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(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; 71 err: 72 clk_put(pclk); 73 return rc; 74 } 75 76 static 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 */ 131 int 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 } 144 EXPORT_SYMBOL_GPL(of_clk_set_defaults); 145