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Date: Fri, 12 Oct 2018 17:11:35 +0200
From: Ulf Hansson <ulf.hansson@...aro.org>
To: Viresh Kumar <viresh.kumar@...aro.org>
Cc: Viresh Kumar <vireshk@...nel.org>, Nishanth Menon <nm@...com>,
Stephen Boyd <sboyd@...nel.org>,
Linux PM <linux-pm@...r.kernel.org>,
Vincent Guittot <vincent.guittot@...aro.org>,
Rafael Wysocki <rjw@...ysocki.net>,
Niklas Cassel <niklas.cassel@...aro.org>,
Rajendra Nayak <rnayak@...eaurora.org>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH V2 3/9] OPP: Populate required opp tables from
"required-opps" property
On 12 October 2018 at 13:11, Viresh Kumar <viresh.kumar@...aro.org> wrote:
> 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.
>
> Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@...aro.org>
> ---
> drivers/opp/core.c | 2 +
> drivers/opp/of.c | 147 +++++++++++++++++++++++++++++++++++++++++++++
> drivers/opp/opp.h | 8 +++
> 3 files changed, 157 insertions(+)
>
> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
> index ebb3b648e0fd..85174a5c4850 100644
> --- a/drivers/opp/core.c
> +++ b/drivers/opp/core.c
> @@ -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);
> diff --git a/drivers/opp/of.c b/drivers/opp/of.c
> index 5f114cd3d88c..b5605196122a 100644
> --- a/drivers/opp/of.c
> +++ b/drivers/opp/of.c
> @@ -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)
> {
> diff --git a/drivers/opp/opp.h b/drivers/opp/opp.h
> index cdb0c2b095e2..024e1be23d37 100644
> --- a/drivers/opp/opp.h
> +++ b/drivers/opp/opp.h
> @@ -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
>
> --
> 2.18.0.rc1.242.g61856ae69a2c
>
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