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@linaro.org Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- 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