Create a new routine of_clk_shared_by_cpus() that finds if clock lines are
shared between two CPUs. This is verified by comparing "clocks" property from
CPU's DT node.
Returns 1 if clock line is shared between them, 0 if clock isn't shared and
return appropriate errors in case nodes/properties are missing.
Cc: Mike Turquette <mturquette@xxxxxxxxxx>
Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
drivers/clk/clk.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/clk.h | 6 ++++++
2 files changed, 62 insertions(+)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 8b73ede..497735c 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -10,6 +10,7 @@
*/
#include <linux/clk-private.h>
+#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
@@ -2528,6 +2529,61 @@ const char *of_clk_get_parent_name(struct device_node *np, int index)
}
EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
+/**
+ * of_clk_shared_by_cpus - Finds if clock line is shared between CPUs
+ * @cpu1, cpu2: CPU numbers
+ *
+ * Finds if clock lines are shared by two CPUs. This is verified by comparing
+ * "clocks" property from CPU's DT node.
+ *
+ * Returns 1 if clock line is shared between them, 0 if clock isn't shared.
+ * Return appropriate errors in case some requirements aren't met.
+ */
+int of_clk_shared_by_cpus(int cpu1, int cpu2)
+{
+ struct device *cpu1_dev, *cpu2_dev;
+ struct device_node *np1, *np2;
+ int ret;
+
+ cpu1_dev = get_cpu_device(cpu1);
+ if (!cpu1_dev) {
+ pr_err("%s: failed to get cpu_dev for cpu%d\n", __func__, cpu1);
+ return -ENODEV;
+ }
+
+ cpu2_dev = get_cpu_device(cpu2);
+ if (!cpu2_dev) {
+ pr_err("%s: failed to get cpu_dev for cpu%d\n", __func__, cpu2);
+ return -ENODEV;
+ }
+
+ np1 = of_node_get(cpu1_dev->of_node);
+ if (!np1) {
+ pr_err("%s: failed to find of_node for cpu%d\n", __func__,
+ cpu1);
+ return -ENODEV;
+ }
+
+ np2 = of_node_get(cpu2_dev->of_node);
+ if (!np2) {
+ pr_err("%s: failed to find of_node for cpu%d\n", __func__,
+ cpu2);
+ ret = -ENODEV;
+ goto put_np1;
+ }
+
+ /* Match "clocks" property */
+ ret = of_property_match(np1, np2, "clocks");
+
+ of_node_put(np2);
+
+put_np1:
+ of_node_put(np1);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(of_clk_shared_by_cpus);
+
struct clock_provider {
of_clk_init_cb_t clk_init_cb;
struct device_node *np;
diff --git a/include/linux/clk.h b/include/linux/clk.h
index fb5e097..58e281a 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -399,6 +399,7 @@ struct of_phandle_args;
struct clk *of_clk_get(struct device_node *np, int index);
struct clk *of_clk_get_by_name(struct device_node *np, const char *name);
struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec);
+int of_clk_shared_by_cpus(int cpu1, int cpu2);
#else
static inline struct clk *of_clk_get(struct device_node *np, int index)
{
@@ -409,6 +410,11 @@ static inline struct clk *of_clk_get_by_name(struct device_node *np,
{
return ERR_PTR(-ENOENT);
}
+
+static inline int of_clk_shared_by_cpus(int cpu1, int cpu2)
+{
+ return -ENOSYS;
+}
#endif
#endif
--
2.0.0.rc2
--
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