On 18/10/16 20:36, Juliana Rodrigues wrote:
> On Sat, Oct 15, 2016 at 03:36:47PM +0100, Jonathan Cameron wrote:
>> On 14/10/16 03:20, Juliana Rodrigues wrote:
>>> Moved functionality from IIO_DEV_ATTR_SAMP_FREQ macro into
>>> IIO_CHAN_INFO_SAMP_FREQ in order to create a generic attribute.
>>> Modified inv_mpu6050_read_raw and inv_mpu6050_write_raw to allow
>>> reading and writing the element.
>>>
>>> Signed-off-by: Juliana Rodrigues <juliana.orod@xxxxxxxxx>
>> Hi Juliana,
>>
>> This driver does things a little differently from some others, so you need
>> to take a little more care when reworking elements to add them to the
>> write_raw callback.
>>
>> Anyhow, take another look at that, and perhaps whilst you are there
>> check out the odd error handling path in that function which I'm embarrassed
>> to say I've never noticed before!
>>
>> Jonathan
>
> Hi Jonathan,
>
> Thank you for your comments. I'll write a new patch to fix the issues
> you've mentioned. I just have a few questions bellow.
>
> Juliana
>>> ---
>>> drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 187 ++++++++++++++---------------
>>> 1 file changed, 92 insertions(+), 95 deletions(-)
>>>
>>> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
>>> index b9fcbf1..20722c8 100644
>>> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
>>> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
>>> @@ -263,6 +263,88 @@ static int inv_mpu6050_sensor_set(struct inv_mpu6050_state *st, int reg,
>>> return 0;
>>> }
>>>
>>> +/**
>>> + * inv_mpu6050_set_lpf() - set low pass filer based on fifo rate.
>>> + *
>>> + * Based on the Nyquist principle, the sampling rate must
>>> + * exceed twice of the bandwidth of the signal, or there
>>> + * would be alising. This function basically search for the
>>> + * correct low pass parameters based on the fifo rate, e.g,
>>> + * sampling frequency.
>>> + */
>>> +static int inv_mpu6050_set_lpf(struct inv_mpu6050_state *st, int rate)
>>> +{
>>> + const int hz[] = {188, 98, 42, 20, 10, 5};
>>> + const int d[] = {INV_MPU6050_FILTER_188HZ, INV_MPU6050_FILTER_98HZ,
>>> + INV_MPU6050_FILTER_42HZ, INV_MPU6050_FILTER_20HZ,
>>> + INV_MPU6050_FILTER_10HZ, INV_MPU6050_FILTER_5HZ};
>>> + int i, h, result;
>>> + u8 data;
>>> +
>>> + h = (rate >> 1);
>>> + i = 0;
>>> + while ((h < hz[i]) && (i < ARRAY_SIZE(d) - 1))
>>> + i++;
>>> + data = d[i];
>>> + result = regmap_write(st->map, st->reg->lpf, data);
>>> + if (result)
>>> + return result;
>>> + st->chip_config.lpf = data;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +/**
>>> + * inv_mpu6050_write_raw_samp_freq() - Set current raw sampling rate.
>>> + */
>>> +static int inv_mpu6050_write_raw_samp_freq(struct iio_dev *indio_dev,
>>> + struct inv_mpu6050_state *st,
>>> + int val) {
>>> +
>>> + u8 d;
>>> + int result;
>>> +
>>> + if (val < INV_MPU6050_MIN_FIFO_RATE || val > INV_MPU6050_MAX_FIFO_RATE)
>>> + return -EINVAL;
>>> + if (val == st->chip_config.fifo_rate)
>>> + return 0;
>>> +
>>> + mutex_lock(&indio_dev->mlock);
>> Please take a close look at the write_raw function... It is doing various
>> things before calling this - including taking mlock. Also does some stuff
>> afterwards, including some truely mistifying error handling which definitely
>> looks buggy.
>>
>
> Maybe would be better to move checks and mutex locks outside?
Might do. Have a go and see if looks simpler that way.
>
> About the error handling, looks like it's trying to turn on, write,
> and turn off with a lot of gotos in the middle to check if it was
> sucessful. I don't see, though, how it's buggy. Can you enlighten me? (:
>
>>> + if (st->chip_config.enable) {
>>> + result = -EBUSY;
>>> + goto fifo_rate_fail;
>>> + }
>>> +
>>> + result = inv_mpu6050_set_power_itg(st, true);
>>> + if (result)
>>> + goto fifo_rate_fail;
>>> +
>>> + d = INV_MPU6050_ONE_K_HZ / val - 1;
>>> +
>>> + result = regmap_write(st->map, st->reg->sample_rate_div, d);
>>> +
>>> + if (result)
>>> + goto fifo_rate_fail;
>>> +
>>> + st->chip_config.fifo_rate = val;
>>> +
>>> + result = inv_mpu6050_set_lpf(st, val);
>>> +
>>> + if (result)
>>> + goto fifo_rate_fail;
>>> +
>>> +fifo_rate_fail:
>>> + result |= inv_mpu6050_set_power_itg(st, false);
What is result now set to?
>>> + mutex_unlock(&indio_dev->mlock);
>>> +
>>> + if (result)
>>> + return result;
>>> +
>>> + return 0;
simple return result in all cases should be fine once the above mysterious
| is dealt with. If we are in a fail condition we should not overwrite
or scramble the original error.
>>> +
>>> +}
>>> +
>>> +
>>> static int inv_mpu6050_sensor_show(struct inv_mpu6050_state *st, int reg,
>>> int axis, int *val)
>>> {
>>> @@ -399,6 +481,10 @@ inv_mpu6050_read_raw(struct iio_dev *indio_dev,
>>> default:
>>> return -EINVAL;
>>> }
>>> + case IIO_CHAN_INFO_SAMP_FREQ:
>>> + *val = st->chip_config.fifo_rate;
>>> +
>>> + return IIO_VAL_INT;
>>> default:
>>> return -EINVAL;
>>> }
>>> @@ -511,6 +597,10 @@ static int inv_mpu6050_write_raw(struct iio_dev *indio_dev,
>>> default:
>>> result = -EINVAL;
>>> }
>>> + break;
>>> + case IIO_CHAN_INFO_SAMP_FREQ:
>>> + result = inv_mpu6050_write_raw_samp_freq(indio_dev, st, val);
>> Sanity check that val2 == 0 please.
>>> + break;
>>> default:
>>> result = -EINVAL;
>>> break;
>>> @@ -524,98 +614,6 @@ static int inv_mpu6050_write_raw(struct iio_dev *indio_dev,
>>> }
>>>
>>> /**
>>> - * inv_mpu6050_set_lpf() - set low pass filer based on fifo rate.
>>> - *
>>> - * Based on the Nyquist principle, the sampling rate must
>>> - * exceed twice of the bandwidth of the signal, or there
>>> - * would be alising. This function basically search for the
>>> - * correct low pass parameters based on the fifo rate, e.g,
>>> - * sampling frequency.
>>> - */
>>> -static int inv_mpu6050_set_lpf(struct inv_mpu6050_state *st, int rate)
>>> -{
>>> - const int hz[] = {188, 98, 42, 20, 10, 5};
>>> - const int d[] = {INV_MPU6050_FILTER_188HZ, INV_MPU6050_FILTER_98HZ,
>>> - INV_MPU6050_FILTER_42HZ, INV_MPU6050_FILTER_20HZ,
>>> - INV_MPU6050_FILTER_10HZ, INV_MPU6050_FILTER_5HZ};
>>> - int i, h, result;
>>> - u8 data;
>>> -
>>> - h = (rate >> 1);
>>> - i = 0;
>>> - while ((h < hz[i]) && (i < ARRAY_SIZE(d) - 1))
>>> - i++;
>>> - data = d[i];
>>> - result = regmap_write(st->map, st->reg->lpf, data);
>>> - if (result)
>>> - return result;
>>> - st->chip_config.lpf = data;
>>> -
>>> - return 0;
>>> -}
>>> -
>>> -/**
>>> - * inv_mpu6050_fifo_rate_store() - Set fifo rate.
>>> - */
>>> -static ssize_t
>>> -inv_mpu6050_fifo_rate_store(struct device *dev, struct device_attribute *attr,
>>> - const char *buf, size_t count)
>>> -{
>>> - s32 fifo_rate;
>>> - u8 d;
>>> - int result;
>>> - struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>>> - struct inv_mpu6050_state *st = iio_priv(indio_dev);
>>> -
>>> - if (kstrtoint(buf, 10, &fifo_rate))
>>> - return -EINVAL;
>>> - if (fifo_rate < INV_MPU6050_MIN_FIFO_RATE ||
>>> - fifo_rate > INV_MPU6050_MAX_FIFO_RATE)
>>> - return -EINVAL;
>>> - if (fifo_rate == st->chip_config.fifo_rate)
>>> - return count;
>>> -
>>> - mutex_lock(&indio_dev->mlock);
>>> - if (st->chip_config.enable) {
>>> - result = -EBUSY;
>>> - goto fifo_rate_fail;
>>> - }
>>> - result = inv_mpu6050_set_power_itg(st, true);
>>> - if (result)
>>> - goto fifo_rate_fail;
>>> -
>>> - d = INV_MPU6050_ONE_K_HZ / fifo_rate - 1;
>>> - result = regmap_write(st->map, st->reg->sample_rate_div, d);
>>> - if (result)
>>> - goto fifo_rate_fail;
>>> - st->chip_config.fifo_rate = fifo_rate;
>>> -
>>> - result = inv_mpu6050_set_lpf(st, fifo_rate);
>>> - if (result)
>>> - goto fifo_rate_fail;
>>> -
>>> -fifo_rate_fail:
>>> - result |= inv_mpu6050_set_power_itg(st, false);
>>> - mutex_unlock(&indio_dev->mlock);
>>> - if (result)
>>> - return result;
>>> -
>>> - return count;
>>> -}
>>> -
>>> -/**
>>> - * inv_fifo_rate_show() - Get the current sampling rate.
>>> - */
>>> -static ssize_t
>>> -inv_fifo_rate_show(struct device *dev, struct device_attribute *attr,
>>> - char *buf)
>>> -{
>>> - struct inv_mpu6050_state *st = iio_priv(dev_to_iio_dev(dev));
>>> -
>>> - return sprintf(buf, "%d\n", st->chip_config.fifo_rate);
>>> -}
>>> -
>>> -/**
>>> * inv_attr_show() - calling this function will show current
>>> * parameters.
>>> *
>>> @@ -686,6 +684,7 @@ static const struct iio_chan_spec_ext_info inv_ext_info[] = {
>>> .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
>>> .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
>>> BIT(IIO_CHAN_INFO_CALIBBIAS), \
>>> + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
>>> .scan_index = _index, \
>>> .scan_type = { \
>>> .sign = 's', \
>>> @@ -708,6 +707,7 @@ static const struct iio_chan_spec inv_mpu_channels[] = {
>>> .info_mask_separate = BIT(IIO_CHAN_INFO_RAW)
>>> | BIT(IIO_CHAN_INFO_OFFSET)
>>> | BIT(IIO_CHAN_INFO_SCALE),
>>> + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
>>> .scan_index = -1,
>>> },
>>> INV_MPU6050_CHAN(IIO_ANGL_VEL, IIO_MOD_X, INV_MPU6050_SCAN_GYRO_X),
>>> @@ -725,8 +725,6 @@ static IIO_CONST_ATTR(in_anglvel_scale_available,
>>> "0.000133090 0.000266181 0.000532362 0.001064724");
>>> static IIO_CONST_ATTR(in_accel_scale_available,
>>> "0.000598 0.001196 0.002392 0.004785");
>>> -static IIO_DEV_ATTR_SAMP_FREQ(S_IRUGO | S_IWUSR, inv_fifo_rate_show,
>>> - inv_mpu6050_fifo_rate_store);
>>>
>>> /* Deprecated: kept for userspace backward compatibility. */
>>> static IIO_DEVICE_ATTR(in_gyro_matrix, S_IRUGO, inv_attr_show, NULL,
>>> @@ -737,7 +735,6 @@ static IIO_DEVICE_ATTR(in_accel_matrix, S_IRUGO, inv_attr_show, NULL,
>>> static struct attribute *inv_attributes[] = {
>>> &iio_dev_attr_in_gyro_matrix.dev_attr.attr, /* deprecated */
>>> &iio_dev_attr_in_accel_matrix.dev_attr.attr, /* deprecated */
>>> - &iio_dev_attr_sampling_frequency.dev_attr.attr,
>>> &iio_const_attr_sampling_frequency_available.dev_attr.attr,
>>> &iio_const_attr_in_accel_scale_available.dev_attr.attr,
>>> &iio_const_attr_in_anglvel_scale_available.dev_attr.attr,
>>>
>>
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