[v2,0/3] clk: samsung: introduce nMUX to reparent MUX clocks

Message

Tudor Ambarus March 26, 2024, 5:28 p.m. UTC

All samsung MUX clocks that are defined with MUX() set the
CLK_SET_RATE_NO_REPARENT flag in __MUX(), which prevents MUXes to be
reparented during clk_set_rate().
    
Introduce nMUX() for MUX clocks that can be reparented. nMUX is used
in GS101 to reparent the USI MUX to OSCCLK on low SPI clock rates.

Each instance of the USI IP in GS101 has its own MUX_USI clock, thus
the reparenting of a MUX_USI clock corresponds to a single instance
of the USI IP. We allow the reparenting of the MUX_USIx clocks to
OSCCLK. The datasheet mentions OSCCLK just in the low-power mode
context, but the downstream driver reparents too the MUX_USI clocks
to OSCCLK. Follow the downstream driver and do the same.

Tested with USI6 and USI13 SPI.

Find discussion on MUX reparenting to OSCCLK at:
https://lore.kernel.org/linux-samsung-soc/[e-mail]/

v2:
- reword commit messages
- drop exynos850 patch on Sam's request

v1: https://lore.kernel.org/linux-samsung-soc/[e-mail]/

Tudor Ambarus (3):
  clk: samsung: introduce nMUX for MUX clks that can reparented
  clk: samsung: gs101: propagate PERIC1 USI SPI clock rate
  clk: samsung: gs101: propagate PERIC0 USI SPI clock rate

 drivers/clk/samsung/clk-gs101.c | 225 +++++++++++++++++---------------
 drivers/clk/samsung/clk.h       |  20 +++
 2 files changed, 140 insertions(+), 105 deletions(-)