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6b63f023 CX |
1 | /* |
2 | * mmp factor clock operation source file | |
3 | * | |
4 | * Copyright (C) 2012 Marvell | |
5 | * Chao Xie <xiechao.mail@gmail.com> | |
6 | * | |
7 | * This file is licensed under the terms of the GNU General Public | |
8 | * License version 2. This program is licensed "as is" without any | |
9 | * warranty of any kind, whether express or implied. | |
10 | */ | |
11 | ||
12 | #include <linux/clk-provider.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/io.h> | |
15 | #include <linux/err.h> | |
16 | ||
17 | #include "clk.h" | |
18 | /* | |
19 | * It is M/N clock | |
20 | * | |
21 | * Fout from synthesizer can be given from two equations: | |
22 | * numerator/denominator = Fin / (Fout * factor) | |
23 | */ | |
24 | ||
25 | #define to_clk_factor(hw) container_of(hw, struct clk_factor, hw) | |
26 | struct clk_factor { | |
27 | struct clk_hw hw; | |
28 | void __iomem *base; | |
29 | struct clk_factor_masks *masks; | |
30 | struct clk_factor_tbl *ftbl; | |
31 | unsigned int ftbl_cnt; | |
32 | }; | |
33 | ||
34 | static long clk_factor_round_rate(struct clk_hw *hw, unsigned long drate, | |
35 | unsigned long *prate) | |
36 | { | |
37 | struct clk_factor *factor = to_clk_factor(hw); | |
38 | unsigned long rate = 0, prev_rate; | |
39 | int i; | |
40 | ||
41 | for (i = 0; i < factor->ftbl_cnt; i++) { | |
42 | prev_rate = rate; | |
43 | rate = (((*prate / 10000) * factor->ftbl[i].num) / | |
44 | (factor->ftbl[i].den * factor->masks->factor)) * 10000; | |
45 | if (rate > drate) | |
46 | break; | |
47 | } | |
48 | if (i == 0) | |
49 | return rate; | |
50 | else | |
51 | return prev_rate; | |
52 | } | |
53 | ||
54 | static unsigned long clk_factor_recalc_rate(struct clk_hw *hw, | |
55 | unsigned long parent_rate) | |
56 | { | |
57 | struct clk_factor *factor = to_clk_factor(hw); | |
58 | struct clk_factor_masks *masks = factor->masks; | |
59 | unsigned int val, num, den; | |
60 | ||
61 | val = readl_relaxed(factor->base); | |
62 | ||
63 | /* calculate numerator */ | |
64 | num = (val >> masks->num_shift) & masks->num_mask; | |
65 | ||
66 | /* calculate denominator */ | |
67 | den = (val >> masks->den_shift) & masks->num_mask; | |
68 | ||
69 | if (!den) | |
70 | return 0; | |
71 | ||
72 | return (((parent_rate / 10000) * den) / | |
73 | (num * factor->masks->factor)) * 10000; | |
74 | } | |
75 | ||
76 | /* Configures new clock rate*/ | |
77 | static int clk_factor_set_rate(struct clk_hw *hw, unsigned long drate, | |
78 | unsigned long prate) | |
79 | { | |
80 | struct clk_factor *factor = to_clk_factor(hw); | |
81 | struct clk_factor_masks *masks = factor->masks; | |
82 | int i; | |
83 | unsigned long val; | |
84 | unsigned long prev_rate, rate = 0; | |
85 | ||
86 | for (i = 0; i < factor->ftbl_cnt; i++) { | |
87 | prev_rate = rate; | |
88 | rate = (((prate / 10000) * factor->ftbl[i].num) / | |
89 | (factor->ftbl[i].den * factor->masks->factor)) * 10000; | |
90 | if (rate > drate) | |
91 | break; | |
92 | } | |
93 | if (i > 0) | |
94 | i--; | |
95 | ||
96 | val = readl_relaxed(factor->base); | |
97 | ||
98 | val &= ~(masks->num_mask << masks->num_shift); | |
99 | val |= (factor->ftbl[i].num & masks->num_mask) << masks->num_shift; | |
100 | ||
101 | val &= ~(masks->den_mask << masks->den_shift); | |
102 | val |= (factor->ftbl[i].den & masks->den_mask) << masks->den_shift; | |
103 | ||
104 | writel_relaxed(val, factor->base); | |
105 | ||
106 | return 0; | |
107 | } | |
108 | ||
109 | static struct clk_ops clk_factor_ops = { | |
110 | .recalc_rate = clk_factor_recalc_rate, | |
111 | .round_rate = clk_factor_round_rate, | |
112 | .set_rate = clk_factor_set_rate, | |
113 | }; | |
114 | ||
115 | struct clk *mmp_clk_register_factor(const char *name, const char *parent_name, | |
116 | unsigned long flags, void __iomem *base, | |
117 | struct clk_factor_masks *masks, struct clk_factor_tbl *ftbl, | |
118 | unsigned int ftbl_cnt) | |
119 | { | |
120 | struct clk_factor *factor; | |
121 | struct clk_init_data init; | |
122 | struct clk *clk; | |
123 | ||
124 | if (!masks) { | |
125 | pr_err("%s: must pass a clk_factor_mask\n", __func__); | |
126 | return ERR_PTR(-EINVAL); | |
127 | } | |
128 | ||
129 | factor = kzalloc(sizeof(*factor), GFP_KERNEL); | |
130 | if (!factor) { | |
131 | pr_err("%s: could not allocate factor clk\n", __func__); | |
132 | return ERR_PTR(-ENOMEM); | |
133 | } | |
134 | ||
135 | /* struct clk_aux assignments */ | |
136 | factor->base = base; | |
137 | factor->masks = masks; | |
138 | factor->ftbl = ftbl; | |
139 | factor->ftbl_cnt = ftbl_cnt; | |
140 | factor->hw.init = &init; | |
141 | ||
142 | init.name = name; | |
143 | init.ops = &clk_factor_ops; | |
144 | init.flags = flags; | |
145 | init.parent_names = &parent_name; | |
146 | init.num_parents = 1; | |
147 | ||
148 | clk = clk_register(NULL, &factor->hw); | |
149 | if (IS_ERR_OR_NULL(clk)) | |
150 | kfree(factor); | |
151 | ||
152 | return clk; | |
153 | } |