SPEAr: clk: Add Fractional Synthesizer clock
All SPEAr SoC's contain Fractional Synthesizers. Their Fout is derived from
following equations:
Fout = Fin / (2 * div) (division factor)
div is 17 bits:-
0-13 (fractional part)
14-16 (integer part)
div is (16-14 bits).(13-0 bits) (in binary)
Fout = Fin/(2 * div)
Fout = ((Fin / 10000)/(2 * div)) * 10000
Fout = (2^14 * (Fin / 10000)/(2^14 * (2 * div))) * 10000
Fout = (((Fin / 10000) << 14)/(2 * (div << 14))) * 10000
div << 14 is simply 17 bit value written at register.
This patch adds in support for this type of clock.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Reviewed-by: Mike Turquette <mturquette@linaro.org>
3 files changed