1/* arch/arm/plat-samsung/include/plat/pll6553x.h 2 * partially from arch/arm/mach-s3c64xx/include/mach/pll.h 3 * 4 * Copyright 2008 Openmoko, Inc. 5 * Copyright 2008 Simtec Electronics 6 * Ben Dooks <ben@simtec.co.uk> 7 * http://armlinux.simtec.co.uk/ 8 * 9 * Samsung PLL6553x PLL code 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License version 2 as 13 * published by the Free Software Foundation. 14*/ 15 16/* S3C6400 and compatible (S3C2416, etc.) EPLL code */ 17 18#define PLL6553X_MDIV_MASK ((1 << (23-16)) - 1) 19#define PLL6553X_PDIV_MASK ((1 << (13-8)) - 1) 20#define PLL6553X_SDIV_MASK ((1 << (2-0)) - 1) 21#define PLL6553X_MDIV_SHIFT (16) 22#define PLL6553X_PDIV_SHIFT (8) 23#define PLL6553X_SDIV_SHIFT (0) 24#define PLL6553X_KDIV_MASK (0xffff) 25 26static inline unsigned long s3c_get_pll6553x(unsigned long baseclk, 27 u32 pll0, u32 pll1) 28{ 29 unsigned long result; 30 u32 mdiv, pdiv, sdiv, kdiv; 31 u64 tmp; 32 33 mdiv = (pll0 >> PLL6553X_MDIV_SHIFT) & PLL6553X_MDIV_MASK; 34 pdiv = (pll0 >> PLL6553X_PDIV_SHIFT) & PLL6553X_PDIV_MASK; 35 sdiv = (pll0 >> PLL6553X_SDIV_SHIFT) & PLL6553X_SDIV_MASK; 36 kdiv = pll1 & PLL6553X_KDIV_MASK; 37 38 /* We need to multiple baseclk by mdiv (the integer part) and kdiv 39 * which is in 2^16ths, so shift mdiv up (does not overflow) and 40 * add kdiv before multiplying. The use of tmp is to avoid any 41 * overflows before shifting bac down into result when multipling 42 * by the mdiv and kdiv pair. 43 */ 44 45 tmp = baseclk; 46 tmp *= (mdiv << 16) + kdiv; 47 do_div(tmp, (pdiv << sdiv)); 48 result = tmp >> 16; 49 50 return result; 51} 52