Commit 5d6d106f authored by Viresh Kumar's avatar Viresh Kumar
Browse files

OPP: Populate required opp tables from "required-opps" property 



The current implementation works only for the case where a single
phandle is present in the "required-opps" property, while DT allows
multiple phandles to be present there.

This patch adds new infrastructure to parse all the phandles present in
"required-opps" property and save pointers of the required OPP's OPP
tables. These will be used by later commits.

Reviewed-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
parent 7e535993

drivers/opp/core.c

+2 −0
Original line number Diff line number Diff line
@@ -901,6 +901,8 @@ static void _opp_table_kref_release(struct kref *kref) 
	struct opp_table *opp_table = container_of(kref, struct opp_table, kref);

	struct opp_device *opp_dev, *temp;



	_of_clear_opp_table(opp_table);



	/* Release clk */

	if (!IS_ERR(opp_table->clk))

		clk_put(opp_table->clk);

drivers/opp/of.c

+147 −0
Original line number Diff line number Diff line
@@ -73,6 +73,147 @@ struct opp_table *_managed_opp(struct device *dev, int index) 
	return managed_table;

}



/* The caller must call dev_pm_opp_put() after the OPP is used */

static struct dev_pm_opp *_find_opp_of_np(struct opp_table *opp_table,

					  struct device_node *opp_np)

{

	struct dev_pm_opp *opp;



	lockdep_assert_held(&opp_table_lock);



	mutex_lock(&opp_table->lock);



	list_for_each_entry(opp, &opp_table->opp_list, node) {

		if (opp->np == opp_np) {

			dev_pm_opp_get(opp);

			mutex_unlock(&opp_table->lock);

			return opp;

		}

	}



	mutex_unlock(&opp_table->lock);



	return NULL;

}



static struct device_node *of_parse_required_opp(struct device_node *np,

						 int index)

{

	struct device_node *required_np;



	required_np = of_parse_phandle(np, "required-opps", index);

	if (unlikely(!required_np)) {

		pr_err("%s: Unable to parse required-opps: %pOF, index: %d\n",

		       __func__, np, index);

	}



	return required_np;

}



/* The caller must call dev_pm_opp_put_opp_table() after the table is used */

static struct opp_table *_find_table_of_opp_np(struct device_node *opp_np)

{

	struct opp_table *opp_table;

	struct dev_pm_opp *opp;



	lockdep_assert_held(&opp_table_lock);



	list_for_each_entry(opp_table, &opp_tables, node) {

		opp = _find_opp_of_np(opp_table, opp_np);

		if (opp) {

			dev_pm_opp_put(opp);

			_get_opp_table_kref(opp_table);

			return opp_table;

		}

	}



	return ERR_PTR(-ENODEV);

}



/* Free resources previously acquired by _opp_table_alloc_required_tables() */

static void _opp_table_free_required_tables(struct opp_table *opp_table)

{

	struct opp_table **required_opp_tables = opp_table->required_opp_tables;

	int i;



	if (!required_opp_tables)

		return;



	for (i = 0; i < opp_table->required_opp_count; i++) {

		if (IS_ERR_OR_NULL(required_opp_tables[i]))

			break;



		dev_pm_opp_put_opp_table(required_opp_tables[i]);

	}



	kfree(required_opp_tables);



	opp_table->required_opp_count = 0;

	opp_table->required_opp_tables = NULL;

}



/*

 * Populate all devices and opp tables which are part of "required-opps" list.

 * Checking only the first OPP node should be enough.

 */

static void _opp_table_alloc_required_tables(struct opp_table *opp_table,

					     struct device *dev,

					     struct device_node *opp_np)

{

	struct opp_table **required_opp_tables;

	struct device_node *required_np, *np;

	int count, i;



	/* Traversing the first OPP node is all we need */

	np = of_get_next_available_child(opp_np, NULL);

	if (!np) {

		dev_err(dev, "Empty OPP table\n");

		return;

	}



	count = of_count_phandle_with_args(np, "required-opps", NULL);

	if (!count)

		goto put_np;



	required_opp_tables = kcalloc(count, sizeof(*required_opp_tables),

				      GFP_KERNEL);

	if (!required_opp_tables)

		goto put_np;



	opp_table->required_opp_tables = required_opp_tables;

	opp_table->required_opp_count = count;



	for (i = 0; i < count; i++) {

		required_np = of_parse_required_opp(np, i);

		if (!required_np)

			goto free_required_tables;



		required_opp_tables[i] = _find_table_of_opp_np(required_np);

		of_node_put(required_np);



		if (IS_ERR(required_opp_tables[i]))

			goto free_required_tables;



		/*

		 * We only support genpd's OPPs in the "required-opps" for now,

		 * as we don't know how much about other cases. Error out if the

		 * required OPP doesn't belong to a genpd.

		 */

		if (!required_opp_tables[i]->is_genpd) {

			dev_err(dev, "required-opp doesn't belong to genpd: %pOF\n",

				required_np);

			goto free_required_tables;

		}

	}



	goto put_np;



free_required_tables:

	_opp_table_free_required_tables(opp_table);

put_np:

	of_node_put(np);

}



void _of_init_opp_table(struct opp_table *opp_table, struct device *dev,

			int index)

{
@@ -109,9 +250,15 @@ void _of_init_opp_table(struct opp_table *opp_table, struct device *dev, 


	opp_table->np = opp_np;



	_opp_table_alloc_required_tables(opp_table, dev, opp_np);

	of_node_put(opp_np);

}



void _of_clear_opp_table(struct opp_table *opp_table)

{

	_opp_table_free_required_tables(opp_table);

}



static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table,

			      struct device_node *np)

{

drivers/opp/opp.h

+8 −0
Original line number Diff line number Diff line
@@ -133,6 +133,9 @@ enum opp_table_access { 
 * @parsed_static_opps: True if OPPs are initialized from DT.

 * @shared_opp: OPP is shared between multiple devices.

 * @suspend_opp: Pointer to OPP to be used during device suspend.

 * @required_opp_tables: List of device OPP tables that are required by OPPs in

 *		this table.

 * @required_opp_count: Number of required devices.

 * @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.
@@ -172,6 +175,9 @@ struct opp_table { 
	enum opp_table_access shared_opp;

	struct dev_pm_opp *suspend_opp;



	struct opp_table **required_opp_tables;

	unsigned int required_opp_count;



	unsigned int *supported_hw;

	unsigned int supported_hw_count;

	const char *prop_name;
@@ -208,9 +214,11 @@ void _put_opp_list_kref(struct opp_table *opp_table); 


#ifdef CONFIG_OF

void _of_init_opp_table(struct opp_table *opp_table, struct device *dev, int index);

void _of_clear_opp_table(struct opp_table *opp_table);

struct opp_table *_managed_opp(struct device *dev, int index);

#else

static inline void _of_init_opp_table(struct opp_table *opp_table, struct device *dev, int index) {}

static inline void _of_clear_opp_table(struct opp_table *opp_table) {}

static inline struct opp_table *_managed_opp(struct device *dev, int index) { return NULL; }

#endif

CRA Git | Maintained and supported by SUSTech CRA and CCSE