arch/arm/plat-s3c64xx/include/plat/pll.h

   1 /* arch/arm/plat-s3c64xx/include/plat/pll.h
   2  *
   3  * Copyright 2008 Openmoko, Inc.
   4  * Copyright 2008 Simtec Electronics
   5  *      Ben Dooks <ben@simtec.co.uk>
   6  *      http://armlinux.simtec.co.uk/
   7  *
   8  * S3C64XX PLL code
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13 */
  14
  15 #define S3C6400_PLL_MDIV_MASK   ((1 << (25-16+1)) - 1)
  16 #define S3C6400_PLL_PDIV_MASK   ((1 << (13-8+1)) - 1)
  17 #define S3C6400_PLL_SDIV_MASK   ((1 << (2-0+1)) - 1)
  18 #define S3C6400_PLL_MDIV_SHIFT  (16)
  19 #define S3C6400_PLL_PDIV_SHIFT  (8)
  20 #define S3C6400_PLL_SDIV_SHIFT  (0)
  21
  22 #include <asm/div64.h>
  23
  24 static inline unsigned long s3c6400_get_pll(unsigned long baseclk,
  25                                             u32 pllcon)
  26 {
  27         u32 mdiv, pdiv, sdiv;
  28         u64 fvco = baseclk;
  29
  30         mdiv = (pllcon >> S3C6400_PLL_MDIV_SHIFT) & S3C6400_PLL_MDIV_MASK;
  31         pdiv = (pllcon >> S3C6400_PLL_PDIV_SHIFT) & S3C6400_PLL_PDIV_MASK;
  32         sdiv = (pllcon >> S3C6400_PLL_SDIV_SHIFT) & S3C6400_PLL_SDIV_MASK;
  33
  34         fvco *= mdiv;
  35         do_div(fvco, (pdiv << sdiv));
  36
  37         return (unsigned long)fvco;
  38 }
  39
  40 #define S3C6400_EPLL_MDIV_MASK  ((1 << (23-16)) - 1)
  41 #define S3C6400_EPLL_PDIV_MASK  ((1 << (13-8)) - 1)
  42 #define S3C6400_EPLL_SDIV_MASK  ((1 << (2-0)) - 1)
  43 #define S3C6400_EPLL_MDIV_SHIFT (16)
  44 #define S3C6400_EPLL_PDIV_SHIFT (8)
  45 #define S3C6400_EPLL_SDIV_SHIFT (0)
  46 #define S3C6400_EPLL_KDIV_MASK  (0xffff)
  47
  48 static inline unsigned long s3c6400_get_epll(unsigned long baseclk)
  49 {
  50         unsigned long result;
  51         u32 epll0 = __raw_readl(S3C_EPLL_CON0);
  52         u32 epll1 = __raw_readl(S3C_EPLL_CON1);
  53         u32 mdiv, pdiv, sdiv, kdiv;
  54         u64 tmp;
  55
  56         mdiv = (epll0 >> S3C6400_EPLL_MDIV_SHIFT) & S3C6400_EPLL_MDIV_MASK;
  57         pdiv = (epll0 >> S3C6400_EPLL_PDIV_SHIFT) & S3C6400_EPLL_PDIV_MASK;
  58         sdiv = (epll0 >> S3C6400_EPLL_SDIV_SHIFT) & S3C6400_EPLL_SDIV_MASK;
  59         kdiv = epll1 & S3C6400_EPLL_KDIV_MASK;
  60
  61         /* We need to multiple baseclk by mdiv (the integer part) and kdiv
  62          * which is in 2^16ths, so shift mdiv up (does not overflow) and
  63          * add kdiv before multiplying. The use of tmp is to avoid any
  64          * overflows before shifting bac down into result when multipling
  65          * by the mdiv and kdiv pair.
  66          */
  67
  68         tmp = baseclk;
  69         tmp *= (mdiv << 16) + kdiv;
  70         do_div(tmp, (pdiv << sdiv));
  71         result = tmp >> 16;
  72
  73         return result;
  74 }