view doc/C139-notes @ 72:7bf39f5e834d

backlight control on Luna: switch PWL instead of LEDB This change is preliminary toward upcoming rework of backlight control logic in our UI firmware. LEDB does not exist on Tango-based platforms (it is not brought out on Tango modules), thus turning it on and off produces absolutely no effect beyond making L1 disable deep sleep when LEDB is turned on. However, both iWOW DSK and our upcoming FC Caramel2 boards have a PWL LED, so let's switch that LED on and off to indicate the state of the UI firmware's backlight control. Note that we are NOT switching the actual Luna LCD backlight here, even though it is trivially controlled with a GPIO. The reason for this seemingly strange choice is that we don't want to turn this development board LCD backlight off until we bring the higher-level backlight control logic up to par, including new logic to "swallow" the first keypress that turns on the darkened LCD.
author Mychaela Falconia <falcon@freecalypso.org>
date Sat, 24 Oct 2020 07:39:54 +0000
parents a62e5bf88434
children
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FC Tourmaline firmware differs from Magnetite in two principal ways when it
comes to Mot C139 target support:

* C139 LCD support is implemented in a more forward-looking manner: instead of
  emulating TI's C-Sample at the lowest R2D driver level and therefore being
  forever limited to 84x48 pixel display size, Tourmaline implements a new
  96x64 pixel framebuffer, matching the native LCD size of C1xx phones.  The UI
  configuration is still black&white only though - the Mother of FreeCalypso
  has no current plans to support color UI on smaller LCD sizes than TI's
  original 176x220 pix.

* Our aftermarket FFS configuration has been changed from 64x3 at 0x3C0000 to
  64x7 at 0x300000.  Our earlier 64x3 config was chosen back in 2015, at that
  time we didn't know how much room we would end up needing for the firmware
  image vs. how much FFS content we would eventually have, and this 64x3 config
  is now deemed to be too small, allowing only one 64 KiB sector for FFS
  content.  Our new FC Tourmaline aftermarket FFS config supports up to 320 KiB
  of FFS content, matches what we use on other platforms with 4 MiB flash chips,
  leaves 3 MiB for the firmware image (our current smallbw UI fw is only 2 MiB),
  and still avoids intersection with Motorola's (or rather Compal's) original
  FFS, which is important for avoiding problems in converting C139 phones back
  and forth between Motorola and FreeCalypso firmwares.