[PATCH 5.11 035/601] iio: sx9310: Fix write_.._debounce()

Greg Kroah-Hartman
2021-05-12T16:53:41Z

From: Gwendal Grignou <gwendal@chromium.org>

commit fc948409ccc1e8afe8655cee77c686eedbfbee60 upstream.

Check input to be sure it matches Semtech sx9310 specification and
can fit into debounce register.
Compare argument writen to thresh_.._period with read from same
sysfs attribute:

Before: Afer:
write | read write | read
-1 | 8 -1 fails: -EINVAL
0 | 8 0 | 0
1 | 0 1 | 0
2..15 | 2^log2(N) 2..15 | 2^log2(N)
16 | 0 >= 16 fails: -EINVAL

Fixes: 1b6872015f0b ("iio: sx9310: Support setting debounce values")
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Cc: stable@vger.kernel.org
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20210331182222.219533-1-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/iio/proximity/sx9310.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

--- a/drivers/iio/proximity/sx9310.c
+++ b/drivers/iio/proximity/sx9310.c
@@ -763,7 +763,11 @@ static int sx9310_write_far_debounce(str
int ret;
unsigned int regval;

- val = ilog2(val);
+ if (val > 0)
+ val = ilog2(val);
+ if (!FIELD_FIT(SX9310_REG_PROX_CTRL10_FAR_DEBOUNCE_MASK, val))
+ return -EINVAL;
+
regval = FIELD_PREP(SX9310_REG_PROX_CTRL10_FAR_DEBOUNCE_MASK, val);

mutex_lock(&data->mutex);
@@ -780,7 +784,11 @@ static int sx9310_write_close_debounce(s
int ret;
unsigned int regval;

- val = ilog2(val);
+ if (val > 0)
+ val = ilog2(val);
+ if (!FIELD_FIT(SX9310_REG_PROX_CTRL10_CLOSE_DEBOUNCE_MASK, val))
+ return -EINVAL;
+
regval = FIELD_PREP(SX9310_REG_PROX_CTRL10_CLOSE_DEBOUNCE_MASK, val);

mutex_lock(&data->mutex);