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
13 struct _ccu_nk {
14 unsigned long n, min_n, max_n;
15 unsigned long k, min_k, max_k;
16 };
17
ccu_nk_find_best(unsigned long parent,u64 rate,struct _ccu_nk * nk)18 static void ccu_nk_find_best(unsigned long parent, u64 rate,
19 struct _ccu_nk *nk)
20 {
21 u64 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 u64 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
ccu_nk_disable(struct clk_hw * hw)44 static void ccu_nk_disable(struct clk_hw *hw)
45 {
46 struct ccu_nk *nk = hw_to_ccu_nk(hw);
47
48 return ccu_gate_helper_disable(&nk->common, nk->enable);
49 }
50
ccu_nk_enable(struct clk_hw * hw)51 static int ccu_nk_enable(struct clk_hw *hw)
52 {
53 struct ccu_nk *nk = hw_to_ccu_nk(hw);
54
55 return ccu_gate_helper_enable(&nk->common, nk->enable);
56 }
57
ccu_nk_is_enabled(struct clk_hw * hw)58 static int ccu_nk_is_enabled(struct clk_hw *hw)
59 {
60 struct ccu_nk *nk = hw_to_ccu_nk(hw);
61
62 return ccu_gate_helper_is_enabled(&nk->common, nk->enable);
63 }
64
ccu_nk_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)65 static unsigned long ccu_nk_recalc_rate(struct clk_hw *hw,
66 unsigned long parent_rate)
67 {
68 struct ccu_nk *nk = hw_to_ccu_nk(hw);
69 unsigned long n, k;
70 u64 rate;
71 u32 reg;
72
73 reg = readl(nk->common.base + nk->common.reg);
74
75 n = reg >> nk->n.shift;
76 n &= (1 << nk->n.width) - 1;
77 n += nk->n.offset;
78 if (!n)
79 n++;
80
81 k = reg >> nk->k.shift;
82 k &= (1 << nk->k.width) - 1;
83 k += nk->k.offset;
84 if (!k)
85 k++;
86
87 rate = parent_rate * n * k;
88 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
89 do_div(rate, nk->fixed_post_div);
90
91 return rate;
92 }
93
ccu_nk_round_rate(struct clk_hw * hw,unsigned long _rate,unsigned long * parent_rate)94 static long ccu_nk_round_rate(struct clk_hw *hw, unsigned long _rate,
95 unsigned long *parent_rate)
96 {
97 struct ccu_nk *nk = hw_to_ccu_nk(hw);
98 struct _ccu_nk _nk;
99 u64 rate = _rate;
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 ccu_nk_find_best(*parent_rate, rate, &_nk);
110 rate = *parent_rate * _nk.n * _nk.k;
111
112 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
113 do_div(rate, nk->fixed_post_div);
114
115 return rate;
116 }
117
ccu_nk_set_rate(struct clk_hw * hw,unsigned long _rate,unsigned long parent_rate)118 static int ccu_nk_set_rate(struct clk_hw *hw, unsigned long _rate,
119 unsigned long parent_rate)
120 {
121 struct ccu_nk *nk = hw_to_ccu_nk(hw);
122 unsigned long flags;
123 struct _ccu_nk _nk;
124 u64 rate = _rate;
125 u32 reg;
126
127 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
128 rate = rate * nk->fixed_post_div;
129
130 _nk.min_n = nk->n.min ?: 1;
131 _nk.max_n = nk->n.max ?: 1 << nk->n.width;
132 _nk.min_k = nk->k.min ?: 1;
133 _nk.max_k = nk->k.max ?: 1 << nk->k.width;
134
135 ccu_nk_find_best(parent_rate, rate, &_nk);
136
137 spin_lock_irqsave(nk->common.lock, flags);
138
139 reg = readl(nk->common.base + nk->common.reg);
140 reg &= ~GENMASK(nk->n.width + nk->n.shift - 1, nk->n.shift);
141 reg &= ~GENMASK(nk->k.width + nk->k.shift - 1, nk->k.shift);
142
143 reg |= (_nk.k - nk->k.offset) << nk->k.shift;
144 reg |= (_nk.n - nk->n.offset) << nk->n.shift;
145 writel(reg, nk->common.base + nk->common.reg);
146
147 spin_unlock_irqrestore(nk->common.lock, flags);
148
149 ccu_helper_wait_for_lock(&nk->common, nk->lock);
150
151 return 0;
152 }
153
154 const struct clk_ops ccu_nk_ops = {
155 .disable = ccu_nk_disable,
156 .enable = ccu_nk_enable,
157 .is_enabled = ccu_nk_is_enabled,
158
159 .recalc_rate = ccu_nk_recalc_rate,
160 .round_rate = ccu_nk_round_rate,
161 .set_rate = ccu_nk_set_rate,
162 };
163