summaryrefslogtreecommitdiffstats
path: root/drivers/clk/sunxi-ng/ccu_nkm.c
blob: 9b840a47a94d8774aef65388058dfc7f0d589c5d (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
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
/*
 * 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 "ccu_gate.h"
#include "ccu_nkm.h"

struct _ccu_nkm {
	unsigned long	n, min_n, max_n;
	unsigned long	k, min_k, max_k;
	unsigned long	m, min_m, max_m;
};

static void ccu_nkm_find_best(unsigned long parent, unsigned long rate,
			      struct _ccu_nkm *nkm)
{
	unsigned long best_rate = 0;
	unsigned long best_n = 0, best_k = 0, best_m = 0;
	unsigned long _n, _k, _m;

	for (_k = nkm->min_k; _k <= nkm->max_k; _k++) {
		for (_n = nkm->min_n; _n <= nkm->max_n; _n++) {
			for (_m = nkm->min_m; _m <= nkm->max_m; _m++) {
				unsigned long tmp_rate;

				tmp_rate = parent * _n * _k / _m;

				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;
				}
			}
		}
	}

	nkm->n = best_n;
	nkm->k = best_k;
	nkm->m = best_m;
}

static void ccu_nkm_disable(struct clk_hw *hw)
{
	struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);

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

static int ccu_nkm_enable(struct clk_hw *hw)
{
	struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);

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

static int ccu_nkm_is_enabled(struct clk_hw *hw)
{
	struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);

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

static unsigned long ccu_nkm_recalc_rate(struct clk_hw *hw,
					unsigned long parent_rate)
{
	struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
	unsigned long n, m, k;
	u32 reg;

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

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

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

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

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

static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,
					unsigned long parent_rate,
					unsigned long rate,
					void *data)
{
	struct ccu_nkm *nkm = data;
	struct _ccu_nkm _nkm;

	_nkm.min_n = nkm->n.min;
	_nkm.max_n = 1 << nkm->n.width;
	_nkm.min_k = nkm->k.min;
	_nkm.max_k = 1 << nkm->k.width;
	_nkm.min_m = 1;
	_nkm.max_m = nkm->m.max ?: 1 << nkm->m.width;

	ccu_nkm_find_best(parent_rate, rate, &_nkm);

	return parent_rate * _nkm.n * _nkm.k / _nkm.m;
}

static int ccu_nkm_determine_rate(struct clk_hw *hw,
				  struct clk_rate_request *req)
{
	struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);

	return ccu_mux_helper_determine_rate(&nkm->common, &nkm->mux,
					     req, ccu_nkm_round_rate, nkm);
}

static int ccu_nkm_set_rate(struct clk_hw *hw, unsigned long rate,
			   unsigned long parent_rate)
{
	struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
	struct _ccu_nkm _nkm;
	unsigned long flags;
	u32 reg;

	_nkm.min_n = nkm->n.min;
	_nkm.max_n = 1 << nkm->n.width;
	_nkm.min_k = nkm->k.min;
	_nkm.max_k = 1 << nkm->k.width;
	_nkm.min_m = 1;
	_nkm.max_m = nkm->m.max ?: 1 << nkm->m.width;

	ccu_nkm_find_best(parent_rate, rate, &_nkm);

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

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

	reg |= (_nkm.n - 1) << nkm->n.shift;
	reg |= (_nkm.k - 1) << nkm->k.shift;
	reg |= (_nkm.m - 1) << nkm->m.shift;

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

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

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

	return 0;
}

static u8 ccu_nkm_get_parent(struct clk_hw *hw)
{
	struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);

	return ccu_mux_helper_get_parent(&nkm->common, &nkm->mux);
}

static int ccu_nkm_set_parent(struct clk_hw *hw, u8 index)
{
	struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);

	return ccu_mux_helper_set_parent(&nkm->common, &nkm->mux, index);
}

const struct clk_ops ccu_nkm_ops = {
	.disable	= ccu_nkm_disable,
	.enable		= ccu_nkm_enable,
	.is_enabled	= ccu_nkm_is_enabled,

	.get_parent	= ccu_nkm_get_parent,
	.set_parent	= ccu_nkm_set_parent,

	.determine_rate	= ccu_nkm_determine_rate,
	.recalc_rate	= ccu_nkm_recalc_rate,
	.set_rate	= ccu_nkm_set_rate,
};