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
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