LeapPad2 now is working quite well as a retro emulator console

[ceratophyllum]

I got it working!! Fullscreen and buttons.

I used debugfs on the stock rom to figure out where the GPIOs are mapped. There was a little more to it than just finding them, but anyway here's my uImage:

https://mega.nz/#!GAgQVSCY!Gg6JeCnS7W6v2...YBbN4726TY



You can flash it the same way as mac2612's original version; all I changed was the uImage so only retroarch is installed in rootfs.




I'm not sure about the code you quoted; after mounting debugfs, this is what I found running the stock kernel :

>mount -t debugfs none /sys/kernel/debug
>cat /sys/kernel/debug/gpio

GPIOs 0-87, lf2000_virtual_gpio:

GPIOs 2048-2175, lf2000_physical_gpio:
 
gpio-2057 (hi253-front clock en) out hi
 gpio-2058 (hi253-front enable  ) out hi
 gpio-2059 (hi253-front reset   ) out hi
 gpio-2060 (hi253-rear reset    ) out hi
 gpio-2061 (Volume Down         ) in  hi irq-93 edge-both
 gpio-2062 (Volume Up           ) in  hi irq-94 edge-both
 gpio-2079 (hi253-rear clock ena) out hi
 gpio-2114 (hi253-rear enable   ) out hi
 gpio-2127 (TS_Y2               ) out lo
 gpio-2128 (TS_X2               ) in  hi
 gpio-2129 (TS_Y1               ) out lo
 gpio-2130 (TS_X1               ) in  hi
 gpio-2133 (Headphone Jack      ) in  lo irq-165 edge-both
 gpio-2136 (Cartridge Detect    ) in  hi
 gpio-2153 (DPAD Left           ) in  hi irq-185 edge-both
 gpio-2154 (DPAD Right          ) in  hi irq-186 edge-both
 gpio-2155 (Escape Button       ) in  hi irq-187 edge-both
 gpio-2157 (DPAD Down           ) in  hi irq-189 edge-both
 gpio-2158 (LFP100 INT          ) in  hi irq-190 edge-falling
 gpio-2159 (DPAD Up             ) in  hi irq-191 edge-both


For example,

DPAD Left 2153 translates to


LF2000_GPIO_PORT_D | 9


Work:
2153 -2048 = 105


105 -96 = 9


(A starts at 2048 +0, B at 2048+32, C at 2048+64, D at 2048 +96 )


Yay! Now I can play retroarch at the crazy resolution of 480x272 without enough buttons.  Hmm GBA might not look too bad....