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1/*
2 * Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 */
10
11#include <linux/clk-provider.h>
12#include <linux/clkdev.h>
13#include <linux/clk/at91_pmc.h>
14#include <linux/of.h>
15#include <linux/mfd/syscon.h>
16#include <linux/regmap.h>
17
18#include "pmc.h"
19
20#define SYSTEM_MAX_ID 31
21
22#define SYSTEM_MAX_NAME_SZ 32
23
24#define to_clk_system(hw) container_of(hw, struct clk_system, hw)
25struct clk_system {
26 struct clk_hw hw;
27 struct regmap *regmap;
28 u8 id;
29};
30
31static inline int is_pck(int id)
32{
33 return (id >= 8) && (id <= 15);
34}
35
36static inline bool clk_system_ready(struct regmap *regmap, int id)
37{
38 unsigned int status;
39
40 regmap_read(regmap, AT91_PMC_SR, &status);
41
42 return status & (1 << id) ? 1 : 0;
43}
44
45static int clk_system_prepare(struct clk_hw *hw)
46{
47 struct clk_system *sys = to_clk_system(hw);
48
49 regmap_write(sys->regmap, AT91_PMC_SCER, 1 << sys->id);
50
51 if (!is_pck(sys->id))
52 return 0;
53
54 while (!clk_system_ready(sys->regmap, sys->id))
55 cpu_relax();
56
57 return 0;
58}
59
60static void clk_system_unprepare(struct clk_hw *hw)
61{
62 struct clk_system *sys = to_clk_system(hw);
63
64 regmap_write(sys->regmap, AT91_PMC_SCDR, 1 << sys->id);
65}
66
67static int clk_system_is_prepared(struct clk_hw *hw)
68{
69 struct clk_system *sys = to_clk_system(hw);
70 unsigned int status;
71
72 regmap_read(sys->regmap, AT91_PMC_SCSR, &status);
73
74 if (!(status & (1 << sys->id)))
75 return 0;
76
77 if (!is_pck(sys->id))
78 return 1;
79
80 regmap_read(sys->regmap, AT91_PMC_SR, &status);
81
82 return status & (1 << sys->id) ? 1 : 0;
83}
84
85static const struct clk_ops system_ops = {
86 .prepare = clk_system_prepare,
87 .unprepare = clk_system_unprepare,
88 .is_prepared = clk_system_is_prepared,
89};
90
91struct clk_hw * __init
92at91_clk_register_system(struct regmap *regmap, const char *name,
93 const char *parent_name, u8 id)
94{
95 struct clk_system *sys;
96 struct clk_hw *hw;
97 struct clk_init_data init;
98 int ret;
99
100 if (!parent_name || id > SYSTEM_MAX_ID)
101 return ERR_PTR(-EINVAL);
102
103 sys = kzalloc(sizeof(*sys), GFP_KERNEL);
104 if (!sys)
105 return ERR_PTR(-ENOMEM);
106
107 init.name = name;
108 init.ops = &system_ops;
109 init.parent_names = &parent_name;
110 init.num_parents = 1;
111 init.flags = CLK_SET_RATE_PARENT;
112
113 sys->id = id;
114 sys->hw.init = &init;
115 sys->regmap = regmap;
116
117 hw = &sys->hw;
118 ret = clk_hw_register(NULL, &sys->hw);
119 if (ret) {
120 kfree(sys);
121 hw = ERR_PTR(ret);
122 }
123
124 return hw;
125}
126

Warning: That file was not part of the compilation database. It may have many parsing errors.