1 // SPDX-License-Identifier: GPL-2.0 2 /* 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 12 int 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