summaryrefslogtreecommitdiff
path: root/drivers/clk/clk-conf.c
blob: 43a218f35b190a21e62bc520cdac38f275f5da82 (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
/*
 * Copyright (C) 2014 Samsung Electronics Co., Ltd.
 * Sylwester Nawrocki <s.nawrocki@samsung.com>
 *
 * 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.
 */

#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/clk/clk-conf.h>
#include <linux/device.h>
#include <linux/of.h>
#include <linux/printk.h>

static int __set_clk_parents(struct device_node *node, bool clk_supplier)
{
	struct of_phandle_args clkspec;
	int index, rc, num_parents;
	struct clk *clk, *pclk;

	num_parents = of_count_phandle_with_args(node, "assigned-clock-parents",
						 "#clock-cells");
	if (num_parents == -EINVAL)
		pr_err("clk: invalid value of clock-parents property at %s\n",
		       node->full_name);

	for (index = 0; index < num_parents; index++) {
		rc = of_parse_phandle_with_args(node, "assigned-clock-parents",
					"#clock-cells",	index, &clkspec);
		if (rc < 0) {
			/* skip empty (null) phandles */
			if (rc == -ENOENT)
				continue;
			else
				return rc;
		}
		if (clkspec.np == node && !clk_supplier)
			return 0;
		pclk = of_clk_get_from_provider(&clkspec);
		if (IS_ERR(pclk)) {
			pr_warn("clk: couldn't get parent clock %d for %s\n",
				index, node->full_name);
			return PTR_ERR(pclk);
		}

		rc = of_parse_phandle_with_args(node, "assigned-clocks",
					"#clock-cells", index, &clkspec);
		if (rc < 0)
			goto err;
		if (clkspec.np == node && !clk_supplier) {
			rc = 0;
			goto err;
		}
		clk = of_clk_get_from_provider(&clkspec);
		if (IS_ERR(clk)) {
			pr_warn("clk: couldn't get parent clock %d for %s\n",
				index, node->full_name);
			rc = PTR_ERR(clk);
			goto err;
		}

		rc = clk_set_parent(clk, pclk);
		if (rc < 0)
			pr_err("clk: failed to reparent %s to %s: %d\n",
			       __clk_get_name(clk), __clk_get_name(pclk), rc);
		clk_put(clk);
		clk_put(pclk);
	}
	return 0;
err:
	clk_put(pclk);
	return rc;
}

static int __set_clk_rates(struct device_node *node, bool clk_supplier)
{
	struct of_phandle_args clkspec;
	struct property	*prop;
	const __be32 *cur;
	int rc, index = 0;
	struct clk *clk;
	u32 rate;

	of_property_for_each_u32(node, "assigned-clock-rates", prop, cur, rate) {
		if (rate) {
			rc = of_parse_phandle_with_args(node, "assigned-clocks",
					"#clock-cells",	index, &clkspec);
			if (rc < 0) {
				/* skip empty (null) phandles */
				if (rc == -ENOENT)
					continue;
				else
					return rc;
			}
			if (clkspec.np == node && !clk_supplier)
				return 0;

			clk = of_clk_get_from_provider(&clkspec);
			if (IS_ERR(clk)) {
				pr_warn("clk: couldn't get clock %d for %s\n",
					index, node->full_name);
				return PTR_ERR(clk);
			}

			rc = clk_set_rate(clk, rate);
			if (rc < 0)
				pr_err("clk: couldn't set %s clk rate to %d (%d), current rate: %ld\n",
				       __clk_get_name(clk), rate, rc,
				       clk_get_rate(clk));
			clk_put(clk);
		}
		index++;
	}
	return 0;
}

/**
 * of_clk_set_defaults() - parse and set assigned clocks configuration
 * @node: device node to apply clock settings for
 * @clk_supplier: true if clocks supplied by @node should also be considered
 *
 * This function parses 'assigned-{clocks/clock-parents/clock-rates}' properties
 * and sets any specified clock parents and rates. The @clk_supplier argument
 * should be set to true if @node may be also a clock supplier of any clock
 * listed in its 'assigned-clocks' or 'assigned-clock-parents' properties.
 * If @clk_supplier is false the function exits returning 0 as soon as it
 * determines the @node is also a supplier of any of the clocks.
 */
int of_clk_set_defaults(struct device_node *node, bool clk_supplier)
{
	int rc;

	if (!node)
		return 0;

	rc = __set_clk_parents(node, clk_supplier);
	if (rc < 0)
		return rc;

	return __set_clk_rates(node, clk_supplier);
}
EXPORT_SYMBOL_GPL(of_clk_set_defaults);