On 11/30/13 12:15, Jonathan Cameron wrote:
> On 11/19/13 10:36, Maxime Ripard wrote:
>> From: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
>>
>> The mxs LRADC is able to read an internal die temperature sensor. The
>> temperature has to be calculated from the value read on channel 8 and channel 9.
>> To be able to expose the result to hwmon, implement iio channel 8 as
>> (channel 9 - channel 8). Then, implement IIO_CHAN_INFO_SCALE and
>> IIO_CHAN_INFO_OFFSET so that it can be processed by hwmon through the in kernel
>> provider/consumer mechanism.
>>
>> Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
>> Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
>> Reviewed-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
> As this is still in staging, I think we can get away with the resulting
> ABI change from this patch.
>
> Applied to the togreg branch of iio.git
>
> Thanks,
>
> Jonathan
Having said that, there is an odd bit inline that I've just dropped whilst
applying the patch. Shout if I've done this wrong.
>> ---
>> drivers/staging/iio/adc/mxs-lradc.c | 91 +++++++++++++++++++++++++++++++------
>> 1 file changed, 78 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/staging/iio/adc/mxs-lradc.c b/drivers/staging/iio/adc/mxs-lradc.c
>> index a08c1736458b..fec76090dae5 100644
>> --- a/drivers/staging/iio/adc/mxs-lradc.c
>> +++ b/drivers/staging/iio/adc/mxs-lradc.c
>> @@ -231,20 +231,11 @@ struct mxs_lradc {
>> /*
>> * Raw I/O operations
>> */
>> -static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
>> - const struct iio_chan_spec *chan,
>> - int *val, int *val2, long m)
>> +static int mxs_lradc_read_single(struct iio_dev *iio_dev, int chan, int *val)
>> {
>> struct mxs_lradc *lradc = iio_priv(iio_dev);
>> int ret;
>>
>> - if (m != IIO_CHAN_INFO_RAW)
>> - return -EINVAL;
>> -
>> - /* Check for invalid channel */
>> - if (chan->channel > LRADC_MAX_TOTAL_CHANS)
>> - return -EINVAL;
>> -
>> /*
>> * See if there is no buffered operation in progess. If there is, simply
>> * bail out. This can be improved to support both buffered and raw IO at
>> @@ -269,7 +260,7 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
>> /* Clean the slot's previous content, then set new one. */
>> writel(LRADC_CTRL4_LRADCSELECT_MASK(0),
>> lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR);
>> - writel(chan->channel, lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET);
>> + writel(chan, lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET);
This doesn't make any sense. I'm guessing it drifted in from a different patch?
THere is a lot of fuzz in here in general. Please do check this - for now
it'll be pushed to my testing branch for some build testing.
>>
>> writel(0, lradc->base + LRADC_CH(0));
>>
>> @@ -298,6 +289,71 @@ err:
>> return ret;
>> }
>>
>> +static int mxs_lradc_read_temp(struct iio_dev *iio_dev, int *val)
>> +{
>> + int ret, min, max;
>> +
>> + ret = mxs_lradc_read_single(iio_dev, 8, &min);
>> + if (ret != IIO_VAL_INT)
>> + return ret;
>> +
>> + ret = mxs_lradc_read_single(iio_dev, 9, &max);
>> + if (ret != IIO_VAL_INT)
>> + return ret;
>> +
>> + *val = max - min;
>> +
>> + return IIO_VAL_INT;
>> +}
>> +
>> +static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
>> + const struct iio_chan_spec *chan,
>> + int *val, int *val2, long m)
>> +{
>> + /* Check for invalid channel */
>> + if (chan->channel > LRADC_MAX_TOTAL_CHANS)
>> + return -EINVAL;
>> +
>> + switch (m) {
>> + case IIO_CHAN_INFO_RAW:
>> + if (chan->type == IIO_TEMP)
>> + return mxs_lradc_read_temp(iio_dev, val);
>> +
>> + return mxs_lradc_read_single(iio_dev, chan->channel, val);
>> +
>> + case IIO_CHAN_INFO_SCALE:
>> + if (chan->type == IIO_TEMP) {
>> + /* From the datasheet, we have to multiply by 1.012 and
>> + * divide by 4
>> + */
>> + *val = 0;
>> + *val2 = 253000;
>> + return IIO_VAL_INT_PLUS_MICRO;
>> + }
>> +
>> + return -EINVAL;
>> +
>> + case IIO_CHAN_INFO_OFFSET:
>> + if (chan->type == IIO_TEMP) {
>> + /* The calculated value from the ADC is in Kelvin, we
>> + * want Celsius for hwmon so the offset is
>> + * -272.15 * scale
>> + */
>> + *val = -1075;
>> + *val2 = 691699;
>> +
>> + return IIO_VAL_INT_PLUS_MICRO;
>> + }
>> +
>> + return -EINVAL;
>> +
>> + default:
>> + break;
>> + }
>> +
>> + return -EINVAL;
>> +}
>> +
>> static const struct iio_info mxs_lradc_iio_info = {
>> .driver_module = THIS_MODULE,
>> .read_raw = mxs_lradc_read_raw,
>> @@ -835,8 +891,17 @@ static const struct iio_chan_spec mxs_lradc_chan_spec[] = {
>> MXS_ADC_CHAN(5, IIO_VOLTAGE),
>> MXS_ADC_CHAN(6, IIO_VOLTAGE),
>> MXS_ADC_CHAN(7, IIO_VOLTAGE), /* VBATT */
>> - MXS_ADC_CHAN(8, IIO_TEMP), /* Temp sense 0 */
>> - MXS_ADC_CHAN(9, IIO_TEMP), /* Temp sense 1 */
>> + /* Combined Temperature sensors */
>> + {
>> + .type = IIO_TEMP,
>> + .indexed = 1,
>> + .scan_index = 8,
>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
>> + BIT(IIO_CHAN_INFO_OFFSET) |
>> + BIT(IIO_CHAN_INFO_SCALE),
>> + .channel = 8,
>> + .scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,},
>> + },
>> MXS_ADC_CHAN(10, IIO_VOLTAGE), /* VDDIO */
>> MXS_ADC_CHAN(11, IIO_VOLTAGE), /* VTH */
>> MXS_ADC_CHAN(12, IIO_VOLTAGE), /* VDDA */
>>
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