iio: adc: meson_saradc: Use regmap_read_poll_timeout() for busy wait

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>
Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> # GXM VIM2
Link: https://lore.kernel.org/r/20220603100004.70336-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c
index c100f93..c18be3c 100644 (file)
--- 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;
                }
        }