *channel, int *val,
> + int *val2, long mask)
> +{
> + struct tmp117_data *data = iio_priv(indio_dev);
> + u16 tmp, off;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + tmp = tmp117_read_reg(data, TMP117_REG_TEMP);
> + *val = tmp;
No need for tmp here. Just directly assign to val.
> + return IIO_VAL_INT;
> +
> + case IIO_CHAN_INFO_CALIBBIAS:
> + off = tmp117_read_reg(data, TMP117_REG_TEMP_OFFSET);
> + *val = ((int16_t)off * (int32_t)TMP117_RESOLUTION) / 10000000;
> + *val2 = ((int16_t)off * (int32_t)TMP117_RESOLUTION) % 10000000;
> + return IIO_VAL_INT_PLUS_MICRO;
> +
> + case IIO_CHAN_INFO_SCALE:
> + *val = 0;
> + *val2 = TMP117_SCALE;
> + return IIO_VAL_INT_PLUS_NANO;
> +
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int tmp117_write_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *channel, int val,
> + int val2, long mask)
> +{
> + struct tmp117_data *data = iio_priv(indio_dev);
> + u16 off;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_CALIBBIAS:
> + off = ((val * 10000000) + (val2 * 10))
> + / (int32_t)TMP117_RESOLUTION;
This needs some input validation. Writing a too large or too small value
will cause an overflow/underflow and a bogus value will be written to
the register.
You can either reject invalid values by returning -EINVAL or clamp them
into the right range. Up to you how you want to handle this.
> + return tmp117_write_reg(data, TMP117_REG_TEMP_OFFSET, off);
> +
> + default:
> + return -EINVAL;
> + }
> +}
next prev parent reply other threads:[~2021-03-21 5:08 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-20 6:45 [PATCH v1 0/2] iio: temperature: add support for tmp117 Puranjay Mohan
2021-03-20 6:45 ` [PATCH v1 1/2] dt-bindings: iio: temperature: Add DT bindings for TMP117 Puranjay Mohan
2021-03-20 17:51 ` Jonathan Cameron
2021-03-22 0:15 ` Rob Herring
2021-03-20 6:45 ` [PATCH v1 2/2] iio: temperature: add driver support for ti tmp117 Puranjay Mohan
2021-03-20 18:15 ` Jonathan Cameron
2021-03-21 5:07 ` Lars-Peter Clausen [this message]
2021-03-21 5:23 ` Lars-Peter Clausen
[not found] ` <CAHp75VdYU1VPGEHWii77wXnwp55aUd8FZ54yhO31fs_qzmTBSQ@mail.gmail.com>
2021-03-21 11:27 ` Andy Shevchenko
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