Re: [PATCH V3 2/2] PM / OPP: Parse 'opp-<prop>-<name>' bindings

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

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