iio: adc: at91-sama5d2_adc: move the check of oversampling in its function

Oversampling values are checked anyway in at91_adc_emr_config(). Remove
the checking of these from at91_adc_write_raw() and return -EINVAL
instead in at91_adc_emr_config().

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-8-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
index 0283c8c..ace4cc4 100644 (file)
--- a/drivers/iio/adc/at91-sama5d2_adc.c
+++ b/drivers/iio/adc/at91-sama5d2_adc.c
@@ -728,8 +728,8 @@ static void at91_adc_eoc_ena(struct at91_adc_state *st, unsigned int channel)
                at91_adc_writel(st, EOC_IER, BIT(channel));
 }
 
-static void at91_adc_config_emr(struct at91_adc_state *st,
-                               u32 oversampling_ratio)
+static int at91_adc_config_emr(struct at91_adc_state *st,
+                              u32 oversampling_ratio)
 {
        /* configure the extended mode register */
        unsigned int emr = at91_adc_readl(st, EMR);
@@ -755,9 +755,13 @@ static void at91_adc_config_emr(struct at91_adc_state *st,
                emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_16SAMPLES,
                                            osr_mask);
                break;
+       default:
+               return -EINVAL;
        }
 
        at91_adc_writel(st, EMR, emr);
+
+       return 0;
 }
 
 static int at91_adc_adjust_val_osr(struct at91_adc_state *st, int *val)
@@ -1650,9 +1654,6 @@ static int at91_adc_write_raw(struct iio_dev *indio_dev,
 
        switch (mask) {
        case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
-               if ((val != AT91_OSR_1SAMPLES) && (val != AT91_OSR_4SAMPLES) &&
-                   (val != AT91_OSR_16SAMPLES))
-                       return -EINVAL;
                /* if no change, optimize out */
                if (val == st->oversampling_ratio)
                        return 0;
@@ -1661,12 +1662,13 @@ static int at91_adc_write_raw(struct iio_dev *indio_dev,
                if (ret)
                        return ret;
                mutex_lock(&st->lock);
-               st->oversampling_ratio = val;
                /* update ratio */
-               at91_adc_config_emr(st, val);
+               ret = at91_adc_config_emr(st, val);
+               if (!ret)
+                       st->oversampling_ratio = val;
                mutex_unlock(&st->lock);
                iio_device_release_direct_mode(indio_dev);
-               return 0;
+               return ret;
        case IIO_CHAN_INFO_SAMP_FREQ:
                if (val < st->soc_info.min_sample_rate ||
                    val > st->soc_info.max_sample_rate)