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6174a1e2 MR |
1 | /* |
2 | * Copyright (C) 2016 Maxime Ripard | |
3 | * Maxime Ripard <maxime.ripard@free-electrons.com> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU General Public License as | |
7 | * published by the Free Software Foundation; either version 2 of | |
8 | * the License, or (at your option) any later version. | |
9 | */ | |
10 | ||
11 | #include <linux/clk-provider.h> | |
12 | #include <linux/rational.h> | |
13 | ||
14 | #include "ccu_frac.h" | |
15 | #include "ccu_gate.h" | |
16 | #include "ccu_nm.h" | |
17 | ||
18 | static void ccu_nm_disable(struct clk_hw *hw) | |
19 | { | |
20 | struct ccu_nm *nm = hw_to_ccu_nm(hw); | |
21 | ||
22 | return ccu_gate_helper_disable(&nm->common, nm->enable); | |
23 | } | |
24 | ||
25 | static int ccu_nm_enable(struct clk_hw *hw) | |
26 | { | |
27 | struct ccu_nm *nm = hw_to_ccu_nm(hw); | |
28 | ||
29 | return ccu_gate_helper_enable(&nm->common, nm->enable); | |
30 | } | |
31 | ||
32 | static int ccu_nm_is_enabled(struct clk_hw *hw) | |
33 | { | |
34 | struct ccu_nm *nm = hw_to_ccu_nm(hw); | |
35 | ||
36 | return ccu_gate_helper_is_enabled(&nm->common, nm->enable); | |
37 | } | |
38 | ||
39 | static unsigned long ccu_nm_recalc_rate(struct clk_hw *hw, | |
40 | unsigned long parent_rate) | |
41 | { | |
42 | struct ccu_nm *nm = hw_to_ccu_nm(hw); | |
43 | unsigned long n, m; | |
44 | u32 reg; | |
45 | ||
46 | if (ccu_frac_helper_is_enabled(&nm->common, &nm->frac)) | |
47 | return ccu_frac_helper_read_rate(&nm->common, &nm->frac); | |
48 | ||
49 | reg = readl(nm->common.base + nm->common.reg); | |
50 | ||
51 | n = reg >> nm->n.shift; | |
52 | n &= (1 << nm->n.width) - 1; | |
53 | ||
54 | m = reg >> nm->m.shift; | |
55 | m &= (1 << nm->m.width) - 1; | |
56 | ||
57 | return parent_rate * (n + 1) / (m + 1); | |
58 | } | |
59 | ||
60 | static long ccu_nm_round_rate(struct clk_hw *hw, unsigned long rate, | |
61 | unsigned long *parent_rate) | |
62 | { | |
63 | struct ccu_nm *nm = hw_to_ccu_nm(hw); | |
87ba9e59 | 64 | unsigned long max_n, max_m; |
6174a1e2 MR |
65 | unsigned long n, m; |
66 | ||
87ba9e59 MR |
67 | max_n = 1 << nm->n.width; |
68 | max_m = nm->m.max ?: 1 << nm->m.width; | |
69 | ||
70 | rational_best_approximation(rate, *parent_rate, max_n, max_m, &n, &m); | |
6174a1e2 MR |
71 | |
72 | return *parent_rate * n / m; | |
73 | } | |
74 | ||
75 | static int ccu_nm_set_rate(struct clk_hw *hw, unsigned long rate, | |
76 | unsigned long parent_rate) | |
77 | { | |
78 | struct ccu_nm *nm = hw_to_ccu_nm(hw); | |
79 | unsigned long flags; | |
87ba9e59 | 80 | unsigned long max_n, max_m; |
6174a1e2 MR |
81 | unsigned long n, m; |
82 | u32 reg; | |
83 | ||
84 | if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate)) | |
85 | return ccu_frac_helper_set_rate(&nm->common, &nm->frac, rate); | |
86 | else | |
87 | ccu_frac_helper_disable(&nm->common, &nm->frac); | |
88 | ||
87ba9e59 MR |
89 | max_n = 1 << nm->n.width; |
90 | max_m = nm->m.max ?: 1 << nm->m.width; | |
91 | ||
92 | rational_best_approximation(rate, parent_rate, max_n, max_m, &n, &m); | |
6174a1e2 MR |
93 | |
94 | spin_lock_irqsave(nm->common.lock, flags); | |
95 | ||
96 | reg = readl(nm->common.base + nm->common.reg); | |
97 | reg &= ~GENMASK(nm->n.width + nm->n.shift - 1, nm->n.shift); | |
98 | reg &= ~GENMASK(nm->m.width + nm->m.shift - 1, nm->m.shift); | |
99 | ||
100 | writel(reg | ((m - 1) << nm->m.shift) | ((n - 1) << nm->n.shift), | |
101 | nm->common.base + nm->common.reg); | |
102 | ||
103 | spin_unlock_irqrestore(nm->common.lock, flags); | |
104 | ||
105 | ccu_helper_wait_for_lock(&nm->common, nm->lock); | |
106 | ||
107 | return 0; | |
108 | } | |
109 | ||
110 | const struct clk_ops ccu_nm_ops = { | |
111 | .disable = ccu_nm_disable, | |
112 | .enable = ccu_nm_enable, | |
113 | .is_enabled = ccu_nm_is_enabled, | |
114 | ||
115 | .recalc_rate = ccu_nm_recalc_rate, | |
116 | .round_rate = ccu_nm_round_rate, | |
117 | .set_rate = ccu_nm_set_rate, | |
118 | }; |