PM / devfreq: Bandwidth driver

This is a snapshot of the Bandwidth driver as of msm-3.10 commit:

acdce027751d5a7488b283f0ce3111f873a5816d (Merge "defconfig: arm64:
Enable ONESHOT_SYNC for msm8994")

Signed-off-by: Kumar Gala <galak@codeaurora.org>
[junjiew@codeaurora.org: resolved conflicts]
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>

Change-Id: I30d48abdfe19a421b4d05003c56c47423c6d0456

drivers/devfreq/Kconfig

@@ -146,6 +146,20 @@ config DEVFREQ_SIMPLE_DEV
 	  Device driver for simple devices that control their frequency using
 	  clock APIs and don't have any form of status reporting.
 
+config MSM_DEVFREQ_DEVBW
+	bool "MSM DEVFREQ device for device master <-> slave IB/AB BW voting"
+	depends on ARCH_MSM
+	select DEVFREQ_GOV_PERFORMANCE
+	select DEVFREQ_GOV_POWERSAVE
+	select DEVFREQ_GOV_USERSPACE
+	select DEVFREQ_GOV_CPUFREQ
+	default n
+	help
+	  Different devfreq governors use this devfreq device to make CPU to
+	  DDR IB/AB bandwidth votes. This driver provides a SoC topology
+	  agnostic interface to so that some of the devfreq governors can be
+	  shared across SoCs.
+
 source "drivers/devfreq/event/Kconfig"
 
 endif # PM_DEVFREQ

drivers/devfreq/Makefile

@@ -14,6 +14,7 @@ obj-$(CONFIG_DEVFREQ_GOV_MSM_CACHE_HWMON)	+= governor_cache_hwmon.o
 obj-$(CONFIG_ARM_EXYNOS4_BUS_DEVFREQ)	+= exynos/
 obj-$(CONFIG_ARM_EXYNOS5_BUS_DEVFREQ)	+= exynos/
 obj-$(CONFIG_ARM_TEGRA_DEVFREQ)		+= tegra-devfreq.o
+obj-$(CONFIG_MSM_DEVFREQ_DEVBW)		+= devfreq_devbw.o
 obj-$(CONFIG_DEVFREQ_SIMPLE_DEV)	+= devfreq_simple_dev.o
 
 # DEVFREQ Event Drivers

drivers/devfreq/devfreq_devbw.c

@@ -0,0 +1,258 @@
+/*
+ * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt) "devbw: " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/ktime.h>
+#include <linux/time.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/mutex.h>
+#include <linux/interrupt.h>
+#include <linux/devfreq.h>
+#include <linux/of.h>
+#include <trace/events/power.h>
+#include <linux/msm-bus.h>
+#include <linux/msm-bus-board.h>
+
+/* Has to be ULL to prevent overflow where this macro is used. */
+#define MBYTE (1ULL << 20)
+#define MAX_PATHS	2
+#define DBL_BUF		2
+
+struct dev_data {
+	struct msm_bus_vectors vectors[MAX_PATHS * DBL_BUF];
+	struct msm_bus_paths bw_levels[DBL_BUF];
+	struct msm_bus_scale_pdata bw_data;
+	int num_paths;
+	u32 bus_client;
+	int cur_idx;
+	int cur_ab;
+	int cur_ib;
+	long gov_ab;
+	struct devfreq *df;
+	struct devfreq_dev_profile dp;
+};
+
+static int set_bw(struct device *dev, int new_ib, int new_ab)
+{
+	struct dev_data *d = dev_get_drvdata(dev);
+	int i, ret;
+
+	if (d->cur_ib == new_ib && d->cur_ab == new_ab)
+		return 0;
+
+	i = (d->cur_idx + 1) % DBL_BUF;
+
+	d->bw_levels[i].vectors[0].ib = new_ib * MBYTE;
+	d->bw_levels[i].vectors[0].ab = new_ab / d->num_paths * MBYTE;
+	d->bw_levels[i].vectors[1].ib = new_ib * MBYTE;
+	d->bw_levels[i].vectors[1].ab = new_ab / d->num_paths * MBYTE;
+
+	dev_dbg(dev, "BW MBps: AB: %d IB: %d\n", new_ab, new_ib);
+
+	ret = msm_bus_scale_client_update_request(d->bus_client, i);
+	if (ret) {
+		dev_err(dev, "bandwidth request failed (%d)\n", ret);
+	} else {
+		d->cur_idx = i;
+		d->cur_ib = new_ib;
+		d->cur_ab = new_ab;
+	}
+
+	return ret;
+}
+
+static void find_freq(struct devfreq_dev_profile *p, unsigned long *freq,
+			u32 flags)
+{
+	int i;
+	unsigned long atmost, atleast, f;
+
+	atmost = p->freq_table[0];
+	atleast = p->freq_table[p->max_state-1];
+	for (i = 0; i < p->max_state; i++) {
+		f = p->freq_table[i];
+		if (f <= *freq)
+			atmost = max(f, atmost);
+		if (f >= *freq)
+			atleast = min(f, atleast);
+	}
+
+	if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND)
+		*freq = atmost;
+	else
+		*freq = atleast;
+}
+
+static int devbw_target(struct device *dev, unsigned long *freq, u32 flags)
+{
+	struct dev_data *d = dev_get_drvdata(dev);
+
+	find_freq(&d->dp, freq, flags);
+	return set_bw(dev, *freq, d->gov_ab);
+}
+
+static int devbw_get_dev_status(struct device *dev,
+				struct devfreq_dev_status *stat)
+{
+	struct dev_data *d = dev_get_drvdata(dev);
+
+	stat->private_data = &d->gov_ab;
+	return 0;
+}
+
+#define PROP_PORTS "qcom,src-dst-ports"
+#define PROP_TBL "qcom,bw-tbl"
+#define PROP_ACTIVE "qcom,active-only"
+
+int devfreq_add_devbw(struct device *dev)
+{
+	struct dev_data *d;
+	struct devfreq_dev_profile *p;
+	u32 *data, ports[MAX_PATHS * 2];
+	const char *gov_name;
+	int ret, len, i, num_paths;
+
+	d = devm_kzalloc(dev, sizeof(*d), GFP_KERNEL);
+	if (!d)
+		return -ENOMEM;
+	dev_set_drvdata(dev, d);
+
+	if (of_find_property(dev->of_node, PROP_PORTS, &len)) {
+		len /= sizeof(ports[0]);
+		if (len % 2 || len > ARRAY_SIZE(ports)) {
+			dev_err(dev, "Unexpected number of ports\n");
+			return -EINVAL;
+		}
+
+		ret = of_property_read_u32_array(dev->of_node, PROP_PORTS,
+						 ports, len);
+		if (ret)
+			return ret;
+
+		num_paths = len / 2;
+	} else {
+		return -EINVAL;
+	}
+
+	d->bw_levels[0].vectors = &d->vectors[0];
+	d->bw_levels[1].vectors = &d->vectors[MAX_PATHS];
+	d->bw_data.usecase = d->bw_levels;
+	d->bw_data.num_usecases = ARRAY_SIZE(d->bw_levels);
+	d->bw_data.name = dev_name(dev);
+	d->bw_data.active_only = of_property_read_bool(dev->of_node,
+							PROP_ACTIVE);
+
+	for (i = 0; i < num_paths; i++) {
+		d->bw_levels[0].vectors[i].src = ports[2 * i];
+		d->bw_levels[0].vectors[i].dst = ports[2 * i + 1];
+		d->bw_levels[1].vectors[i].src = ports[2 * i];
+		d->bw_levels[1].vectors[i].dst = ports[2 * i + 1];
+	}
+	d->bw_levels[0].num_paths = num_paths;
+	d->bw_levels[1].num_paths = num_paths;
+	d->num_paths = num_paths;
+
+	p = &d->dp;
+	p->polling_ms = 50;
+	p->target = devbw_target;
+	p->get_dev_status = devbw_get_dev_status;
+
+	if (of_find_property(dev->of_node, PROP_TBL, &len)) {
+		len /= sizeof(*data);
+		data = devm_kzalloc(dev, len * sizeof(*data), GFP_KERNEL);
+		if (!data)
+			return -ENOMEM;
+
+		p->freq_table = devm_kzalloc(dev,
+					     len * sizeof(*p->freq_table),
+					     GFP_KERNEL);
+		if (!p->freq_table)
+			return -ENOMEM;
+
+		ret = of_property_read_u32_array(dev->of_node, PROP_TBL,
+						 data, len);
+		if (ret)
+			return ret;
+
+		for (i = 0; i < len; i++)
+			p->freq_table[i] = data[i];
+		p->max_state = len;
+	}
+
+	d->bus_client = msm_bus_scale_register_client(&d->bw_data);
+	if (!d->bus_client) {
+		dev_err(dev, "Unable to register bus client\n");
+		return -ENODEV;
+	}
+
+	if (of_property_read_string(dev->of_node, "governor", &gov_name))
+		gov_name = "performance";
+
+	d->df = devfreq_add_device(dev, p, gov_name, NULL);
+	if (IS_ERR(d->df)) {
+		msm_bus_scale_unregister_client(d->bus_client);
+		return PTR_ERR(d->df);
+	}
+
+	return 0;
+}
+
+static int devfreq_devbw_probe(struct platform_device *pdev)
+{
+	return devfreq_add_devbw(&pdev->dev);
+}
+
+int devfreq_remove_devbw(struct device *dev)
+{
+	struct dev_data *d = dev_get_drvdata(dev);
+	msm_bus_scale_unregister_client(d->bus_client);
+	devfreq_remove_device(d->df);
+	return 0;
+}
+
+static int devfreq_devbw_remove(struct platform_device *pdev)
+{
+	return devfreq_remove_devbw(&pdev->dev);
+}
+
+static struct of_device_id match_table[] = {
+	{ .compatible = "qcom,devbw" },
+	{}
+};
+
+static struct platform_driver devbw_driver = {
+	.probe = devfreq_devbw_probe,
+	.remove = devfreq_devbw_remove,
+	.driver = {
+		.name = "devbw",
+		.of_match_table = match_table,
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init devbw_init(void)
+{
+	platform_driver_register(&devbw_driver);
+	return 0;
+}
+device_initcall(devbw_init);
+
+MODULE_DESCRIPTION("Device DDR bandwidth voting driver MSM SoCs");
+MODULE_LICENSE("GPL v2");