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?
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);
> > + mutex_unlock(&indio_dev->mlock);
> > +
> > + if (result)
> > + return result;
> > +
> > + return 0;
> > +
> > +}
> > +
> > +
> > 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,
> >
>
--
To unsubscribe from this list: send the line "unsubscribe linux-iio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
