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 | |
14 | static 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; |
76 | err: |
77 | clk_put(clk: pclk); |
78 | return rc; |
79 | } |
80 | |
81 | static 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 | */ |
139 | int 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 | } |
152 | EXPORT_SYMBOL_GPL(of_clk_set_defaults); |
153 | |