staging:iio:adc:ad7280a: Use bitfield ops to managed fields in transfers.

The write and two types of read transfer are sufficiently complex that
they benefit from the clarity of using FIELD_PREP() and FIELD_GET().
This also applies to the handling in ad7280_event_handler() so
use a similar approach there as well.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Link: https://lore.kernel.org/r/20220206190328.333093-6-jic23@kernel.org

drivers/staging/iio/adc/ad7280a.c

@@ -95,6 +95,23 @@
 #define   AD7280A_READ_ADDR_MSK				GENMASK(7, 2)
 #define AD7280A_CNVST_CTRL_REG			0x1D /* D7 to D0, Read/write */
 
+/* Transfer fields */
+#define AD7280A_TRANS_WRITE_DEVADDR_MSK		GENMASK(31, 27)
+#define AD7280A_TRANS_WRITE_ADDR_MSK		GENMASK(26, 21)
+#define AD7280A_TRANS_WRITE_VAL_MSK		GENMASK(20, 13)
+#define AD7280A_TRANS_WRITE_ALL_MSK		BIT(12)
+#define AD7280A_TRANS_WRITE_CRC_MSK		GENMASK(10, 3)
+#define AD7280A_TRANS_WRITE_RES_PATTERN		0x2
+
+/* Layouts differ for channel vs other registers */
+#define AD7280A_TRANS_READ_DEVADDR_MSK		GENMASK(31, 27)
+#define AD7280A_TRANS_READ_CONV_CHANADDR_MSK	GENMASK(26, 23)
+#define AD7280A_TRANS_READ_CONV_DATA_MSK	GENMASK(22, 11)
+#define AD7280A_TRANS_READ_REG_REGADDR_MSK	GENMASK(26, 21)
+#define AD7280A_TRANS_READ_REG_DATA_MSK		GENMASK(20, 13)
+#define AD7280A_TRANS_READ_WRITE_ACK_MSK	BIT(10)
+#define AD7280A_TRANS_READ_CRC_MSK		GENMASK(9, 2)
+
 /* Magic value used to indicate this special case */
 #define AD7280A_ALL_CELLS				(0xAD << 16)
 
@@ -216,10 +233,16 @@ static int __ad7280_read32(struct ad7280_state *st, unsigned int *val)
 static int ad7280_write(struct ad7280_state *st, unsigned int devaddr,
 			unsigned int addr, bool all, unsigned int val)
 {
-	unsigned int reg = devaddr << 27 | addr << 21 |
-			(val & 0xFF) << 13 | all << 12;
+	unsigned int reg = FIELD_PREP(AD7280A_TRANS_WRITE_DEVADDR_MSK, devaddr) |
+		FIELD_PREP(AD7280A_TRANS_WRITE_ADDR_MSK, addr) |
+		FIELD_PREP(AD7280A_TRANS_WRITE_VAL_MSK, val) |
+		FIELD_PREP(AD7280A_TRANS_WRITE_ALL_MSK, all);
+
+	reg |= FIELD_PREP(AD7280A_TRANS_WRITE_CRC_MSK,
+			ad7280_calc_crc8(st->crc_tab, reg >> 11));
+	/* Reserved b010 pattern not included crc calc */
+	reg |= AD7280A_TRANS_WRITE_RES_PATTERN;
 
-	reg |= ad7280_calc_crc8(st->crc_tab, reg >> 11) << 3 | 0x2;
 	st->tx = cpu_to_be32(reg);
 
 	return spi_write(st->spi, &st->tx, sizeof(st->tx));
@@ -264,10 +287,11 @@ static int ad7280_read_reg(struct ad7280_state *st, unsigned int devaddr,
 	if (ad7280_check_crc(st, tmp))
 		return -EIO;
 
-	if (((tmp >> 27) != devaddr) || (((tmp >> 21) & 0x3F) != addr))
+	if ((FIELD_GET(AD7280A_TRANS_READ_DEVADDR_MSK, tmp) != devaddr) ||
+	    (FIELD_GET(AD7280A_TRANS_READ_REG_REGADDR_MSK, tmp) != addr))
 		return -EFAULT;
 
-	return (tmp >> 13) & 0xFF;
+	return FIELD_GET(AD7280A_TRANS_READ_REG_DATA_MSK, tmp);
 }
 
 static int ad7280_read_channel(struct ad7280_state *st, unsigned int devaddr,
@@ -310,10 +334,11 @@ static int ad7280_read_channel(struct ad7280_state *st, unsigned int devaddr,
 	if (ad7280_check_crc(st, tmp))
 		return -EIO;
 
-	if (((tmp >> 27) != devaddr) || (((tmp >> 23) & 0xF) != addr))
+	if ((FIELD_GET(AD7280A_TRANS_READ_DEVADDR_MSK, tmp) != devaddr) ||
+	    (FIELD_GET(AD7280A_TRANS_READ_CONV_CHANADDR_MSK, tmp) != addr))
 		return -EFAULT;
 
-	return (tmp >> 11) & 0xFFF;
+	return FIELD_GET(AD7280A_TRANS_READ_CONV_DATA_MSK, tmp);
 }
 
 static int ad7280_read_all_channels(struct ad7280_state *st, unsigned int cnt,
@@ -351,8 +376,9 @@ static int ad7280_read_all_channels(struct ad7280_state *st, unsigned int cnt,
 		if (array)
 			array[i] = tmp;
 		/* only sum cell voltages */
-		if (((tmp >> 23) & 0xF) <= AD7280A_CELL_VOLTAGE_6_REG)
-			sum += ((tmp >> 11) & 0xFFF);
+		if (FIELD_GET(AD7280A_TRANS_READ_CONV_CHANADDR_MSK, tmp) <=
+		    AD7280A_CELL_VOLTAGE_6_REG)
+			sum += FIELD_GET(AD7280A_TRANS_READ_CONV_DATA_MSK, tmp);
 	}
 
 	return sum;
@@ -407,7 +433,7 @@ static int ad7280_chain_setup(struct ad7280_state *st)
 			goto error_power_down;
 		}
 
-		if (n != ad7280a_devaddr(val >> 27)) {
+		if (n != ad7280a_devaddr(FIELD_GET(AD7280A_TRANS_READ_DEVADDR_MSK, val))) {
 			ret = -EIO;
 			goto error_power_down;
 		}
@@ -806,17 +832,19 @@ static irqreturn_t ad7280_event_handler(int irq, void *private)
 		goto out;
 
 	for (i = 0; i < st->scan_cnt; i++) {
-		if (((channels[i] >> 23) & 0xF) <= AD7280A_CELL_VOLTAGE_6_REG) {
-			if (((channels[i] >> 11) & 0xFFF) >=
-			    st->cell_threshhigh) {
+		unsigned int val;
+
+		val = FIELD_GET(AD7280A_TRANS_READ_CONV_DATA_MSK, channels[i]);
+		if (FIELD_GET(AD7280A_TRANS_READ_CONV_CHANADDR_MSK, channels[i]) <=
+		    AD7280A_CELL_VOLTAGE_6_REG) {
+			if (val >= st->cell_threshhigh) {
 				u64 tmp = IIO_EVENT_CODE(IIO_VOLTAGE, 1, 0,
 							 IIO_EV_DIR_RISING,
 							 IIO_EV_TYPE_THRESH,
 							 0, 0, 0);
 				iio_push_event(indio_dev, tmp,
 					       iio_get_time_ns(indio_dev));
-			} else if (((channels[i] >> 11) & 0xFFF) <=
-				   st->cell_threshlow) {
+			} else if (val <= st->cell_threshlow) {
 				u64 tmp = IIO_EVENT_CODE(IIO_VOLTAGE, 1, 0,
 							 IIO_EV_DIR_FALLING,
 							 IIO_EV_TYPE_THRESH,
@@ -825,15 +853,13 @@ static irqreturn_t ad7280_event_handler(int irq, void *private)
 					       iio_get_time_ns(indio_dev));
 			}
 		} else {
-			if (((channels[i] >> 11) & 0xFFF) >=
-				st->aux_threshhigh) {
+			if (val >= st->aux_threshhigh) {
 				u64 tmp = IIO_UNMOD_EVENT_CODE(IIO_TEMP, 0,
 							IIO_EV_TYPE_THRESH,
 							IIO_EV_DIR_RISING);
 				iio_push_event(indio_dev, tmp,
 					       iio_get_time_ns(indio_dev));
-			} else if (((channels[i] >> 11) & 0xFFF) <=
-				st->aux_threshlow) {
+			} else if (val <= st->aux_threshlow) {
 				u64 tmp = IIO_UNMOD_EVENT_CODE(IIO_TEMP, 0,
 							IIO_EV_TYPE_THRESH,
 							IIO_EV_DIR_FALLING);