On 19/01/17 21:47, jacopo mondi wrote:
> Hi Peter,
>
> On 19/01/2017 19:15, Peter Meerwald-Stadler wrote:
>>
>>> Add iio driver for Maxim MAX11100 single-channel ADC.
>>
>> minor comments, maybe Jonathan can fix it up when taking this...
>>
>>> +struct max11100_state {
>>> + const struct max11100_chip_desc *desc;
>>> + struct regulator *vref_reg;
>>> + struct spi_device *spi;
>>> +
>>> + /*
>>> + * DMA (thus cache coherency maintenance) requires the
>>> + * transfer buffers to live in their own cache lines.
>>> + */
>>> + u8 buffer[3] ____cacheline_aligned;
>>> +};
>>> +
>>> +static struct iio_chan_spec max11100_channels[] = {
>>> + { /* [0] */
>>> + .type = IIO_VOLTAGE,
>>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
>>> + BIT(IIO_CHAN_INFO_SCALE),
>>> + },
>>> +};
>>> +
>>> +static struct max11100_chip_desc {
>>> + unsigned int num_chan;
>>> + const struct iio_chan_spec *channels;
>>> +} max11100_desc = {
>>> + .num_chan = ARRAY_SIZE(max11100_channels),
>>> + .channels = max11100_channels,
>>> +};
>>
>> for just one supported chip, this is more complicated than necessary...
>>
>
> I can get rid of this, yes, but it's much nicer than hard-coding
> those values in indio_dev fields ;)
It's abstraction for something that doesn't need to be abstracted. Adds
a few lines of code that needs checking for no gain. Hence
it's gone.
>>> +
>>> +static int max11100_read_single(struct iio_dev *indio_dev, int *val)
>>> +{
>>> + int ret;
>>> + struct max11100_state *state = iio_priv(indio_dev);
>>> +
>>> + ret = spi_read(state->spi, state->buffer, sizeof(state->buffer));
>>> + if (ret) {
>>> + dev_err(&indio_dev->dev, "SPI transfer failed\n");
>>> + return ret;
>>> + }
>>> +
>>> + /* the first 8 bits sent out from ADC must be 0s */
>>> + if (state->buffer[0]) {
>>> + dev_err(&indio_dev->dev, "Invalid value: buffer[0] != 0\n");
>>> + return -EINVAL;
>>> + }
>>> +
>>> + *val = (state->buffer[1] << 8) | state->buffer[2];
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int max11100_read_raw(struct iio_dev *indio_dev,
>>> + struct iio_chan_spec const *chan,
>>> + int *val, int *val2, long info)
>>> +{
>>> + int ret, vref_uv;
>>> + struct max11100_state *state = iio_priv(indio_dev);
>>> +
>>> + switch (info) {
>>> + case IIO_CHAN_INFO_RAW:
>>> + ret = max11100_read_single(indio_dev, val);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + return IIO_VAL_INT;
>>> +
>>> + case IIO_CHAN_INFO_SCALE:
>>> + vref_uv = regulator_get_voltage(state->vref_reg);
>>> + if (vref_uv < 0)
>>> + /* dummy regulator "get_voltage" returns -EINVAL */
>>> + return -EINVAL;
>>> +
>>> + *val = vref_uv / 1000;
>>> + *val2 = MAX11100_LSB_DIV;
>>> + return IIO_VAL_FRACTIONAL;
>>> + }
>>> +
>>> + return -EINVAL;
>>> +}
>>> +
>>> +static const struct iio_info max11100_info = {
>>> + .driver_module = THIS_MODULE,
>>> + .read_raw = max11100_read_raw,
>>> +};
>>> +
>>> +static int max11100_probe(struct spi_device *spi)
>>> +{
>>> + int ret;
>>> + struct iio_dev *indio_dev;
>>> + struct max11100_state *state;
>>> +
>>> + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*state));
>>> + if (!indio_dev)
>>> + return -ENOMEM;
>>> +
>>> + spi_set_drvdata(spi, indio_dev);
>>> +
>>> + state = iio_priv(indio_dev);
>>> + state->spi = spi;
>>> + state->desc = &max11100_desc;
>>> +
>>> + indio_dev->dev.parent = &spi->dev;
>>> + indio_dev->dev.of_node = spi->dev.of_node;
>>> + indio_dev->name = "max11100";
>>> + indio_dev->info = &max11100_info;
>>> + indio_dev->modes = INDIO_DIRECT_MODE;
>>> + indio_dev->channels = state->desc->channels;
>>> + indio_dev->num_channels = state->desc->num_chan;
>>> +
>>> + state->vref_reg = devm_regulator_get(&spi->dev, "vref");
>>> + if (IS_ERR(state->vref_reg))
>>> + return PTR_ERR(state->vref_reg);
>>> +
>>> + ret = regulator_enable(state->vref_reg);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + ret = iio_device_register(indio_dev);
>>> + if (ret)
>>> + goto disable_regulator;
>>> +
>>> + return 0;
>>> +
>>> +disable_regulator:
>>> + regulator_disable(state->vref_reg);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static int max11100_remove(struct spi_device *spi)
>>> +{
>>> + struct iio_dev *indio_dev = spi_get_drvdata(spi);
>>> + struct max11100_state *state = iio_priv(indio_dev);
>>> +
>>> + regulator_disable(state->vref_reg);
>>
>> should be the other way around, first _unregister(), then
>> regulator_disable()
>>
>> reverse order as in _probe()
>>
>
> Yeah, that's right...
Fixed up.
>
> Let's see, I can send v6 with no issues, or Jonathan can do that if he prefers to.
> Just let me know :)
I'll do it as minor stuff.
Applied with changes as above to the togreg branch of iio.git and pushed out
as testing for the autobuilders to play with it.
Thanks,
Jonathan
>
> Thanks
> j
>
>
>>> +
>>> + iio_device_unregister(indio_dev);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static const struct of_device_id max11100_ids[] = {
>>> + {.compatible = "maxim,max11100"},
>>> + { },
>>> +};
>>> +MODULE_DEVICE_TABLE(of, max11100_ids);
>>> +
>>> +static struct spi_driver max11100_driver = {
>>> + .driver = {
>>> + .name = "max11100",
>>> + .owner = THIS_MODULE,
>>> + .of_match_table = of_match_ptr(max11100_ids),
>>> + },
>>> + .probe = max11100_probe,
>>> + .remove = max11100_remove,
>>> +};
>>> +
>>> +module_spi_driver(max11100_driver);
>>> +
>>> +MODULE_AUTHOR("Jacopo Mondi <jacopo@xxxxxxxxxx>");
>>> +MODULE_DESCRIPTION("Maxim max11100 ADC Driver");
>>> +MODULE_LICENSE("GPL v2");
>>>
>>
>
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