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(np: node, list_name: "assigned-clock-parents",
21 cells_name: "#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(np: node, list_name: "assigned-clock-parents",
28 cells_name: "#clock-cells", index, out_args: &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 of_node_put(node: clkspec.np);
38 return 0;
39 }
40 pclk = of_clk_get_from_provider(clkspec: &clkspec);
41 of_node_put(node: clkspec.np);
42 if (IS_ERR(ptr: pclk)) {
43 if (PTR_ERR(ptr: pclk) != -EPROBE_DEFER)
44 pr_warn("clk: couldn't get parent clock %d for %pOF\n",
45 index, node);
46 return PTR_ERR(ptr: pclk);
47 }
48
49 rc = of_parse_phandle_with_args(np: node, list_name: "assigned-clocks",
50 cells_name: "#clock-cells", index, out_args: &clkspec);
51 if (rc < 0)
52 goto err;
53 if (clkspec.np == node && !clk_supplier) {
54 of_node_put(node: clkspec.np);
55 rc = 0;
56 goto err;
57 }
58 clk = of_clk_get_from_provider(clkspec: &clkspec);
59 of_node_put(node: clkspec.np);
60 if (IS_ERR(ptr: clk)) {
61 if (PTR_ERR(ptr: clk) != -EPROBE_DEFER)
62 pr_warn("clk: couldn't get assigned clock %d for %pOF\n",
63 index, node);
64 rc = PTR_ERR(ptr: clk);
65 goto err;
66 }
67
68 rc = clk_set_parent(clk, parent: pclk);
69 if (rc < 0)
70 pr_err("clk: failed to reparent %s to %s: %d\n",
71 __clk_get_name(clk), __clk_get_name(pclk), rc);
72 clk_put(clk);
73 clk_put(clk: pclk);
74 }
75 return 0;
76err:
77 clk_put(clk: pclk);
78 return rc;
79}
80
81static int __set_clk_rates(struct device_node *node, bool clk_supplier)
82{
83 struct of_phandle_args clkspec;
84 struct property *prop;
85 const __be32 *cur;
86 int rc, index = 0;
87 struct clk *clk;
88 u32 rate;
89
90 of_property_for_each_u32(node, "assigned-clock-rates", prop, cur, rate) {
91 if (rate) {
92 rc = of_parse_phandle_with_args(np: node, list_name: "assigned-clocks",
93 cells_name: "#clock-cells", index, out_args: &clkspec);
94 if (rc < 0) {
95 /* skip empty (null) phandles */
96 if (rc == -ENOENT)
97 continue;
98 else
99 return rc;
100 }
101 if (clkspec.np == node && !clk_supplier) {
102 of_node_put(node: clkspec.np);
103 return 0;
104 }
105
106 clk = of_clk_get_from_provider(clkspec: &clkspec);
107 of_node_put(node: clkspec.np);
108 if (IS_ERR(ptr: clk)) {
109 if (PTR_ERR(ptr: clk) != -EPROBE_DEFER)
110 pr_warn("clk: couldn't get clock %d for %pOF\n",
111 index, node);
112 return PTR_ERR(ptr: clk);
113 }
114
115 rc = clk_set_rate(clk, rate);
116 if (rc < 0)
117 pr_err("clk: couldn't set %s clk rate to %u (%d), current rate: %lu\n",
118 __clk_get_name(clk), rate, rc,
119 clk_get_rate(clk));
120 clk_put(clk);
121 }
122 index++;
123 }
124 return 0;
125}
126
127/**
128 * of_clk_set_defaults() - parse and set assigned clocks configuration
129 * @node: device node to apply clock settings for
130 * @clk_supplier: true if clocks supplied by @node should also be considered
131 *
132 * This function parses 'assigned-{clocks/clock-parents/clock-rates}' properties
133 * and sets any specified clock parents and rates. The @clk_supplier argument
134 * should be set to true if @node may be also a clock supplier of any clock
135 * listed in its 'assigned-clocks' or 'assigned-clock-parents' properties.
136 * If @clk_supplier is false the function exits returning 0 as soon as it
137 * determines the @node is also a supplier of any of the clocks.
138 */
139int of_clk_set_defaults(struct device_node *node, bool clk_supplier)
140{
141 int rc;
142
143 if (!node)
144 return 0;
145
146 rc = __set_clk_parents(node, clk_supplier);
147 if (rc < 0)
148 return rc;
149
150 return __set_clk_rates(node, clk_supplier);
151}
152EXPORT_SYMBOL_GPL(of_clk_set_defaults);
153

source code of linux/drivers/clk/clk-conf.c