This now works, I think.
So this is a cold-coded attempt to move the TI nspire over to using DRM. It is more or less the last user of the old fbdev driver so it is a noble cause and interesting usecase.
This can be applied on top of a vanilla Torvalds v5.3-rc1 kernel out since sunday.
I do not expect these patches to "just work", I expect them to need some hacking, so someone who is actually working on the hardware will need to step in and fix it up.
It does outline the overall idea of how to do this.
I found no defconfig for nspire in the kernel so I used ARMv4t multi.
Configuring the driver for nspire:
- Disable CONFIG_FB_ARMCLCD - Enable CONFIG_DRM_PL111, CONFIG_DRM_PANEL_SIMPLE
The ARM patch will be merged separately through ARM SoC.
Linus Walleij (4): drm/pl111: Support grayscale drm/panel: simple: Add TI nspire panel bindings drm/panel: simple: Support TI nspire panels ARM: nspire: Move CLCD set-up to device tree
.../bindings/display/panel/ti,nspire.yaml | 36 ++++++ arch/arm/boot/dts/nspire-classic.dtsi | 19 ++- arch/arm/boot/dts/nspire-cx.dts | 18 ++- arch/arm/boot/dts/nspire.dtsi | 10 +- arch/arm/mach-nspire/Makefile | 1 - arch/arm/mach-nspire/clcd.c | 114 ------------------ arch/arm/mach-nspire/clcd.h | 10 -- arch/arm/mach-nspire/nspire.c | 25 ---- drivers/gpu/drm/panel/panel-simple.c | 64 ++++++++++ drivers/gpu/drm/pl111/pl111_display.c | 29 ++++- include/linux/amba/clcd-regs.h | 1 + 11 files changed, 171 insertions(+), 156 deletions(-) create mode 100644 Documentation/devicetree/bindings/display/panel/ti,nspire.yaml delete mode 100644 arch/arm/mach-nspire/clcd.c delete mode 100644 arch/arm/mach-nspire/clcd.h