Ben Dooks | e561aac | 2010-04-28 18:10:02 +0900 | [diff] [blame] | 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 | |
| 26 | static 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 | } |