When multiple displays are connected to the same SPI bus, the data/command switch is sometimes considered part of the bus and is shared among the displays.
This series adds the GPIO_FLAGS_BIT_NONEXCLUSIVE flag for this GPIO and SPI bus locking to the panel-mipi-dbi/drm_mipi_dbi drivers to support this hardware setup. Otto Pflüger (2): drm/mipi-dbi: Lock SPI bus before setting D/C GPIO drm/tiny: panel-mipi-dbi: Allow sharing the D/C GPIO drivers/gpu/drm/drm_mipi_dbi.c | 22 +++++++++++++++++----- drivers/gpu/drm/tiny/panel-mipi-dbi.c | 3 ++- include/drm/drm_mipi_dbi.h | 2 +- 3 files changed, 20 insertions(+), 7 deletions(-) -- 2.39.1