Re: [PATCH v3 2/2] PM / devfreq: Add devfreq driver for interconnect bandwidth voting

From: skannan
Date: Thu Aug 02 2018 - 15:07:12 EST


On 2018-08-02 03:13, MyungJoo Ham wrote:
This driver registers itself as a devfreq device that allows devfreq
governors to make bandwidth votes for an interconnect path. This allows
applying various policies for different interconnect paths using devfreq
governors.


First of all, the name, "devfreq_icbw", is not appropriate for a
devfreq device driver. It confuses; it looks like a part of the
framework itself.

diff --git a/drivers/devfreq/devfreq_icbw.c b/drivers/devfreq/devfreq_icbw.c
new file mode 100644
index 0000000..231fb21
--- /dev/null
+++ b/drivers/devfreq/devfreq_icbw.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2013-2014, 2018, The Linux Foundation. All rights reserved.
+ */
+
+#define pr_fmt(fmt) "icbw: " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/mutex.h>
+#include <linux/devfreq.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/interconnect.h>

Where can I find this file?

Sorry, meant to mention this in the email specific portion of the commit text. This is on top of the interconnect framework series that Georgi has been working on. linux-pm should have those patches.


+
+struct dev_data {
+ struct icc_path *path;
+ u32 cur_ab;
+ u32 cur_pb;
+ unsigned long gov_ab;
+ struct devfreq *df;
+ struct devfreq_dev_profile dp;
+};
+
+static int icbw_target(struct device *dev, unsigned long *freq, u32 flags)
+{
+ struct dev_data *d = dev_get_drvdata(dev);
+ int ret;
+ u32 new_pb = *freq, new_ab = d->gov_ab;
+
+ if (d->cur_pb == new_pb && d->cur_ab == new_ab)
+ return 0;
+
+ dev_dbg(dev, "BW KBps: AB: %u PB: %u\n", new_ab, new_pb);
+
+ ret = icc_set(d->path, new_ab, new_pb);

I'm not sure if icc_set is available.

Yeah, it's available on that patch series.

-Saravana