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: 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>
diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index 6aa172b..55cf1a9 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -559,6 +559,9 @@
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 @@
}
/**
+ * 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 @@
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
