Messages in this thread Patch in this message | | | From | Viresh Kumar <> | Subject | [PATCH 2/7] PM / OPP: Implement of_dev_pm_opp_find_required_opp() | Date | Fri, 22 Dec 2017 12:56:26 +0530 |
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A device's DT node or its OPP nodes can contain a phandle to other device's OPP node, in the "required-opp" property.
This patch implements a routine to find that required OPP from the node that contains the "required-opp" property.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- drivers/opp/core.c | 4 +--- drivers/opp/of.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++++++ drivers/opp/opp.h | 1 + include/linux/pm_opp.h | 6 ++++++ 4 files changed, 61 insertions(+), 3 deletions(-)
diff --git a/drivers/opp/core.c b/drivers/opp/core.c index 92fa94a6dcc1..bfcad8983fd1 100644 --- a/drivers/opp/core.c +++ b/drivers/opp/core.c @@ -33,8 +33,6 @@ LIST_HEAD(opp_tables); /* Lock to allow exclusive modification to the device and opp lists */ DEFINE_MUTEX(opp_table_lock); -static void dev_pm_opp_get(struct dev_pm_opp *opp); - static struct opp_device *_find_opp_dev(const struct device *dev, struct opp_table *opp_table) { @@ -892,7 +890,7 @@ static void _opp_kref_release(struct kref *kref) dev_pm_opp_put_opp_table(opp_table); } -static void dev_pm_opp_get(struct dev_pm_opp *opp) +void dev_pm_opp_get(struct dev_pm_opp *opp) { kref_get(&opp->kref); } diff --git a/drivers/opp/of.c b/drivers/opp/of.c index 22c9bd191f62..2d1bb348ae73 100644 --- a/drivers/opp/of.c +++ b/drivers/opp/of.c @@ -665,3 +665,56 @@ int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev, return ret; } EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus); + +/** + * of_dev_pm_opp_find_required_opp() - Search for required OPP. + * @dev: The device whose OPP node is referenced by the 'np' DT node. + * @np: Node that contains the "required-opp" property. + * + * Returns the OPP of the device 'dev', whose phandle is present in the "np" + * node. + * + * Return: Matching opp, else returns ERR_PTR in case of error and should be + * handled using IS_ERR. + * + * The callers are required to call dev_pm_opp_put() for the returned OPP after + * use. + */ +struct dev_pm_opp *of_dev_pm_opp_find_required_opp(struct device *dev, + struct device_node *np) +{ + struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ENODEV); + struct device_node *required_np; + struct opp_table *opp_table; + + opp_table = _find_opp_table(dev); + if (IS_ERR(opp_table)) + return ERR_CAST(opp_table); + + required_np = of_parse_phandle(np, "required-opp", 0); + if (unlikely(!required_np)) { + dev_err(dev, "Unable to parse required-opp\n"); + goto put_opp_table; + } + + mutex_lock(&opp_table->lock); + + list_for_each_entry(temp_opp, &opp_table->opp_list, node) { + if (temp_opp->available && temp_opp->np == required_np) { + opp = temp_opp; + + /* Increment the reference count of OPP */ + dev_pm_opp_get(opp); + break; + } + } + + mutex_unlock(&opp_table->lock); + + of_node_put(required_np); +put_opp_table: + dev_pm_opp_put_opp_table(opp_table); + + return opp; +} +EXPORT_SYMBOL_GPL(of_dev_pm_opp_find_required_opp); diff --git a/drivers/opp/opp.h b/drivers/opp/opp.h index 4d00061648a3..b181032e6938 100644 --- a/drivers/opp/opp.h +++ b/drivers/opp/opp.h @@ -187,6 +187,7 @@ struct opp_table { }; /* Routines internal to opp core */ +void dev_pm_opp_get(struct dev_pm_opp *opp); void _get_opp_table_kref(struct opp_table *opp_table); struct opp_table *_find_opp_table(struct device *dev); struct opp_device *_add_opp_dev(const struct device *dev, struct opp_table *opp_table); diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h index f042fdeaaa3c..70686f434c13 100644 --- a/include/linux/pm_opp.h +++ b/include/linux/pm_opp.h @@ -309,6 +309,7 @@ int dev_pm_opp_of_cpumask_add_table(const struct cpumask *cpumask); void dev_pm_opp_of_cpumask_remove_table(const struct cpumask *cpumask); int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask); struct device_node *dev_pm_opp_of_get_opp_desc_node(struct device *dev); +struct dev_pm_opp *of_dev_pm_opp_find_required_opp(struct device *dev, struct device_node *np); #else static inline int dev_pm_opp_of_add_table(struct device *dev) { @@ -342,6 +343,11 @@ static inline struct device_node *dev_pm_opp_of_get_opp_desc_node(struct device { return NULL; } + +static inline struct dev_pm_opp *of_dev_pm_opp_find_required_opp(struct device *dev, struct device_node *np) +{ + return NULL; +} #endif #endif /* __LINUX_OPP_H__ */ -- 2.15.0.194.g9af6a3dea062
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