clk: cs2000-cp: add support for dynamic mode

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The CS2000 chip features two input clocks, REF_CLK and CLK_IN.

In static mode, the output clock (CLK_OUT) is directly derived from
REF_CLK, and CLK_IN is ignored. In dynamic mode, CLK_IN is used by the
digital PLL.

In dynamic mode, a low-frequency ratio configuration that uses a higher
multiplier factor.

Until now, only the static mode and high-frequency divider rations of
the hardware was supported by the driver. This patch adds support for
dynamic mode and both ratios:

 * Parse a new OF property 'cirrus,dynamic-mode' to determine the mode
 * In dynamic mode, present CLK_IN as parent clock, else use REF_CLK
 * The low-frequency ratio mode is automatically selected, depending
   on the mode of operation and the given input and output rates

Signed-off-by: Daniel Mack <daniel@zonque.org>
Link: https://lore.kernel.org/r/20220125093336.226787-7-daniel@zonque.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

...

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Daniel Mack 2022-01-25 10:33:33 +01:00 • committed by Stephen Boyd

parent a6e11bb24e

commit da1eb4e8b4

1 changed files with 74 additions and 37 deletions

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drivers/clk/clk-cs2000-cp.c

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