iio: adc: ti-ads7950: use spi_optimize_message()

Use spi_optimize_message() to reduce CPU usage during buffered reads.

On hardware with support for SPI_CS_WORD, this reduced the CPU usage
of the threaded interrupt by about 5%. On hardware without support, this
should reduce CPU usage even more since it won't have to split the SPI
transfers each time the interrupt handler is called.

The .update_scan_mode() callback hand to be moved to the buffer preenable
callback since the SPI transfer mode can't be changed after
spi_optimize_message() has been called. (The buffer postenable callback
can't be used because it happens after the trigger is enabled, so the
SPI message needs to be optimized before that.)

The indent of the pointer to ti_ads7950_read_raw() in the assignment
is changed since there is no longer anything else in the struct to
align with since removal of use of the pointer to
ti_ads7950_update_scan_mode().

Signed-off-by: David Lechner <dlechner@baylibre.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

0 files changed, 0 insertions, 0 deletions