This device operates in DIRECT_MODE and BUFFER_HARDWARE mode.
Replace usages of iio_dev->mlock with iio_device_{claim|release}_direct_mode()
helper functions to guarantee DIRECT mode and consequently protect
BUFFER mode too.
Add and use a device private lock to protect against conflicting access of the
state data.
This helps with IIO subsystem redefining iio_dev->mlock to be used by
the IIO core only for protecting device operating mode changes.
ie. Changes between INDIO_DIRECT_MODE, INDIO_BUFFER_* modes.
Protect changing of attributes inside ad5933_store(). Attributes
can no longer be changed while in buffered mode.
Remove lock from ad5933_work() because buffer mode should be enabled
when we reach this, and claiming DIRECT mode in all the other places
should protect it.
Signed-off-by: Narcisa Ana Maria Vasile <narcisaanamaria12@xxxxxxxxx>
---
Changes in v2:
- Make the commit message clearer
drivers/staging/iio/impedance-analyzer/ad5933.c | 50 ++++++++++++++-----------
1 file changed, 28 insertions(+), 22 deletions(-)
diff --git a/drivers/staging/iio/impedance-analyzer/ad5933.c b/drivers/staging/iio/impedance-analyzer/ad5933.c
index 297665d..3d539ee 100644
--- a/drivers/staging/iio/impedance-analyzer/ad5933.c
+++ b/drivers/staging/iio/impedance-analyzer/ad5933.c
@@ -98,6 +98,7 @@ struct ad5933_state {
struct i2c_client *client;
struct regulator *reg;
struct delayed_work work;
+ struct mutex lock; /* Protect sensor state */
unsigned long mclk_hz;
unsigned char ctrl_hb;
unsigned char ctrl_lb;
@@ -306,9 +307,11 @@ static ssize_t ad5933_show_frequency(struct device *dev,
u8 d8[4];
} dat;
- mutex_lock(&indio_dev->mlock);
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
ret = ad5933_i2c_read(st->client, this_attr->address, 3, &dat.d8[1]);
- mutex_unlock(&indio_dev->mlock);
+ iio_device_release_direct_mode(indio_dev);
if (ret < 0)
return ret;
@@ -338,9 +341,11 @@ static ssize_t ad5933_store_frequency(struct device *dev,
if (val > AD5933_MAX_OUTPUT_FREQ_Hz)
return -EINVAL;
- mutex_lock(&indio_dev->mlock);
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
ret = ad5933_set_freq(st, this_attr->address, val);
- mutex_unlock(&indio_dev->mlock);
+ iio_device_release_direct_mode(indio_dev);
return ret ? ret : len;
}
@@ -364,7 +369,7 @@ static ssize_t ad5933_show(struct device *dev,
struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
int ret = 0, len = 0;
- mutex_lock(&indio_dev->mlock);
+ mutex_lock(&st->lock);
switch ((u32)this_attr->address) {
case AD5933_OUT_RANGE:
len = sprintf(buf, "%u\n",
@@ -393,7 +398,7 @@ static ssize_t ad5933_show(struct device *dev,
ret = -EINVAL;
}
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&st->lock);
return ret ? ret : len;
}
@@ -415,7 +420,10 @@ static ssize_t ad5933_store(struct device *dev,
return ret;
}
- mutex_lock(&indio_dev->mlock);
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+ mutex_lock(&st->lock);
switch ((u32)this_attr->address) {
case AD5933_OUT_RANGE:
ret = -EINVAL;
@@ -465,7 +473,8 @@ static ssize_t ad5933_store(struct device *dev,
ret = -EINVAL;
}
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&st->lock);
+ iio_device_release_direct_mode(indio_dev);
return ret ? ret : len;
}
@@ -532,11 +541,9 @@ static int ad5933_read_raw(struct iio_dev *indio_dev,
switch (m) {
case IIO_CHAN_INFO_RAW:
- mutex_lock(&indio_dev->mlock);
- if (iio_buffer_enabled(indio_dev)) {
- ret = -EBUSY;
- goto out;
- }
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
ret = ad5933_cmd(st, AD5933_CTRL_MEASURE_TEMP);
if (ret < 0)
goto out;
@@ -549,7 +556,7 @@ static int ad5933_read_raw(struct iio_dev *indio_dev,
2, (u8 *)&dat);
if (ret < 0)
goto out;
- mutex_unlock(&indio_dev->mlock);
+ iio_device_release_direct_mode(indio_dev);
*val = sign_extend32(be16_to_cpu(dat), 13);
return IIO_VAL_INT;
@@ -561,7 +568,7 @@ static int ad5933_read_raw(struct iio_dev *indio_dev,
return -EINVAL;
out:
- mutex_unlock(&indio_dev->mlock);
+ iio_device_release_direct_mode(indio_dev);
return ret;
}
@@ -657,18 +664,17 @@ static void ad5933_work(struct work_struct *work)
unsigned char status;
int ret;
- mutex_lock(&indio_dev->mlock);
if (st->state == AD5933_CTRL_INIT_START_FREQ) {
/* start sweep */
ad5933_cmd(st, AD5933_CTRL_START_SWEEP);
st->state = AD5933_CTRL_START_SWEEP;
schedule_delayed_work(&st->work, st->poll_time_jiffies);
- goto out;
+ return;
}
ret = ad5933_i2c_read(st->client, AD5933_REG_STATUS, 1, &status);
if (ret)
- goto out;
+ return;
if (status & AD5933_STAT_DATA_VALID) {
int scan_count = bitmap_weight(indio_dev->active_scan_mask,
@@ -678,7 +684,7 @@ static void ad5933_work(struct work_struct *work)
AD5933_REG_REAL_DATA : AD5933_REG_IMAG_DATA,
scan_count * 2, (u8 *)buf);
if (ret)
- goto out;
+ return;
if (scan_count == 2) {
val[0] = be16_to_cpu(buf[0]);
@@ -690,7 +696,7 @@ static void ad5933_work(struct work_struct *work)
} else {
/* no data available - try again later */
schedule_delayed_work(&st->work, st->poll_time_jiffies);
- goto out;
+ return;
}
if (status & AD5933_STAT_SWEEP_DONE) {
@@ -703,8 +709,6 @@ static void ad5933_work(struct work_struct *work)
ad5933_cmd(st, AD5933_CTRL_INC_FREQ);
schedule_delayed_work(&st->work, st->poll_time_jiffies);
}
-out:
- mutex_unlock(&indio_dev->mlock);
}
static int ad5933_probe(struct i2c_client *client,
@@ -723,6 +727,8 @@ static int ad5933_probe(struct i2c_client *client,
i2c_set_clientdata(client, indio_dev);
st->client = client;
+ mutex_init(&st->lock);
+
if (!pdata)
pdata = &ad5933_default_pdata;
--
1.9.1
--
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