diff options
Diffstat (limited to 'drivers/iio/adc/vf610_adc.c')
| -rw-r--r-- | drivers/iio/adc/vf610_adc.c | 104 |
1 files changed, 62 insertions, 42 deletions
diff --git a/drivers/iio/adc/vf610_adc.c b/drivers/iio/adc/vf610_adc.c index c6b16cf6e367..ae31aafd2653 100644 --- a/drivers/iio/adc/vf610_adc.c +++ b/drivers/iio/adc/vf610_adc.c @@ -7,6 +7,7 @@ #include <linux/mod_devicetable.h> #include <linux/module.h> +#include <linux/mutex.h> #include <linux/property.h> #include <linux/platform_device.h> #include <linux/interrupt.h> @@ -156,6 +157,9 @@ struct vf610_adc { void __iomem *regs; struct clk *clk; + /* lock to protect against multiple access to the device */ + struct mutex lock; + u32 vref_uv; u32 value; struct regulator *vref; @@ -467,11 +471,11 @@ static int vf610_set_conversion_mode(struct iio_dev *indio_dev, { struct vf610_adc *info = iio_priv(indio_dev); - mutex_lock(&indio_dev->mlock); + mutex_lock(&info->lock); info->adc_feature.conv_mode = mode; vf610_adc_calculate_rates(info); vf610_adc_hw_init(info); - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&info->lock); return 0; } @@ -622,6 +626,58 @@ static const struct attribute_group vf610_attribute_group = { .attrs = vf610_attributes, }; +static int vf610_read_sample(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val) +{ + struct vf610_adc *info = iio_priv(indio_dev); + unsigned int hc_cfg; + int ret; + + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; + + mutex_lock(&info->lock); + reinit_completion(&info->completion); + hc_cfg = VF610_ADC_ADCHC(chan->channel); + hc_cfg |= VF610_ADC_AIEN; + writel(hc_cfg, info->regs + VF610_REG_ADC_HC0); + ret = wait_for_completion_interruptible_timeout(&info->completion, + VF610_ADC_TIMEOUT); + if (ret == 0) { + ret = -ETIMEDOUT; + goto out_unlock; + } + + if (ret < 0) + goto out_unlock; + + switch (chan->type) { + case IIO_VOLTAGE: + *val = info->value; + break; + case IIO_TEMP: + /* + * Calculate in degree Celsius times 1000 + * Using the typical sensor slope of 1.84 mV/°C + * and VREFH_ADC at 3.3V, V at 25°C of 699 mV + */ + *val = 25000 - ((int)info->value - VF610_VTEMP25_3V3) * + 1000000 / VF610_TEMP_SLOPE_COEFF; + + break; + default: + ret = -EINVAL; + break; + } + +out_unlock: + mutex_unlock(&info->lock); + iio_device_release_direct_mode(indio_dev); + + return ret; +} + static int vf610_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, @@ -629,53 +685,15 @@ static int vf610_read_raw(struct iio_dev *indio_dev, long mask) { struct vf610_adc *info = iio_priv(indio_dev); - unsigned int hc_cfg; long ret; switch (mask) { case IIO_CHAN_INFO_RAW: case IIO_CHAN_INFO_PROCESSED: - mutex_lock(&indio_dev->mlock); - if (iio_buffer_enabled(indio_dev)) { - mutex_unlock(&indio_dev->mlock); - return -EBUSY; - } - - reinit_completion(&info->completion); - hc_cfg = VF610_ADC_ADCHC(chan->channel); - hc_cfg |= VF610_ADC_AIEN; - writel(hc_cfg, info->regs + VF610_REG_ADC_HC0); - ret = wait_for_completion_interruptible_timeout - (&info->completion, VF610_ADC_TIMEOUT); - if (ret == 0) { - mutex_unlock(&indio_dev->mlock); - return -ETIMEDOUT; - } - if (ret < 0) { - mutex_unlock(&indio_dev->mlock); + ret = vf610_read_sample(indio_dev, chan, val); + if (ret < 0) return ret; - } - switch (chan->type) { - case IIO_VOLTAGE: - *val = info->value; - break; - case IIO_TEMP: - /* - * Calculate in degree Celsius times 1000 - * Using the typical sensor slope of 1.84 mV/°C - * and VREFH_ADC at 3.3V, V at 25°C of 699 mV - */ - *val = 25000 - ((int)info->value - VF610_VTEMP25_3V3) * - 1000000 / VF610_TEMP_SLOPE_COEFF; - - break; - default: - mutex_unlock(&indio_dev->mlock); - return -EINVAL; - } - - mutex_unlock(&indio_dev->mlock); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: @@ -878,6 +896,8 @@ static int vf610_adc_probe(struct platform_device *pdev) goto error_iio_device_register; } + mutex_init(&info->lock); + ret = iio_device_register(indio_dev); if (ret) { dev_err(&pdev->dev, "Couldn't register the device.\n"); |