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From: Saravana Kannan <saravanak@google.com>
To: Georgi Djakov <georgi.djakov@linaro.org>,
	Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Viresh Kumar <vireshk@kernel.org>, Nishanth Menon <nm@ti.com>,
	Stephen Boyd <sboyd@kernel.org>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	MyungJoo Ham <myungjoo.ham@samsung.com>,
	Kyungmin Park <kyungmin.park@samsung.com>,
	Chanwoo Choi <cw00.choi@samsung.com>
Cc: Saravana Kannan <saravanak@google.com>,
	Rajendra Nayak <rnayak@codeaurora.org>,
	Jordan Crouse <jcrouse@codeaurora.org>,
	vincent.guittot@linaro.org, bjorn.andersson@linaro.org,
	amit.kucheria@linaro.org, seansw@qti.qualcomm.com,
	daidavid1@codeaurora.org, evgreen@chromium.org,
	sibis@codeaurora.org, kernel-team@android.com,
	linux-pm@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v2 11/11] interconnect: Add devfreq support
Date: Thu, 13 Jun 2019 21:17:33 -0700
Message-ID: <20190614041733.120807-12-saravanak@google.com> (raw)
In-Reply-To: <20190614041733.120807-1-saravanak@google.com>

Add a icc_create_devfreq() and icc_remove_devfreq() to create and remove
devfreq devices for interconnect paths. A driver can create/remove devfreq
devices for the interconnects needed for its device by calling these APIs.
This would allow various devfreq governors to work with interconnect paths
and the device driver itself doesn't have to actively manage the bandwidth
votes for the interconnects.

Signed-off-by: Saravana Kannan <saravanak@google.com>
---
 drivers/interconnect/Makefile      |   2 +-
 drivers/interconnect/icc-devfreq.c | 156 +++++++++++++++++++++++++++++
 include/linux/interconnect.h       |  14 +++
 3 files changed, 171 insertions(+), 1 deletion(-)
 create mode 100644 drivers/interconnect/icc-devfreq.c

diff --git a/drivers/interconnect/Makefile b/drivers/interconnect/Makefile
index 28f2ab0824d5..ddfb65b7fa55 100644
--- a/drivers/interconnect/Makefile
+++ b/drivers/interconnect/Makefile
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 
-icc-core-objs				:= core.o
+icc-core-objs				:= core.o icc-devfreq.o
 
 obj-$(CONFIG_INTERCONNECT)		+= icc-core.o
 obj-$(CONFIG_INTERCONNECT_QCOM)		+= qcom/
diff --git a/drivers/interconnect/icc-devfreq.c b/drivers/interconnect/icc-devfreq.c
new file mode 100644
index 000000000000..608716fbe612
--- /dev/null
+++ b/drivers/interconnect/icc-devfreq.c
@@ -0,0 +1,156 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * A devfreq device driver for interconnect paths
+ *
+ * Copyright (C) 2019 Google, Inc
+ */
+
+#include <linux/devfreq.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/slab.h>
+#include <linux/interconnect.h>
+#include <linux/limits.h>
+
+struct icc_devfreq {
+	struct device icc_dev;
+	struct icc_path *path;
+	struct devfreq_dev_profile dp;
+	struct devfreq *df;
+	unsigned long peak_bw;
+	unsigned long avg_bw;
+#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
+	struct devfreq_passive_data p_data;
+#endif
+};
+
+static int icc_target(struct device *dev, unsigned long *freq,
+				u32 flags)
+{
+	struct icc_devfreq *d = dev_get_drvdata(dev);
+	struct dev_pm_opp *opp;
+	unsigned long peak_bw, avg_bw;
+
+	opp = devfreq_recommended_opp(dev, &peak_bw, flags);
+	if (IS_ERR(opp)) {
+		dev_err(dev, "Failed to find opp for %lu KHz\n", *freq);
+		return PTR_ERR(opp);
+	}
+	peak_bw = dev_pm_opp_get_bw(opp, &avg_bw);
+	dev_pm_opp_put(opp);
+
+	if (!icc_set_bw(d->path, avg_bw, peak_bw)) {
+		*freq = peak_bw;
+		d->peak_bw = peak_bw;
+		d->avg_bw = avg_bw;
+	}
+
+	return 0;
+}
+
+static int icc_get_dev_status(struct device *dev,
+					struct devfreq_dev_status *stat)
+{
+	struct icc_devfreq *d = dev_get_drvdata(dev);
+
+	stat->current_frequency = d->peak_bw;
+	return 0;
+}
+
+#define icc_dev_to_data(DEV)	container_of((DEV), struct icc_devfreq, icc_dev)
+static void icc_dev_release(struct device *dev)
+{
+	struct icc_devfreq *d = icc_dev_to_data(dev);
+
+	kfree(d);
+}
+
+struct icc_devfreq *icc_create_devfreq(struct device *dev, char *name,
+				       struct devfreq *devf)
+{
+	struct icc_devfreq *d;
+	struct icc_path *path;
+	struct opp_table *opp_table;
+	struct dev_pm_opp *opp;
+	void *p_data = NULL;
+	unsigned long peak_bw = U32_MAX, avg_bw = U32_MAX;
+	int err;
+
+	if (!name)
+		return ERR_PTR(-EINVAL);
+
+	path = of_icc_get(dev, name);
+	if (IS_ERR(path))
+		return (void *) path;
+
+	opp_table = icc_get_opp_table(path);
+	if (!opp_table) {
+		err = -EINVAL;
+		goto out_path;
+	}
+
+	d = kzalloc(sizeof(*d), GFP_KERNEL);
+	if (!d) {
+		err = -ENOMEM;
+		goto out_path;
+	}
+	d->path = path;
+
+	d->icc_dev.parent = dev;
+	d->icc_dev.release = icc_dev_release;
+	dev_set_name(&d->icc_dev, "%s-icc-%s", dev_name(dev), name);
+	err = device_register(&d->icc_dev);
+	if (err) {
+		put_device(&d->icc_dev);
+		goto out_path;
+	}
+
+	dev_pm_opp_add_opp_table(&d->icc_dev, opp_table);
+	opp = dev_pm_opp_find_peak_bw_floor(dev, &peak_bw);
+	peak_bw = dev_pm_opp_get_bw(opp, &avg_bw);
+	dev_pm_opp_put(opp);
+
+	if (!icc_set_bw(d->path, avg_bw, peak_bw)) {
+		d->peak_bw = peak_bw;
+		d->avg_bw = avg_bw;
+	}
+
+#if !IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
+	if (devf) {
+		d->p_data.parent = devf;
+		pdata = &d->p_data;
+	}
+#endif
+	d->dp.initial_freq = peak_bw;
+	d->dp.polling_ms = 0;
+	d->dp.target = icc_target;
+	d->dp.get_dev_status = icc_get_dev_status;
+	d->df = devm_devfreq_add_device(&d->icc_dev,
+					&d->dp,
+					p_data ? "passive" : "performance",
+					p_data);
+	if (IS_ERR(d->df)) {
+		err = PTR_ERR(d->df);
+		goto out_dev;
+	}
+
+	return d;
+out_dev:
+	put_device(&d->icc_dev);
+out_path:
+	icc_put(path);
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(icc_create_devfreq);
+
+void icc_remove_devfreq(struct icc_devfreq *d)
+{
+	icc_put(d->path);
+	put_device(&d->icc_dev);
+}
+EXPORT_SYMBOL_GPL(icc_remove_devfreq);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("interconnect devfreq device driver");
+MODULE_AUTHOR("Saravana Kannan <saravanak@google.com>");
diff --git a/include/linux/interconnect.h b/include/linux/interconnect.h
index 0c0bc55f0e89..ec5879a79301 100644
--- a/include/linux/interconnect.h
+++ b/include/linux/interconnect.h
@@ -10,6 +10,7 @@
 #include <linux/mutex.h>
 #include <linux/types.h>
 #include <linux/pm_opp.h>
+#include <linux/devfreq.h>
 
 /* macros for converting to icc units */
 #define Bps_to_icc(x)	((x) / 1000)
@@ -23,6 +24,7 @@
 
 struct icc_path;
 struct device;
+struct icc_devfreq;
 
 #if IS_ENABLED(CONFIG_INTERCONNECT)
 
@@ -32,6 +34,9 @@ struct icc_path *of_icc_get(struct device *dev, const char *name);
 struct opp_table *icc_get_opp_table(struct icc_path *path);
 void icc_put(struct icc_path *path);
 int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw);
+struct icc_devfreq *icc_create_devfreq(struct device *dev, char *name,
+				       struct devfreq *devf);
+void icc_remove_devfreq(struct icc_devfreq *d);
 
 #else
 
@@ -61,6 +66,15 @@ static inline int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw)
 	return 0;
 }
 
+static inline struct icc_devfreq *icc_create_devfreq(struct device *dev,
+						     char *name,
+						     struct devfreq *devf);
+{
+	return NULL;
+}
+
+void icc_remove_devfreq(struct icc_devfreq *d) {}
+
 #endif /* CONFIG_INTERCONNECT */
 
 #endif /* __LINUX_INTERCONNECT_H */
-- 
2.22.0.rc2.383.gf4fbbf30c2-goog


  parent reply index

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-14  4:17 [PATCH v2 00/11] Introduce Bandwidth OPPs & interconnect devfreq driver Saravana Kannan
2019-06-14  4:17 ` [PATCH v2 01/11] OPP: Allow required-opps even if the device doesn't have power-domains Saravana Kannan
2019-06-14  4:17 ` [PATCH v2 02/11] OPP: Add function to look up required OPP's for a given OPP Saravana Kannan
2019-06-14  4:17 ` [PATCH v2 03/11] PM / devfreq: Add required OPPs support to passive governor Saravana Kannan
2019-06-14  4:17 ` [PATCH v2 04/11] dt-bindings: opp: Introduce opp-peak-KBps and opp-avg-KBps bindings Saravana Kannan
2019-06-14  4:17 ` [PATCH v2 05/11] OPP: Add support for bandwidth OPP tables Saravana Kannan
2019-06-14  4:17 ` [PATCH v2 06/11] OPP: Add helper function " Saravana Kannan
2019-06-14  4:17 ` [PATCH v2 07/11] OPP: Add API to find an OPP table from its DT node Saravana Kannan
2019-06-14  4:17 ` [PATCH v2 08/11] dt-bindings: interconnect: Add interconnect-opp-table property Saravana Kannan
2019-06-14  4:17 ` [PATCH v2 09/11] interconnect: Add OPP table support for interconnects Saravana Kannan
2019-06-14  4:17 ` [PATCH v2 10/11] OPP: Allow copying OPPs tables between devices Saravana Kannan
2019-06-14  4:17 ` Saravana Kannan [this message]
2019-06-17 15:43   ` [PATCH v2 11/11] interconnect: Add devfreq support Georgi Djakov
2019-06-17 21:18     ` Saravana Kannan
2019-07-16 18:12       ` Sibi Sankar
2019-07-16 19:17         ` Saravana Kannan

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