[ Upstream commit 0499942928341d572a42199580433c2b0725211e ] Commit 679875d1d880 ("sc16is7xx: Separate GPIOs from modem control lines") and commit 21144bab4f11 ("sc16is7xx: Handle modem status lines") changed the function of the GPIOs pins to act as modem control lines without any possibility of selecting GPIO function. As a consequence, applications that depends on GPIO lines configured by default as GPIO pins no longer work as expected. Also, the change to select modem control lines function was done only for channel A of dual UART variants (752/762). This was not documented in the log message. Allow to specify GPIO or modem control line function in the device tree, and for each of the ports (A or B). Do so by using the new device-tree property named "nxp,modem-control-line-ports" (property added in separate patch). When registering GPIO chip controller, mask-out GPIO pins declared as modem control lines according to this new DT property. Fixes: 679875d1d880 ("sc16is7xx: Separate GPIOs from modem control lines") Fixes: 21144bab4f11 ("sc16is7xx: Handle modem status lines") Cc: stable@vger.kernel.org Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Lech Perczak <lech.perczak@camlingroup.com> Tested-by: Lech Perczak <lech.perczak@camlingroup.com> Acked-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20230807214556.540627-5-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>