[PATCH v4] staging: iio: ad5933: Correct settling cycles encoding per datasheet

[Gabriel Shahrouzi <gshahrouzi@gmail.com>]

The AD5933 datasheet (Table 13) lists the maximum cycles to be 0x7FC
(2044).

Clamp the user input to the maximum effective value of 0x7FC cycles.

Fixes: f94aa354d676 ("iio: impedance-analyzer: New driver for AD5933/4 Impedance Converter, Network Analyzer")
Cc: stable@vger.kernel.org
Signed-off-by: Gabriel Shahrouzi <gshahrouzi@gmail.com>
---
Changes in v4:
	- Provide clear git body description.
Changes in v3:
	- Only include fix (remove refactoring which will be its own
	  separate patch).
Changes in v2:
        - Fix spacing in comment around '+'.
        - Define mask and values for settling cycle multipliers.
---
 drivers/staging/iio/impedance-analyzer/ad5933.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/iio/impedance-analyzer/ad5933.c b/drivers/staging/iio/impedance-analyzer/ad5933.c
index d5544fc2fe989..f8fcc10ea8150 100644
--- a/drivers/staging/iio/impedance-analyzer/ad5933.c
+++ b/drivers/staging/iio/impedance-analyzer/ad5933.c
@@ -411,7 +411,7 @@ static ssize_t ad5933_store(struct device *dev,
 		ret = ad5933_cmd(st, 0);
 		break;
 	case AD5933_OUT_SETTLING_CYCLES:
-		val = clamp(val, (u16)0, (u16)0x7FF);
+		val = clamp(val, (u16)0, (u16)0x7FC);
 		st->settling_cycles = val;
 
 		/* 2x, 4x handling, see datasheet */
-- 
2.43.0