add utility macros for: * bit field operations * log2n functions
Signed-off-by: Aneesh V aneesh@ti.com --- arch/arm/include/asm/utils.h | 80 ++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 80 insertions(+), 0 deletions(-) create mode 100644 arch/arm/include/asm/utils.h
diff --git a/arch/arm/include/asm/utils.h b/arch/arm/include/asm/utils.h new file mode 100644 index 0000000..d581539 --- /dev/null +++ b/arch/arm/include/asm/utils.h @@ -0,0 +1,80 @@ +/* + * (C) Copyright 2010 + * Texas Instruments, <www.ti.com> + * + * Aneesh V aneesh@ti.com + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ +#ifndef _UTILS_H_ +#define _UTILS_H_ + +/* extract a bit field from a bit vector */ +#define get_bit_field(nr, start, mask)\ + (((nr) & (mask)) >> (start)) + +/* Set a field in a bit vector */ +#define set_bit_field(nr, start, mask, val)\ + do { \ + (nr) = ((nr) & ~(mask)) | (((val) << (start)) & (mask));\ + } while (0); + +/* + * Utility macro for read-modify-write of a hardware register + * addr - address of the register + * shift - starting bit position of the field to be modified + * msk - mask for the field + * val - value to be shifted masked and written to the field + */ +#define modify_reg_32(addr, shift, msk, val) \ + do {\ + writel(((readl(addr) & ~(msk))|(((val) << (shift)) & (msk))),\ + (addr));\ + } while (0); + +static inline s32 log_2_n_round_up(u32 n) +{ + s32 log2n = -1; + u32 temp = n; + + while (temp) { + log2n++; + temp >>= 1; + } + + if (n & (n - 1)) + return log2n + 1; /* not power of 2 - round up */ + else + return log2n; /* power of 2 */ +} + +static inline s32 log_2_n_round_down(u32 n) +{ + s32 log2n = -1; + u32 temp = n; + + while (temp) { + log2n++; + temp >>= 1; + } + + return log2n; +} + +#endif /* _OMAP_COMMON_H_ */