iio: dac: ds4424: reject -128 RAW value

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commit 5187e03b81 upstream.

The DS442x DAC uses sign-magnitude encoding, so -128 cannot be represented
in hardware (7-bit magnitude).

Previously, passing -128 resulted in a truncated value that programmed
0mA (magnitude 0) instead of the expected maximum negative current,
effectively failing silently.

Reject -128 to avoid producing the wrong current.

Fixes: d632a2bd8f ("iio: dac: ds4422/ds4424 dac driver")
Cc: stable@vger.kernel.org
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

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Oleksij Rempel 2026-02-04 15:00:33 +01:00 • committed by Greg Kroah-Hartman

parent 014a021075

commit 1b2d9e2345

1 changed files with 1 additions and 1 deletions

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drivers/iio/dac/ds4424.c

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