1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2014 Samsung Electronics Co., Ltd.
4 * Sylwester Nawrocki <s.nawrocki@samsung.com>
5 */
6
7#include <linux/clk.h>
8#include <linux/clk-provider.h>
9#include <linux/clk/clk-conf.h>
10#include <linux/device.h>
11#include <linux/of.h>
12#include <linux/printk.h>
13
14static int __set_clk_parents(struct device_node *node, bool clk_supplier)
15{
16 struct of_phandle_args clkspec;
17 int index, rc, num_parents;
18 struct clk *clk, *pclk;
19
20 num_parents = of_count_phandle_with_args(node, "assigned-clock-parents",
21 "#clock-cells");
22 if (num_parents == -EINVAL)
23 pr_err("clk: invalid value of clock-parents property at %pOF\n",
24 node);
25
26 for (index = 0; index < num_parents; index++) {
27 rc = of_parse_phandle_with_args(node, "assigned-clock-parents",
28 "#clock-cells", index, &clkspec);
29 if (rc < 0) {
30 /* skip empty (null) phandles */
31 if (rc == -ENOENT)
32 continue;
33 else
34 return rc;
35 }
36 if (clkspec.np == node && !clk_supplier)
37 return 0;
38 pclk = of_clk_get_from_provider(&clkspec);
39 if (IS_ERR(pclk)) {
40 if (PTR_ERR(pclk) != -EPROBE_DEFER)
41 pr_warn("clk: couldn't get parent clock %d for %pOF\n",
42 index, node);
43 return PTR_ERR(pclk);
44 }
45
46 rc = of_parse_phandle_with_args(node, "assigned-clocks",
47 "#clock-cells", index, &clkspec);
48 if (rc < 0)
49 goto err;
50 if (clkspec.np == node && !clk_supplier) {
51 rc = 0;
52 goto err;
53 }
54 clk = of_clk_get_from_provider(&clkspec);
55 if (IS_ERR(clk)) {
56 if (PTR_ERR(clk) != -EPROBE_DEFER)
57 pr_warn("clk: couldn't get assigned clock %d for %pOF\n",
58 index, node);
59 rc = PTR_ERR(clk);
60 goto err;
61 }
62
63 rc = clk_set_parent(clk, pclk);
64 if (rc < 0)
65 pr_err("clk: failed to reparent %s to %s: %d\n",
66 __clk_get_name(clk), __clk_get_name(pclk), rc);
67 clk_put(clk);
68 clk_put(pclk);
69 }
70 return 0;
71err:
72 clk_put(pclk);
73 return rc;
74}
75
76static int __set_clk_rates(struct device_node *node, bool clk_supplier)
77{
78 struct of_phandle_args clkspec;
79 struct property *prop;
80 const __be32 *cur;
81 int rc, index = 0;
82 struct clk *clk;
83 u32 rate;
84
85 of_property_for_each_u32(node, "assigned-clock-rates", prop, cur, rate) {
86 if (rate) {
87 rc = of_parse_phandle_with_args(node, "assigned-clocks",
88 "#clock-cells", index, &clkspec);
89 if (rc < 0) {
90 /* skip empty (null) phandles */
91 if (rc == -ENOENT)
92 continue;
93 else
94 return rc;
95 }
96 if (clkspec.np == node && !clk_supplier)
97 return 0;
98
99 clk = of_clk_get_from_provider(&clkspec);
100 if (IS_ERR(clk)) {
101 if (PTR_ERR(clk) != -EPROBE_DEFER)
102 pr_warn("clk: couldn't get clock %d for %pOF\n",
103 index, node);
104 return PTR_ERR(clk);
105 }
106
107 rc = clk_set_rate(clk, rate);
108 if (rc < 0)
109 pr_err("clk: couldn't set %s clk rate to %u (%d), current rate: %lu\n",
110 __clk_get_name(clk), rate, rc,
111 clk_get_rate(clk));
112 clk_put(clk);
113 }
114 index++;
115 }
116 return 0;
117}
118
119/**
120 * of_clk_set_defaults() - parse and set assigned clocks configuration
121 * @node: device node to apply clock settings for
122 * @clk_supplier: true if clocks supplied by @node should also be considered
123 *
124 * This function parses 'assigned-{clocks/clock-parents/clock-rates}' properties
125 * and sets any specified clock parents and rates. The @clk_supplier argument
126 * should be set to true if @node may be also a clock supplier of any clock
127 * listed in its 'assigned-clocks' or 'assigned-clock-parents' properties.
128 * If @clk_supplier is false the function exits returning 0 as soon as it
129 * determines the @node is also a supplier of any of the clocks.
130 */
131int of_clk_set_defaults(struct device_node *node, bool clk_supplier)
132{
133 int rc;
134
135 if (!node)
136 return 0;
137
138 rc = __set_clk_parents(node, clk_supplier);
139 if (rc < 0)
140 return rc;
141
142 return __set_clk_rates(node, clk_supplier);
143}
144EXPORT_SYMBOL_GPL(of_clk_set_defaults);
145