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12#define pr_fmt(fmt) "clk-frac-synth: " fmt
13
14#include <linux/clk-provider.h>
15#include <linux/slab.h>
16#include <linux/io.h>
17#include <linux/err.h>
18#include "clk.h"
19
20#define DIV_FACTOR_MASK 0x1FFFF
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42#define to_clk_frac(_hw) container_of(_hw, struct clk_frac, hw)
43
44static unsigned long frac_calc_rate(struct clk_hw *hw, unsigned long prate,
45 int index)
46{
47 struct clk_frac *frac = to_clk_frac(hw);
48 struct frac_rate_tbl *rtbl = frac->rtbl;
49
50 prate /= 10000;
51 prate <<= 14;
52 prate /= (2 * rtbl[index].div);
53 prate *= 10000;
54
55 return prate;
56}
57
58static long clk_frac_round_rate(struct clk_hw *hw, unsigned long drate,
59 unsigned long *prate)
60{
61 struct clk_frac *frac = to_clk_frac(hw);
62 int unused;
63
64 return clk_round_rate_index(hw, drate, *prate, frac_calc_rate,
65 frac->rtbl_cnt, &unused);
66}
67
68static unsigned long clk_frac_recalc_rate(struct clk_hw *hw,
69 unsigned long parent_rate)
70{
71 struct clk_frac *frac = to_clk_frac(hw);
72 unsigned long flags = 0;
73 unsigned int div = 1, val;
74
75 if (frac->lock)
76 spin_lock_irqsave(frac->lock, flags);
77
78 val = readl_relaxed(frac->reg);
79
80 if (frac->lock)
81 spin_unlock_irqrestore(frac->lock, flags);
82
83 div = val & DIV_FACTOR_MASK;
84
85 if (!div)
86 return 0;
87
88 parent_rate = parent_rate / 10000;
89
90 parent_rate = (parent_rate << 14) / (2 * div);
91 return parent_rate * 10000;
92}
93
94
95static int clk_frac_set_rate(struct clk_hw *hw, unsigned long drate,
96 unsigned long prate)
97{
98 struct clk_frac *frac = to_clk_frac(hw);
99 struct frac_rate_tbl *rtbl = frac->rtbl;
100 unsigned long flags = 0, val;
101 int i;
102
103 clk_round_rate_index(hw, drate, prate, frac_calc_rate, frac->rtbl_cnt,
104 &i);
105
106 if (frac->lock)
107 spin_lock_irqsave(frac->lock, flags);
108
109 val = readl_relaxed(frac->reg) & ~DIV_FACTOR_MASK;
110 val |= rtbl[i].div & DIV_FACTOR_MASK;
111 writel_relaxed(val, frac->reg);
112
113 if (frac->lock)
114 spin_unlock_irqrestore(frac->lock, flags);
115
116 return 0;
117}
118
119struct clk_ops clk_frac_ops = {
120 .recalc_rate = clk_frac_recalc_rate,
121 .round_rate = clk_frac_round_rate,
122 .set_rate = clk_frac_set_rate,
123};
124
125struct clk *clk_register_frac(const char *name, const char *parent_name,
126 unsigned long flags, void __iomem *reg,
127 struct frac_rate_tbl *rtbl, u8 rtbl_cnt, spinlock_t *lock)
128{
129 struct clk_init_data init;
130 struct clk_frac *frac;
131 struct clk *clk;
132
133 if (!name || !parent_name || !reg || !rtbl || !rtbl_cnt) {
134 pr_err("Invalid arguments passed");
135 return ERR_PTR(-EINVAL);
136 }
137
138 frac = kzalloc(sizeof(*frac), GFP_KERNEL);
139 if (!frac) {
140 pr_err("could not allocate frac clk\n");
141 return ERR_PTR(-ENOMEM);
142 }
143
144
145 frac->reg = reg;
146 frac->rtbl = rtbl;
147 frac->rtbl_cnt = rtbl_cnt;
148 frac->lock = lock;
149 frac->hw.init = &init;
150
151 init.name = name;
152 init.ops = &clk_frac_ops;
153 init.flags = flags;
154 init.parent_names = &parent_name;
155 init.num_parents = 1;
156
157 clk = clk_register(NULL, &frac->hw);
158 if (!IS_ERR_OR_NULL(clk))
159 return clk;
160
161 pr_err("clk register failed\n");
162 kfree(frac);
163
164 return NULL;
165}
166