diff options
Diffstat (limited to 'drivers/clk/clk-conf.c')
| -rw-r--r-- | drivers/clk/clk-conf.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/drivers/clk/clk-conf.c b/drivers/clk/clk-conf.c new file mode 100644 index 000000000..49819b546 --- /dev/null +++ b/drivers/clk/clk-conf.c @@ -0,0 +1,147 @@ +/* + * 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 %pOF\n", + node); + + 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 %pOF\n", + index, node); + 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 %pOF\n", + index, node); + 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 %pOF\n", + index, node); + return PTR_ERR(clk); + } + + rc = clk_set_rate(clk, rate); + if (rc < 0) + pr_err("clk: couldn't set %s clk rate to %u (%d), current rate: %lu\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); |