[PATCH v3 0/4] PWM changes for rk3288-evb

Doug Anderson dianders at chromium.org
Tue Aug 19 09:07:52 PDT 2014

These patches enable the PWM backlight for the rk3288-evb board.
There were tested by watching the backlight grow from off to max with
the following instructions:

  cd /sys/class/backlight/backlight*/
  for i in $(seq 255); do echo $i > brightness; sleep .01; done

The first patch enables the proper IP.  I think it could land in
Heiko's tree.

The second patch switches PWM cells from 2 to 3 on rk3288.  I think it
could land in Thierry's tree.  With the PWM subsystem as currently
structured, I believe this will break backward compatibility.  However
the rk3288 PWM driver was added so recently (and the rk3288 is so new)
that this seems OK.  In the worst case if someone yells that they are
broken, I believe we could fix this in Linux by saying that if a PWM
driver specifies 3 cells and the DTS definition of the PWM says 2
cells that we'll just pretend that we have no flags.

The 3rd and 4th patches are DTS ones.  They could land in Heiko's tree
after the second patch has landed.  They are based atop his current
WIP 3.18 dts tree.  Note that instantiating the PWM backlight will
cause the system to hang unless Heiko's (clk: rockchip: protect
critical clocks from getting disabled)
<patchwork.kernel.org/patch/4725391> is landed.

There are no compile time or runtime dependencies between these
patches except that patch #3 needs to come before patch #4.  ...and of
course the PWM won't work without all 4 patches.

Changes in v3:
- Don't store a private copy of polarity.
- Use true instead of 1.
- Cleanup init order with "has_invert".
- Fix space to tab in 2 places in DTS.
- Make sure PWM is upper case in prose.

Changes in v2:
- Check for failed ioremap()

Doug Anderson (4):
  ARM: rockchip: rk3288: Switch to use the proper PWM IP
  pwm: rockchip: Allow polarity invert on rk3288
  ARM: dts: Add main PWM info to rk3288
  ARM: dts: Enable PWM backlight on rk3288-EVB

 .../devicetree/bindings/pwm/pwm-rockchip.txt       |  4 +-
 arch/arm/boot/dts/rk3288-evb.dtsi                  | 53 +++++++++++++++++
 arch/arm/boot/dts/rk3288.dtsi                      | 68 ++++++++++++++++++++++
 arch/arm/mach-rockchip/rockchip.c                  | 24 ++++++++
 drivers/pwm/pwm-rockchip.c                         | 48 ++++++++++++---
 5 files changed, 188 insertions(+), 9 deletions(-)


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