From 86be408bfbd846fab3c4ac21d6f9298bd2e4b790 Mon Sep 17 00:00:00 2001 From: Sylwester Nawrocki Date: Wed, 18 Jun 2014 17:29:32 +0200 Subject: clk: Support for clock parents and rates assigned from device tree This patch adds helper functions to configure clock parents and rates as specified through 'assigned-clock-parents', 'assigned-clock-rates' DT properties for a clock provider or clock consumer device. The helpers are now being called by the bus code for the platform, I2C and SPI busses, before the driver probing and also in the clock core after registration of a clock provider. Signed-off-by: Sylwester Nawrocki Acked-by: Kyungmin Park Signed-off-by: Mike Turquette --- drivers/clk/clk-conf.c | 143 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 143 insertions(+) create mode 100644 drivers/clk/clk-conf.c (limited to 'drivers/clk/clk-conf.c') diff --git a/drivers/clk/clk-conf.c b/drivers/clk/clk-conf.c new file mode 100644 index 000000000000..1f73019a27c8 --- /dev/null +++ b/drivers/clk/clk-conf.c @@ -0,0 +1,143 @@ +/* + * Copyright (C) 2014 Samsung Electronics Co., Ltd. + * Sylwester Nawrocki + * + * 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 +#include +#include +#include +#include +#include +#include "clk.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_by_clkspec(&clkspec); + if (IS_ERR(pclk)) { + 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_by_clkspec(&clkspec); + if (IS_ERR(pclk)) { + pr_warn("clk: couldn't get parent clock %d for %s\n", + index, node->full_name); + rc = PTR_ERR(pclk); + 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_by_clkspec(&clkspec); + if (IS_ERR(clk)) { + 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 clock rate: %d\n", + __clk_get_name(clk), rc); + 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 returnning 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); +} -- cgit v1.2.3