/* * Copyright (C) 2014 Samsung Electronics Co., Ltd. * Sylwester Nawrocki <s.nawrocki@samsung.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/clk.h> #include <linux/clk-provider.h> #include <linux/clk/clk-conf.h> #include <linux/device.h> #include <linux/of.h> #include <linux/printk.h> static int __set_clk_parents(struct device_node *node, bool clk_supplier) { struct of_phandle_args clkspec; int index, rc, num_parents; struct clk *clk, *pclk; num_parents = of_count_phandle_with_args(node, "assigned-clock-parents", "#clock-cells"); if (num_parents == -EINVAL) pr_err("clk: invalid value of clock-parents property at %s\n", node->full_name); for (index = 0; index < num_parents; index++) { rc = of_parse_phandle_with_args(node, "assigned-clock-parents", "#clock-cells", index, &clkspec); if (rc < 0) { /* skip empty (null) phandles */ if (rc == -ENOENT) continue; else return rc; } if (clkspec.np == node && !clk_supplier) return 0; pclk = of_clk_get_from_provider(&clkspec); if (IS_ERR(pclk)) { if (PTR_ERR(pclk) != -EPROBE_DEFER) pr_warn("clk: couldn't get parent clock %d for %s\n", index, node->full_name); return PTR_ERR(pclk); } rc = of_parse_phandle_with_args(node, "assigned-clocks", "#clock-cells", index, &clkspec); if (rc < 0) goto err; if (clkspec.np == node && !clk_supplier) { rc = 0; goto err; } clk = of_clk_get_from_provider(&clkspec); if (IS_ERR(clk)) { if (PTR_ERR(clk) != -EPROBE_DEFER) pr_warn("clk: couldn't get assigned clock %d for %s\n", index, node->full_name); rc = PTR_ERR(clk); goto err; } rc = clk_set_parent(clk, pclk); if (rc < 0) pr_err("clk: failed to reparent %s to %s: %d\n", __clk_get_name(clk), __clk_get_name(pclk), rc); clk_put(clk); clk_put(pclk); } return 0; err: clk_put(pclk); return rc; } static int __set_clk_rates(struct device_node *node, bool clk_supplier) { struct of_phandle_args clkspec; struct property *prop; const __be32 *cur; int rc, index = 0; struct clk *clk; u32 rate; of_property_for_each_u32(node, "assigned-clock-rates", prop, cur, rate) { if (rate) { rc = of_parse_phandle_with_args(node, "assigned-clocks", "#clock-cells", index, &clkspec); if (rc < 0) { /* skip empty (null) phandles */ if (rc == -ENOENT) continue; else return rc; } if (clkspec.np == node && !clk_supplier) return 0; clk = of_clk_get_from_provider(&clkspec); if (IS_ERR(clk)) { if (PTR_ERR(clk) != -EPROBE_DEFER) pr_warn("clk: couldn't get clock %d for %s\n", index, node->full_name); return PTR_ERR(clk); } rc = clk_set_rate(clk, rate); if (rc < 0) pr_err("clk: couldn't set %s clk rate to %d (%d), current rate: %ld\n", __clk_get_name(clk), rate, rc, clk_get_rate(clk)); clk_put(clk); } index++; } return 0; } /** * of_clk_set_defaults() - parse and set assigned clocks configuration * @node: device node to apply clock settings for * @clk_supplier: true if clocks supplied by @node should also be considered * * This function parses 'assigned-{clocks/clock-parents/clock-rates}' properties * and sets any specified clock parents and rates. The @clk_supplier argument * should be set to true if @node may be also a clock supplier of any clock * listed in its 'assigned-clocks' or 'assigned-clock-parents' properties. * If @clk_supplier is false the function exits returning 0 as soon as it * determines the @node is also a supplier of any of the clocks. */ int of_clk_set_defaults(struct device_node *node, bool clk_supplier) { int rc; if (!node) return 0; rc = __set_clk_parents(node, clk_supplier); if (rc < 0) return rc; return __set_clk_rates(node, clk_supplier); } EXPORT_SYMBOL_GPL(of_clk_set_defaults);