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  1. May 29, 2024
  2. May 28, 2024
  3. May 27, 2024
  4. May 24, 2024
  5. May 20, 2024
    • Gianfranco Mariotti's avatar
      [DRIVER] clk: imx: pll1443x: add PLL SSCG support · 23ee9c0f
      Gianfranco Mariotti authored
      In some situations, users might face EMI issues due to spikes around specific
      frequencies: enabling Spread Spectrum Clocking is indicated to reduce the
      electromagnetic peak around that specific frequency.
      
      From the i.MX8MP SoC Reference Manual document, Section 5.1.8 "CCM Analog
      Memory Map/Register Definition", the DRAM PLL, Audio PLL1, Audio PLL2 and
      Video PLL1 have available the spread spectrum function.
      
      The spread spectrum mode parameters of these PLLs can be calculated using
      the formulas below:
      * Modulation frequency: MF = Fin / p / mfr / (2^5) [Hz]
      * Modulation rate: MR = mfr * mrr / m / (2^6) × 100 [%: percentage of the PLL output frequency]
      * Where:
        * 0 <= mfr <= 255, 1 <= mrr <= 63, 0 <= mrr × mfr <= 512
        * Fin - PLL input clock frequency (typically, 24MHz = 24 * (10^6) Hz)
        * p = CCM_ANALOG_XXX_YYY_FDIV_CTL0[PLL_PRE_DIV] - reference frequency pre-divider value
        * m = CCM_ANALOG_XXX_YYY_FDIV_CTL0[PLL_MAIN_DIV] - PLL main divider value
        * mfr = CCM_ANALOG_XXX_YYY_SSCG_CTRL[PLL_MFREQ_CTL] - modulation frequency factor
        * mrr = CCM_ANALOG_XXX_YYY_SSCG_CTRL[PLL_MRAT_CTL] - modulation range factor
      
      fsl,imx8mm-anatop optional properties:
       - anatop-<$1>,sscg-enable
         - type: boolean
         - <$1>: PLL clk name
         - description: enable SSCG
       - anatop-<$1>,mfr
         - type: u32
         - <$1>: PLL clk name
         - description: modulation frequency control value
       - anatop-<$1>,mrr
         - type: u32
         - <$1>: PLL clk name
         - description: modulation rate control value
       - anatop-<$1>,sel-pf
         - type: u32
         - <$1>: PLL clk name
         - description: modulation method control value
      
      fsl,imx8mm-anatop dts example:
      &anatop {
        anatop-video_pll1,sscg-enable;
        anatop-video_pll1,mfr = <12>;
        anatop-video_pll1,mrr = <14>;
        anatop-video_pll1,sel-pf = <2>;
      };
      23ee9c0f
    • Gianfranco Mariotti's avatar
      [DRIVER] clk: imx: pll14xx: fix and use macros for FDIV_CTL regs · 6714a8fa
      Gianfranco Mariotti authored and Michele Cirinei's avatar Michele Cirinei committed
      Correct the definitions of "Divide and Fraction Data Control" registers,
      and use them in the appropriate code sections.
      6714a8fa
  6. May 16, 2024
  7. May 14, 2024
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