[PATCH v4 00/32] Make charlcd device independent

[poeschel]

From: Lars Poeschel <poeschel@xxxxxxxxxxx>

This tries to make charlcd device independent. At the moment hd44780
device specific code is contained deep in charlcd. This moves this out
into a hd44780_common module, where the two hd44780 drivers we have at
the moment (hd44780 and panel) can use this from. The goal is that at
the end other drivers can use the charlcd interface.
I add one such driver at the end with the last patch.
I submitted this already some time ago, where the wish was so split
this into smaller chunks what I try to do with this new patchset.
Most of the patches pick one specific function in charlcd and move the
device specific code into hd44780_common.

As a note to patch 30:
This might slightly change behaviour.
On hd44780 displays with one or two lines the previous implementation
did still write characters to the buffer of the display even if they are
currently not visible. The shift_display command could be used so set
the "viewing window" to a new position in the buffer and then you could
see the characters previously written.
This described behaviour does not work for hd44780 displays with more
than two display lines. There simply is not enough buffer.
So the behaviour was a bit inconsistens across different displays.
The new behaviour is to stop writing character at the end of a visible
line, even if there would be room in the buffer. This allows us to have
an easy implementation, that should behave equal on all supported
displays. This is not hd44780 hardware dependents anymore.

Link: https://lore.kernel.org/lkml/20191016082430.5955-1-poeschel@xxxxxxxxxxx/
Link: https://lore.kernel.org/lkml/CANiq72kS-u_Xd_m+2CQVh-JCncPf1XNXrXAZ=4z+mze8fwv2kw@xxxxxxxxxxxxxx/

Lars Poeschel (32):
  auxdisplay: Use an enum for charlcd  backlight on/off ops
  auxdisplay: Introduce hd44780_common.[ch]
  auxdisplay: Move hwidth and bwidth to struct hd44780_common
  auxdisplay: Move ifwidth to struct hd44780_common
  auxdisplay: Move write_data pointer to hd44780_common
  auxdisplay: Move write_cmd pointers to hd44780 drivers
  auxdisplay: Move addr out of charlcd_priv
  auxdisplay: hd44780_common_print
  auxdisplay: provide hd44780_common_gotoxy
  auxdisplay: add home to charlcd_ops
  auxdisplay: Move clear_display to hd44780_common
  auxdisplay: make charlcd_backlight visible to hd44780_common
  auxdisplay: Make use of enum for backlight on / off
  auxdisplay: Move init_display to hd44780_common
  auxdisplay: implement hd44780_common_shift_cursor
  auxdisplay: Implement hd44780_common_display_shift
  auxdisplay: Implement a hd44780_common_display
  auxdisplay: Implement hd44780_common_cursor
  auxdisplay: Implement hd44780_common_blink
  auxdisplay: cleanup unnecessary hd44780 code in charlcd
  auxdisplay: Implement hd44780_common_fontsize
  auxdisplay: Implement hd44780_common_lines
  auxdisplay: Remove unnecessary hd44780 from charlcd
  auxdisplay: Move char redefine code to hd44780_common
  auxdisplay: Call charlcd_backlight in place
  auxdisplay: hd44780_common: Reduce clear_display timeout
  auxdisplay: hd44780: Remove clear_fast
  auxdisplay: charlcd: replace last device specific stuff
  auxdisplay: Change gotoxy calling interface
  auxdisplay: charlcd: Do not print chars at end of line
  auxdisplay: lcd2s DT binding doc
  auxdisplay: add a driver for lcd2s character display

 .../bindings/auxdisplay/modtronix,lcd2s.yaml  |  58 +++
 .../devicetree/bindings/vendor-prefixes.yaml  |   2 +
 drivers/auxdisplay/Kconfig                    |  30 ++
 drivers/auxdisplay/Makefile                   |   2 +
 drivers/auxdisplay/charlcd.c                  | 412 +++++-------------
 drivers/auxdisplay/charlcd.h                  |  86 +++-
 drivers/auxdisplay/hd44780.c                  | 120 +++--
 drivers/auxdisplay/hd44780_common.c           | 368 ++++++++++++++++
 drivers/auxdisplay/hd44780_common.h           |  34 ++
 drivers/auxdisplay/lcd2s.c                    | 409 +++++++++++++++++
 drivers/auxdisplay/panel.c                    | 180 ++++----
 11 files changed, 1251 insertions(+), 450 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/auxdisplay/modtronix,lcd2s.yaml
 create mode 100644 drivers/auxdisplay/hd44780_common.c
 create mode 100644 drivers/auxdisplay/hd44780_common.h
 create mode 100644 drivers/auxdisplay/lcd2s.c

-- 
2.28.0