1 /* 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> 16 #include "clk.h" 17 18 static int __set_clk_parents(struct device_node *node, bool clk_supplier) 19 { 20 struct of_phandle_args clkspec; 21 int index, rc, num_parents; 22 struct clk *clk, *pclk; 23 24 num_parents = of_count_phandle_with_args(node, "assigned-clock-parents", 25 "#clock-cells"); 26 if (num_parents == -EINVAL) 27 pr_err("clk: invalid value of clock-parents property at %s\n", 28 node->full_name); 29 30 for (index = 0; index < num_parents; index++) { 31 rc = of_parse_phandle_with_args(node, "assigned-clock-parents", 32 "#clock-cells", index, &clkspec); 33 if (rc < 0) { 34 /* skip empty (null) phandles */ 35 if (rc == -ENOENT) 36 continue; 37 else 38 return rc; 39 } 40 if (clkspec.np == node && !clk_supplier) 41 return 0; 42 pclk = of_clk_get_by_clkspec(&clkspec); 43 if (IS_ERR(pclk)) { 44 pr_warn("clk: couldn't get parent clock %d for %s\n", 45 index, node->full_name); 46 return PTR_ERR(pclk); 47 } 48 49 rc = of_parse_phandle_with_args(node, "assigned-clocks", 50 "#clock-cells", index, &clkspec); 51 if (rc < 0) 52 goto err; 53 if (clkspec.np == node && !clk_supplier) { 54 rc = 0; 55 goto err; 56 } 57 clk = of_clk_get_by_clkspec(&clkspec); 58 if (IS_ERR(clk)) { 59 pr_warn("clk: couldn't get parent clock %d for %s\n", 60 index, node->full_name); 61 rc = PTR_ERR(clk); 62 goto err; 63 } 64 65 rc = clk_set_parent(clk, pclk); 66 if (rc < 0) 67 pr_err("clk: failed to reparent %s to %s: %d\n", 68 __clk_get_name(clk), __clk_get_name(pclk), rc); 69 clk_put(clk); 70 clk_put(pclk); 71 } 72 return 0; 73 err: 74 clk_put(pclk); 75 return rc; 76 } 77 78 static int __set_clk_rates(struct device_node *node, bool clk_supplier) 79 { 80 struct of_phandle_args clkspec; 81 struct property *prop; 82 const __be32 *cur; 83 int rc, index = 0; 84 struct clk *clk; 85 u32 rate; 86 87 of_property_for_each_u32(node, "assigned-clock-rates", prop, cur, rate) { 88 if (rate) { 89 rc = of_parse_phandle_with_args(node, "assigned-clocks", 90 "#clock-cells", index, &clkspec); 91 if (rc < 0) { 92 /* skip empty (null) phandles */ 93 if (rc == -ENOENT) 94 continue; 95 else 96 return rc; 97 } 98 if (clkspec.np == node && !clk_supplier) 99 return 0; 100 101 clk = of_clk_get_by_clkspec(&clkspec); 102 if (IS_ERR(clk)) { 103 pr_warn("clk: couldn't get clock %d for %s\n", 104 index, node->full_name); 105 return PTR_ERR(clk); 106 } 107 108 rc = clk_set_rate(clk, rate); 109 if (rc < 0) 110 pr_err("clk: couldn't set %s clock rate: %d\n", 111 __clk_get_name(clk), rc); 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 returnning 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