From: Stephen Boyd <swboyd@chromium.org>
Date: Wed, 2 Dec 2020 20:02:52 +0000 (-0800)
Subject: iio: sx9310: Fix semtech,avg-pos-strength setting when > 16
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=b8653aff1c8876142f965fc69e12ba217da13182;p=linux.git

iio: sx9310: Fix semtech,avg-pos-strength setting when > 16

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 31. Also use clamp() because we're here.

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>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20201202200252.986230-1-swboyd@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---

diff --git a/drivers/iio/proximity/sx9310.c b/drivers/iio/proximity/sx9310.c
index 62eacb22e9bcb..37fd0b65a0140 100644
--- a/drivers/iio/proximity/sx9310.c
+++ b/drivers/iio/proximity/sx9310.c
@@ -1305,7 +1305,8 @@ sx9310_get_default_reg(struct sx9310_data *data, int i,
 		if (ret)
 			break;
 
-		pos = min(max(ilog2(pos), 3), 10) - 3;
+		/* Powers of 2, except for a gap between 16 and 64 */
+		pos = clamp(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);