linux/drivers/clk/clk-conf.c

148 lines
3.9 KiB
C

/*
* 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 %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);