1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
|
/*
* Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
*/
#include <linux/clk-provider.h>
#include <linux/clkdev.h>
#include <linux/clk/at91_pmc.h>
#include <linux/of.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include "pmc.h"
#define SYSTEM_MAX_ID 31
#define SYSTEM_MAX_NAME_SZ 32
#define to_clk_system(hw) container_of(hw, struct clk_system, hw)
struct clk_system {
struct clk_hw hw;
struct regmap *regmap;
u8 id;
};
static inline int is_pck(int id)
{
return (id >= 8) && (id <= 15);
}
static inline bool clk_system_ready(struct regmap *regmap, int id)
{
unsigned int status;
regmap_read(regmap, AT91_PMC_SR, &status);
return status & (1 << id) ? 1 : 0;
}
static int clk_system_prepare(struct clk_hw *hw)
{
struct clk_system *sys = to_clk_system(hw);
regmap_write(sys->regmap, AT91_PMC_SCER, 1 << sys->id);
if (!is_pck(sys->id))
return 0;
while (!clk_system_ready(sys->regmap, sys->id))
cpu_relax();
return 0;
}
static void clk_system_unprepare(struct clk_hw *hw)
{
struct clk_system *sys = to_clk_system(hw);
regmap_write(sys->regmap, AT91_PMC_SCDR, 1 << sys->id);
}
static int clk_system_is_prepared(struct clk_hw *hw)
{
struct clk_system *sys = to_clk_system(hw);
unsigned int status;
regmap_read(sys->regmap, AT91_PMC_SCSR, &status);
if (!(status & (1 << sys->id)))
return 0;
if (!is_pck(sys->id))
return 1;
regmap_read(sys->regmap, AT91_PMC_SR, &status);
return status & (1 << sys->id) ? 1 : 0;
}
static const struct clk_ops system_ops = {
.prepare = clk_system_prepare,
.unprepare = clk_system_unprepare,
.is_prepared = clk_system_is_prepared,
};
static struct clk * __init
at91_clk_register_system(struct regmap *regmap, const char *name,
const char *parent_name, u8 id)
{
struct clk_system *sys;
struct clk *clk = NULL;
struct clk_init_data init;
if (!parent_name || id > SYSTEM_MAX_ID)
return ERR_PTR(-EINVAL);
sys = kzalloc(sizeof(*sys), GFP_KERNEL);
if (!sys)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &system_ops;
init.parent_names = &parent_name;
init.num_parents = 1;
init.flags = CLK_SET_RATE_PARENT;
sys->id = id;
sys->hw.init = &init;
sys->regmap = regmap;
clk = clk_register(NULL, &sys->hw);
if (IS_ERR(clk))
kfree(sys);
return clk;
}
static void __init of_at91rm9200_clk_sys_setup(struct device_node *np)
{
int num;
u32 id;
struct clk *clk;
const char *name;
struct device_node *sysclknp;
const char *parent_name;
struct regmap *regmap;
num = of_get_child_count(np);
if (num > (SYSTEM_MAX_ID + 1))
return;
regmap = syscon_node_to_regmap(of_get_parent(np));
if (IS_ERR(regmap))
return;
for_each_child_of_node(np, sysclknp) {
if (of_property_read_u32(sysclknp, "reg", &id))
continue;
if (of_property_read_string(np, "clock-output-names", &name))
name = sysclknp->name;
parent_name = of_clk_get_parent_name(sysclknp, 0);
clk = at91_clk_register_system(regmap, name, parent_name, id);
if (IS_ERR(clk))
continue;
of_clk_add_provider(sysclknp, of_clk_src_simple_get, clk);
}
}
CLK_OF_DECLARE(at91rm9200_clk_sys, "atmel,at91rm9200-clk-system",
of_at91rm9200_clk_sys_setup);
|
