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
div_frac_get(unsigned long rate,unsigned parent_rate,u8 width,u8 frac_width,u8 flags)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