Re: [PATCH 2/7] iio: gyro: itg3200 switch sampling frequency attr to core support.

[Jonathan Cameron <jic23@kernel.org>]

On 29/06/14 13:04, Hartmut Knaack wrote:
> Jonathan Cameron schrieb:
>> By using the info_mask_shared_by_all element of the channel spec, access
>> to the sampling frequency becomes available to in kernel users of the
>> driver.  It also shortens and simplifies the code a little.
>>
>> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
>> Cc: Manuel Stahl <manuel.stahl@iis.fraunhofer.de>
>> Cc: Thorsten Nowak <thorsten.nowak@iis.fraunhofer.de>
>> Cc: Christian Strobel <christian.strobel@iis.fraunhofer.de>
> Reviewed-by: Hartmut Knaack <knaack.h@gmx.de>
Applied to the togreg branch of iio.git

>> ---
> Looks good to me.
>>   drivers/iio/gyro/itg3200_core.c | 101 +++++++++++++++++-----------------------
>>   1 file changed, 43 insertions(+), 58 deletions(-)
>>
>> diff --git a/drivers/iio/gyro/itg3200_core.c b/drivers/iio/gyro/itg3200_core.c
>> index 8295e31..6a8020d 100644
>> --- a/drivers/iio/gyro/itg3200_core.c
>> +++ b/drivers/iio/gyro/itg3200_core.c
>> @@ -90,6 +90,7 @@ static int itg3200_read_raw(struct iio_dev *indio_dev,
>>   {
>>   	int ret = 0;
>>   	u8 reg;
>> +	u8 regval;
>>
>>   	switch (info) {
>>   	case IIO_CHAN_INFO_RAW:
>> @@ -107,65 +108,60 @@ static int itg3200_read_raw(struct iio_dev *indio_dev,
>>   		/* Only the temperature channel has an offset */
>>   		*val = 23000;
>>   		return IIO_VAL_INT;
>> -	default:
>> -		return -EINVAL;
>> -	}
>> -}
>> -
>> -static ssize_t itg3200_read_frequency(struct device *dev,
>> -		struct device_attribute *attr, char *buf)
>> -{
>> -	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>> -	int ret, sps;
>> -	u8 val;
>> -
>> -	ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val);
>> -	if (ret)
>> -		return ret;
>> +	case IIO_CHAN_INFO_SAMP_FREQ:
>> +		ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &regval);
>> +		if (ret)
>> +			return ret;
>>
>> -	sps = (val & ITG3200_DLPF_CFG_MASK) ? 1000 : 8000;
>> +		*val = (regval & ITG3200_DLPF_CFG_MASK) ? 1000 : 8000;
>>
>> -	ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_SAMPLE_RATE_DIV, &val);
>> -	if (ret)
>> -		return ret;
>> +		ret = itg3200_read_reg_8(indio_dev,
>> +					 ITG3200_REG_SAMPLE_RATE_DIV,
>> +					 &regval);
>> +		if (ret)
>> +			return ret;
>>
>> -	sps /= val + 1;
>> +		*val /= regval + 1;
>> +		return IIO_VAL_INT;
>>
>> -	return sprintf(buf, "%d\n", sps);
>> +	default:
>> +		return -EINVAL;
>> +	}
>>   }
>>
>> -static ssize_t itg3200_write_frequency(struct device *dev,
>> -		struct device_attribute *attr,
>> -		const char *buf,
>> -		size_t len)
>> +static int itg3200_write_raw(struct iio_dev *indio_dev,
>> +			     struct iio_chan_spec const *chan,
>> +			     int val,
>> +			     int val2,
>> +			     long mask)
>>   {
>> -	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>> -	unsigned val;
>>   	int ret;
>>   	u8 t;
>>
>> -	ret = kstrtouint(buf, 10, &val);
>> -	if (ret)
>> -		return ret;
>> +	switch (mask) {
>> +	case IIO_CHAN_INFO_SAMP_FREQ:
>> +		if (val == 0 || val2 != 0)
>> +			return -EINVAL;
>>
>> -	mutex_lock(&indio_dev->mlock);
>> +		mutex_lock(&indio_dev->mlock);
>>
>> -	ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &t);
>> -	if (ret)
>> -		goto err_ret;
>> +		ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &t);
>> +		if (ret) {
>> +			mutex_unlock(&indio_dev->mlock);
>> +			return ret;
>> +		}
>> +		t = ((t & ITG3200_DLPF_CFG_MASK) ? 1000u : 8000u) / val - 1;
>>
>> -	if (val == 0) {
>> -		ret = -EINVAL;
>> -		goto err_ret;
>> -	}
>> -	t = ((t & ITG3200_DLPF_CFG_MASK) ? 1000u : 8000u) / val - 1;
>> +		ret = itg3200_write_reg_8(indio_dev,
>> +					  ITG3200_REG_SAMPLE_RATE_DIV,
>> +					  t);
>>
>> -	ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_SAMPLE_RATE_DIV, t);
>> -
>> -err_ret:
>> -	mutex_unlock(&indio_dev->mlock);
>> +		mutex_unlock(&indio_dev->mlock);
>> +	return ret;
>>
>> -	return ret ? ret : len;
>> +	default:
>> +		return -EINVAL;
>> +	}
>>   }
>>
>>   /*
>> @@ -255,6 +251,7 @@ err_ret:
>>   	.channel2 = IIO_MOD_ ## _mod, \
>>   	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
>>   	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
>> +	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
>>   	.address = ITG3200_REG_GYRO_ ## _mod ## OUT_H, \
>>   	.scan_index = ITG3200_SCAN_GYRO_ ## _mod, \
>>   	.scan_type = ITG3200_ST, \
>> @@ -267,6 +264,7 @@ static const struct iio_chan_spec itg3200_channels[] = {
>>   		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
>>   		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
>>   		BIT(IIO_CHAN_INFO_SCALE),
>> +		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
>>   		.address = ITG3200_REG_TEMP_OUT_H,
>>   		.scan_index = ITG3200_SCAN_TEMP,
>>   		.scan_type = ITG3200_ST,
>> @@ -277,22 +275,9 @@ static const struct iio_chan_spec itg3200_channels[] = {
>>   	IIO_CHAN_SOFT_TIMESTAMP(ITG3200_SCAN_ELEMENTS),
>>   };
>>
>> -/* IIO device attributes */
>> -static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO, itg3200_read_frequency,
>> -		itg3200_write_frequency);
>> -
>> -static struct attribute *itg3200_attributes[] = {
>> -	&iio_dev_attr_sampling_frequency.dev_attr.attr,
>> -	NULL
>> -};
>> -
>> -static const struct attribute_group itg3200_attribute_group = {
>> -	.attrs = itg3200_attributes,
>> -};
>> -
>>   static const struct iio_info itg3200_info = {
>> -	.attrs = &itg3200_attribute_group,
>>   	.read_raw = &itg3200_read_raw,
>> +	.write_raw = &itg3200_write_raw,
>>   	.driver_module = THIS_MODULE,
>>   };
>>
>