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Subject[PATCH v2 08/11] iio: imu: adis16400: rework locks using ADIS library's state lock
Date
This change removes the use of indio_dev's mlock in favor using the state
lock from the ADIS library.

The set_freq() & get_freq() hooks are unlocked, so they require specific
locking. That is because in some cases the get_freq() hook is used in
combination with adis16400_set_filter().

In cases where only one read/write is done, the functions that hold the
state lock are used.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---
drivers/iio/imu/adis16400.c | 51 ++++++++++++++++++-------------------
1 file changed, 25 insertions(+), 26 deletions(-)

diff --git a/drivers/iio/imu/adis16400.c b/drivers/iio/imu/adis16400.c
index 44e46dc96e00..662cb5367c11 100644
--- a/drivers/iio/imu/adis16400.c
+++ b/drivers/iio/imu/adis16400.c
@@ -162,6 +162,7 @@ struct adis16400_chip_info {
unsigned int accel_scale_micro;
int temp_scale_nano;
int temp_offset;
+ /* set_freq() & get_freq() need to avoid using ADIS lib's state lock */
int (*set_freq)(struct adis16400_state *st, unsigned int freq);
int (*get_freq)(struct adis16400_state *st);
};
@@ -326,7 +327,7 @@ static int adis16334_get_freq(struct adis16400_state *st)
int ret;
uint16_t t;

- ret = adis_read_reg_16(&st->adis, ADIS16400_SMPL_PRD, &t);
+ ret = __adis_read_reg_16(&st->adis, ADIS16400_SMPL_PRD, &t);
if (ret)
return ret;

@@ -350,7 +351,7 @@ static int adis16334_set_freq(struct adis16400_state *st, unsigned int freq)
t <<= ADIS16334_RATE_DIV_SHIFT;
t |= ADIS16334_RATE_INT_CLK;

- return adis_write_reg_16(&st->adis, ADIS16400_SMPL_PRD, t);
+ return __adis_write_reg_16(&st->adis, ADIS16400_SMPL_PRD, t);
}

static int adis16400_get_freq(struct adis16400_state *st)
@@ -358,7 +359,7 @@ static int adis16400_get_freq(struct adis16400_state *st)
int sps, ret;
uint16_t t;

- ret = adis_read_reg_16(&st->adis, ADIS16400_SMPL_PRD, &t);
+ ret = __adis_read_reg_16(&st->adis, ADIS16400_SMPL_PRD, &t);
if (ret)
return ret;

@@ -390,7 +391,7 @@ static int adis16400_set_freq(struct adis16400_state *st, unsigned int freq)
else
st->adis.spi->max_speed_hz = ADIS16400_SPI_FAST;

- return adis_write_reg_8(&st->adis, ADIS16400_SMPL_PRD, val);
+ return __adis_write_reg_8(&st->adis, ADIS16400_SMPL_PRD, val);
}

static const unsigned int adis16400_3db_divisors[] = {
@@ -404,7 +405,7 @@ static const unsigned int adis16400_3db_divisors[] = {
[7] = 200, /* Not a valid setting */
};

-static int adis16400_set_filter(struct iio_dev *indio_dev, int sps, int val)
+static int __adis16400_set_filter(struct iio_dev *indio_dev, int sps, int val)
{
struct adis16400_state *st = iio_priv(indio_dev);
uint16_t val16;
@@ -415,11 +416,11 @@ static int adis16400_set_filter(struct iio_dev *indio_dev, int sps, int val)
break;
}

- ret = adis_read_reg_16(&st->adis, ADIS16400_SENS_AVG, &val16);
+ ret = __adis_read_reg_16(&st->adis, ADIS16400_SENS_AVG, &val16);
if (ret)
return ret;

- ret = adis_write_reg_16(&st->adis, ADIS16400_SENS_AVG,
+ ret = __adis_write_reg_16(&st->adis, ADIS16400_SENS_AVG,
(val16 & ~0x07) | i);
return ret;
}
@@ -507,32 +508,31 @@ static int adis16400_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int val, int val2, long info)
{
struct adis16400_state *st = iio_priv(indio_dev);
+ struct mutex *slock = &st->adis.state_lock;
int ret, sps;

switch (info) {
case IIO_CHAN_INFO_CALIBBIAS:
- mutex_lock(&indio_dev->mlock);
ret = adis_write_reg_16(&st->adis,
adis16400_addresses[chan->scan_index], val);
- mutex_unlock(&indio_dev->mlock);
return ret;
case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
/*
* Need to cache values so we can update if the frequency
* changes.
*/
- mutex_lock(&indio_dev->mlock);
+ mutex_lock(slock);
st->filt_int = val;
/* Work out update to current value */
sps = st->variant->get_freq(st);
if (sps < 0) {
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(slock);
return sps;
}

- ret = adis16400_set_filter(indio_dev, sps,
+ ret = __adis16400_set_filter(indio_dev, sps,
val * 1000 + val2 / 1000);
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(slock);
return ret;
case IIO_CHAN_INFO_SAMP_FREQ:
sps = val * 1000 + val2 / 1000;
@@ -540,9 +540,9 @@ static int adis16400_write_raw(struct iio_dev *indio_dev,
if (sps <= 0)
return -EINVAL;

- mutex_lock(&indio_dev->mlock);
+ mutex_lock(slock);
ret = st->variant->set_freq(st, sps);
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(slock);
return ret;
default:
return -EINVAL;
@@ -553,6 +553,7 @@ static int adis16400_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val, int *val2, long info)
{
struct adis16400_state *st = iio_priv(indio_dev);
+ struct mutex *slock = &st->adis.state_lock;
int16_t val16;
int ret;

@@ -596,10 +597,8 @@ static int adis16400_read_raw(struct iio_dev *indio_dev,
return -EINVAL;
}
case IIO_CHAN_INFO_CALIBBIAS:
- mutex_lock(&indio_dev->mlock);
ret = adis_read_reg_16(&st->adis,
adis16400_addresses[chan->scan_index], &val16);
- mutex_unlock(&indio_dev->mlock);
if (ret)
return ret;
val16 = sign_extend32(val16, 11);
@@ -610,27 +609,27 @@ static int adis16400_read_raw(struct iio_dev *indio_dev,
*val = st->variant->temp_offset;
return IIO_VAL_INT;
case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
- mutex_lock(&indio_dev->mlock);
+ mutex_lock(slock);
/* Need both the number of taps and the sampling frequency */
- ret = adis_read_reg_16(&st->adis,
+ ret = __adis_read_reg_16(&st->adis,
ADIS16400_SENS_AVG,
&val16);
if (ret) {
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(slock);
return ret;
}
ret = st->variant->get_freq(st);
- if (ret >= 0) {
- ret /= adis16400_3db_divisors[val16 & 0x07];
- *val = ret / 1000;
- *val2 = (ret % 1000) * 1000;
- }
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(slock);
if (ret)
return ret;
+ ret /= adis16400_3db_divisors[val16 & 0x07];
+ *val = ret / 1000;
+ *val2 = (ret % 1000) * 1000;
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_SAMP_FREQ:
+ mutex_lock(slock);
ret = st->variant->get_freq(st);
+ mutex_unlock(slock);
if (ret)
return ret;
*val = ret / 1000;
--
2.20.1
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