[0/3] clk: sifive: Fix chip hang when booting linux directly

Message

Bo Gan Aug. 28, 2024, 6:55 a.m. UTC

This patch adds the release_reset hook interface to __prci_wrpll_data.
For gemgxlpll/cltxpll clocks in fu540/fu740, the reset pins also have to
be relased for the device to function properly. This was missing in Linux.
The board (Sifive Unmatched/Unleashed) happened to work because previous
boot stage (u-boot) usually already enables the clocks when trying to boot
from PXE/network, and the release_reset logic is present in u-boot. When
booting directly from firmware (OpenSBI) or when u-boot isn't configured
with networking enabled, the board will hang when cadence/macb driver
starts initializing the device.

Fix that by taking the same logic in u-boot and apply to linux.

Bo Gan (3):
  dt-bindings: reset: sifive: add fu540/fu740 reset indexes
  riscv: dts: sifive: fu740: Use reset index from header
  clk: sifive: prci: Add release_reset hooks for gemgxlpll/cltxpll

 arch/riscv/boot/dts/sifive/fu740-c000.dtsi    |  3 +-
 drivers/clk/sifive/fu540-prci.h               | 16 ++++++++++
 drivers/clk/sifive/fu740-prci.h               | 31 +++++++++++++++++++
 drivers/clk/sifive/sifive-prci.c              | 23 ++++++++++++++
 drivers/clk/sifive/sifive-prci.h              |  8 +++++
 include/dt-bindings/reset/sifive-fu540-prci.h | 19 ++++++++++++
 include/dt-bindings/reset/sifive-fu740-prci.h | 19 ++++++++++++
 7 files changed, 118 insertions(+), 1 deletion(-)
 create mode 100644 include/dt-bindings/reset/sifive-fu540-prci.h
 create mode 100644 include/dt-bindings/reset/sifive-fu740-prci.h