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
 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 %pOF\n",
 27		       node);
 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;
 41		pclk = of_clk_get_from_provider(&clkspec);
 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			rc = 0;
 55			goto err;
 56		}
 57		clk = of_clk_get_from_provider(&clkspec);
 58		if (IS_ERR(clk)) {
 59			if (PTR_ERR(clk) != -EPROBE_DEFER)
 60				pr_warn("clk: couldn't get assigned clock %d for %pOF\n",
 61					index, node);
 62			rc = PTR_ERR(clk);
 63			goto err;
 64		}
 65
 66		rc = clk_set_parent(clk, pclk);
 67		if (rc < 0)
 68			pr_err("clk: failed to reparent %s to %s: %d\n",
 69			       __clk_get_name(clk), __clk_get_name(pclk), rc);
 70		clk_put(clk);
 71		clk_put(pclk);
 72	}
 73	return 0;
 74err:
 75	clk_put(pclk);
 76	return rc;
 77}
 78
 79static int __set_clk_rates(struct device_node *node, bool clk_supplier)
 80{
 81	struct of_phandle_args clkspec;
 82	struct property	*prop;
 83	const __be32 *cur;
 84	int rc, index = 0;
 85	struct clk *clk;
 86	u32 rate;
 87
 88	of_property_for_each_u32(node, "assigned-clock-rates", prop, cur, rate) {
 89		if (rate) {
 90			rc = of_parse_phandle_with_args(node, "assigned-clocks",
 91					"#clock-cells",	index, &clkspec);
 92			if (rc < 0) {
 93				/* skip empty (null) phandles */
 94				if (rc == -ENOENT)
 95					continue;
 96				else
 97					return rc;
 98			}
 99			if (clkspec.np == node && !clk_supplier)
100				return 0;
101
102			clk = of_clk_get_from_provider(&clkspec);
103			if (IS_ERR(clk)) {
104				if (PTR_ERR(clk) != -EPROBE_DEFER)
105					pr_warn("clk: couldn't get clock %d for %pOF\n",
106						index, node);
107				return PTR_ERR(clk);
108			}
109
110			rc = clk_set_rate(clk, rate);
111			if (rc < 0)
112				pr_err("clk: couldn't set %s clk rate to %u (%d), current rate: %lu\n",
113				       __clk_get_name(clk), rate, rc,
114				       clk_get_rate(clk));
115			clk_put(clk);
116		}
117		index++;
118	}
119	return 0;
120}
121
122/**
123 * of_clk_set_defaults() - parse and set assigned clocks configuration
124 * @node: device node to apply clock settings for
125 * @clk_supplier: true if clocks supplied by @node should also be considered
126 *
127 * This function parses 'assigned-{clocks/clock-parents/clock-rates}' properties
128 * and sets any specified clock parents and rates. The @clk_supplier argument
129 * should be set to true if @node may be also a clock supplier of any clock
130 * listed in its 'assigned-clocks' or 'assigned-clock-parents' properties.
131 * If @clk_supplier is false the function exits returning 0 as soon as it
132 * determines the @node is also a supplier of any of the clocks.
133 */
134int of_clk_set_defaults(struct device_node *node, bool clk_supplier)
135{
136	int rc;
137
138	if (!node)
139		return 0;
140
141	rc = __set_clk_parents(node, clk_supplier);
142	if (rc < 0)
143		return rc;
144
145	return __set_clk_rates(node, clk_supplier);
146}
147EXPORT_SYMBOL_GPL(of_clk_set_defaults);