On Fri, 21 Jul 2023 13:24:19 -0600 Rob Herring robh+dt@kernel.org wrote:
On Fri, Jul 21, 2023 at 10:19 AM Hugo Villeneuve hugo@hugovil.com wrote:
From: Hugo Villeneuve hvilleneuve@dimonoff.com
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.
Requiring a new DT property is not fixing a kernel regression. You should be returning the kernel to original behavior and then have a new DT property for new behavior.
Hi Rob, please read the entire patch history starting from V1 and you will understand why this course of action was not selected.
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 "modem-control-line-ports" (property added in separate patch).
That's not the name in the patch.
We added a "nxp," prefix at some point.
Do you want me to send a V9 only with this change?
Hugo.
When registering GPIO chip controller, mask-out GPIO pins declared as modem control lines according to this new "modem-control-line-ports" DT property.
Boards that need to have GPIOS configured as modem control lines should add that property to their device tree. Here is a list of boards using the sc16is7xx driver in their device tree and that may need to be modified: arm64/boot/dts/freescale/fsl-ls1012a-frdm.dts mips/boot/dts/ingenic/cu1830-neo.dts mips/boot/dts/ingenic/cu1000-neo.dts
Then again, if no one cares about those boards needing a change then it can be okay.
Rob