Re: [PATCH 4/4] iio: ti_am335x_adc: Add continuous sampling and trigger support

[Sebastian Andrzej Siewior <bigeasy-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>]

* Zubair Lutfullah | 2013-08-13 21:05:03 [+0100]:

>diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
>index 3ceac3e..0d7e313 100644
>--- a/drivers/iio/adc/ti_am335x_adc.c
>+++ b/drivers/iio/adc/ti_am335x_adc.c
>@@ -24,16 +24,28 @@
…
>+static irqreturn_t tiadc_irq(int irq, void *private)
>+{
>+	struct iio_dev *idev = private;
>+	struct tiadc_device *adc_dev = iio_priv(idev);
>+	unsigned int status, config;
>+	status = tiadc_readl(adc_dev, REG_IRQSTATUS);
>+
>+	/* FIFO Overrun. Clear flag. Disable/Enable ADC to recover */
>+	if (status & IRQENB_FIFO1OVRRUN) {
>+		config = tiadc_readl(adc_dev, REG_CTRL);
>+		config &= ~(CNTRLREG_TSCSSENB);
>+		tiadc_writel(adc_dev, REG_CTRL, config);
>+		tiadc_writel(adc_dev, REG_IRQSTATUS, IRQENB_FIFO1OVRRUN |
>+				IRQENB_FIFO1UNDRFLW | IRQENB_FIFO1THRES);
>+		tiadc_writel(adc_dev, REG_CTRL, (config | CNTRLREG_TSCSSENB));

I have no idea how other handle this but shouldn't you somehow inform
*anyone* that you lost some samples due to this overrun?

>+	} else if (status & IRQENB_FIFO1THRES) {
>+		/* Wake adc_work that pushes FIFO data to iio buffer */
>+		tiadc_writel(adc_dev, REG_IRQCLR, IRQENB_FIFO1THRES);
>+		adc_dev->data_avail = 1;
>+		wake_up_interruptible(&adc_dev->wq_data_avail);
>+	} else
>+		return IRQ_NONE;

Sebastian