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pll6553x.h

/* arch/arm/plat-samsung/include/plat/pll6553x.h
 *    partially from arch/arm/mach-s3c64xx/include/mach/pll.h
 *
 * Copyright 2008 Openmoko, Inc.
 * Copyright 2008 Simtec Electronics
 *    Ben Dooks <ben@simtec.co.uk>
 *    http://armlinux.simtec.co.uk/
 *
 * Samsung PLL6553x PLL code
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
*/

/* S3C6400 and compatible (S3C2416, etc.) EPLL code */

#define PLL6553X_MDIV_MASK    ((1 << (23-16)) - 1)
#define PLL6553X_PDIV_MASK    ((1 << (13-8)) - 1)
#define PLL6553X_SDIV_MASK    ((1 << (2-0)) - 1)
#define PLL6553X_MDIV_SHIFT   (16)
#define PLL6553X_PDIV_SHIFT   (8)
#define PLL6553X_SDIV_SHIFT   (0)
#define PLL6553X_KDIV_MASK    (0xffff)

static inline unsigned long s3c_get_pll6553x(unsigned long baseclk,
                                   u32 pll0, u32 pll1)
{
      unsigned long result;
      u32 mdiv, pdiv, sdiv, kdiv;
      u64 tmp;

      mdiv = (pll0 >> PLL6553X_MDIV_SHIFT) & PLL6553X_MDIV_MASK;
      pdiv = (pll0 >> PLL6553X_PDIV_SHIFT) & PLL6553X_PDIV_MASK;
      sdiv = (pll0 >> PLL6553X_SDIV_SHIFT) & PLL6553X_SDIV_MASK;
      kdiv = pll1 & PLL6553X_KDIV_MASK;

      /* We need to multiple baseclk by mdiv (the integer part) and kdiv
       * which is in 2^16ths, so shift mdiv up (does not overflow) and
       * add kdiv before multiplying. The use of tmp is to avoid any
       * overflows before shifting bac down into result when multipling
       * by the mdiv and kdiv pair.
       */

      tmp = baseclk;
      tmp *= (mdiv << 16) + kdiv;
      do_div(tmp, (pdiv << sdiv));
      result = tmp >> 16;

      return result;
}

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