Commit 7de36b0a authored by Viresh Kumar's avatar Viresh Kumar Committed by Rafael J. Wysocki

PM / OPP: Parse 'opp-supported-hw' binding

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: default avatarViresh Kumar <viresh.kumar@linaro.org>
Tested-by: default avatarLee Jones <lee.jones@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent dc4e7b1f
......@@ -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);
......@@ -833,6 +836,145 @@ static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev)
return 0;
}
/**
* 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
......@@ -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
......
......@@ -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];
......
......@@ -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)
......
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