apply a DTS change from upstream to reduce pwm frequency for the backlight.

should fix buzzing sometimes seen with the display. do this as an override
rather than patching the dts source. (tested with a hack to ensure that
the new value is set in the configuration.)

XXX: pullup-10, perhaps pullup-9.

upstream commit message:


arm64: dts: rockchip: Raise Pinebook Pro's panel backlight PWM frequency

Increase the frequency of the PWM signal that drives the LED backlight of
the Pinebook Pro's panel, from about 1.35 KHz (which equals to the PWM
period of 740,740 ns), to exactly 8 kHz (which equals to the PWM period of
125,000 ns). Using a higher PWM frequency for the panel backlight, which
reduces the flicker, can only be beneficial to the end users' eyes.

On top of that, increasing the backlight PWM signal frequency reportedly
eliminates the buzzing emitted from the Pinebook Pro's built-in speakers
when certain backlight levels are set, which cause some weird interference
with some of the components of the Pinebook Pro's audio chain.

The old value for the backlight PWM period, i.e. 740,740 ns, is pretty much
an arbitrary value that was selected during the very early bring-up of the
Pinebook Pro, only because that value seemed to minimize horizontal line
distortion on the display, which resulted from the old X.org drivers causing
screen tearing when dragging windows around. That's no longer an issue, so
there are no reasons to stick with the old PWM period value.

The lower and the upper backlight PWM frequency limits for the Pinebook Pro's
panel, according to its datasheet, are 200 Hz and 10 kHz, respectively. [1]
These changes still leave some headroom, which may have some positive effects
on the lifetime expectancy of the panel's backlight LEDs.

[1] https://files.pine64.org/doc/datasheet/PinebookPro/NV140FHM-N49_Rev.P0_20160804_201710235838.pdf

Fixes: 5a65505a6988 ("arm64: dts: rockchip: Add initial support for Pinebook Pro")
Cc: stable@vger.kernel.org
Reported-by: Nikola Radojevic <nikola@radojevic.rs>
Signed-off-by: Dragan Simic <dsimic@manjaro.org>
Tested-by: Nikola Radojevi# <nikola@radojevic.rs>
Link: https://lore.kernel.org/r/2a23b6cfd8c0513e5b233b4006ee3d3ed09b824f.1722805655.git.dsimic@manjaro.org
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

branches: 1.7.6;
Enable crypto engine on Pinebook Pro.

Only used for rng at present.

don't disable the spi any more. it works fine (and i'm booting
from it on one pbp directly to nvme.)

arm: dts: adapt for dts-5.15

default RK3399 PCIe to 1.x.

sometime in mid-2019, rockchip disabled PCIe 2.x referrencing a
non-public errata in linux and the dts, both of which were changed
to default to only PCIe 1.x (in code, and in DT.) see:

https://lore.kernel.org/all/1481881357-1793-1-git-send-email-shawn.lin@rock-chips.com/

we haven't observed any specific problems, but we've also tested
far fewer cards than linux. there are other issues such as what
happens for a PCI abort depending on which CPU triggers it we do
not currently handle either.

tested on rockpro64 with nvme & ahcisata, and pinebook pro nvme.

still allows DT to set back to '2' if the user so desires.

Rockchip crypto engine RNG driver.

As found on the rk3288 and rk3399. This driver only supports the
TRNG, not the rest of the crypto engine, although it uses the AES unit
to do a self-test at attach time to verify that the engine works.

There seem to be two versions of the Rockchip crypto engine, v1 and
v2; this one is for v1. Can't name a driver `rkcryptov1' so we'll
clumsily call it `rkv1crypto' instead to leave room for `rkv2crypto'
later on.

The crypto binding derived from the Rockchip BSP Linux kernel, in the
location it appears on the rk3399, is in rk3399-crypto.dtsi, since
there doesn't seem to be a better place to put it at the moment among
this twisty maze of inclusions, all different.

branches: 1.2.4; 1.2.8;
Disable SPI for now (rkspi driver hangs at boot)

Add Pinebook Pro dts, from Manjaro Linux.

https://gitlab.manjaro.org/tsys/linux-pinebook-pro/blob/877ca0e7283596f37845de50dc36bff5b88b91e1/arch/arm64/boot/dts/rockchip/rk3399-pinebook-pro.dts