mfd: ti_am335x_tscadc: Clarify the maximum values for DT entries

Clearly define the maximum open delay and sample delay. Use these
definitions in place of a mask (which works because this is the first
field in the register) and an open-coded value. While at it reword a
little bit the error messages to make them look clearer and similar.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-29-miquel.raynal@bootlin.com

drivers/iio/adc/ti_am335x_adc.c

@@ -126,7 +126,7 @@ static void tiadc_step_config(struct iio_dev *indio_dev)
 		chan = adc_dev->channel_line[i];
 
 		if (adc_dev->step_avg[i] > STEPCONFIG_AVG_16) {
-			dev_warn(dev, "chan %d step_avg truncating to %ld\n",
+			dev_warn(dev, "chan %d: wrong step avg, truncated to %ld\n",
 				 chan, STEPCONFIG_AVG_16);
 			adc_dev->step_avg[i] = STEPCONFIG_AVG_16;
 		}
@@ -147,16 +147,16 @@ static void tiadc_step_config(struct iio_dev *indio_dev)
 				STEPCONFIG_RFP_VREFP |
 				STEPCONFIG_RFM_VREFN);
 
-		if (adc_dev->open_delay[i] > STEPDELAY_OPEN_MASK) {
-			dev_warn(dev, "chan %d open delay truncating to 0x3FFFF\n",
-				 chan);
-			adc_dev->open_delay[i] = STEPDELAY_OPEN_MASK;
+		if (adc_dev->open_delay[i] > STEPCONFIG_MAX_OPENDLY) {
+			dev_warn(dev, "chan %d: wrong open delay, truncated to 0x%lX\n",
+				 chan, STEPCONFIG_MAX_OPENDLY);
+			adc_dev->open_delay[i] = STEPCONFIG_MAX_OPENDLY;
 		}
 
-		if (adc_dev->sample_delay[i] > 0xFF) {
-			dev_warn(dev, "chan %d sample delay truncating to 0xFF\n",
-				 chan);
-			adc_dev->sample_delay[i] = 0xFF;
+		if (adc_dev->sample_delay[i] > STEPCONFIG_MAX_SAMPLE) {
+			dev_warn(dev, "chan %d: wrong sample delay, truncated to 0x%lX\n",
+				 chan, STEPCONFIG_MAX_SAMPLE);
+			adc_dev->sample_delay[i] = STEPCONFIG_MAX_SAMPLE;
 		}
 
 		tiadc_writel(adc_dev, REG_STEPDELAY(steps),

include/linux/mfd/ti_am335x_tscadc.h

@@ -84,7 +84,9 @@
 #define STEPCONFIG_OPENDLY	STEPDELAY_OPEN(0x098)
 #define STEPDELAY_SAMPLE_MASK	GENMASK(31, 24)
 #define STEPDELAY_SAMPLE(val)	FIELD_PREP(STEPDELAY_SAMPLE_MASK, (val))
+#define STEPCONFIG_MAX_OPENDLY	GENMASK(17, 0)
 #define STEPCONFIG_SAMPLEDLY	STEPDELAY_SAMPLE(0)
+#define STEPCONFIG_MAX_SAMPLE	GENMASK(7, 0)
 
 /* Charge Config */
 #define STEPCHARGE_RFP_MASK	GENMASK(14, 12)