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 viresh.kumar@linaro.org --- 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(+)
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)