blob: 20cabc257a807bdf463f541f99bc979e90c50457 [file] [log] [blame]
/*
* Copyright (c) 2013, 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) "cpubw: " 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 <mach/msm_bus.h>
#include <mach/msm_bus_board.h>
/* Has to be ULL to prevent overflow where this macro is used. */
#define MBYTE (1ULL << 20)
#define MAX_PATHS 2
static struct msm_bus_vectors vectors[MAX_PATHS * 2];
static struct msm_bus_paths bw_levels[] = {
{ .vectors = &vectors[0] },
{ .vectors = &vectors[MAX_PATHS] },
};
static struct msm_bus_scale_pdata bw_data = {
.usecase = bw_levels,
.num_usecases = ARRAY_SIZE(bw_levels),
.name = "devfreq_cpubw",
.active_only = 1,
};
static int num_paths;
static u32 bus_client;
static int set_bw(int new_ib, int new_ab)
{
static int cur_idx, cur_ab, cur_ib;
int i, ret;
if (cur_ib == new_ib && cur_ab == new_ab)
return 0;
i = (cur_idx + 1) % ARRAY_SIZE(bw_levels);
bw_levels[i].vectors[0].ib = new_ib * MBYTE;
bw_levels[i].vectors[0].ab = new_ab / num_paths * MBYTE;
bw_levels[i].vectors[1].ib = new_ib * MBYTE;
bw_levels[i].vectors[1].ab = new_ab / num_paths * MBYTE;
pr_debug("BW MBps: AB: %d IB: %d\n", new_ab, new_ib);
ret = msm_bus_scale_client_update_request(bus_client, i);
if (ret) {
pr_err("bandwidth request failed (%d)\n", ret);
} else {
cur_idx = i;
cur_ib = new_ib;
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;
}
struct devfreq_dev_profile cpubw_profile;
static long gov_ab;
int cpubw_target(struct device *dev, unsigned long *freq, u32 flags)
{
find_freq(&cpubw_profile, freq, flags);
return set_bw(*freq, gov_ab);
}
static struct devfreq_governor_data gov_data[] = {
{ .name = "performance" },
{ .name = "powersave" },
{ .name = "userspace" },
{ .name = "msm_cpufreq" },
{ .name = "cpubw_hwmon", .data = &gov_ab },
};
struct devfreq_dev_profile cpubw_profile = {
.polling_ms = 50,
.target = cpubw_target,
.governor_data = gov_data,
.num_governor_data = ARRAY_SIZE(gov_data),
};
#define PROP_PORTS "qcom,cpu-mem-ports"
#define PROP_TBL "qcom,bw-tbl"
static int __init cpubw_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct devfreq_dev_profile *p = &cpubw_profile;
struct devfreq *df;
u32 *data, ports[MAX_PATHS * 2];
int ret, len, i;
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;
}
for (i = 0; i < num_paths; i++) {
bw_levels[0].vectors[i].src = ports[2 * i];
bw_levels[0].vectors[i].dst = ports[2 * i + 1];
bw_levels[1].vectors[i].src = ports[2 * i];
bw_levels[1].vectors[i].dst = ports[2 * i + 1];
}
bw_levels[0].num_paths = num_paths;
bw_levels[1].num_paths = num_paths;
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;
}
bus_client = msm_bus_scale_register_client(&bw_data);
if (!bus_client) {
dev_err(dev, "Unable to register bus client\n");
return -ENODEV;
}
df = devfreq_add_device(dev, &cpubw_profile, "msm_cpufreq", NULL);
if (IS_ERR(df)) {
msm_bus_scale_unregister_client(bus_client);
return PTR_ERR(df);
}
return 0;
}
static struct of_device_id match_table[] = {
{ .compatible = "qcom,cpubw" },
{}
};
static struct platform_driver cpubw_driver = {
.driver = {
.name = "cpubw",
.of_match_table = match_table,
.owner = THIS_MODULE,
},
};
static int __init cpubw_init(void)
{
platform_driver_probe(&cpubw_driver, cpubw_probe);
return 0;
}
device_initcall(cpubw_init);
MODULE_DESCRIPTION("CPU DDR bandwidth voting driver MSM CPUs");
MODULE_LICENSE("GPL v2");