hwmon: (ads7871) Use DMA-safe buffer for SPI writes

The driver currently passes a stack-allocated buffer to spi_write(),
which is incompatible with DMA on systems with CONFIG_VMAP_STACK
enabled.

Move the transfer buffer into the driver's private data structure
to ensure it is DMA-safe. Since this shared buffer now requires
serialization, this change depends on the previous commit which
migrated the driver to the hwmon 'with_info' API.

While moving the logic, also:
- Corrected the sign extension for 14-bit data by casting to s16.
- Scaled the output to millivolts (2500mV full scale
) to comply with the hwmon ABI.

Signed-off-by: Tabrez Ahmed <tabreztalks@gmail.com>
Link: https://lore.kernel.org/r/20260502020844.110038-4-tabreztalks@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

0 files changed, 0 insertions, 0 deletions