[PATCH v2] iio: sx9310: Fix semtech,avg-pos-strength setting when > 16

[Stephen Boyd <swboyd@chromium.org>]

This DT property can be 0, 16, and then 64, but not 32. The math here
doesn't recognize this slight bump in the power of 2 numbers and
translates a DT property of 64 into the register value '3' when it
really should be '2'. Fix it by subtracting one more if the number being
translated is larger than 16.

Cc: Daniel Campello <campello@chromium.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Gwendal Grignou <gwendal@chromium.org>
Cc: Evan Green <evgreen@chromium.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---

Changes from v1 (https://lore.kernel.org/r/20201120073842.3232458-1-swboyd@chromium.org):
 * Changed ternary to consider 17 to 31 as the same as 16

 drivers/iio/proximity/sx9310.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/proximity/sx9310.c b/drivers/iio/proximity/sx9310.c
index a2f820997afc..ee1b4ff05a37 100644
--- a/drivers/iio/proximity/sx9310.c
+++ b/drivers/iio/proximity/sx9310.c
@@ -1305,7 +1305,7 @@ sx9310_get_default_reg(struct sx9310_data *data, int i,
 		if (ret)
 			break;
 
-		pos = min(max(ilog2(pos), 3), 10) - 3;
+		pos = min(max(ilog2(pos), 3), 11) - (pos >= 32 ? 4 : 3);
 		reg_def->def &= ~SX9310_REG_PROX_CTRL7_AVGPOSFILT_MASK;
 		reg_def->def |= FIELD_PREP(SX9310_REG_PROX_CTRL7_AVGPOSFILT_MASK,
 					   pos);

base-commit: 5b19ca2c78a0838976064c0347e46a2c859b541d
-- 
https://chromeos.dev