diff options
Diffstat (limited to 'drivers/iio/adc')
| -rw-r--r-- | drivers/iio/adc/ti_am335x_adc.c | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c index 1cc2efbb2875..0a4d66a541ed 100644 --- a/drivers/iio/adc/ti_am335x_adc.c +++ b/drivers/iio/adc/ti_am335x_adc.c @@ -25,6 +25,7 @@ #include <linux/of_device.h> #include <linux/iio/machine.h> #include <linux/iio/driver.h> +#include <linux/iopoll.h> #include <linux/mfd/ti_am335x_tscadc.h> #include <linux/iio/buffer.h> @@ -102,6 +103,15 @@ static u32 get_adc_step_bit(struct tiadc_device *adc_dev, int chan) return 1 << adc_dev->channel_step[chan]; } +static int tiadc_wait_idle(struct tiadc_device *adc_dev) +{ + u32 val; + + return readl_poll_timeout(adc_dev->mfd_tscadc->tscadc_base + REG_ADCFSM, + val, !(val & SEQ_STATUS), 10, + IDLE_TIMEOUT * 1000 * adc_dev->channels); +} + static void tiadc_step_config(struct iio_dev *indio_dev) { struct tiadc_device *adc_dev = iio_priv(indio_dev); @@ -295,6 +305,11 @@ static int tiadc_buffer_preenable(struct iio_dev *indio_dev) { struct tiadc_device *adc_dev = iio_priv(indio_dev); int i, fifo1count; + int ret; + + ret = tiadc_wait_idle(adc_dev); + if (ret) + return ret; tiadc_writel(adc_dev, REG_IRQCLR, (IRQENB_FIFO1THRES | IRQENB_FIFO1OVRRUN | @@ -446,12 +461,12 @@ static int tiadc_read_raw(struct iio_dev *indio_dev, int *val, int *val2, long mask) { struct tiadc_device *adc_dev = iio_priv(indio_dev); - int ret = IIO_VAL_INT; int i, map_val; unsigned int fifo1count, read, stepid; bool found = false; u32 step_en; unsigned long timeout; + int ret; if (iio_buffer_enabled(indio_dev)) return -EBUSY; @@ -461,6 +476,11 @@ static int tiadc_read_raw(struct iio_dev *indio_dev, return -EINVAL; mutex_lock(&adc_dev->fifo1_lock); + + ret = tiadc_wait_idle(adc_dev); + if (ret) + goto err_unlock; + fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT); while (fifo1count--) tiadc_readl(adc_dev, REG_FIFO1); @@ -508,7 +528,7 @@ static int tiadc_read_raw(struct iio_dev *indio_dev, err_unlock: mutex_unlock(&adc_dev->fifo1_lock); - return ret; + return ret ? ret : IIO_VAL_INT; } static const struct iio_info tiadc_info = { |