diff mbox series

[RFC,v3,6/6] iio: adc: meson_saradc: Use regmap_read_poll_timeout() for busy wait

Message ID 20220603100004.70336-6-andriy.shevchenko@linux.intel.com (mailing list archive)
State Accepted
Headers show
Series [v3,1/6] iio: adc: meson_saradc: Don't attach managed resource to IIO device object | expand

Commit Message

Andy Shevchenko June 3, 2022, 10 a.m. UTC 
Simplify busy wait stages by using regmap_read_poll_timeout().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
v3: new patch, but RFC, not always the read_poll_timeout() can be used, would
    be nice to have it tested.

 drivers/iio/adc/meson_saradc.c | 31 +++++++++++++------------------
 1 file changed, 13 insertions(+), 18 deletions(-)

Comments

Martin Blumenstingl June 5, 2022, 9:59 p.m. UTC | #1 
On Fri, Jun 3, 2022 at 12:00 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> Simplify busy wait stages by using regmap_read_poll_timeout().
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

> v3: new patch, but RFC, not always the read_poll_timeout() can be used, would
>     be nice to have it tested.
and also:
Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> # GXM VIM2
Andy Shevchenko June 6, 2022, 10:10 a.m. UTC | #2 
On Sun, Jun 05, 2022 at 11:59:53PM +0200, Martin Blumenstingl wrote:
> On Fri, Jun 3, 2022 at 12:00 PM Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> >
> > Simplify busy wait stages by using regmap_read_poll_timeout().
> >
> > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> 
> > v3: new patch, but RFC, not always the read_poll_timeout() can be used, would
> >     be nice to have it tested.
> and also:
> Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> # GXM VIM2

Thanks for testing!
diff mbox series

Patch

diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c
index c100f933c12e..c18be3c519af 100644
--- a/drivers/iio/adc/meson_saradc.c
+++ b/drivers/iio/adc/meson_saradc.c
@@ -322,22 +322,17 @@  static int meson_sar_adc_calib_val(struct iio_dev *indio_dev, int val)
 static int meson_sar_adc_wait_busy_clear(struct iio_dev *indio_dev)
 {
 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
-	int regval, timeout = 10000;
+	int val;
 
 	/*
 	 * NOTE: we need a small delay before reading the status, otherwise
 	 * the sample engine may not have started internally (which would
 	 * seem to us that sampling is already finished).
 	 */
-	do {
-		udelay(1);
-		regmap_read(priv->regmap, MESON_SAR_ADC_REG0, &regval);
-	} while (FIELD_GET(MESON_SAR_ADC_REG0_BUSY_MASK, regval) && timeout--);
-
-	if (timeout < 0)
-		return -ETIMEDOUT;
-
-	return 0;
+	udelay(1);
+	return regmap_read_poll_timeout_atomic(priv->regmap, MESON_SAR_ADC_REG0, val,
+					       !FIELD_GET(MESON_SAR_ADC_REG0_BUSY_MASK, val),
+					       1, 10000);
 }
 
 static int meson_sar_adc_read_raw_sample(struct iio_dev *indio_dev,
@@ -489,7 +484,7 @@  static void meson_sar_adc_stop_sample_engine(struct iio_dev *indio_dev)
 static int meson_sar_adc_lock(struct iio_dev *indio_dev)
 {
 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
-	int val, timeout = 10000;
+	int val, ret;
 
 	mutex_lock(&indio_dev->mlock);
 
@@ -499,18 +494,18 @@  static int meson_sar_adc_lock(struct iio_dev *indio_dev)
 				   MESON_SAR_ADC_DELAY_KERNEL_BUSY,
 				   MESON_SAR_ADC_DELAY_KERNEL_BUSY);
 
+		udelay(1);
+
 		/*
 		 * wait until BL30 releases it's lock (so we can use the SAR
 		 * ADC)
 		 */
-		do {
-			udelay(1);
-			regmap_read(priv->regmap, MESON_SAR_ADC_DELAY, &val);
-		} while (val & MESON_SAR_ADC_DELAY_BL30_BUSY && timeout--);
-
-		if (timeout < 0) {
+		ret = regmap_read_poll_timeout_atomic(priv->regmap, MESON_SAR_ADC_DELAY, val,
+						      !(val & MESON_SAR_ADC_DELAY_BL30_BUSY),
+						      1, 10000);
+		if (ret) {
 			mutex_unlock(&indio_dev->mlock);
-			return -ETIMEDOUT;
+			return ret;
 		}
 	}