Messages in this thread | | | Date | Thu, 10 Dec 2015 09:54:45 +0000 | Subject | Re: [PATCH V3 2/2] PM / OPP: Parse 'opp-<prop>-<name>' bindings | From | Lee Jones <> |
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On 9 December 2015 at 02:31, Viresh Kumar <viresh.kumar@linaro.org> wrote: > OPP bindings (for few properties) allow a platform to choose a > value/range among a set of available options. The options are present as > opp-<prop>-<name>, where the platform needs to supply the <name> string. > > The OPP properties which allow such an option are: opp-microvolt and > opp-microamp. > > Add support to the OPP-core to parse these bindings, by introducing > dev_pm_opp_{set|put}_prop_name() APIs. > > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> > --- > drivers/base/power/opp/core.c | 165 ++++++++++++++++++++++++++++++++++++++---- > drivers/base/power/opp/opp.h | 2 + > include/linux/pm_opp.h | 9 +++ > 3 files changed, 161 insertions(+), 15 deletions(-)
Tested-by: Lee Jones <lee.jones@linaro.org>
> diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c > index 55cf1a99b532..5c01fec1ed14 100644 > --- a/drivers/base/power/opp/core.c > +++ b/drivers/base/power/opp/core.c > @@ -562,6 +562,9 @@ static void _remove_device_opp(struct device_opp *dev_opp) > if (dev_opp->supported_hw) > return; > > + if (dev_opp->prop_name) > + return; > + > list_dev = list_first_entry(&dev_opp->dev_list, struct device_list_opp, > node); > > @@ -794,35 +797,48 @@ static int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt, > } > > /* TODO: Support multiple regulators */ > -static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev) > +static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev, > + struct device_opp *dev_opp) > { > u32 microvolt[3] = {0}; > u32 val; > int count, ret; > + struct property *prop = NULL; > + char name[NAME_MAX]; > + > + /* Search for "opp-microvolt-<name>" */ > + if (dev_opp->prop_name) { > + sprintf(name, "opp-microvolt-%s", dev_opp->prop_name); > + prop = of_find_property(opp->np, name, NULL); > + } > + > + if (!prop) { > + /* Search for "opp-microvolt" */ > + name[13] = '\0'; > + prop = of_find_property(opp->np, name, NULL); > > - /* Missing property isn't a problem, but an invalid entry is */ > - if (!of_find_property(opp->np, "opp-microvolt", NULL)) > - return 0; > + /* Missing property isn't a problem, but an invalid entry is */ > + if (!prop) > + return 0; > + } > > - count = of_property_count_u32_elems(opp->np, "opp-microvolt"); > + count = of_property_count_u32_elems(opp->np, name); > if (count < 0) { > - dev_err(dev, "%s: Invalid opp-microvolt property (%d)\n", > - __func__, count); > + dev_err(dev, "%s: Invalid %s property (%d)\n", > + __func__, name, count); > return count; > } > > /* There can be one or three elements here */ > if (count != 1 && count != 3) { > - dev_err(dev, "%s: Invalid number of elements in opp-microvolt property (%d)\n", > - __func__, count); > + dev_err(dev, "%s: Invalid number of elements in %s property (%d)\n", > + __func__, name, count); > return -EINVAL; > } > > - ret = of_property_read_u32_array(opp->np, "opp-microvolt", microvolt, > - count); > + ret = of_property_read_u32_array(opp->np, name, microvolt, count); > if (ret) { > - dev_err(dev, "%s: error parsing opp-microvolt: %d\n", __func__, > - ret); > + dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret); > return -EINVAL; > } > > @@ -830,7 +846,20 @@ static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev) > opp->u_volt_min = microvolt[1]; > opp->u_volt_max = microvolt[2]; > > - if (!of_property_read_u32(opp->np, "opp-microamp", &val)) > + /* Search for "opp-microamp-<name>" */ > + prop = NULL; > + if (dev_opp->prop_name) { > + sprintf(name, "opp-microamp-%s", dev_opp->prop_name); > + prop = of_find_property(opp->np, name, NULL); > + } > + > + if (!prop) { > + /* Search for "opp-microamp" */ > + name[12] = '\0'; > + prop = of_find_property(opp->np, name, NULL); > + } > + > + if (prop && !of_property_read_u32(opp->np, name, &val)) > opp->u_amp = val; > > return 0; > @@ -948,6 +977,112 @@ void dev_pm_opp_put_supported_hw(struct device *dev) > } > EXPORT_SYMBOL_GPL(dev_pm_opp_put_supported_hw); > > +/** > + * dev_pm_opp_set_prop_name() - Set prop-extn name > + * @dev: Device for which the regulator has to be set. > + * @name: name to postfix to properties. > + * > + * This is required only for the V2 bindings, and it enables a platform to > + * specify the extn to be used for certain property names. The properties to > + * which the extension will apply are opp-microvolt and opp-microamp. OPP core > + * should postfix the property name with -<name> while looking for them. > + * > + * 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_prop_name(struct device *dev, const char *name) > +{ > + 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 prop-name associated with dev_opp? */ > + if (dev_opp->prop_name) { > + dev_err(dev, "%s: Already have prop-name %s\n", __func__, > + dev_opp->prop_name); > + ret = -EBUSY; > + goto err; > + } > + > + dev_opp->prop_name = kstrdup(name, GFP_KERNEL); > + if (!dev_opp->prop_name) { > + ret = -ENOMEM; > + goto err; > + } > + > + 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_prop_name); > + > +/** > + * dev_pm_opp_put_prop_name() - Releases resources blocked for prop-name > + * @dev: Device for which the regulator has to be set. > + * > + * This is required only for the V2 bindings, and is called for a matching > + * dev_pm_opp_set_prop_name(). 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_prop_name(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->prop_name) { > + dev_err(dev, "%s: Doesn't have a prop-name\n", __func__); > + goto unlock; > + } > + > + kfree(dev_opp->prop_name); > + dev_opp->prop_name = NULL; > + > + /* 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_prop_name); > + > static bool _opp_is_supported(struct device *dev, struct device_opp *dev_opp, > struct device_node *np) > { > @@ -1042,7 +1177,7 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np) > if (!of_property_read_u32(np, "clock-latency-ns", &val)) > new_opp->clock_latency_ns = val; > > - ret = opp_parse_supplies(new_opp, dev); > + ret = opp_parse_supplies(new_opp, dev, dev_opp); > if (ret) > goto free_opp; > > diff --git a/drivers/base/power/opp/opp.h b/drivers/base/power/opp/opp.h > index 70f4564a6ab9..690638ef36ee 100644 > --- a/drivers/base/power/opp/opp.h > +++ b/drivers/base/power/opp/opp.h > @@ -131,6 +131,7 @@ struct device_list_opp { > * @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. > + * @prop_name: A name to postfix to many DT properties, while parsing them. > * @dentry: debugfs dentry pointer of the real device directory (not links). > * @dentry_name: Name of the real dentry. > * > @@ -157,6 +158,7 @@ struct device_opp { > > unsigned int *supported_hw; > unsigned int supported_hw_count; > + const char *prop_name; > > #ifdef CONFIG_DEBUG_FS > struct dentry *dentry; > diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h > index 3a85110242f0..95403d2ccaf5 100644 > --- a/include/linux/pm_opp.h > +++ b/include/linux/pm_opp.h > @@ -58,6 +58,8 @@ 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); > +int dev_pm_opp_set_prop_name(struct device *dev, const char *name); > +void dev_pm_opp_put_prop_name(struct device *dev); > #else > static inline unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp) > { > @@ -142,6 +144,13 @@ static inline int dev_pm_opp_set_supported_hw(struct device *dev, > > static inline void dev_pm_opp_put_supported_hw(struct device *dev) {} > > +static inline int dev_pm_opp_set_prop_name(struct device *dev, const char *name) > +{ > + return -EINVAL; > +} > + > +static inline void dev_pm_opp_put_prop_name(struct device *dev) {} > + > #endif /* CONFIG_PM_OPP */ > > #if defined(CONFIG_PM_OPP) && defined(CONFIG_OF) > -- > 2.6.2.198.g614a2ac > > _______________________________________________ > linaro-kernel mailing list > linaro-kernel@lists.linaro.org > 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
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