1. 13 5月, 2012 1 次提交
    • V
      SPEAr: clk: Add Fractional Synthesizer clock · 270b9f42
      Viresh Kumar 提交于
      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: NViresh Kumar <viresh.kumar@st.com>
      Reviewed-by: NMike Turquette <mturquette@linaro.org>
      270b9f42