("pll" and "pll-switched").
* The UART has its baud clock connected the external oscillator and its
register clock connected to the PLL clock (the "pll-switched" signal)
+
+==Assigned clock parents and rates==
+
+Some platforms may require initial configuration of default parent clocks
+and clock frequencies. Such a configuration can be specified in a device tree
+node through assigned-clocks, assigned-clock-parents and assigned-clock-rates
+properties. The assigned-clock-parents property should contain a list of parent
+clocks in form of phandle and clock specifier pairs, the assigned-clock-parents
+property the list of assigned clock frequency values - corresponding to clocks
+listed in the assigned-clocks property.
+
+To skip setting parent or rate of a clock its corresponding entry should be
+set to 0, or can be omitted if it is not followed by any non-zero entry.
+
+ uart@a000 {
+ compatible = "fsl,imx-uart";
+ reg = <0xa000 0x1000>;
+ ...
+ clocks = <&osc 0>, <&pll 1>;
+ clock-names = "baud", "register";
+
+ assigned-clocks = <&clkcon 0>, <&pll 2>;
+ assigned-clock-parents = <&pll 2>;
+ assigned-clock-rates = <0>, <460800>;
+ };
+
+In this example the <&pll 2> clock is set as parent of clock <&clkcon 0> and
+the <&pll 2> clock is assigned a frequency value of 460800 Hz.
+
+Configuring a clock's parent and rate through the device node that consumes
+the clock can be done only for clocks that have a single user. Specifying
+conflicting parent or rate configuration in multiple consumer nodes for
+a shared clock is forbidden.
+
+Configuration of common clocks, which affect multiple consumer devices can
+be similarly specified in the clock provider node.
#include <linux/pm_runtime.h>
#include <linux/idr.h>
#include <linux/acpi.h>
+#include <linux/clk/clk-conf.h>
#include "base.h"
#include "power/power.h"
struct platform_device *dev = to_platform_device(_dev);
int ret;
+ ret = of_clk_set_defaults(_dev->of_node, false);
+ if (ret < 0)
+ return ret;
+
acpi_dev_pm_attach(_dev, true);
ret = drv->probe(dev);
obj-$(CONFIG_COMMON_CLK) += clk-mux.o
obj-$(CONFIG_COMMON_CLK) += clk-composite.o
obj-$(CONFIG_COMMON_CLK) += clk-fractional-divider.o
+ifeq ($(CONFIG_OF), y)
+obj-$(CONFIG_COMMON_CLK) += clk-conf.o
+endif
# hardware specific clock types
# please keep this section sorted lexicographically by file/directory path name
--- /dev/null
+/*
+ * 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>
+#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);
+}
*/
#include <linux/clk-private.h>
+#include <linux/clk/clk-conf.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
void *data)
{
struct of_clk_provider *cp;
+ int ret;
cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL);
if (!cp)
mutex_unlock(&of_clk_mutex);
pr_debug("Added clock from %s\n", np->full_name);
- return 0;
+ ret = of_clk_set_defaults(np, true);
+ if (ret < 0)
+ of_clk_del_provider(np);
+
+ return ret;
}
EXPORT_SYMBOL_GPL(of_clk_add_provider);
list_for_each_entry_safe(clk_provider, next,
&clk_provider_list, node) {
if (force || parent_ready(clk_provider->np)) {
+
clk_provider->clk_init_cb(clk_provider->np);
+ of_clk_set_defaults(clk_provider->np, true);
+
list_del(&clk_provider->node);
kfree(clk_provider);
is_init_done = true;
*/
if (!is_init_done)
force = true;
-
}
}
#endif
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
+#include <linux/clk/clk-conf.h>
#include <linux/completion.h>
#include <linux/hardirq.h>
#include <linux/irqflags.h>
client->flags & I2C_CLIENT_WAKE);
dev_dbg(dev, "probe\n");
+ status = of_clk_set_defaults(dev->of_node, false);
+ if (status < 0)
+ return status;
+
acpi_dev_pm_attach(&client->dev, true);
status = driver->probe(client, i2c_match_id(driver->id_table, client));
if (status)
#include <linux/mutex.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
+#include <linux/clk/clk-conf.h>
#include <linux/slab.h>
#include <linux/mod_devicetable.h>
#include <linux/spi/spi.h>
const struct spi_driver *sdrv = to_spi_driver(dev->driver);
int ret;
+ ret = of_clk_set_defaults(dev->of_node, false);
+ if (ret)
+ return ret;
+
acpi_dev_pm_attach(dev, true);
ret = sdrv->probe(to_spi_device(dev));
if (ret)
--- /dev/null
+/*
+ * 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.
+ */
+
+struct device_node;
+
+#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
+int of_clk_set_defaults(struct device_node *node, bool clk_supplier);
+#else
+static inline int of_clk_set_defaults(struct device_node *node,
+ bool clk_supplier)
+{
+ return 0;
+}
+#endif
projects / deliverable / linux.git / commitdiff
