[PATCH] staging: iio: frequency: ad9832/ad9834: use div64_ul instead of do_div

[Mohamad Raizudeen]

Coccinelle warns that do_div() should not be used when the divisor is an unsigned long, because do_div() expects a 32-bit divisor.

In this case, the 'mclk' divisor is an 'unsigned long', which can be 64-bit on certain architectures. The correct function to use here is div64_ul().

Because do_div() modifies the dividend in place, while div64_ul() returns the result, the code was updated to directly return the result of div64_ul. This keeps the math exactly the same but fixes the warning and makes the code safer.

Signed-off-by: Mohamad Raizudeen <raizudeen.kerneldev@xxxxxxxxx>
---
 drivers/staging/iio/frequency/ad9832.c | 3 +--
 drivers/staging/iio/frequency/ad9834.c | 3 +--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/iio/frequency/ad9832.c b/drivers/staging/iio/frequency/ad9832.c
index b87ea1781b27..91df7ee65bfc 100644
--- a/drivers/staging/iio/frequency/ad9832.c
+++ b/drivers/staging/iio/frequency/ad9832.c
@@ -115,8 +115,7 @@ static unsigned long ad9832_calc_freqreg(unsigned long mclk, unsigned long fout)
 {
 	unsigned long long freqreg = (u64)fout *
 				     (u64)((u64)1L << AD9832_FREQ_BITS);
-	do_div(freqreg, mclk);
-	return freqreg;
+	return div64_ul(freqreg, mclk);
 }
 
 static int ad9832_write_frequency(struct ad9832_state *st,
diff --git a/drivers/staging/iio/frequency/ad9834.c b/drivers/staging/iio/frequency/ad9834.c
index bdb2580e29bf..70b310488237 100644
--- a/drivers/staging/iio/frequency/ad9834.c
+++ b/drivers/staging/iio/frequency/ad9834.c
@@ -101,8 +101,7 @@ static unsigned int ad9834_calc_freqreg(unsigned long mclk, unsigned long fout)
 {
 	unsigned long long freqreg = (u64)fout * (u64)BIT(AD9834_FREQ_BITS);
 
-	do_div(freqreg, mclk);
-	return freqreg;
+	return div64_ul(freqreg, mclk);
 }
 
 static int ad9834_write_frequency(struct ad9834_state *st,
-- 
2.53.0