diff options
Diffstat (limited to 'drivers/iio/adc/palmas_gpadc.c')
| -rw-r--r-- | drivers/iio/adc/palmas_gpadc.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/drivers/iio/adc/palmas_gpadc.c b/drivers/iio/adc/palmas_gpadc.c index 889b88768b63..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; } @@ -516,8 +523,11 @@ 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); - dev_set_drvdata(&pdev->dev, indio_dev); + platform_set_drvdata(pdev, indio_dev); adc->auto_conversion_period = gpadc_pdata->auto_conversion_period_ms; adc->irq = palmas_irq_get_virq(adc->palmas, PALMAS_GPADC_EOC_SW_IRQ); |