From:   Viresh Kumar <viresh.kumar@linaro.org>
To:     Jun Nie <jun.nie@linaro.org>, Viresh Kumar <vireshk@kernel.org>,
        Nishanth Menon <nm@ti.com>, Stephen Boyd <sboyd@kernel.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>
Cc:     Viresh Kumar <viresh.kumar@linaro.org>, linux-pm@vger.kernel.org,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>,
        linux-kernel@vger.kernel.org
Subject: [PATCH 3/3] OPP: Allow platforms to add a set_required_opps() callback
Date:   Wed, 22 Feb 2023 16:36:39 +0530
Message-Id: <c71a39caa8f1c64c24ce0c4ba070fc8b5226747d.1677063656.git.viresh.kumar@linaro.org>
In-Reply-To: <cover.1677063656.git.viresh.kumar@linaro.org>
References: <cover.1677063656.git.viresh.kumar@linaro.org>
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We currently configure required-opps only for genpds, as we aren't
really sure what's required of the other use cases. This patch allows
platforms to add their own set_required_opps() helper.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

---
Jun,

I think this can replace the cpufreq notification from the devfreq driver
(get_target_freq_with_cpufreq()), which is used currently only by
mtk-cci-devfreq.c. Instead of the notification, the aggregation of the requests
for the devfreq device can be done within this callback.

What do you say ?
---
 drivers/opp/core.c     | 35 +++++++++++++++++++++++++++++++++++
 drivers/opp/opp.h      |  4 ++--
 include/linux/pm_opp.h |  5 +++++
 3 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 954c94865cf5..22985ad7af79 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -2421,8 +2421,35 @@ static void _opp_detach_genpd(struct opp_table *opp_table)
 	mutex_unlock(&opp_table->genpd_virt_dev_lock);
 }
 
+/**
+ * _opp_set_required_opps_helper() - Register custom set required opps helper.
+ * @dev: Device for which the helper is getting registered.
+ * @set_required_opps: Custom set required opps helper.
+ *
+ * This must be called before any OPPs are initialized for the device.
+ */
+static void _opp_set_required_opps_helper(struct opp_table *opp_table,
+					  set_required_opps_t set_required_opps)
+{
+	opp_table->set_required_opps = set_required_opps;
+}
+
+/**
+ * _opp_put_required_opps_helper() - Releases resources blocked for
+ *					 required opps helper.
+ * @opp_table: OPP table returned from _opp_set_required_opps_helper().
+ *
+ * Release resources blocked for platform specific required opps helper.
+ */
+static void _opp_put_required_opps_helper(struct opp_table *opp_table)
+{
+	opp_table->set_required_opps = NULL;
+}
+
 static void _opp_clear_config(struct opp_config_data *data)
 {
+	if (data->flags & OPP_CONFIG_REQUIRED_OPPS)
+		_opp_put_required_opps_helper(data->opp_table);
 	if (data->flags & OPP_CONFIG_GENPD)
 		_opp_detach_genpd(data->opp_table);
 	if (data->flags & OPP_CONFIG_REGULATOR)
@@ -2546,6 +2573,14 @@ int dev_pm_opp_set_config(struct device *dev, struct dev_pm_opp_config *config)
 		data->flags |= OPP_CONFIG_GENPD;
 	}
 
+	/* Required opps helper */
+	if (config->set_required_opps) {
+		_opp_set_required_opps_helper(opp_table,
+					      config->set_required_opps);
+
+		data->flags |= OPP_CONFIG_REQUIRED_OPPS;
+	}
+
 	ret = xa_alloc(&opp_configs, &id, data, XA_LIMIT(1, INT_MAX),
 		       GFP_KERNEL);
 	if (ret)
diff --git a/drivers/opp/opp.h b/drivers/opp/opp.h
index 2a057c42ddf4..54cfeb894f5d 100644
--- a/drivers/opp/opp.h
+++ b/drivers/opp/opp.h
@@ -35,6 +35,7 @@ extern struct list_head opp_tables, lazy_opp_tables;
 #define OPP_CONFIG_PROP_NAME		BIT(3)
 #define OPP_CONFIG_SUPPORTED_HW		BIT(4)
 #define OPP_CONFIG_GENPD		BIT(5)
+#define OPP_CONFIG_REQUIRED_OPPS	BIT(6)
 
 /**
  * struct opp_config_data - data for set config operations
@@ -235,8 +236,7 @@ struct opp_table {
 	bool enabled;
 	bool genpd_performance_state;
 	bool is_genpd;
-	int (*set_required_opps)(struct device *dev,
-		struct opp_table *opp_table, struct dev_pm_opp *opp, bool scaling_down);
+	set_required_opps_t set_required_opps;
 
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *dentry;
diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
index dc1fb5890792..5a8c0cc50c96 100644
--- a/include/linux/pm_opp.h
+++ b/include/linux/pm_opp.h
@@ -64,6 +64,9 @@ typedef int (*config_regulators_t)(struct device *dev,
 typedef int (*config_clks_t)(struct device *dev, struct opp_table *opp_table,
 			struct dev_pm_opp *opp, void *data, bool scaling_down);
 
+typedef int (*set_required_opps_t)(struct device *dev, struct opp_table *opp_table,
+			struct dev_pm_opp *opp, bool scaling_down);
+
 /**
  * struct dev_pm_opp_config - Device OPP configuration values
  * @clk_names: Clk names, NULL terminated array.
@@ -76,6 +79,7 @@ typedef int (*config_clks_t)(struct device *dev, struct opp_table *opp_table,
  * @genpd_names: Null terminated array of pointers containing names of genpd to
  *		 attach.
  * @virt_devs: Pointer to return the array of virtual devices.
+ * @set_required_opps: Custom set required opps helper.
  *
  * This structure contains platform specific OPP configurations for the device.
  */
@@ -90,6 +94,7 @@ struct dev_pm_opp_config {
 	const char * const *regulator_names;
 	const char * const *genpd_names;
 	struct device ***virt_devs;
+	set_required_opps_t set_required_opps;
 };
 
 #if defined(CONFIG_PM_OPP)
-- 
2.31.1.272.g89b43f80a514