[PATCH v4 0/4] rockchip: odroid-m1/m1s/rk3566 watchdog support

[Andreas Zdziarstek]

This series makes the Synopsys DesignWare watchdog usable on rk3566/rk3568
and enables it on the Hardkernel ODROID-M1 and ODROID-M1S.

On current next the dw-wdt driver already probes (d62801d09441), but a
timeout or "wdt expire" still hangs the SoC: CRU_GLB_RST_CON routes the
watchdog to the second global reset by default, which causes a hung SoC.

Patch 1 routes the watchdog to the first global reset instead, same as
the PX30 implementation. Patch 2 does the same for the TSADC, so a
thermal shutdown also resets the whole SoC. Patch 3 makes the dw-wdt
driver the default for the rk3566/rk3568 family. Patch 4 enables the
watchdog (wdt command only, no autostart to be non-breaking) on the
ODROID-M1 and ODROID-M1S.

Verified on the ODROID-M1S (RK3566): a watchdog timeout cleanly reboots
the board.

Changes in v4:
- patch 3 (new): imply DESIGNWARE_WATCHDOG for the rk3568 family instead
  of enabling the driver per board (review comment by Jonas)
- patch 4 (was 3/3): enable the watchdog on both ODROID-M1 and M1S, not
  just M1S (review comment by Jonas); dropped Quentin's Reviewed-by as the
  patch changed

Changes in v3:
- patch 1: keep the glb_rst_con write inside CONFIG_XPL_BUILD (review
  comment by Jonas)
- patch 2: fold the WDT and TSADC bits into a single glb_rst_con
  read-modify-write instead of two separate ones (review comment by Jonas)

Changes in v2:
- patch 1: access CRU_GLB_RST_CON through the rk3568_cru struct, matching
  PX30's arch_cpu_init() (review comment by Quentin)
- patch 2 (new): also route the TSADC to a first global reset (review
  comment by Quentin)

On the TSADC (patch 2): while checking how the ODROID-M1S comes up, I
noticed the rkbin DDR init (probably, at least I don't know what else
could set it at that stage) already sets the TSADC bit in CRU_GLB_RST_CON
before U-Boot runs. So, on this board the patch is effectively a no-op. It
still seems right to configure it explicitly in U-Boot rather than depend
on the firmware blob, and it matches what PX30 does.

Jonas: Per your note, v4 treats the dw watchdog as a SoC feature. Patch 3
implies the driver for the rk3568 family, and patch 4 enables the command
on both the M1 and the M1S.

Andreas Zdziarstek (4):
  rockchip: rk3568: make the WDT trigger a first global reset
  rockchip: rk3568: make the TSADC trigger a first global reset
  rockchip: rk3568: imply DESIGNWARE_WATCHDOG
  rockchip: odroid-m1/m1s: enable watchdog support

 arch/arm/mach-rockchip/Kconfig         |  1 +
 arch/arm/mach-rockchip/rk3568/rk3568.c | 11 +++++++++++
 configs/odroid-m1-rk3568_defconfig     |  4 ++++
 configs/odroid-m1s-rk3566_defconfig    |  4 ++++
 4 files changed, 20 insertions(+)


base-commit: 835a18f80f25731dc818bf9b771bfa111ea3dbeb
-- 
2.53.0