On 07/12/2013 11:25 AM, Alexandre Belloni wrote:
> Hi,
>
> On 01/07/2013 19:16, Alexandre Belloni wrote:
>> 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>
>
> I didn't get any review on that patch. I know it will already conflict
> with what Hector has been working on but would that be the good way to go ?
Yes, looks good to me. If you don't make any other fixes than resolving the
conflict you can add my
Reviewed-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
>
>
>> ---
>> drivers/staging/iio/adc/mxs-lradc.c | 99 ++++++++++++++++++++++++++++++-------
>> 1 file changed, 82 insertions(+), 17 deletions(-)
>>
>> diff --git a/drivers/staging/iio/adc/mxs-lradc.c b/drivers/staging/iio/adc/mxs-lradc.c
>> index 163c638..df1d81e 100644
>> --- a/drivers/staging/iio/adc/mxs-lradc.c
>> +++ b/drivers/staging/iio/adc/mxs-lradc.c
>> @@ -225,26 +225,14 @@ struct mxs_lradc {
>> #define LRADC_CTRL4_LRADCSELECT_MASK(n) (0xf << ((n) * 4))
>> #define LRADC_CTRL4_LRADCSELECT_OFFSET(n) ((n) * 4)
>>
>> -/*
>> - * 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;
>> unsigned long mask;
>>
>> - if (m != IIO_CHAN_INFO_RAW)
>> - return -EINVAL;
>> -
>> - /* Check for invalid channel */
>> - if (chan->channel > LRADC_MAX_TOTAL_CHANS)
>> - return -EINVAL;
>> -
>> /* Validate the channel if it doesn't intersect with reserved chans. */
>> - bitmap_set(&mask, chan->channel, 1);
>> + bitmap_set(&mask, chan, 1);
>> ret = iio_validate_scan_mask_onehot(iio_dev, &mask);
>> if (ret)
>> return -EINVAL;
>> @@ -273,7 +261,7 @@ 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);
>>
>> writel(0, lradc->base + LRADC_CH(0));
>>
>> @@ -302,6 +290,74 @@ 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;
>> +}
>> +
>> +/*
>> + * 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)
>> +{
>> + /* 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,
>> @@ -836,8 +892,17 @@ 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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