44 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (c) 2018, NVIDIA CORPORATION. All rights reserved.4 */5 6#include <asm/div64.h>7 8#include "clk.h"9 10#define div_mask(w) ((1 << (w)) - 1)11 12int div_frac_get(unsigned long rate, unsigned parent_rate, u8 width,13 u8 frac_width, u8 flags)14{15 u64 divider_ux1 = parent_rate;16 int mul;17 18 if (!rate)19 return 0;20 21 mul = 1 << frac_width;22 23 if (!(flags & TEGRA_DIVIDER_INT))24 divider_ux1 *= mul;25 26 if (flags & TEGRA_DIVIDER_ROUND_UP)27 divider_ux1 += rate - 1;28 29 do_div(divider_ux1, rate);30 31 if (flags & TEGRA_DIVIDER_INT)32 divider_ux1 *= mul;33 34 if (divider_ux1 < mul)35 return 0;36 37 divider_ux1 -= mul;38 39 if (divider_ux1 > div_mask(width))40 return div_mask(width);41 42 return divider_ux1;43}44