Re: [PATCH v2] iio: light: ltr501: claim direct mode during raw writes

[Jonathan Cameron]

On 17/10/16 22:10, Peter Meerwald-Stadler wrote:
> On Sun, 16 Oct 2016, Jonathan Cameron wrote:
> 
>> On 16/10/16 06:02, Alison Schofield wrote:
>>> Driver was checking for direct mode but not locking it.  Use
>>> claim/release helper functions to guarantee the device stays
>>> in direct mode during all raw write operations.
>>>
>>> Signed-off-by: Alison Schofield <amsfield22@xxxxxxxxx>
>>> ---
>>> Changes in v2:
>>>   Replaced 'goto release' statements with breaks.
>>>   The release helper function remains in the same place as in version
>>>   one of patch, but now break statements control the flow rather than
>>>   jumping out with goto's.
>>>   
>>>   I may have 'break'd more than needed at tail end of nested switch.
>>>   Tried to follow official c language definition.  
>>>
>> I'd have done it exactly the same
>>
>> Applied to the togreg branch of iio.git.  Again, Peter, if you have
>> a chance to look at this that would be great.  If not then not to worry!
> 
> Acked-by: Peter Meerwald-Stadler <pmeerw@xxxxxxxxxx>
Added to both this and the raw reads patch (on basis I'm assuming you
don't mind that one 
>  
>> Jonathan
>>>
>>>  drivers/iio/light/ltr501.c | 81 +++++++++++++++++++++++++++++-----------------
>>>  1 file changed, 51 insertions(+), 30 deletions(-)
>>>
>>> diff --git a/drivers/iio/light/ltr501.c b/drivers/iio/light/ltr501.c
>>> index 3afc53a..8f9d5cf 100644
>>> --- a/drivers/iio/light/ltr501.c
>>> +++ b/drivers/iio/light/ltr501.c
>>> @@ -729,8 +729,9 @@ static int ltr501_write_raw(struct iio_dev *indio_dev,
>>>  	int i, ret, freq_val, freq_val2;
>>>  	struct ltr501_chip_info *info = data->chip_info;
>>>  
>>> -	if (iio_buffer_enabled(indio_dev))
>>> -		return -EBUSY;
>>> +	ret = iio_device_claim_direct_mode(indio_dev);
>>> +	if (ret)
>>> +		return ret;
>>>  
>>>  	switch (mask) {
>>>  	case IIO_CHAN_INFO_SCALE:
>>> @@ -739,85 +740,105 @@ static int ltr501_write_raw(struct iio_dev *indio_dev,
>>>  			i = ltr501_get_gain_index(info->als_gain,
>>>  						  info->als_gain_tbl_size,
>>>  						  val, val2);
>>> -			if (i < 0)
>>> -				return -EINVAL;
>>> +			if (i < 0) {
>>> +				ret = -EINVAL;
>>> +				break;
>>> +			}
>>>  
>>>  			data->als_contr &= ~info->als_gain_mask;
>>>  			data->als_contr |= i << info->als_gain_shift;
>>>  
>>> -			return regmap_write(data->regmap, LTR501_ALS_CONTR,
>>> -					    data->als_contr);
>>> +			ret = regmap_write(data->regmap, LTR501_ALS_CONTR,
>>> +					   data->als_contr);
>>> +			break;
>>>  		case IIO_PROXIMITY:
>>>  			i = ltr501_get_gain_index(info->ps_gain,
>>>  						  info->ps_gain_tbl_size,
>>>  						  val, val2);
>>> -			if (i < 0)
>>> -				return -EINVAL;
>>> +			if (i < 0) {
>>> +				ret = -EINVAL;
>>> +				break;
>>> +			}
>>>  			data->ps_contr &= ~LTR501_CONTR_PS_GAIN_MASK;
>>>  			data->ps_contr |= i << LTR501_CONTR_PS_GAIN_SHIFT;
>>>  
>>> -			return regmap_write(data->regmap, LTR501_PS_CONTR,
>>> -					    data->ps_contr);
>>> +			ret = regmap_write(data->regmap, LTR501_PS_CONTR,
>>> +					   data->ps_contr);
>>> +			break;
>>>  		default:
>>> -			return -EINVAL;
>>> +			ret = -EINVAL;
>>> +			break;
>>>  		}
>>> +		break;
>>> +
>>>  	case IIO_CHAN_INFO_INT_TIME:
>>>  		switch (chan->type) {
>>>  		case IIO_INTENSITY:
>>> -			if (val != 0)
>>> -				return -EINVAL;
>>> +			if (val != 0) {
>>> +				ret = -EINVAL;
>>> +				break;
>>> +			}
>>>  			mutex_lock(&data->lock_als);
>>> -			i = ltr501_set_it_time(data, val2);
>>> +			ret = ltr501_set_it_time(data, val2);
>>>  			mutex_unlock(&data->lock_als);
>>> -			return i;
>>> +			break;
>>>  		default:
>>> -			return -EINVAL;
>>> +			ret = -EINVAL;
>>> +			break;
>>>  		}
>>> +		break;
>>> +
>>>  	case IIO_CHAN_INFO_SAMP_FREQ:
>>>  		switch (chan->type) {
>>>  		case IIO_INTENSITY:
>>>  			ret = ltr501_als_read_samp_freq(data, &freq_val,
>>>  							&freq_val2);
>>>  			if (ret < 0)
>>> -				return ret;
>>> +				break;
>>>  
>>>  			ret = ltr501_als_write_samp_freq(data, val, val2);
>>>  			if (ret < 0)
>>> -				return ret;
>>> +				break;
>>>  
>>>  			/* update persistence count when changing frequency */
>>>  			ret = ltr501_write_intr_prst(data, chan->type,
>>>  						     0, data->als_period);
>>>  
>>>  			if (ret < 0)
>>> -				return ltr501_als_write_samp_freq(data,
>>> -								  freq_val,
>>> -								  freq_val2);
>>> -			return ret;
>>> +				ret = ltr501_als_write_samp_freq(data, freq_val,
>>> +								 freq_val2);
>>> +			break;
>>>  		case IIO_PROXIMITY:
>>>  			ret = ltr501_ps_read_samp_freq(data, &freq_val,
>>>  						       &freq_val2);
>>>  			if (ret < 0)
>>> -				return ret;
>>> +				break;
>>>  
>>>  			ret = ltr501_ps_write_samp_freq(data, val, val2);
>>>  			if (ret < 0)
>>> -				return ret;
>>> +				break;
>>>  
>>>  			/* update persistence count when changing frequency */
>>>  			ret = ltr501_write_intr_prst(data, chan->type,
>>>  						     0, data->ps_period);
>>>  
>>>  			if (ret < 0)
>>> -				return ltr501_ps_write_samp_freq(data,
>>> -								 freq_val,
>>> -								 freq_val2);
>>> -			return ret;
>>> +				ret = ltr501_ps_write_samp_freq(data, freq_val,
>>> +								freq_val2);
>>> +			break;
>>>  		default:
>>> -			return -EINVAL;
>>> +			ret = -EINVAL;
>>> +			break;
>>>  		}
>>> +		break;
>>> +
>>> +	default:
>>> +		ret = -EINVAL;
>>> +		break;
>>>  	}
>>> -	return -EINVAL;
>>> +
>>> +	iio_device_release_direct_mode(indio_dev);
>>> +	return ret;
>>>  }
>>>  
>>>  static int ltr501_read_thresh(struct iio_dev *indio_dev,
>>>
>>
>