1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2016 Maxime Ripard
4 * Maxime Ripard <maxime.ripard@free-electrons.com>
5 */
6
7#include <linux/clk-provider.h>
8#include <linux/io.h>
9
10#include "ccu_gate.h"
11#include "ccu_nk.h"
12
13struct _ccu_nk {
14 unsigned long n, min_n, max_n;
15 unsigned long k, min_k, max_k;
16};
17
18static unsigned long ccu_nk_find_best(unsigned long parent, unsigned long rate,
19 struct _ccu_nk *nk)
20{
21 unsigned long best_rate = 0;
22 unsigned int best_k = 0, best_n = 0;
23 unsigned int _k, _n;
24
25 for (_k = nk->min_k; _k <= nk->max_k; _k++) {
26 for (_n = nk->min_n; _n <= nk->max_n; _n++) {
27 unsigned long tmp_rate = parent * _n * _k;
28
29 if (tmp_rate > rate)
30 continue;
31
32 if ((rate - tmp_rate) < (rate - best_rate)) {
33 best_rate = tmp_rate;
34 best_k = _k;
35 best_n = _n;
36 }
37 }
38 }
39
40 nk->k = best_k;
41 nk->n = best_n;
42
43 return best_rate;
44}
45
46static void ccu_nk_disable(struct clk_hw *hw)
47{
48 struct ccu_nk *nk = hw_to_ccu_nk(hw);
49
50 return ccu_gate_helper_disable(common: &nk->common, gate: nk->enable);
51}
52
53static int ccu_nk_enable(struct clk_hw *hw)
54{
55 struct ccu_nk *nk = hw_to_ccu_nk(hw);
56
57 return ccu_gate_helper_enable(common: &nk->common, gate: nk->enable);
58}
59
60static int ccu_nk_is_enabled(struct clk_hw *hw)
61{
62 struct ccu_nk *nk = hw_to_ccu_nk(hw);
63
64 return ccu_gate_helper_is_enabled(common: &nk->common, gate: nk->enable);
65}
66
67static unsigned long ccu_nk_recalc_rate(struct clk_hw *hw,
68 unsigned long parent_rate)
69{
70 struct ccu_nk *nk = hw_to_ccu_nk(hw);
71 unsigned long rate, n, k;
72 u32 reg;
73
74 reg = readl(addr: nk->common.base + nk->common.reg);
75
76 n = reg >> nk->n.shift;
77 n &= (1 << nk->n.width) - 1;
78 n += nk->n.offset;
79 if (!n)
80 n++;
81
82 k = reg >> nk->k.shift;
83 k &= (1 << nk->k.width) - 1;
84 k += nk->k.offset;
85 if (!k)
86 k++;
87
88 rate = parent_rate * n * k;
89 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
90 rate /= nk->fixed_post_div;
91
92 return rate;
93}
94
95static long ccu_nk_round_rate(struct clk_hw *hw, unsigned long rate,
96 unsigned long *parent_rate)
97{
98 struct ccu_nk *nk = hw_to_ccu_nk(hw);
99 struct _ccu_nk _nk;
100
101 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
102 rate *= nk->fixed_post_div;
103
104 _nk.min_n = nk->n.min ?: 1;
105 _nk.max_n = nk->n.max ?: 1 << nk->n.width;
106 _nk.min_k = nk->k.min ?: 1;
107 _nk.max_k = nk->k.max ?: 1 << nk->k.width;
108
109 rate = ccu_nk_find_best(parent: *parent_rate, rate, nk: &_nk);
110
111 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
112 rate = rate / nk->fixed_post_div;
113
114 return rate;
115}
116
117static int ccu_nk_set_rate(struct clk_hw *hw, unsigned long rate,
118 unsigned long parent_rate)
119{
120 struct ccu_nk *nk = hw_to_ccu_nk(hw);
121 unsigned long flags;
122 struct _ccu_nk _nk;
123 u32 reg;
124
125 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
126 rate = rate * nk->fixed_post_div;
127
128 _nk.min_n = nk->n.min ?: 1;
129 _nk.max_n = nk->n.max ?: 1 << nk->n.width;
130 _nk.min_k = nk->k.min ?: 1;
131 _nk.max_k = nk->k.max ?: 1 << nk->k.width;
132
133 ccu_nk_find_best(parent: parent_rate, rate, nk: &_nk);
134
135 spin_lock_irqsave(nk->common.lock, flags);
136
137 reg = readl(addr: nk->common.base + nk->common.reg);
138 reg &= ~GENMASK(nk->n.width + nk->n.shift - 1, nk->n.shift);
139 reg &= ~GENMASK(nk->k.width + nk->k.shift - 1, nk->k.shift);
140
141 reg |= (_nk.k - nk->k.offset) << nk->k.shift;
142 reg |= (_nk.n - nk->n.offset) << nk->n.shift;
143 writel(val: reg, addr: nk->common.base + nk->common.reg);
144
145 spin_unlock_irqrestore(lock: nk->common.lock, flags);
146
147 ccu_helper_wait_for_lock(common: &nk->common, lock: nk->lock);
148
149 return 0;
150}
151
152const struct clk_ops ccu_nk_ops = {
153 .disable = ccu_nk_disable,
154 .enable = ccu_nk_enable,
155 .is_enabled = ccu_nk_is_enabled,
156
157 .recalc_rate = ccu_nk_recalc_rate,
158 .round_rate = ccu_nk_round_rate,
159 .set_rate = ccu_nk_set_rate,
160};
161EXPORT_SYMBOL_NS_GPL(ccu_nk_ops, SUNXI_CCU);
162

source code of linux/drivers/clk/sunxi-ng/ccu_nk.c