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
159
160
161
162
163
|
/*
* Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
* Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Gated clock implementation
*/
#include <linux/clk-provider.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/string.h>
#include "clk.h"
/**
* DOC: basic gatable clock which can gate and ungate it's ouput
*
* Traits of this clock:
* prepare - clk_(un)prepare only ensures parent is (un)prepared
* enable - clk_enable and clk_disable are functional & control gating
* rate - inherits rate from parent. No clk_set_rate support
* parent - fixed parent. No clk_set_parent support
*/
struct clk_gate2 {
struct clk_hw hw;
void __iomem *reg;
u8 bit_idx;
u8 cgr_val;
u8 flags;
spinlock_t *lock;
unsigned int *share_count;
};
#define to_clk_gate2(_hw) container_of(_hw, struct clk_gate2, hw)
static int clk_gate2_enable(struct clk_hw *hw)
{
struct clk_gate2 *gate = to_clk_gate2(hw);
u32 reg;
unsigned long flags = 0;
spin_lock_irqsave(gate->lock, flags);
if (gate->share_count && (*gate->share_count)++ > 0)
goto out;
reg = readl(gate->reg);
reg &= ~(3 << gate->bit_idx);
reg |= gate->cgr_val << gate->bit_idx;
writel(reg, gate->reg);
out:
spin_unlock_irqrestore(gate->lock, flags);
return 0;
}
static void clk_gate2_disable(struct clk_hw *hw)
{
struct clk_gate2 *gate = to_clk_gate2(hw);
u32 reg;
unsigned long flags = 0;
spin_lock_irqsave(gate->lock, flags);
if (gate->share_count) {
if (WARN_ON(*gate->share_count == 0))
goto out;
else if (--(*gate->share_count) > 0)
goto out;
}
reg = readl(gate->reg);
reg &= ~(3 << gate->bit_idx);
writel(reg, gate->reg);
out:
spin_unlock_irqrestore(gate->lock, flags);
}
static int clk_gate2_reg_is_enabled(void __iomem *reg, u8 bit_idx)
{
u32 val = readl(reg);
if (((val >> bit_idx) & 1) == 1)
return 1;
return 0;
}
static int clk_gate2_is_enabled(struct clk_hw *hw)
{
struct clk_gate2 *gate = to_clk_gate2(hw);
return clk_gate2_reg_is_enabled(gate->reg, gate->bit_idx);
}
static void clk_gate2_disable_unused(struct clk_hw *hw)
{
struct clk_gate2 *gate = to_clk_gate2(hw);
unsigned long flags = 0;
u32 reg;
spin_lock_irqsave(gate->lock, flags);
if (!gate->share_count || *gate->share_count == 0) {
reg = readl(gate->reg);
reg &= ~(3 << gate->bit_idx);
writel(reg, gate->reg);
}
spin_unlock_irqrestore(gate->lock, flags);
}
static const struct clk_ops clk_gate2_ops = {
.enable = clk_gate2_enable,
.disable = clk_gate2_disable,
.disable_unused = clk_gate2_disable_unused,
.is_enabled = clk_gate2_is_enabled,
};
struct clk *clk_register_gate2(struct device *dev, const char *name,
const char *parent_name, unsigned long flags,
void __iomem *reg, u8 bit_idx, u8 cgr_val,
u8 clk_gate2_flags, spinlock_t *lock,
unsigned int *share_count)
{
struct clk_gate2 *gate;
struct clk *clk;
struct clk_init_data init;
gate = kzalloc(sizeof(struct clk_gate2), GFP_KERNEL);
if (!gate)
return ERR_PTR(-ENOMEM);
/* struct clk_gate2 assignments */
gate->reg = reg;
gate->bit_idx = bit_idx;
gate->cgr_val = cgr_val;
gate->flags = clk_gate2_flags;
gate->lock = lock;
gate->share_count = share_count;
init.name = name;
init.ops = &clk_gate2_ops;
init.flags = flags;
init.parent_names = parent_name ? &parent_name : NULL;
init.num_parents = parent_name ? 1 : 0;
gate->hw.init = &init;
clk = clk_register(dev, &gate->hw);
if (IS_ERR(clk))
kfree(gate);
return clk;
}
|
