arch/arm/plat-s3c24xx/include/plat/pll.h

   1 /* linux/arch/arm/plat-s3c24xx/include/plat/pll.h
   2  *
   3  * Copyright 2008 Simtec Electronics
   4  *      Ben Dooks <ben@simtec.co.uk>
   5  *      http://armlinux.simtec.co.uk/
   6  *
   7  * S3C24xx - common pll registers and code
   8  */
   9
  10 #define S3C24XX_PLLCON_MDIVSHIFT        12
  11 #define S3C24XX_PLLCON_PDIVSHIFT        4
  12 #define S3C24XX_PLLCON_SDIVSHIFT        0
  13 #define S3C24XX_PLLCON_MDIVMASK         ((1<<(1+(19-12)))-1)
  14 #define S3C24XX_PLLCON_PDIVMASK         ((1<<5)-1)
  15 #define S3C24XX_PLLCON_SDIVMASK         3
  16
  17 #include <asm/div64.h>
  18
  19 static inline unsigned int
  20 s3c24xx_get_pll(unsigned int pllval, unsigned int baseclk)
  21 {
  22         unsigned int mdiv, pdiv, sdiv;
  23         uint64_t fvco;
  24
  25         mdiv = pllval >> S3C24XX_PLLCON_MDIVSHIFT;
  26         pdiv = pllval >> S3C24XX_PLLCON_PDIVSHIFT;
  27         sdiv = pllval >> S3C24XX_PLLCON_SDIVSHIFT;
  28
  29         mdiv &= S3C24XX_PLLCON_MDIVMASK;
  30         pdiv &= S3C24XX_PLLCON_PDIVMASK;
  31         sdiv &= S3C24XX_PLLCON_SDIVMASK;
  32
  33         fvco = (uint64_t)baseclk * (mdiv + 8);
  34         do_div(fvco, (pdiv + 2) << sdiv);
  35
  36         return (unsigned int)fvco;
  37 }