msm: devfreq_cpubw: Add devfreq driver for CPU to DDR bandwidth voting
This driver registers itself as a devfreq device that allows devfreq
governors to make CPU to DDR IB/AB bandwidth votes. This driver allows the
governors to be agnostic of the bandwidth voting APIs, the number of CPU
master ports or DDR slave ports, the actual port numbers, the system
topology, the available DDR frequencies, etc.
Change-Id: If055ddd580afd41f9668b111e6c09a047488b2e0
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
diff --git a/Documentation/devicetree/bindings/devfreq/devbw.txt b/Documentation/devicetree/bindings/devfreq/devbw.txt
new file mode 100644
index 0000000..ece0fa7
--- /dev/null
+++ b/Documentation/devicetree/bindings/devfreq/devbw.txt
@@ -0,0 +1,39 @@
+MSM device bandwidth device
+
+devbw is a device that represents a MSM device's BW requirements from its
+master port(s) to a different device's slave port(s) in a MSM SoC. This
+device is typically used to vote for BW requirements from a device's (Eg:
+CPU, GPU) master port(s) to the slave (Eg: DDR) port(s).
+
+Required properties:
+- compatible: Must be "qcom,devbw"
+- qcom,src-dst-ports: A list of tuples where each tuple consists of a bus
+ master port number and a bus slave port number.
+- qcom,bw-tbl: A list of meaningful instantaneous bandwidth values
+ (in MB/s) that can be requested from the device
+ master port to the slave port. The list of values
+ depend on the supported bus/slave frequencies and the
+ bus width.
+
+Optional properties:
+- qcom,active-only: Indicates that the bandwidth votes need to be
+ enforced only when the CPU subsystem is active.
+- governor: Initial governor to use for the device.
+ Default: "performance"
+
+Example:
+
+ qcom,cpubw {
+ compatible = "qcom,devbw";
+ qcom,src-dst-ports = <1 512>, <2 512>;
+ qcom,active-only;
+ qcom,bw-tbl =
+ < 572 /* 75 MHz */ >,
+ < 1144 /* 150 MHz */ >,
+ < 1525 /* 200 MHz */ >,
+ < 2342 /* 307 MHz */ >,
+ < 3509 /* 460 MHz */ >,
+ < 4684 /* 614 MHz */ >,
+ < 6103 /* 800 MHz */ >,
+ < 7102 /* 931 MHz */ >;
+ };
diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
index cbcbc38..4c97010 100644
--- a/drivers/devfreq/Kconfig
+++ b/drivers/devfreq/Kconfig
@@ -158,6 +158,20 @@
Device driver for simple devices that control their frequency using
clock APIs and don't have any form of status reporting.
+config QCOM_DEVFREQ_DEVBW
+ bool "QCOM DEVFREQ device for device master <-> slave IB/AB BW voting"
+ depends on ARCH_QCOM
+ 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
diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile
index 78a0933..4fe4356 100644
--- a/drivers/devfreq/Makefile
+++ b/drivers/devfreq/Makefile
@@ -15,6 +15,7 @@
obj-$(CONFIG_ARM_EXYNOS_BUS_DEVFREQ) += exynos-bus.o
obj-$(CONFIG_ARM_RK3399_DMC_DEVFREQ) += rk3399_dmc.o
obj-$(CONFIG_ARM_TEGRA_DEVFREQ) += tegra-devfreq.o
+obj-$(CONFIG_QCOM_DEVFREQ_DEVBW) += devfreq_devbw.o
obj-$(CONFIG_DEVFREQ_SIMPLE_DEV) += devfreq_simple_dev.o
# DEVFREQ Event Drivers
diff --git a/drivers/devfreq/devfreq_devbw.c b/drivers/devfreq/devfreq_devbw.c
new file mode 100644
index 0000000..f6c660a
--- /dev/null
+++ b/drivers/devfreq/devfreq_devbw.c
@@ -0,0 +1,252 @@
+/*
+ * 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 const struct of_device_id devbw_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 = devbw_match_table,
+ },
+};
+
+module_platform_driver(devbw_driver);
+MODULE_DESCRIPTION("Device DDR bandwidth voting driver MSM SoCs");
+MODULE_LICENSE("GPL v2");
diff --git a/include/soc/qcom/devfreq_devbw.h b/include/soc/qcom/devfreq_devbw.h
new file mode 100644
index 0000000..77f816c
--- /dev/null
+++ b/include/soc/qcom/devfreq_devbw.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 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.
+ */
+
+#ifndef _DEVFREQ_DEVBW_H
+#define _DEVFREQ_DEVBW_H
+
+#include <linux/devfreq.h>
+
+#ifdef CONFIG_MSM_DEVFREQ_DEVBW
+int devfreq_add_devbw(struct device *dev);
+int devfreq_remove_devbw(struct device *dev);
+#else
+static inline int devfreq_add_devbw(struct device *dev)
+{
+ return 0;
+}
+static inline int devfreq_remove_devbw(struct device *dev)
+{
+ return 0;
+}
+#endif
+
+#endif /* _DEVFREQ_DEVBW_H */