iio: dac: ti-dac7612: Replace indio_dev->mlock with own device lock

As part of the general cleanup of indio_dev->mlock, this change replaces
it with a local lock on the device's state from potential concurrent write
accesses from userspace. The write operation requires an SPI write, then
toggling of a GPIO, so the lock aims to protect the sanity of the entire
sequence of operation.

This is part of a bigger cleanup.
Link: https://lore.kernel.org/linux-iio/CA+U=Dsoo6YABe5ODLp+eFNPGFDjk5ZeQEceGkqjxXcVEhLWubw@mail.gmail.com/

Signed-off-by: Sergiu Cuciurean <[email protected]>
Signed-off-by: Alexandru Ardelean <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jonathan Cameron <[email protected]>

0 files changed, 0 insertions, 0 deletions