summaryrefslogtreecommitdiff
path: root/drivers/clk/clk-fixed-rate.c
blob: 00ef4f5e53fe247d946100efcfe5ee93d12fa642 (plain)
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
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
 * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
 *
 * Fixed rate 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/of.h>
#include <linux/platform_device.h>

/*
 * DOC: basic fixed-rate clock that cannot gate
 *
 * Traits of this clock:
 * prepare - clk_(un)prepare only ensures parents are prepared
 * enable - clk_enable only ensures parents are enabled
 * rate - rate is always a fixed value.  No clk_set_rate support
 * parent - fixed parent.  No clk_set_parent support
 */

static unsigned long clk_fixed_rate_recalc_rate(struct clk_hw *hw,
		unsigned long parent_rate)
{
	return to_clk_fixed_rate(hw)->fixed_rate;
}

static unsigned long clk_fixed_rate_recalc_accuracy(struct clk_hw *hw,
		unsigned long parent_accuracy)
{
	return to_clk_fixed_rate(hw)->fixed_accuracy;
}

const struct clk_ops clk_fixed_rate_ops = {
	.recalc_rate = clk_fixed_rate_recalc_rate,
	.recalc_accuracy = clk_fixed_rate_recalc_accuracy,
};
EXPORT_SYMBOL_GPL(clk_fixed_rate_ops);

/**
 * clk_hw_register_fixed_rate_with_accuracy - register fixed-rate clock with
 * the clock framework
 * @dev: device that is registering this clock
 * @name: name of this clock
 * @parent_name: name of clock's parent
 * @flags: framework-specific flags
 * @fixed_rate: non-adjustable clock rate
 * @fixed_accuracy: non-adjustable clock rate
 */
struct clk_hw *clk_hw_register_fixed_rate_with_accuracy(struct device *dev,
		const char *name, const char *parent_name, unsigned long flags,
		unsigned long fixed_rate, unsigned long fixed_accuracy)
{
	struct clk_fixed_rate *fixed;
	struct clk_hw *hw;
	struct clk_init_data init;
	int ret;

	/* allocate fixed-rate clock */
	fixed = kzalloc(sizeof(*fixed), GFP_KERNEL);
	if (!fixed)
		return ERR_PTR(-ENOMEM);

	init.name = name;
	init.ops = &clk_fixed_rate_ops;
	init.flags = flags | CLK_IS_BASIC;
	init.parent_names = (parent_name ? &parent_name: NULL);
	init.num_parents = (parent_name ? 1 : 0);

	/* struct clk_fixed_rate assignments */
	fixed->fixed_rate = fixed_rate;
	fixed->fixed_accuracy = fixed_accuracy;
	fixed->hw.init = &init;

	/* register the clock */
	hw = &fixed->hw;
	ret = clk_hw_register(dev, hw);
	if (ret) {
		kfree(fixed);
		hw = ERR_PTR(ret);
	}

	return hw;
}
EXPORT_SYMBOL_GPL(clk_hw_register_fixed_rate_with_accuracy);

struct clk *clk_register_fixed_rate_with_accuracy(struct device *dev,
		const char *name, const char *parent_name, unsigned long flags,
		unsigned long fixed_rate, unsigned long fixed_accuracy)
{
	struct clk_hw *hw;

	hw = clk_hw_register_fixed_rate_with_accuracy(dev, name, parent_name,
			flags, fixed_rate, fixed_accuracy);
	if (IS_ERR(hw))
		return ERR_CAST(hw);
	return hw->clk;
}
EXPORT_SYMBOL_GPL(clk_register_fixed_rate_with_accuracy);

/**
 * clk_hw_register_fixed_rate - register fixed-rate clock with the clock
 * framework
 * @dev: device that is registering this clock
 * @name: name of this clock
 * @parent_name: name of clock's parent
 * @flags: framework-specific flags
 * @fixed_rate: non-adjustable clock rate
 */
struct clk_hw *clk_hw_register_fixed_rate(struct device *dev, const char *name,
		const char *parent_name, unsigned long flags,
		unsigned long fixed_rate)
{
	return clk_hw_register_fixed_rate_with_accuracy(dev, name, parent_name,
						     flags, fixed_rate, 0);
}
EXPORT_SYMBOL_GPL(clk_hw_register_fixed_rate);

struct clk *clk_register_fixed_rate(struct device *dev, const char *name,
		const char *parent_name, unsigned long flags,
		unsigned long fixed_rate)
{
	return clk_register_fixed_rate_with_accuracy(dev, name, parent_name,
						     flags, fixed_rate, 0);
}
EXPORT_SYMBOL_GPL(clk_register_fixed_rate);

void clk_unregister_fixed_rate(struct clk *clk)
{
	struct clk_hw *hw;

	hw = __clk_get_hw(clk);
	if (!hw)
		return;

	clk_unregister(clk);
	kfree(to_clk_fixed_rate(hw));
}
EXPORT_SYMBOL_GPL(clk_unregister_fixed_rate);

void clk_hw_unregister_fixed_rate(struct clk_hw *hw)
{
	struct clk_fixed_rate *fixed;

	fixed = to_clk_fixed_rate(hw);

	clk_hw_unregister(hw);
	kfree(fixed);
}
EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_rate);

#ifdef CONFIG_OF
static struct clk *_of_fixed_clk_setup(struct device_node *node)
{
	struct clk *clk;
	const char *clk_name = node->name;
	u32 rate;
	u32 accuracy = 0;
	int ret;

	if (of_property_read_u32(node, "clock-frequency", &rate))
		return ERR_PTR(-EIO);

	of_property_read_u32(node, "clock-accuracy", &accuracy);

	of_property_read_string(node, "clock-output-names", &clk_name);

	clk = clk_register_fixed_rate_with_accuracy(NULL, clk_name, NULL,
						    0, rate, accuracy);
	if (IS_ERR(clk))
		return clk;

	ret = of_clk_add_provider(node, of_clk_src_simple_get, clk);
	if (ret) {
		clk_unregister(clk);
		return ERR_PTR(ret);
	}

	return clk;
}

/**
 * of_fixed_clk_setup() - Setup function for simple fixed rate clock
 */
void __init of_fixed_clk_setup(struct device_node *node)
{
	_of_fixed_clk_setup(node);
}
CLK_OF_DECLARE(fixed_clk, "fixed-clock", of_fixed_clk_setup);

static int of_fixed_clk_remove(struct platform_device *pdev)
{
	struct clk *clk = platform_get_drvdata(pdev);

	of_clk_del_provider(pdev->dev.of_node);
	clk_unregister_fixed_rate(clk);

	return 0;
}

static int of_fixed_clk_probe(struct platform_device *pdev)
{
	struct clk *clk;

	/*
	 * This function is not executed when of_fixed_clk_setup
	 * succeeded.
	 */
	clk = _of_fixed_clk_setup(pdev->dev.of_node);
	if (IS_ERR(clk))
		return PTR_ERR(clk);

	platform_set_drvdata(pdev, clk);

	return 0;
}

static const struct of_device_id of_fixed_clk_ids[] = {
	{ .compatible = "fixed-clock" },
	{ }
};
MODULE_DEVICE_TABLE(of, of_fixed_clk_ids);

static struct platform_driver of_fixed_clk_driver = {
	.driver = {
		.name = "of_fixed_clk",
		.of_match_table = of_fixed_clk_ids,
	},
	.probe = of_fixed_clk_probe,
	.remove = of_fixed_clk_remove,
};
builtin_platform_driver(of_fixed_clk_driver);
#endif