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| author | Sergiu Cuciurean <sergiu.cuciurean@analog.com> | 2020-09-28 16:13:30 +0300 |
|---|---|---|
| committer | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2021-03-25 22:13:49 +0300 |
| commit | 3a27d11fbf58e7b29930376b0b869882c780dd5b (patch) | |
| tree | 9a23c09537156c53ae682832f6a92e2eca9e449b | |
| parent | 31e2d42a86201d32c345bebd4d324b8d8424f4c2 (diff) | |
| download | linux-3a27d11fbf58e7b29930376b0b869882c780dd5b.tar.xz | |
iio: adc: palmas_gpadc: Replace indio_dev->mlock with own device lock
As part of the general cleanup of indio_dev->mlock, this change replaces
it with a local lock on the device's state structure.
This is part of a bigger cleanup.
Link: https://lore.kernel.org/linux-iio/CA+U=Dsoo6YABe5ODLp+eFNPGFDjk5ZeQEceGkqjxXcVEhLWubw@mail.gmail.com/
Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
Signed-off-by: Mircea Caprioru <mircea.caprioru@analog.com>
Link: https://lore.kernel.org/r/20200928131333.36646-2-mircea.caprioru@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
| -rw-r--r-- | drivers/iio/adc/palmas_gpadc.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/drivers/iio/adc/palmas_gpadc.c b/drivers/iio/adc/palmas_gpadc.c index 9ae0d7f73155..6ef09609be9f 100644 --- a/drivers/iio/adc/palmas_gpadc.c +++ b/drivers/iio/adc/palmas_gpadc.c @@ -90,6 +90,12 @@ static struct palmas_gpadc_info palmas_gpadc_info[] = { * 3: 800 uA * @extended_delay: enable the gpadc extended delay mode * @auto_conversion_period: define the auto_conversion_period + * @lock: Lock to protect the device state during a potential concurrent + * read access from userspace. Reading a raw value requires a sequence + * of register writes, then a wait for a completion callback, + * and finally a register read, during which userspace could issue + * another read request. This lock protects a read access from + * ocurring before another one has finished. * * This is the palmas_gpadc structure to store run-time information * and pointers for this driver instance. @@ -110,6 +116,7 @@ struct palmas_gpadc { bool wakeup1_enable; bool wakeup2_enable; int auto_conversion_period; + struct mutex lock; }; /* @@ -388,7 +395,7 @@ static int palmas_gpadc_read_raw(struct iio_dev *indio_dev, if (adc_chan > PALMAS_ADC_CH_MAX) return -EINVAL; - mutex_lock(&indio_dev->mlock); + mutex_lock(&adc->lock); switch (mask) { case IIO_CHAN_INFO_RAW: @@ -414,12 +421,12 @@ static int palmas_gpadc_read_raw(struct iio_dev *indio_dev, goto out; } - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&adc->lock); return ret; out: palmas_gpadc_read_done(adc, adc_chan); - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&adc->lock); return ret; } @@ -516,6 +523,9 @@ static int palmas_gpadc_probe(struct platform_device *pdev) adc->dev = &pdev->dev; adc->palmas = dev_get_drvdata(pdev->dev.parent); adc->adc_info = palmas_gpadc_info; + + mutex_init(&adc->lock); + init_completion(&adc->conv_completion); platform_set_drvdata(pdev, indio_dev); |