qcom-cpufreq-hw.c
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2018, The Linux Foundation. All rights reserved.
*/
#include <linux/bitfield.h>
#include <linux/cpufreq.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/pm_opp.h>
#include <linux/slab.h>
#define LUT_MAX_ENTRIES 40U
#define LUT_SRC GENMASK(31, 30)
#define LUT_L_VAL GENMASK(7, 0)
#define LUT_CORE_COUNT GENMASK(18, 16)
#define LUT_VOLT GENMASK(11, 0)
#define LUT_ROW_SIZE 32
#define CLK_HW_DIV 2
/* Register offsets */
#define REG_ENABLE 0x0
#define REG_FREQ_LUT 0x110
#define REG_VOLT_LUT 0x114
#define REG_PERF_STATE 0x920
static unsigned long cpu_hw_rate, xo_rate;
static struct platform_device *global_pdev;
static int qcom_cpufreq_hw_target_index(struct cpufreq_policy *policy,
unsigned int index)
{
void __iomem *perf_state_reg = policy->driver_data;
writel_relaxed(index, perf_state_reg);
return 0;
}
static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
{
void __iomem *perf_state_reg;
struct cpufreq_policy *policy;
unsigned int index;
policy = cpufreq_cpu_get_raw(cpu);
if (!policy)
return 0;
perf_state_reg = policy->driver_data;
index = readl_relaxed(perf_state_reg);
index = min(index, LUT_MAX_ENTRIES - 1);
return policy->freq_table[index].frequency;
}
static unsigned int qcom_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
unsigned int target_freq)
{
void __iomem *perf_state_reg = policy->driver_data;
int index;
index = policy->cached_resolved_idx;
if (index < 0)
return 0;
writel_relaxed(index, perf_state_reg);
return policy->freq_table[index].frequency;
}
static int qcom_cpufreq_hw_read_lut(struct device *cpu_dev,
struct cpufreq_policy *policy,
void __iomem *base)
{
u32 data, src, lval, i, core_count, prev_cc = 0, prev_freq = 0, freq;
u32 volt;
unsigned int max_cores = cpumask_weight(policy->cpus);
struct cpufreq_frequency_table *table;
table = kcalloc(LUT_MAX_ENTRIES + 1, sizeof(*table), GFP_KERNEL);
if (!table)
return -ENOMEM;
for (i = 0; i < LUT_MAX_ENTRIES; i++) {
data = readl_relaxed(base + REG_FREQ_LUT +
i * LUT_ROW_SIZE);
src = FIELD_GET(LUT_SRC, data);
lval = FIELD_GET(LUT_L_VAL, data);
core_count = FIELD_GET(LUT_CORE_COUNT, data);
data = readl_relaxed(base + REG_VOLT_LUT +
i * LUT_ROW_SIZE);
volt = FIELD_GET(LUT_VOLT, data) * 1000;
if (src)
freq = xo_rate * lval / 1000;
else
freq = cpu_hw_rate / 1000;
if (freq != prev_freq && core_count == max_cores) {
table[i].frequency = freq;
dev_pm_opp_add(cpu_dev, freq * 1000, volt);
dev_dbg(cpu_dev, "index=%d freq=%d, core_count %d\n", i,
freq, core_count);
} else {
table[i].frequency = CPUFREQ_ENTRY_INVALID;
}
/*
* Two of the same frequencies with the same core counts means
* end of table
*/
if (i > 0 && prev_freq == freq && prev_cc == core_count) {
struct cpufreq_frequency_table *prev = &table[i - 1];
/*
* Only treat the last frequency that might be a boost
* as the boost frequency
*/
if (prev_cc != max_cores) {
prev->frequency = prev_freq;
prev->flags = CPUFREQ_BOOST_FREQ;
dev_pm_opp_add(cpu_dev, prev_freq * 1000, volt);
}
break;
}
prev_cc = core_count;
prev_freq = freq;
}
table[i].frequency = CPUFREQ_TABLE_END;
policy->freq_table = table;
dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);
return 0;
}
static void qcom_get_related_cpus(int index, struct cpumask *m)
{
struct device_node *cpu_np;
struct of_phandle_args args;
int cpu, ret;
for_each_possible_cpu(cpu) {
cpu_np = of_cpu_device_node_get(cpu);
if (!cpu_np)
continue;
ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
"#freq-domain-cells", 0,
&args);
of_node_put(cpu_np);
if (ret < 0)
continue;
if (index == args.args[0])
cpumask_set_cpu(cpu, m);
}
}
static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
{
struct device *dev = &global_pdev->dev;
struct of_phandle_args args;
struct device_node *cpu_np;
struct device *cpu_dev;
struct resource *res;
void __iomem *base;
int ret, index;
cpu_dev = get_cpu_device(policy->cpu);
if (!cpu_dev) {
pr_err("%s: failed to get cpu%d device\n", __func__,
policy->cpu);
return -ENODEV;
}
cpu_np = of_cpu_device_node_get(policy->cpu);
if (!cpu_np)
return -EINVAL;
ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
"#freq-domain-cells", 0, &args);
of_node_put(cpu_np);
if (ret)
return ret;
index = args.args[0];
res = platform_get_resource(global_pdev, IORESOURCE_MEM, index);
if (!res)
return -ENODEV;
base = devm_ioremap(dev, res->start, resource_size(res));
if (!base)
return -ENOMEM;
/* HW should be in enabled state to proceed */
if (!(readl_relaxed(base + REG_ENABLE) & 0x1)) {
dev_err(dev, "Domain-%d cpufreq hardware not enabled\n", index);
ret = -ENODEV;
goto error;
}
qcom_get_related_cpus(index, policy->cpus);
if (!cpumask_weight(policy->cpus)) {
dev_err(dev, "Domain-%d failed to get related CPUs\n", index);
ret = -ENOENT;
goto error;
}
policy->driver_data = base + REG_PERF_STATE;
ret = qcom_cpufreq_hw_read_lut(cpu_dev, policy, base);
if (ret) {
dev_err(dev, "Domain-%d failed to read LUT\n", index);
goto error;
}
ret = dev_pm_opp_get_opp_count(cpu_dev);
if (ret <= 0) {
dev_err(cpu_dev, "Failed to add OPPs\n");
ret = -ENODEV;
goto error;
}
dev_pm_opp_of_register_em(policy->cpus);
policy->fast_switch_possible = true;
return 0;
error:
devm_iounmap(dev, base);
return ret;
}
static int qcom_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy)
{
struct device *cpu_dev = get_cpu_device(policy->cpu);
void __iomem *base = policy->driver_data - REG_PERF_STATE;
dev_pm_opp_remove_all_dynamic(cpu_dev);
kfree(policy->freq_table);
devm_iounmap(&global_pdev->dev, base);
return 0;
}
static struct freq_attr *qcom_cpufreq_hw_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
&cpufreq_freq_attr_scaling_boost_freqs,
NULL
};
static struct cpufreq_driver cpufreq_qcom_hw_driver = {
.flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK |
CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
CPUFREQ_IS_COOLING_DEV,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = qcom_cpufreq_hw_target_index,
.get = qcom_cpufreq_hw_get,
.init = qcom_cpufreq_hw_cpu_init,
.exit = qcom_cpufreq_hw_cpu_exit,
.fast_switch = qcom_cpufreq_hw_fast_switch,
.name = "qcom-cpufreq-hw",
.attr = qcom_cpufreq_hw_attr,
};
static int qcom_cpufreq_hw_driver_probe(struct platform_device *pdev)
{
struct clk *clk;
int ret;
clk = clk_get(&pdev->dev, "xo");
if (IS_ERR(clk))
return PTR_ERR(clk);
xo_rate = clk_get_rate(clk);
clk_put(clk);
clk = clk_get(&pdev->dev, "alternate");
if (IS_ERR(clk))
return PTR_ERR(clk);
cpu_hw_rate = clk_get_rate(clk) / CLK_HW_DIV;
clk_put(clk);
global_pdev = pdev;
ret = cpufreq_register_driver(&cpufreq_qcom_hw_driver);
if (ret)
dev_err(&pdev->dev, "CPUFreq HW driver failed to register\n");
else
dev_dbg(&pdev->dev, "QCOM CPUFreq HW driver initialized\n");
return ret;
}
static int qcom_cpufreq_hw_driver_remove(struct platform_device *pdev)
{
return cpufreq_unregister_driver(&cpufreq_qcom_hw_driver);
}
static const struct of_device_id qcom_cpufreq_hw_match[] = {
{ .compatible = "qcom,cpufreq-hw" },
{}
};
MODULE_DEVICE_TABLE(of, qcom_cpufreq_hw_match);
static struct platform_driver qcom_cpufreq_hw_driver = {
.probe = qcom_cpufreq_hw_driver_probe,
.remove = qcom_cpufreq_hw_driver_remove,
.driver = {
.name = "qcom-cpufreq-hw",
.of_match_table = qcom_cpufreq_hw_match,
},
};
static int __init qcom_cpufreq_hw_init(void)
{
return platform_driver_register(&qcom_cpufreq_hw_driver);
}
device_initcall(qcom_cpufreq_hw_init);
static void __exit qcom_cpufreq_hw_exit(void)
{
platform_driver_unregister(&qcom_cpufreq_hw_driver);
}
module_exit(qcom_cpufreq_hw_exit);
MODULE_DESCRIPTION("QCOM CPUFREQ HW Driver");
MODULE_LICENSE("GPL v2");