On 9 December 2015 at 02:31, Viresh Kumar <[email protected]> wrote: > OPP bindings allow a platform to enable OPPs based on the version of the > hardware they are used for. > > Add support to the OPP-core to parse these bindings, by introducing > dev_pm_opp_{set|put}_supported_hw() APIs. > > Signed-off-by: Viresh Kumar <[email protected]> > --- > drivers/base/power/opp/core.c | 148 > ++++++++++++++++++++++++++++++++++++++++++ > drivers/base/power/opp/opp.h | 5 ++ > include/linux/pm_opp.h | 13 ++++ > 3 files changed, 166 insertions(+)
Tested-by: Lee Jones <[email protected]> > diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c > index 6aa172be6e8e..55cf1a99b532 100644 > --- a/drivers/base/power/opp/core.c > +++ b/drivers/base/power/opp/core.c > @@ -559,6 +559,9 @@ static void _remove_device_opp(struct device_opp *dev_opp) > if (!list_empty(&dev_opp->opp_list)) > return; > > + if (dev_opp->supported_hw) > + return; > + > list_dev = list_first_entry(&dev_opp->dev_list, struct > device_list_opp, > node); > > @@ -834,6 +837,145 @@ static int opp_parse_supplies(struct dev_pm_opp *opp, > struct device *dev) > } > > /** > + * dev_pm_opp_set_supported_hw() - Set supported platforms > + * @dev: Device for which supported-hw has to be set. > + * @versions: Array of hierarchy of versions to match. > + * @count: Number of elements in the array. > + * > + * This is required only for the V2 bindings, and it enables a platform to > + * specify the hierarchy of versions it supports. OPP layer will then enable > + * OPPs, which are available for those versions, based on its > 'opp-supported-hw' > + * property. > + * > + * Locking: The internal device_opp and opp structures are RCU protected. > + * Hence this function internally uses RCU updater strategy with mutex locks > + * to keep the integrity of the internal data structures. Callers should > ensure > + * that this function is *NOT* called under RCU protection or in contexts > where > + * mutex cannot be locked. > + */ > +int dev_pm_opp_set_supported_hw(struct device *dev, const u32 *versions, > + unsigned int count) > +{ > + struct device_opp *dev_opp; > + int ret = 0; > + > + /* Hold our list modification lock here */ > + mutex_lock(&dev_opp_list_lock); > + > + dev_opp = _add_device_opp(dev); > + if (!dev_opp) { > + ret = -ENOMEM; > + goto unlock; > + } > + > + /* Make sure there are no concurrent readers while updating dev_opp */ > + WARN_ON(!list_empty(&dev_opp->opp_list)); > + > + /* Do we already have a version hierarchy associated with dev_opp? */ > + if (dev_opp->supported_hw) { > + dev_err(dev, "%s: Already have supported hardware list\n", > + __func__); > + ret = -EBUSY; > + goto err; > + } > + > + dev_opp->supported_hw = kmemdup(versions, count * sizeof(*versions), > + GFP_KERNEL); > + if (!dev_opp->supported_hw) { > + ret = -ENOMEM; > + goto err; > + } > + > + dev_opp->supported_hw_count = count; > + mutex_unlock(&dev_opp_list_lock); > + return 0; > + > +err: > + _remove_device_opp(dev_opp); > +unlock: > + mutex_unlock(&dev_opp_list_lock); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(dev_pm_opp_set_supported_hw); > + > +/** > + * dev_pm_opp_put_supported_hw() - Releases resources blocked for supported > hw > + * @dev: Device for which supported-hw has to be set. > + * > + * This is required only for the V2 bindings, and is called for a matching > + * dev_pm_opp_set_supported_hw(). Until this is called, the device_opp > structure > + * will not be freed. > + * > + * Locking: The internal device_opp and opp structures are RCU protected. > + * Hence this function internally uses RCU updater strategy with mutex locks > + * to keep the integrity of the internal data structures. Callers should > ensure > + * that this function is *NOT* called under RCU protection or in contexts > where > + * mutex cannot be locked. > + */ > +void dev_pm_opp_put_supported_hw(struct device *dev) > +{ > + struct device_opp *dev_opp; > + > + /* Hold our list modification lock here */ > + mutex_lock(&dev_opp_list_lock); > + > + /* Check for existing list for 'dev' first */ > + dev_opp = _find_device_opp(dev); > + if (IS_ERR(dev_opp)) { > + dev_err(dev, "Failed to find dev_opp: %ld\n", > PTR_ERR(dev_opp)); > + goto unlock; > + } > + > + /* Make sure there are no concurrent readers while updating dev_opp */ > + WARN_ON(!list_empty(&dev_opp->opp_list)); > + > + if (!dev_opp->supported_hw) { > + dev_err(dev, "%s: Doesn't have supported hardware list\n", > + __func__); > + goto unlock; > + } > + > + kfree(dev_opp->supported_hw); > + dev_opp->supported_hw = NULL; > + dev_opp->supported_hw_count = 0; > + > + /* Try freeing device_opp if this was the last blocking resource */ > + _remove_device_opp(dev_opp); > + > +unlock: > + mutex_unlock(&dev_opp_list_lock); > +} > +EXPORT_SYMBOL_GPL(dev_pm_opp_put_supported_hw); > + > +static bool _opp_is_supported(struct device *dev, struct device_opp *dev_opp, > + struct device_node *np) > +{ > + unsigned int count = dev_opp->supported_hw_count; > + u32 version; > + int ret; > + > + if (!dev_opp->supported_hw) > + return true; > + > + while (count--) { > + ret = of_property_read_u32_index(np, "opp-supported-hw", > count, > + &version); > + if (ret) { > + dev_warn(dev, "%s: failed to read opp-supported-hw > property at index %d: %d\n", > + __func__, count, ret); > + return false; > + } > + > + /* Both of these are bitwise masks of the versions */ > + if (!(version & dev_opp->supported_hw[count])) > + return false; > + } > + > + return true; > +} > + > +/** > * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings) > * @dev: device for which we do this operation > * @np: device node > @@ -879,6 +1021,12 @@ static int _opp_add_static_v2(struct device *dev, > struct device_node *np) > goto free_opp; > } > > + /* Check if the OPP supports hardware's hierarchy of versions or not > */ > + if (!_opp_is_supported(dev, dev_opp, np)) { > + dev_dbg(dev, "OPP not supported by hardware: %llu\n", rate); > + goto free_opp; > + } > + > /* > * Rate is defined as an unsigned long in clk API, and so casting > * explicitly to its type. Must be fixed once rate is 64 bit > diff --git a/drivers/base/power/opp/opp.h b/drivers/base/power/opp/opp.h > index b8880c7f8be1..70f4564a6ab9 100644 > --- a/drivers/base/power/opp/opp.h > +++ b/drivers/base/power/opp/opp.h > @@ -129,6 +129,8 @@ struct device_list_opp { > * @clock_latency_ns_max: Max clock latency in nanoseconds. > * @shared_opp: OPP is shared between multiple devices. > * @suspend_opp: Pointer to OPP to be used during device suspend. > + * @supported_hw: Array of version number to support. > + * @supported_hw_count: Number of elements in supported_hw array. > * @dentry: debugfs dentry pointer of the real device directory (not > links). > * @dentry_name: Name of the real dentry. > * > @@ -153,6 +155,9 @@ struct device_opp { > bool shared_opp; > struct dev_pm_opp *suspend_opp; > > + unsigned int *supported_hw; > + unsigned int supported_hw_count; > + > #ifdef CONFIG_DEBUG_FS > struct dentry *dentry; > char dentry_name[NAME_MAX]; > diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h > index 9a2e50337af9..3a85110242f0 100644 > --- a/include/linux/pm_opp.h > +++ b/include/linux/pm_opp.h > @@ -55,6 +55,9 @@ int dev_pm_opp_enable(struct device *dev, unsigned long > freq); > int dev_pm_opp_disable(struct device *dev, unsigned long freq); > > struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev); > +int dev_pm_opp_set_supported_hw(struct device *dev, const u32 *versions, > + unsigned int count); > +void dev_pm_opp_put_supported_hw(struct device *dev); > #else > static inline unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp) > { > @@ -129,6 +132,16 @@ static inline struct srcu_notifier_head > *dev_pm_opp_get_notifier( > { > return ERR_PTR(-EINVAL); > } > + > +static inline int dev_pm_opp_set_supported_hw(struct device *dev, > + const u32 *versions, > + unsigned int count) > +{ > + return -EINVAL; > +} > + > +static inline void dev_pm_opp_put_supported_hw(struct device *dev) {} > + > #endif /* CONFIG_PM_OPP */ > > #if defined(CONFIG_PM_OPP) && defined(CONFIG_OF) > -- > 2.6.2.198.g614a2ac > > _______________________________________________ > linaro-kernel mailing list > [email protected] > https://lists.linaro.org/mailman/listinfo/linaro-kernel -- Lee Jones Linaro ST Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
