spi: qcom-geni: Use GPIO to notify master of SPI target activity

When operating in SPI target mode, the GENI controller relies on an
external GPIO to notify the SPI master about the target's active state.

Add support for an optional ready GPIO that is asserted when a target
transfer begins and deasserted when the transfer completes, is aborted,
or hits a timeout. This allows the target to explicitly signal its
availability to the master and ensures the GPIO is released in all error
and completion paths, preventing the master from observing a stale or
incorrect target-ready indication.

The ready GPIO is intentionally made optional and is requested only
when target mode is enabled. This preserves existing behaviour for
systems that do not require the signal and avoids regressions on
deployed platforms where the GPIO is already controlled from userspace.
Targets without a ready GPIO continue to operate unchanged by using
devm_gpiod_get_optional().

Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
Link: https://patch.msgid.link/20260927-use_gpio_to_notify_master_of_spi_target_activity-v5-2-9b973623080f@oss.qualcomm.com
Signed-off-by: Mark Brown <broonie@kernel.org>

0 files changed, 0 insertions, 0 deletions