Re: [PATCH v2 3/4] iio: temperature: tmp117: add TI TMP116 support

Marco Felsch
2022-12-23T15:07:41Z

Hi Jonathan,

On 22-12-23, Jonathan Cameron wrote:
> On Wed, 21 Dec 2022 10:28:00 +0100
> Marco Felsch <m.felsch@pengutronix.de> wrote:
>
> > The TMP116 is the predecessor of the TMP117. The TMP116 don't support
> > custom offset calibration data, instead this register is used as generic
> > EEPROM storage as well.
> >
> > Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> A few comments inline.
> Thanks,
>
> Jonathan
>
> > ---
> > v2:
> > - no changes
> >
> > drivers/iio/temperature/tmp117.c | 40 ++++++++++++++++++++++----------
> > 1 file changed, 28 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/iio/temperature/tmp117.c b/drivers/iio/temperature/tmp117.c
> > index f9b8f2b570f6..468dafa6fa8e 100644
> > --- a/drivers/iio/temperature/tmp117.c
> > +++ b/drivers/iio/temperature/tmp117.c
> > @@ -31,9 +31,11 @@
> > #define TMP117_REG_DEVICE_ID 0xF
> >
> > #define TMP117_RESOLUTION_10UC 78125
> > -#define TMP117_DEVICE_ID 0x0117
> > #define MICRODEGREE_PER_10MILLIDEGREE 10000
> >
> > +#define TMP116_DEVICE_ID 0x1116
> > +#define TMP117_DEVICE_ID 0x0117
> > +
> > struct tmp117_data {
> > struct i2c_client *client;
> > s16 calibbias;
> > @@ -105,6 +107,13 @@ static const struct iio_chan_spec tmp117_channels[] = {
> > .type = IIO_TEMP,
> > .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> > BIT(IIO_CHAN_INFO_CALIBBIAS) | BIT(IIO_CHAN_INFO_SCALE),
> > +};
> > +
> > +static const struct iio_chan_spec tmp116_channels[] = {
> > + {
> > + .type = IIO_TEMP,
> > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> > + BIT(IIO_CHAN_INFO_SCALE),
> > },
> > };
> >
> > @@ -118,27 +127,28 @@ static int tmp117_identify(struct i2c_client *client)
> > int dev_id;
> >
> > dev_id = i2c_smbus_read_word_swapped(client, TMP117_REG_DEVICE_ID);
> > - if (dev_id < 0)
>
> Keep this handling of the smbus read returning an error.
> Otherwise, you end up replacing the error code with -ENODEV rather than
> returning what actually happened.
>
> if (dev_id < 0)
> return dev_id;

You're right, I will change this thanks.

> switch (dev_id) {
> ...
>
> > + switch (dev_id) {
> > + case TMP116_DEVICE_ID:
> > + case TMP117_DEVICE_ID:
> > return dev_id;
> > - if (dev_id != TMP117_DEVICE_ID) {
> > - dev_err(&client->dev, "TMP117 not found\n");
> > + default:
> > + dev_err(&client->dev, "TMP116/117 not found\n");
> > return -ENODEV;
> > }
> > - return 0;
> > }
> >
> > static int tmp117_probe(struct i2c_client *client)
> > {
> > struct tmp117_data *data;
> > struct iio_dev *indio_dev;
> > - int ret;
> > + int dev_id;
> >
> > if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
> > return -EOPNOTSUPP;
> >
> > - ret = tmp117_identify(client);
> > - if (ret < 0)
> > - return ret;
> > + dev_id = tmp117_identify(client);
> > + if (dev_id < 0)
> > + return dev_id;
> >
> > indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> > if (!indio_dev)
> > @@ -148,12 +158,18 @@ static int tmp117_probe(struct i2c_client *client)
> > data->client = client;
> > data->calibbias = 0;
> >
> > - indio_dev->name = "tmp117";
> > indio_dev->modes = INDIO_DIRECT_MODE;
> > indio_dev->info = &tmp117_info;
> >
> > - indio_dev->channels = tmp117_channels;
> > - indio_dev->num_channels = ARRAY_SIZE(tmp117_channels);
> > + if (dev_id == TMP117_DEVICE_ID) {
>
> Probably better to assume we may get more parts in future and use a
> switch statement here to explicitly match each value.

As you want, I will change it.

Regards,
Marco

> > + indio_dev->channels = tmp117_channels;
> > + indio_dev->num_channels = ARRAY_SIZE(tmp117_channels);
> > + indio_dev->name = "tmp117";
> > + } else {
> > + indio_dev->channels = tmp116_channels;
> > + indio_dev->num_channels = ARRAY_SIZE(tmp116_channels);
> > + indio_dev->name = "tmp116";
> > + }
> >
> > return devm_iio_device_register(&client->dev, indio_dev);
> > }
>
>