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(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			of_node_put(clkspec.np);
 38			return 0;
 39		}
 40		pclk = of_clk_get_from_provider(&clkspec);
 41		of_node_put(clkspec.np);
 42		if (IS_ERR(pclk)) {
 43			if (PTR_ERR(pclk) != -EPROBE_DEFER)
 44				pr_warn("clk: couldn't get parent clock %d for %pOF\n",
 45					index, node);
 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			of_node_put(clkspec.np);
 55			rc = 0;
 56			goto err;
 57		}
 58		clk = of_clk_get_from_provider(&clkspec);
 59		of_node_put(clkspec.np);
 60		if (IS_ERR(clk)) {
 61			if (PTR_ERR(clk) != -EPROBE_DEFER)
 62				pr_warn("clk: couldn't get assigned clock %d for %pOF\n",
 63					index, node);
 64			rc = PTR_ERR(clk);
 65			goto err;
 66		}
 67
 68		rc = clk_set_parent(clk, 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(pclk);
 74	}
 75	return 0;
 76err:
 77	clk_put(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(node, "assigned-clocks",
 93					"#clock-cells",	index, &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(clkspec.np);
103				return 0;
104			}
105
106			clk = of_clk_get_from_provider(&clkspec);
107			of_node_put(clkspec.np);
108			if (IS_ERR(clk)) {
109				if (PTR_ERR(clk) != -EPROBE_DEFER)
110					pr_warn("clk: couldn't get clock %d for %pOF\n",
111						index, node);
112				return PTR_ERR(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);