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Sylwester Nawrocki86be4082014-06-18 17:29:32 +02001/*
2 * Copyright (C) 2014 Samsung Electronics Co., Ltd.
3 * Sylwester Nawrocki <s.nawrocki@samsung.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 */
9
10#include <linux/clk.h>
11#include <linux/clk-provider.h>
12#include <linux/clk/clk-conf.h>
13#include <linux/device.h>
14#include <linux/of.h>
15#include <linux/printk.h>
Sylwester Nawrocki86be4082014-06-18 17:29:32 +020016
17static int __set_clk_parents(struct device_node *node, bool clk_supplier)
18{
19 struct of_phandle_args clkspec;
20 int index, rc, num_parents;
21 struct clk *clk, *pclk;
22
23 num_parents = of_count_phandle_with_args(node, "assigned-clock-parents",
24 "#clock-cells");
25 if (num_parents == -EINVAL)
26 pr_err("clk: invalid value of clock-parents property at %s\n",
27 node->full_name);
28
29 for (index = 0; index < num_parents; index++) {
30 rc = of_parse_phandle_with_args(node, "assigned-clock-parents",
31 "#clock-cells", index, &clkspec);
32 if (rc < 0) {
33 /* skip empty (null) phandles */
34 if (rc == -ENOENT)
35 continue;
36 else
37 return rc;
38 }
39 if (clkspec.np == node && !clk_supplier)
40 return 0;
Stephen Boyd306c3422015-02-05 15:39:11 -080041 pclk = of_clk_get_from_provider(&clkspec);
Sylwester Nawrocki86be4082014-06-18 17:29:32 +020042 if (IS_ERR(pclk)) {
43 pr_warn("clk: couldn't get parent clock %d for %s\n",
44 index, node->full_name);
45 return PTR_ERR(pclk);
46 }
47
48 rc = of_parse_phandle_with_args(node, "assigned-clocks",
49 "#clock-cells", index, &clkspec);
50 if (rc < 0)
51 goto err;
52 if (clkspec.np == node && !clk_supplier) {
53 rc = 0;
54 goto err;
55 }
Stephen Boyd306c3422015-02-05 15:39:11 -080056 clk = of_clk_get_from_provider(&clkspec);
Dan Carpenter6ba19bf2014-08-01 11:14:17 +030057 if (IS_ERR(clk)) {
Sylwester Nawrocki86be4082014-06-18 17:29:32 +020058 pr_warn("clk: couldn't get parent clock %d for %s\n",
59 index, node->full_name);
Dan Carpenter6ba19bf2014-08-01 11:14:17 +030060 rc = PTR_ERR(clk);
Sylwester Nawrocki86be4082014-06-18 17:29:32 +020061 goto err;
62 }
63
64 rc = clk_set_parent(clk, pclk);
65 if (rc < 0)
66 pr_err("clk: failed to reparent %s to %s: %d\n",
67 __clk_get_name(clk), __clk_get_name(pclk), rc);
68 clk_put(clk);
69 clk_put(pclk);
70 }
71 return 0;
72err:
73 clk_put(pclk);
74 return rc;
75}
76
77static int __set_clk_rates(struct device_node *node, bool clk_supplier)
78{
79 struct of_phandle_args clkspec;
80 struct property *prop;
81 const __be32 *cur;
82 int rc, index = 0;
83 struct clk *clk;
84 u32 rate;
85
86 of_property_for_each_u32(node, "assigned-clock-rates", prop, cur, rate) {
87 if (rate) {
88 rc = of_parse_phandle_with_args(node, "assigned-clocks",
89 "#clock-cells", index, &clkspec);
90 if (rc < 0) {
91 /* skip empty (null) phandles */
92 if (rc == -ENOENT)
93 continue;
94 else
95 return rc;
96 }
97 if (clkspec.np == node && !clk_supplier)
98 return 0;
99
Stephen Boyd306c3422015-02-05 15:39:11 -0800100 clk = of_clk_get_from_provider(&clkspec);
Sylwester Nawrocki86be4082014-06-18 17:29:32 +0200101 if (IS_ERR(clk)) {
102 pr_warn("clk: couldn't get clock %d for %s\n",
103 index, node->full_name);
104 return PTR_ERR(clk);
105 }
106
107 rc = clk_set_rate(clk, rate);
108 if (rc < 0)
Chanwoo Choi2885c3b2015-04-27 18:29:52 +0900109 pr_err("clk: couldn't set %s clk rate to %d (%d), current rate: %ld\n",
110 __clk_get_name(clk), rate, rc,
111 clk_get_rate(clk));
Sylwester Nawrocki86be4082014-06-18 17:29:32 +0200112 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.
Shailendra Verma004cbb42015-05-21 23:32:56 +0530128 * If @clk_supplier is false the function exits returning 0 as soon as it
Sylwester Nawrocki86be4082014-06-18 17:29:32 +0200129 * 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}
Sylwester Nawrockib11a6fa2014-08-04 12:48:58 +0200144EXPORT_SYMBOL_GPL(of_clk_set_defaults);