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

diff --git a/drivers/staging/iio/adc/ad7280a.c b/drivers/staging/iio/adc/ad7280a.c
index b169826..0db7ac0 100644 (file)
--- a/drivers/staging/iio/adc/ad7280a.c
+++ b/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);