With the growing popularity of running upstream Linux on mobile devices, we're beginning to run into more and more edgecases. The OnePlus 6 is a fairly well supported 2018 era smartphone, selling over a million units in it's first 22 days. With this level of popularity, it's almost inevitable that we get third party replacement displays, and as a result, replacement touchscreen controllers. The OnePlus 6 shipped with an extremely usecase specific touchscreen driver, it implemented only the bare minimum parts of the highly generic rmi4 protocol, instead hardcoding most of the register addresses. As a result, the third party touchscreen controllers that are often found in replacement screens, implement only the registers that the downstream driver reads from. They additionally have other restrictions such as heavy penalties on unaligned reads. This series attempts to implement the necessary workaround to support some of these chips with the rmi4 driver. Although it's worth noting that at the time of writing there are other unofficial controllers in the wild that don't work even with these patches. We have been shipping these patches in postmarketOS for the last several months, and they are known to not cause any regressions on the OnePlus 6/6T (with the official Synaptics controller), however I don't own any other rmi4 hardware to further validate this. These patches were contributed by a community developer who has given permission for me to submit them on their behalf. --- To: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> To: Vincent Huang <vincent.huang@xxxxxxxxxxxxxxxx> Cc: methanal <baclofen@xxxxxxx> Cc: linux-input@xxxxxxxxxxxxxxx Cc: devicetree@xxxxxxxxxxxxxxx Cc: phone-devel@xxxxxxxxxxxxxxx Cc: ~postmarketos/upstreaming@xxxxxxxxxxx --- Changes since v1: - Improve dt-bindings patch (thanks Rob) - Add missing cast in patch 5 to fix the pointer arithmetic - Link to v1: https://lore.kernel.org/r/20230929-caleb-rmi4-quirks-v1-0-cc3c703f022d@xxxxxxxxxx --- Caleb Connolly (2): dt-bindings: input: syna,rmi4: document syna,pdt-fallback-desc Input: synaptics-rmi4 - handle duplicate/unknown PDT entries methanal (5): Input: synaptics-rmi4 - f12: use hardcoded values for aftermarket touch ICs Input: synaptics-rmi4 - f55: handle zero electrode count Input: synaptics-rmi4 - don't do unaligned reads in IRQ context Input: synaptics-rmi4 - read product ID on aftermarket touch ICs Input: synaptics-rmi4 - support fallback values for PDT descriptor bytes .../devicetree/bindings/input/syna,rmi4.yaml | 15 +++ drivers/input/rmi4/rmi_driver.c | 134 ++++++++++++++++++--- drivers/input/rmi4/rmi_driver.h | 8 ++ drivers/input/rmi4/rmi_f01.c | 14 +++ drivers/input/rmi4/rmi_f12.c | 117 ++++++++++++++---- drivers/input/rmi4/rmi_f55.c | 5 + include/linux/rmi.h | 3 + 7 files changed, 252 insertions(+), 44 deletions(-) --- base-commit: b0d95ff7653ef6ace66a24d6c09147d0731825ce // Caleb (they/them)
