summaryrefslogtreecommitdiffstats
path: root/drivers/clk/sunxi-ng/ccu_nkmp.c
blob: 9769dee99511abeb3bab68106572ad56a0a9e0c5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
/*
 * Copyright (C) 2016 Maxime Ripard
 * Maxime Ripard <maxime.ripard@free-electrons.com>
 *
 * 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.
 */

#include <linux/clk-provider.h>
#include <linux/rational.h>

#include "ccu_gate.h"
#include "ccu_nkmp.h"

struct _ccu_nkmp {
	unsigned long	n, max_n;
	unsigned long	k, max_k;
	unsigned long	m, max_m;
	unsigned long	p, max_p;
};

static void ccu_nkmp_find_best(unsigned long parent, unsigned long rate,
			       struct _ccu_nkmp *nkmp)
{
	unsigned long best_rate = 0;
	unsigned long best_n = 0, best_k = 0, best_m = 0, best_p = 0;
	unsigned long _n, _k, _m, _p;

	for (_k = 1; _k <= nkmp->max_k; _k++) {
		for (_p = 1; _p <= nkmp->max_p; _p <<= 1) {
			unsigned long tmp_rate;

			rational_best_approximation(rate / _k, parent / _p,
						    nkmp->max_n, nkmp->max_m,
						    &_n, &_m);

			tmp_rate = parent * _n * _k / (_m * _p);

			if (tmp_rate > rate)
				continue;

			if ((rate - tmp_rate) < (rate - best_rate)) {
				best_rate = tmp_rate;
				best_n = _n;
				best_k = _k;
				best_m = _m;
				best_p = _p;
			}
		}
	}

	nkmp->n = best_n;
	nkmp->k = best_k;
	nkmp->m = best_m;
	nkmp->p = best_p;
}

static void ccu_nkmp_disable(struct clk_hw *hw)
{
	struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);

	return ccu_gate_helper_disable(&nkmp->common, nkmp->enable);
}

static int ccu_nkmp_enable(struct clk_hw *hw)
{
	struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);

	return ccu_gate_helper_enable(&nkmp->common, nkmp->enable);
}

static int ccu_nkmp_is_enabled(struct clk_hw *hw)
{
	struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);

	return ccu_gate_helper_is_enabled(&nkmp->common, nkmp->enable);
}

static unsigned long ccu_nkmp_recalc_rate(struct clk_hw *hw,
					unsigned long parent_rate)
{
	struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
	unsigned long n, m, k, p;
	u32 reg;

	reg = readl(nkmp->common.base + nkmp->common.reg);

	n = reg >> nkmp->n.shift;
	n &= (1 << nkmp->n.width) - 1;

	k = reg >> nkmp->k.shift;
	k &= (1 << nkmp->k.width) - 1;

	m = reg >> nkmp->m.shift;
	m &= (1 << nkmp->m.width) - 1;

	p = reg >> nkmp->p.shift;
	p &= (1 << nkmp->p.width) - 1;

	return (parent_rate * (n + 1) * (k + 1) >> p) / (m + 1);
}

static long ccu_nkmp_round_rate(struct clk_hw *hw, unsigned long rate,
			      unsigned long *parent_rate)
{
	struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
	struct _ccu_nkmp _nkmp;

	_nkmp.max_n = 1 << nkmp->n.width;
	_nkmp.max_k = 1 << nkmp->k.width;
	_nkmp.max_m = nkmp->m.max ?: 1 << nkmp->m.width;
	_nkmp.max_p = nkmp->p.max ?: 1 << ((1 << nkmp->p.width) - 1);

	ccu_nkmp_find_best(*parent_rate, rate, &_nkmp);

	return *parent_rate * _nkmp.n * _nkmp.k / (_nkmp.m * _nkmp.p);
}

static int ccu_nkmp_set_rate(struct clk_hw *hw, unsigned long rate,
			   unsigned long parent_rate)
{
	struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
	struct _ccu_nkmp _nkmp;
	unsigned long flags;
	u32 reg;

	_nkmp.max_n = 1 << nkmp->n.width;
	_nkmp.max_k = 1 << nkmp->k.width;
	_nkmp.max_m = nkmp->m.max ?: 1 << nkmp->m.width;
	_nkmp.max_p = nkmp->p.max ?: 1 << ((1 << nkmp->p.width) - 1);

	ccu_nkmp_find_best(parent_rate, rate, &_nkmp);

	spin_lock_irqsave(nkmp->common.lock, flags);

	reg = readl(nkmp->common.base + nkmp->common.reg);
	reg &= ~GENMASK(nkmp->n.width + nkmp->n.shift - 1, nkmp->n.shift);
	reg &= ~GENMASK(nkmp->k.width + nkmp->k.shift - 1, nkmp->k.shift);
	reg &= ~GENMASK(nkmp->m.width + nkmp->m.shift - 1, nkmp->m.shift);
	reg &= ~GENMASK(nkmp->p.width + nkmp->p.shift - 1, nkmp->p.shift);

	reg |= (_nkmp.n - 1) << nkmp->n.shift;
	reg |= (_nkmp.k - 1) << nkmp->k.shift;
	reg |= (_nkmp.m - 1) << nkmp->m.shift;
	reg |= ilog2(_nkmp.p) << nkmp->p.shift;

	writel(reg, nkmp->common.base + nkmp->common.reg);

	spin_unlock_irqrestore(nkmp->common.lock, flags);

	ccu_helper_wait_for_lock(&nkmp->common, nkmp->lock);

	return 0;
}

const struct clk_ops ccu_nkmp_ops = {
	.disable	= ccu_nkmp_disable,
	.enable		= ccu_nkmp_enable,
	.is_enabled	= ccu_nkmp_is_enabled,

	.recalc_rate	= ccu_nkmp_recalc_rate,
	.round_rate	= ccu_nkmp_round_rate,
	.set_rate	= ccu_nkmp_set_rate,
};