[PATCH v4 07/15] iio: adc: xilinx-xadc: Simplify common coding patterns

[Dileep Kumar Nagavarapu <dileepkumar.nagavarapu@amd.com>]

- Use pointers directly instead of comparing them against NULL.
- Use logical negation instead of comparing bit masks against zero.
- Declare loop counters within the scope of the for() loops.
- Replace the interrupt mask update expression with a
  simpler form that updates only the bits selected by the mask.

The last two items were bundled per Andy Shevchenko's suggestion
during upstream review.

No functional change intended.

Co-developed-by: Sai Krishna Potthuri <sai.krishna.potthuri@amd.com>
Signed-off-by: Sai Krishna Potthuri <sai.krishna.potthuri@amd.com>
Signed-off-by: Dileep Kumar Nagavarapu <dileepkumar.nagavarapu@amd.com>
---
 drivers/iio/adc/xilinx-xadc-core.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/iio/adc/xilinx-xadc-core.c b/drivers/iio/adc/xilinx-xadc-core.c
index 0234c8301c2e..43d3fc46c05f 100644
--- a/drivers/iio/adc/xilinx-xadc-core.c
+++ b/drivers/iio/adc/xilinx-xadc-core.c
@@ -124,9 +124,7 @@ static void xadc_read_reg(struct xadc *xadc, unsigned int reg, u32 *val)
  */
 static void xadc_zynq_write_fifo(struct xadc *xadc, u32 *cmd, unsigned int n)
 {
-	unsigned int i;
-
-	for (i = 0; i < n; i++)
+	for (unsigned int i = 0; i < n; i++)
 		xadc_write_reg(xadc, XADC_ZYNQ_REG_CFIFO, cmd[i]);
 }
 
@@ -144,8 +142,7 @@ static void xadc_zynq_drain_fifo(struct xadc *xadc)
 
 static void xadc_zynq_update_intmsk(struct xadc *xadc, unsigned int mask, unsigned int val)
 {
-	xadc->zynq_intmask &= ~mask;
-	xadc->zynq_intmask |= val;
+	xadc->zynq_intmask = (xadc->zynq_intmask & ~mask) | (val & mask);
 
 	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTMSK, xadc->zynq_intmask | xadc->zynq_masked_alarm);
 }
@@ -653,7 +650,7 @@ static int xadc_trigger_set_state(struct iio_trigger *trigger, bool state)
 
 	if (state) {
 		/* Only one of the two triggers can be active at a time. */
-		if (xadc->trigger != NULL) {
+		if (xadc->trigger) {
 			ret = -EBUSY;
 			goto err_out;
 		} else {
@@ -698,7 +695,7 @@ static struct iio_trigger *xadc_alloc_trigger(struct iio_dev *indio_dev, const c
 
 	trig = devm_iio_trigger_alloc(dev, "%s%d-%s", indio_dev->name,
 				      iio_device_id(indio_dev), name);
-	if (trig == NULL)
+	if (!trig)
 		return ERR_PTR(-ENOMEM);
 
 	trig->ops = &xadc_trigger_ops;
@@ -749,7 +746,7 @@ static int xadc_get_seq_mode(struct xadc *xadc, unsigned long scan_mode)
 	if (xadc->external_mux_mode == XADC_EXTERNAL_MUX_DUAL)
 		return XADC_CONF1_SEQ_SIMULTANEOUS;
 
-	if ((aux_scan_mode & 0xff00) == 0 || (aux_scan_mode & 0x00ff) == 0)
+	if (!(aux_scan_mode & 0xff00) || !(aux_scan_mode & 0x00ff))
 		return XADC_CONF1_SEQ_CONTINUOUS;
 
 	return XADC_CONF1_SEQ_SIMULTANEOUS;
-- 
2.34.1