iio: temperature: ltc2983: Fix n_wires default bypassing rotation check

When adi,number-of-wires is absent, n_wires is left at 0. The binding
documents a default of 2 wires, matching the hardware default. However
the current-rotate validation checks n_wires == 2 || n_wires == 3, so
with n_wires = 0 the guard is bypassed and adi,current-rotate is accepted
for a 2-wire RTD.

Initialize n_wires = 2 to match the binding default and ensure the
rotation check fires correctly when the property is absent.

Fixes: f110f3188e56 ("iio: temperature: Add support for LTC2983")
Signed-off-by: Liviu Stan <liviu.stan@analog.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/iio/temperature/ltc2983.c b/drivers/iio/temperature/ltc2983.c
index 38e6f8dfd3b808ffa5aff73919de66f85bba2ed5..1f835e326b932a4bf3e7efb62d5589602e8f2a2d 100644 (file)
--- a/drivers/iio/temperature/ltc2983.c
+++ b/drivers/iio/temperature/ltc2983.c
@@ -741,7 +741,7 @@ ltc2983_rtd_new(const struct fwnode_handle *child, struct ltc2983_data *st,
        struct ltc2983_rtd *rtd;
        int ret = 0;
        struct device *dev = &st->spi->dev;
-       u32 excitation_current = 0, n_wires = 0;
+       u32 excitation_current = 0, n_wires = 2;
 
        rtd = devm_kzalloc(dev, sizeof(*rtd), GFP_KERNEL);
        if (!rtd)