[PATCH 13/21] IO: ti_adc: Reset and clear overrun status before capture.

[Zubair Lutfullah <zubair.lutfullah@gmail.com>]

While not pulling out samples, the FIFO will fill up causing an

overrun event. Before starting up another continuous sample, clear that

event.

Signed-off-by: Russ Dill <Russ.Dill@ti.com>
Signed-off-by: Zubair Lutfullah <zubair.lutfullah@gmail.com>
---
 drivers/iio/adc/ti_am335x_adc.c |   24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
index 1e48799..eb47385 100644
--- a/drivers/iio/adc/ti_am335x_adc.c
+++ b/drivers/iio/adc/ti_am335x_adc.c
@@ -250,22 +250,28 @@ static int tiadc_buffer_postenable(struct iio_dev *idev)
 {
         struct tiadc_device *adc_dev = iio_priv(idev);
         struct iio_buffer *buffer = idev->buffer;
-        unsigned int enb, fifo1count;
-        int stepnum, i;
+        unsigned int enb, config;
+        int stepnum;
         u8 bit;
 
         if (!adc_dev->is_continuous_mode) {
                 printk("Data cannot be read continuously in one shot mode\n");
                 return -EINVAL;
         } else {
-                tiadc_writel(adc_dev, REG_IRQENABLE,
-                                (IRQENB_FIFO1THRES |
-                                 IRQENB_FIFO1OVRRUN |
-                                 IRQENB_FIFO1UNDRFLW));
 
-                fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
-                for (i = 0; i < fifo1count; i++)
-                        tiadc_readl(adc_dev, REG_FIFO1);
+                config = tiadc_readl(adc_dev, REG_CTRL);
+                tiadc_writel(adc_dev, REG_CTRL,
+                                        config & ~CNTRLREG_TSCSSENB);
+                tiadc_writel(adc_dev, REG_CTRL,
+                                        config |  CNTRLREG_TSCSSENB);
+
+                tiadc_writel(adc_dev,  REG_IRQSTATUS,
+                                 IRQENB_FIFO1THRES |
+                                 IRQENB_FIFO1OVRRUN |
+                                 IRQENB_FIFO1UNDRFLW);
+                tiadc_writel(adc_dev,  REG_IRQENABLE,
+                                 IRQENB_FIFO1THRES |
+                                 IRQENB_FIFO1OVRRUN);
 
                 tiadc_writel(adc_dev, REG_SE, 0x00);
                 for_each_set_bit(bit, buffer->scan_mask,
-- 
1.7.9.5