PM / OPP: Parse 'opp-<prop>-<name>' bindings

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>
Tested-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Viresh Kumar 2015-12-09 08:01:47 +05:30 committed by Rafael J. Wysocki
parent 7de36b0aa5
commit 01fb4d3c39
3 changed files with 161 additions and 15 deletions

View File

@ -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 @@ unlock:
}
/* 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];
/* Missing property isn't a problem, but an invalid entry is */
if (!of_find_property(opp->np, "opp-microvolt", NULL))
return 0;
/* 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);
}
count = of_property_count_u32_elems(opp->np, "opp-microvolt");
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 (!prop)
return 0;
}
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 @@ unlock:
}
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;

View File

@ -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;

View File

@ -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)