> -----Original Message----- > From: Michael Welling [mailto:mwelling79@xxxxxxxxx] On Behalf > Of Michael Welling > Sent: Tuesday, August 18, 2015 3:31 PM > To: Greg Wilson-Lindberg > Cc: Daniel Baluta; linux-iio@xxxxxxxxxxxxxxx > Subject: Re: BBB IIO ADC access not working > > On Tue, Aug 18, 2015 at 03:11:13PM -0700, Greg Wilson-Lindberg wrote: > > > > > > > I found that handling the IRQENB_EOS interrupt in the ADC > is causing > > > an undesired effect. After enabling the ADC buffer mode and > > > disabling it the coordinate readings work but the touch > release is > > > no longer detected. > > > > Can we put your code in the touch screen handler? The tsc > code is writing to the IRQSTATUS register, not the IRQCLR register. > > > > Actually using the IRQCLR disables the IRQ instead of > clearing it and that was not my intent. This is why the pen > releases where not working, the tsc driver relies on the EOS > interrupt to write the step register because it is using a > one shot hardware mode. > > Since the IRQENB_EOS is not used by the ADC driver it can be > disabled when in buffered mode which is triggering faster > than the isr can handle it. > > See patch below. > > Though it allows for the repeated enabling and disabling of > the buffer the touchscreen gets a bunch of unexpected > releases and the readings are very jittery. > > diff --git a/drivers/iio/adc/ti_am335x_adc.c > b/drivers/iio/adc/ti_am335x_adc.c index a0e7161..9945e4a 100644 > --- a/drivers/iio/adc/ti_am335x_adc.c > +++ b/drivers/iio/adc/ti_am335x_adc.c > @@ -177,6 +177,7 @@ static int tiadc_buffer_preenable(struct > iio_dev *indio_dev) > IRQENB_FIFO1OVRRUN | > IRQENB_FIFO1UNDRFLW)); > > + tiadc_writel(adc_dev, REG_IRQCLR, IRQENB_EOS); > /* Flush FIFO. Needed in corner cases in simultaneous > tsc/adc use */ > fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT); > for (i = 0; i < fifo1count; i++) > @@ -213,6 +214,7 @@ static int tiadc_buffer_predisable(struct > iio_dev *indio_dev) > > tiadc_writel(adc_dev, REG_IRQCLR, (IRQENB_FIFO1THRES | > IRQENB_FIFO1OVRRUN | > IRQENB_FIFO1UNDRFLW)); > + tiadc_writel(adc_dev, REG_IRQENABLE, IRQENB_EOS); > am335x_tsc_se_clr(adc_dev->mfd_tscadc, > adc_dev->buffer_en_ch_steps); > adc_dev->buffer_en_ch_steps = 0; > > I'm not sure that it's better, but it is different. The touch screen still locks up, but mouse clicks work. > > > -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
