[PATCH v1 0/7] Add rtc refclk support for PolarFire SoC

Conor Dooley conor.dooley at microchip.com
Fri Apr 8 07:36:40 PDT 2022


Hey,
As I mentioned in my fixes for 5.18 [0], found out that the reference
clock for the rtc is actually missing from the clock driver (and the
dt binding). 

Currently the mpfs clock driver uses a reference clock called the
"msspll", set in the device tree, as the parent for the cpu/axi/ahb
(config) clocks. The frequency of the msspll is determined by the FPGA
bitstream & the bootloader configures the clock to match the bitstream.
The real reference is provided by a 100 or 125 MHz off chip oscillator.

However, the msspll clock is not actually the parent of all clocks on
the system - the reference clock for the rtc/mtimer actually has the
off chip oscillator as its parent.

This series enables reading the rate of the msspll clock, converts
the refclock in the device tree to the external reference & adds
the missing rtc reference clock.

I assume it is okay not to add fixes tags for the rtc dt binding?
Since the clock was previously missing, the binding is wrong, but
idk if that qualifies as a fix?

Clock driver changes depend on the fixes I sent in [0].
Please lmk if you want me to respin into a single series w/ the fixes.
Thanks,
Conor.

[0]: https://lore.kernel.org/linux-riscv/20220408133543.3537118-1-conor.dooley@microchip.com/

Conor Dooley (7):
  dt-bindings: clk: mpfs document msspll dri registers
  dt-bindings: clk: mpfs: add defines for two new clocks
  dt-bindings: rtc: add refclk to mpfs-rtc
  clk: microchip: mpfs: re-parent the configurable clocks
  clk: microchip: mpfs: rename sys_base to base
  clk: microchip: mpfs: add RTCREF clock control
  riscv: dts: microchip: reparent mpfs clocks

 .../bindings/clock/microchip,mpfs.yaml        |  11 +-
 .../bindings/rtc/microchip,mfps-rtc.yaml      |  14 +-
 .../microchip/microchip-mpfs-icicle-kit.dts   |   2 +-
 .../boot/dts/microchip/microchip-mpfs.dtsi    |   8 +-
 drivers/clk/microchip/clk-mpfs.c              | 205 +++++++++++++++---
 .../dt-bindings/clock/microchip,mpfs-clock.h  |   5 +-
 6 files changed, 199 insertions(+), 46 deletions(-)

-- 
2.35.1




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